A Male Monarch Mystery?

A male monarch photographed by Kathy Horn at Cape May Point State Park on May 16, 2020. Could this be a new record early date for a male monarch on our log?

[This post has been updated as of 5/29/20.  See Comments from Emile DeVito and Jack Miller below — and a link to Journey North with further information.]

Kathy Horn’s photograph above sparked a search for comments or other photos on the log of male monarchs arriving in April and May, when the species first reaches our area each spring.  

Female monarchs are fairly easy to find in South Jersey in spring, especially as May nears its end.  Many gardeners with milkweed in their yards have seen their first monarch of the year fly quickly to the new shoots and immediately begin laying eggs.

How often has your first monarch in spring been a male, however? 

The first arriving monarchs are most likely “Generation 1” individuals, off-spring of their long-lived parents that wintered in the Mexican mountains — the “Methuselah” generation.  That brood lives for eight months, emerging from chrysalises in late summer, migrating south in fall to over-winter in the Mexico, and mating there in late winter.  Some Internet searching failed to find information about the percentage of males vs. females that migrate northward back to the U.S. (anyone know a source?).  Female “Methuselahs” cross the border for a second time and lay eggs on emerging milkweeds in Texas, Louisiana, and other southern states in March and April.  Over the next six weeks or so those eggs hatch and the caterpillars emerge, grow through five instars, pupate, and emerge to mate and fly north themselves.  These are “Generation 1,” the first of the new year.  

For details about the timing and migration strategy of all 3-4 annual generations, see the Monarch Joint Venture’s excellent website: 

The Monarch Joint Venture: Annual Cycle

Our Sightings Log allows searches for photographs back to fall 2015 when we adopted the David Reese system.  We collected a couple of dozen reports of monarchs in April and May 2016-2019, but no observer mentioned seeing a male.  Of the eight photos of the species posted during those two months only one shows a certain male:

Our only certain male monarch photographed before June 1, 2016-2019 — and it was found on the last day of the period, May 31, 2017, by Steve Glynn at Lummis Pond, CUM.

Males are most easily differentiated with dorsal views when their two bulging scent patches on the hind wings are generally visible, as in Kathy Horn’s photo.  Sexing monarchs from their ventral sides requires a closer look.  The scent patch on each hind wing creates a slight bulge to the vein that holds it.  Here’s a helpful image from Monarch Butterfy Gardener.net:

You can see this subtle difference by comparing Steve’s photo with Dolores Amesbury’s photo here:

A female monarch:  no bulge evident in the distinguishing vein.  Photo’d by Dolores Amesbury in her garden in Cape May Courthouse, 5-29-19. 

The lack of reports and photographs of males in April and May could very well be due to chance and our scant data. It might also simply be a consequence of females being easier to spot as they come to gardens to oviposit. 

Still, it might be a real pattern, worth trying to track and document.  Could it be more advantageous for adult males of “Generation 1” to remain in the southern areas where they emerged and spend their energy chasing down mates rather than risk the migration northward? If they can fertilize females on their original home grounds, who will carry their DNA northward, why fly north themselves?  

So, this post is a request for comments and/or photographs of male monarchs recorded before June 1 in South Jersey.   You may have some photos from that period that you simply did not submit to the log — or you may have shots of early males that date back to years before 2015. 

Any comments or photos emailed to nacotejackATgmailDOTcom will be included immediately in updates to this post.  (If you would prefer not to have them posted, just let me know.) 

NOTE:  the Comments tool below has been disabled by  spam-bot attacks.  Just email me and I will upload your comments.  

Thanks to anyone who can contribute to this discussion!

Jack Connor

Update, May 26, 2020:

Emile DeVito:

“Who needs males? If the arriving females are fertile and laying eggs, presumably they mated farther south where the generation 1 adults emerged. There is no need for males to migrate north, IF and only IF they fertilize the females upon emergence down south. It would make evolutionary sense for ONLY the fertile females to have to continue the northward expansion, since then fewer individuals would need to succeed on the perilous trip. Only fertile females really need to come north, UNLESS they have to mate here just before laying eggs. Can they store sperm like female rattlesnakes, and make the heavier eggs when they get here?”
 
Thank you, Emile!  Your comment inspired a little more Internet searching and a find of the page linked below from Journey North, quoting Dr. Karen Obenhauser who has been studying monarchs since 1985.  She notes that females can store sperm that remain viable for several weeks and that her studies using mark/release/recapture have found that females generally disperse more quickly from their original place of emergence,
 
“We rarely recapture females in the same locations in which we release them. However, we recapture about 15-20% of the males if we go back to the same area one to four days later. This suggests that females are leaving the areas, while many males remain longer in the same location. Males tend to patrol an area–leading to their being recaptured more frequently in the same locale. In contrast, female flight appears to be more directional. Females are captured less frequently because they do not remain in the same area as long. Rather, they cover more area in their lifetime, probably in pursuit of milkweed.”
 
That suggests males are more likely to remain behind while females migrate away.  However, she also notes, 
 
“When females mate multiple times, most (but not all) of the eggs they lay are fertilized by sperm from the LAST male with which they mated.”
 
That suggests, it would seem, that there might be an advantage to a male flying north to NJ to mate with a newly arriving female. 
 
 
So, the question has complications, which makes it more fun, imho!
 
jc 5/27/20
 
from Jack Miller, 5/29/20:
 
“It makes sense that males might lag behind to greet and mate with arriving or emerging females.  This strategy would be more efficient than flying north and hoping to find milkweed patches where females are present. I have noticed that females in May will often only spend minutes at my yard’s milkweed patch. Later in the summer, they will hang around for hours.  I wonder if the summer bugs were tagged or had significant identifying wear marks if we would find that they might stay for days?  I will pay more attention to that this summer.
 
Where do the males come from that fertilize eggs for future generations as monarchs continue their northward migration?  Do males live longer?  Do southern males eventually fly north to arrive in time to mate with emerging next generation females?  Do next generation males eclose before next generation females? 
 
Almost all of the May and early June monarchs I have seen have been flying due north as fast as they can unless there is a milkweed patch; therefore, there are few opportunities for photos.  It is not surprising that we have so few photos of early season monarchs in our log.”
 
Jack Miller
 
Thank you, Jack.  More questions to try to answer about this butterfly, even though it may be the best-studied butterfly in North America.
 
jc
 
 

PS:  Anyone who would like to try their own hand at finding a male in our other photographs of monarchs, April to May, 2016-2020, can go to the relevant log reports here (corrections will be welcomed):

May 31, 2019 Meredith Koenig Vineland CUM

May 19, 2019 Dave Amadio Wheelabrator GLO

April 22, 2019 Harvey Tomlinson Stimpson Is CMY

May 11, 2018, Fred Kahan Medford Leas BUR

April 26, 2018, Jesse Amesbury Holgate, OCN

May 31, 2017, Debbie Lux Medford Leas BUR

 

Posted in ID Challenges & Tips, Looking At Our Data, Migration, Milkweed Butterflies | Comments Off on A Male Monarch Mystery?

Log Sightings & Park Closures

[May 2 Update: Governor Murphy re-opened the state parks today. Leaving the note below for future reference.]

South Jersey Butterflyers & Friends,

As everyone knows, we are living through a disorienting and frightening time.  Decisions that were so simple two months ago have become problematic.  Even “Where should I go walking today?” has become a complicated question.

Governor Murphy’s Executive Order on April 7 closing all state and county parks has also created a problem for us as moderators of the South Jersey Butterfly Sightings Log.  We want to encourage everyone to get out and search for butterflies — walking outdoors in safe areas is good for any naturalist’s mental and physical health (obviously), and your reports create valuable data. We believe, however, that allowing reports from restricted areas could be seen as disrespect for the Governor’s measures.  

Whether or not it was the right choice to close the parks, the Executive Order came as one component of a much larger and crucially important effort to save lives by flattening the curve of the pandemic.  

Out of respect for that decision and in general support of any attempt to protect NJ residents from the virus, we are encouraging people to stay away from closed areas. 

We are also announcing here that the log will not be posting reports from those closed areas.

Questions, comments, and suggestions are welcome, of course.

Stay safe and keep exploring — when and where you can!

Jack Miller
Jack Connor

Co-Moderators

South Jersey Butterfly Project

Update: Emile DeVito, Manager of Science & Stewardship for the New Jersey Conservation Foundation, has kindly responded to our email about this desicion with a reminder about New Jersey WMAs and NJCF Preserves.  He has also sent a helpful map of Michael Huber Preserve which is linked below.  

He writes, “Southern NJ has so many NJ Div F&W WMAs and they are ALL still open. Please encourage folks to use those areas with proper safeguards until other areas open up. Also, all NJCF Preserves in southern NJ are open except Franklin Parker Preserve. Explore especially Michael Huber Preserve!”

The map is here: NJCF Michael Huber Preserve Trail Map

Posted in Uncategorized | Comments Off on Log Sightings & Park Closures

Marching Back To 2012

An amazing IPhone close-up of  a Henry’s elfin taken by Keara Giannotti, one of our new contributors, at Camp Creek Run, BUR, on March 31. 

We recorded 19 species in March, 2020, the best count for the third month of the year since March 2016, when we also found 19.  We also broke three earliest First-Of-Year records for the log and tied two others.

Our March 2020 list:

  • black swallowtail [3/17/20 FOY ties 3/17/12 for our earliest ever]
  • cabbage white
  • falcate orange-tip [3/20 one day earlier than previous earliest, 3/21/12]
  • clouded sulphur
  • orange sulpur
  • American copper [3/27 one day earlier than previous earliest, 3/28/12]
  • Henry’s elfin [3/14 ties 3/14/12 for our earliest ever]
  • eastern pine elfin
  • gray hairstreak
  • blueberry azure
  • holly azure
  • eastern-tailed blue
  • American snout
  • question mark
  • eastern comma
  • mourning cloak
  • red admiral
  • monarch [3/9 more than month earlier than previous earliest 4/11/08]
  • Juvenal’s duskywing

We totaled 89 reports, our third best total for March since our log began in 2008, and we had reports from 29 observers,  including four new contributors:  Jason Bojcyzk, Lynn Day, Keara Giannotti, and Nancy Larrabee.  Welcome to each of you! 

The monarch flying northbound over Delaware Bay spotted by Tom Reed on March 9 seems the most extraordinary find of the month.  Even today as I write this — April 6th, 27 days later — the closest monarch reports on Journey North are two from the southeastern corner of Virginia:  one from Virginia Beach on 3/29/20 and the other from Newport News on 4/2/20.   Here is Tom’s report: 

Monarch 3-9-20, Cape May Point

A photo from the month worth studying is this intriguing shot from Karen and Brian Johnson taken at Belleplain State Forest on March 14. How many species can you find?

A unusually diverse March puddle party of at least nine individuals at Belleplain from Karen & Brian Johnson on March 14. How many species can you find?

Answer: Guests At The Puddle Party

Another photo worth a careful study is this one by Steve Glynn:

Steve Glynn photo’d this nearly unspotted cabbage white, at Wheelabrator Refuge, GLO on March 27.

Has anyone else seen or photographed this form of cabbage white? Cech & Tudor note in their Butterflies Of The East Coast, “Some spring males are almost pure white and must be distinguished with care from mustard white.” This comment seems to suggest that such individuals are not rare, but I can’t find any similar photos on our log. If you have one, please send along.

Do March Butterfly Numbers Jump In Leap Years?

The three best March counts of our log’s thirteen years have all come in leap years: Both 2020 and 2016 gave us 19 species; 2012, by far our best March ever, yielded 32! Our log began in March of the previous leap year, 2008, with half a dozen observers, too few to confirm or deny any patterns.

To appreciate the numbers of the three recent leap years you have to contrast them with more ordinary March counts, e.g. last year with 10 species; 2018 with 8; and 2017 with a respectable count of 14. In 2015, our worst March, we totaled only three species: mourning cloak, eastern comma, and a spring azure — which squeaked in with a single report of a single individual on the last day of the month.

We gain a day in leap years, of course. March 1 is the 60th day of the year instead of the 59th, but that small difference can’t be the explanation.

More often than not, March’s in-like-a-lion winds, wildly-fluctuating temperatures, occasional sleet and sometimes snow make trouble for butterflies of early spring. Those days also discourage potential observers who know they will have more fun chasing ducks, gannets, and other seabirds out on the coast or staying home with a hot cup of cocoa.

However, every few years — by chance recently every four years — March gives our butterflies and our observers a break.

Dave Amadio photographed this blueberry azure at Glassboro WMA (GLO) on March 9, one of 11 reports and 69 individuals of this species (found in four different counties) recorded in the first ten days of the month.

And could it be that it is just as important that the preceding winter months are warmer than usual? That has been the situation for each of our recent leap year winters.

It does not seem much of a reach to speculate that March 2020’s good butterfly life could have been triggered by the very mild months of December, January, and February that preceded it. (See “A Snoutstanding Winter” below.) Certainly, our numbers for four over-wintering species — snout, question mark, comma, and mourning cloak — seem to reflect that. Individuals of these species almost certainly survived in higher numbers because we had so few days of sleet, snow, and sub-freezing temperatures December to February. This case is clearest with mourning cloak. The species had one of the worst breeding seasons of any South Jersey butterfly in 2019 — with total reports down to a third of its ten-year average and barely a fifth its ten-year average in individual numbers. (See “A Teaser Challenge” post below.) Yet, we had 31 reports of mourning cloaks this past month — many of multiple individuals — which is more than the March report totals for 2019 (10), 2018 (7), and 2017 (8) combined. In fact, our 31 mourning cloak reports in March 2020 nearly matched our total of 38 reports for all months of 2019, January to December.

The weather of the 2015-16 “cold” months also looks like it might have something to do with our previous good butterfly March — in 2016. Remember December 2015 — when violets bloomed and blueberry azures emerged before Christmas? November 2015 was also extraordinarily warm. In fact, November 2015 and December 2015 were — and remain — the warmest November and December ever recorded in southern NJ. March 2016 was also well above average — one of the five warmest March months ever recorded in southern NJ.

Finally, there is March 2012, possibly the most extraordinary single month of any in our log’s history. We found 32 species that month, more than double the March average, and established 23 earliest-ever records, most of which still stand now, eight years later. You can review it here:

A Month To Remember

That explosion too seems set up by the warm four months that preceded it. November 2011 and December 2011 are among the five warmest Novembers and Decembers ever recorded, January and February 2012 were each more than five degrees above average, and March 2012 itself was and remains the warmest March ever documented in southern NJ since record-keeping began in 1895. It was also dry — a rare March with less than two inches of precipitation. We found butterflies on 29 of its 31 days. How often has that happened in any month of the year, much less March?

If you want to review these historical monthly records from the New Jersey Climatologist’s Office yourself (it can be very educational to dive into this rabbit hole!), go here:

New Jersey Historic Monthly Climate Tables

Thanks to all contributors this month:

Cynthia Allen, Pat & Dave Amadio, Dolores Amesbury, Tom Bailey, Tom Baxter, Jason Bojcyzk, Jennifer Bulava, Claire Campbell, Jesse & Jack Connor, Lynn Day, Keara Giannotti, Steven Glynn, Chris Herz, Karen & Brian Johnson, Sandra Keller, Meredith Koenig, Chip Krilowicz, Nancy Larrabee, Mike Lee, Jack Miller, Beth Polvino, Tom Reed, Pat & Clay Sutton, Harvey Tomlinson, and C. Wylunda.

Keep exploring and reporting, everyone. And stay safe!

Jack Connor 4/6/20

One of 101 Henry’s elfins counted by Harvey Tomlinson and Jack Miller on Narrows Road in Belleplain State Forest on March 26.

Update May 6, 2020:

The New Jersey Climatologist’s Office has posted the bar graphs for temperature and precipitation now including March, 2020. Statewide, the month was much warmer than March’s average (South Jersey’s average temperature was 47.6, more than 5 degrees above our March average for the last 30 years). We had slightly less rain than average for the month. (South Jersey recorded 3.86 inches vs our 30-year-March average of 4.19 inches.) Both factors almost certainly contributed to the good number of species and individuals we recorded.

Posted in Compilations, First Emergences, Looking At Our Data | Comments Off on Marching Back To 2012

A Snoutstanding Winter

An American snout photo’d by Sandra Keller in Glassboro Woods on 3-14-20 toward the end of the species’ extraordinary winter in 2019-2020.

As of March 20, the first official full day of spring 2020, we can point to a startling sequence of numbers that spanned the South Jersey winter of 2019-2020:

1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 6, 3, 1, 1, 1, 9 (!), 4, 1, 2, 1, 5, 2, 31 (!!!), 5, 2, 4, 1, 1, 1, 1, 2, 6

Those numbers are the individual American snouts found and reported by our observers between December 21, 2019, the day winter began, and March 19, the day it ended.  We generated thirty-three reports of the species in that period — three reports in the last ten days of December, two reports in January, six in February, and twenty-two (!) in the first nineteen days of March.  Total individuals counted = 94, an average of just over one individual per day for the ninety-three official winter days.

One of seven red admirals Matt Webster found at Cape May Point SP on 12-28-19. They too were far more numerous than usual this winter.

Red admiral has always been a far more likely winter find and generally as likely a winter find of any South Jersey butterfly. The warm winter of 2019-20 was an especially good season for them.  In fact, that species also may have set new record winter totals (haven’t been checked yet) with 32 reports and 45 individuals.  But even the hardy admiral could not match the surprising snout.

Pat Sutton photographed this snout on 3-9-20 in Belleplain State Park.

Another perspective on the extraordinary numbers:  from 2009-10 (when we first began logging individual counts) to last winter, 2018-19, we had seven winters with zero reports of the species and totaled just 29 reports of snout and only 59 individuals in the other four added together.   That’s an average of ~2.6 reports and ~5.4 individuals per winter.  So, winter 2019-20 represents more than an order-of-magnitude leap above the snout’s previous average.

Two apparent reasons for the surge: 

First, American snouts bred with extraordinary success in 2019 throughout the state.  Michael Gochfeld  has noted that it was the best  year for the species in New Jersey since at least the mid-1980s. (See “A Teaser Challenge for Ten-Year Reports” post below.) That meant that far more snouts than usual hunkered down to take their chances on surviving the winter as adults.  

Second, December 21 to March 19 was far from wintry. In South Jersey we had little snow and only a handful of days with temperatures well below freezing.

The latest chart from the New Jersey Climatologist’s Office:  

All but two of the past twelve months have been warmer than average. February 2020 was the third warmest February since 1895, when NJ record-keeping began.

But enough numbers!  Let’s take a few moments to celebrate the snout as a butterfly worth pursuing and enjoying:  its “anteater nose,” its Halloween colors on topside, the zig-zagging flight, its pugnacious attitude and aerial dog-fights, its devoted attention to hackberry. . .   

Did you know that, if you get a close enough look at just the right angle, you can tell male from female – or at least guess at distinguishing them? 

Starting with Sandra Keller’s photo at the top of this post you can find here seven recent photos of snouts in reverse chronological order.  Can you say which are apparently male and which apparently female? Hint: the varying hind-wing underside color patterns are not the key.

Dolores Amesbury photographed this snout in her yard in Cape May Courthouse on 2-3-20.

 

Sam Galick photographed this snout on the Maurice River Bluffs (CUM) on 12-28-19.

 

Snout photographed by Beth Polvino in her yard in North Cape May on 12-24-19.

 

Snout photo’d by Harold Davis at Cape May Point State Park on 10-15-19.

 

Brian Johnson’s photo of a snout at the Glades Preserve (CUM) on 10-10-19.

The answers (in my possibly inaccurate opinion):

Keller’s = male

Sutton’s = male

Amesbury’s = male?

Galick’s = female

Polvino’s = male

Davis’s  = male

Johnson’s = female

American snout is unique among the Nymphalidae in that one of its sexes — the female — has retained all six legs. The male snout, like both genders of the rest the members of the family (including in NJ the Fritillaries, Crescents, Anglewings, Emperors, and the Monarch), has lost its forelegs through evolution.

Some taxonomists place the snouts in a separate family because of this difference. In his wonderful 1966 publication, Butterflies Of The Delaware Valley, Arthur Shapiro followed the thinking of the time and listed the species as a separate family and added, “In this respect the Libytheids [with their six-legged females] seem to form a link between the Nymphaloid[s] and Lycaenoid[s].” James Scott in his The Butterflies of North America (1986) also listed the snout as a separate family.

I do not see evidence of a foreleg pair on the butterflies in Sandra’s, Pat’s, Beth’s, and Harold’s shots. I am not sure about Dolores’s individual — because of the way it is resting with body against the branch — but I am guessing it’s a male. I am more confident about the other two snouts here. Three pairs of legs seem evident in Sam’s and Brian’s photos, making those snouts females. I will happily accept corrections!

Another feature on snouts that’s fun to look for are the different underwing patterns. The hindwings below vary from striated and contrasty, as in Sandra’s and Harold’s photos here, to plain and relatively unmarked, as in Dolores’s, Sam’s and Beth’s shots. Some show intermediate patterns as seen in Pat’s and Brian’s pix. Shapiro called the two basic patterns different “forms” and noted, “The variation is certainly genetic.”

In this sad and scary time of a pandemic virus, I hope everyone can find some good hours to venture outside, at proper social distance, to chase snouts and other butterflies — or whatever else draws your attention in our still delightful natural world.

Stay safe and keep exploring and reporting,

Jack Connor

Posted in Looking At Our Data, Nymphalids | Comments Off on A Snoutstanding Winter

Not A Banner Year For Skippers

Dolores Amesbury photographed this female fiery skipper, an early migrant, in her garden on July 15th. The species had an excellent year in South Jersey in 2019.

The numbers for reports and individual totals of all skippers are now included in the chart comparing the numbers of all species of butterflies seen in 2019 with their ten-year averages, 2009-2018. 

For the spreadsheet and an explanation of what the columns and colors mean, go to the link in our website’s banner above.

For the spreadsheet by itself, click here:

2019 SJ Butterflies & 10-Year Averages

Overall, it seems 2019 was not a great year for Hesperids.

A few did well.  Fiery skipper generated its highest count ever for individuals reported (1315), only the second time we have totaled more than four digits for this southern species (1189 were counted in 2012).  Rare skipper, mulberry wing, dion, and Ocola skipper also had excellent totals for individuals.  

We also had the first clouded skippers reported in South Jersey in five years and we collected 20 reports for a total of 25 individuals, crushing our previous best year’s count of 7 and 7 set in 2012.  

Harvey Tomlinson lifted the curtains on our 2019 clouded skipper drama with this discovery at Cox Hall Creek, CMY, on September 14 — the first find of the species in SJ since August, 2014.

However, as you can see on the spreadsheet, most species were below average in reports generated or individuals counted — or both.  

Salt-marsh skipper, usually among our most numerous butterflies, was noticeably harder to find  in 2019 (as several observers pointed out during the year.)  We had only 31 reports, our second fewest since 2009 (29 in 2015), and the 177 individuals totaled for the  year was by far the fewest ever for our log (previous low 368 in 2012). 

Cobweb skipper, a species that has certainly declined in recent years, was down to only five reports for a total of seventeen individuals in 2019.  Perhaps just as significantly, only one of those reports came from somewhere besides the cobweb’s only-known current stronghold in South Jersey — the flats of Warren Grove.   Brian Johnson found two individuals in Beaver Swamp, WMA, on May 10th — the first find of the species in CMY since 2016. 

Over the last three years, 2017-2019, we have had only two reports of cobweb skipper outside Warren Grove: the two individuals at Beaver Swamp and a single individual found by Steve Glynn on May 14, 2017 at  Muddy Run, SAL.   

Cobweb skipper has become an unofficial “species of concern” in South Jersey Dave Amadio photographed this one on May 7 in what seems their one reliable spot in our area, Warren Grove. Let’s find more in 2020!

What makes skippers so much fun to get to know?  Their muted colors? Their subtle and challenging field marks? Their approachability?  All of the above and other traits as well?  Several of our most active observers have confessed that skippers are their favorite group of butterflies. 

The 2020 skipper season will begin again in April, and over the following six or seven months, we will see if “the sparrows of the butterfly world” can rebound from a mediocre year.  Let’s chase them down wherever they fly!

— Jack Connor

 

A salt marsh skipper photographed by Will Kerling on June 29 in Cape May Courthouse.

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Our Log’s Greatest One-Day Flight (so far)

Scenes like this — photo’d by Pat Sutton at Cape May Point State Park on 10/3/18 — may lead you to guess that our greatest logged flight involved monarchs.

Or you might guess our greatest one day flight involved common buckeyes — here photo’d by Vince Elia, also on October 3, 2018 at CMPt State Park

Our new ten-year-averages chart is available at the link on the banner above, comparing the 2019 numbers of all species reported in 2019 with their average counts from 2009-2018.  Thanks again to David Reese for modifying his reporting system so that we can compile these data.

But wait!  Don’t click on the chart yet.  If you are up for another January quiz question, read on:  

One species had such a magnificent flight one day in our log’s history that its ten-year-average remains distorted still, years later.  Subtract that single day from all our other totals of individuals of the species over the ten years and the species’ average for total individuals/year drops  from 8000+/year to just over 1000/year.     

You might guess that this largest logged-single-day flight would involve monarchs — or possibly common buckeyes.  Both those species undoubtedly occur in 1000+ single-day southbound flights fairly regularly in fall at Cape May Point and other funneling spots in South Jersey.  However, we have documented single-day 1000+ counts of monarchs only four times in our log’s history and have documented a four-digit-single-spot count of common buckeyes only once.

This lack of reports of big flights probably reflects the self-restraint and diligence required for the watcher(s).  An observer determined to do such a count must stay in one spot and monitor hundreds and hundreds of butterflies passing by for several hours.  

Our highest single-day, single-site count for one species did involve an observer remaining in one spot for hours and keeping track as thousands of butterflies flew by him. They weren’t monarchs or buckeyes, however, and it was a spring flight not an autumn one.

The observer was Tom Reed, the date was May 4, 2012, and the spot was Stone Harbor Point.  Here’s Tom’s logged description:

Remarkable afternoon flight– estimated total from 4 hours of observation. 50-100/min from 12 pm through 1 pm, then gradual increase, reaching ~200/min by about 3:15 pm. Definitive peak shortly before 4pm, with minute-long counts of 700+ passing fixed point as viewed through binoculars. Flight tapered along outer beach once sea breeze developed shortly thereafter. Almost all movement SE->NW, coming in off the ocean and continuing inland. A number of dead/exhausted individuals littering the beach. 

Tom estimated 55,000 butterflies of that single species flew by him in those four afternoon hours.

And he was seeing only one small fragment of that flight.  That same afternoon, south and west of Tom’s lookout, Dave Amadio reported so many flying by him as he drove toward Reeds Beach that he had to roll up his car windows “to keep from collecting them.”  He subsequently found hundreds at several different spots throughout the day.  

In Cape May Courthouse that afternoon, in between Tom and Dave, Will Kerling counted 224 stream by him as he took a brief ten-block bicycle ride at 1 pm.  “And their pace continued for the next two hours,” he added in his log note. “Counted out a front window around 3 pm and saw 102 along one fence going rapidly S to N.”

North and west of Tom, Dave, and Will in Cape May County, Sandra Keller saw 300+ go by her in about half an hour at Palmyra Cove Nature Park, Burlington County, “Most were streaming NE over the Delaware River bank. Some were inland, but still heading northerly. This spectacular flight slowed around 4:45 PM. I started counting around 4:10 PM. I presume a lot [more] put down here!”

East of Sandra and north of Tom’s, David’s and Will’s spots, Jesse and I had our largest flight for any species ever in our Port  Republic yard (Atlantic Co). We logged it as 7000 for the day but added on the log, “Conservatively, probably 10K plus; 50 to 100+/5 minutes for 7+ hours, 10:30 am to 5:30 pm; a few still flying by at 6:30 pm.Seemed to peak 3-4:30 pm, when we did two counts: 150/5 minutes 3:30 and 180/5 minute 4:15. All going almost exactly due north by our compass. Wind from south. Jesse was in the garden all day keeping track.”

North of us in Toms River, Ocean County, Shawn Wainright counted 100+ every three minutes several times and by the end of the day estimated 20,000+ had flown through his yard between 8 am and 7 pm.

OK, that’s probably too many hints.

Q: Can you name the species?

Answer

— Jack Connor

Posted in Compilations, Looking At Our Data | Comments Off on Our Log’s Greatest One-Day Flight (so far)

A “Teaser Challenge” for Ten-Year-Averages Report Coming Soon

Robert Koch photo’d this variegated fritillary on September 18 in Lumberton Leas, BUR. Was 2019 a good year for the species or a bad one?

Thanks to good work by David Reese, who has tweaked his already wonderful reporting system, we are now able to post our Early & Late Dates Spreadsheet more quickly and accurately.  You can find the 2019 update at either the link on our banner above (with info about how to read it) or by clicking below for direct access to the spreadsheet by itself:

Early & Late Dates, Updated for 2019

Even better than making the annual dates update easier, David has also made it possible for us to compile two different measures of butterfly abundances through an automated process — the totals of reports we collect for each species each year and the numbers of individuals estimated by all observers totaled for all reports for each species.

With some spread-sheet work on our own, we can also compile and calculate multi-year averages for all species for both measurements of abundance.  I am still working out those numbers, but having already found some surprises, I thought some of you might like to test your own “gut feeling” sense of those numbers against the data, before the full report is uploaded here in another week or so.

The 2019 Teaser Challenge:

Here are six common species in South Jersey (arranged in taxonomic sequence) that had very different levels of success in 2019:

  • Orange Sulphur
  • American Snout 
  • Variegated Fritillary
  • Mourning Cloak
  • Red-spotted Purple
  • Common Wood-nymph

Three of them had very good years; the other three had bad ones.  Can you guess which fit into those two “winner or loser?” categories for 2019?  

This is not a question about their overall abundances compared with one another.  It involves a better measure of annual success (and makes a more challenging question):

How did each species do in 2019 vs. its own ten-year-averages for 2009-2018?

Our “Oscar” Winner For 2019

The biggest winner of the six — the species with the best year of any of our common South Jersey butterflies (vs. its usual performance) — doubled its ten-year average by both our quantifiable measures — in reports and in total individuals counted.  If you were out and about chasing butterflies in 2019 (and you are familiar with normal distributions and numbers of our common species), this might be the easiest of the six species to name. Can you pull 2019’s biggest winner out of the line-up?

Winners Two & Three:  

The other two winners from the list of six couldn’t match Species #1’s success, but they did very well in 2019 nonetheless.  One generated 144% of its yearly average of reports and 136% its average annual individuals total. The third generated 129% its average number of reports and 171% its average number of individuals counted.  Depending on how carefully you follow the log, identifying them may be a tougher challenge than naming Species #1.  

 

Mourning Cloak, photo’d by Beth Polvino in her garden in CMY 9-29-19. Was 2019 a good year or a bad one for this species in South Jersey?

Three Losers in 2019:

One overall hint about the “down” group is that all three species in this category also did poorly in 2018 — and so now have had two bad years in a row.  

For two of them 2018 and 2019 were their two worst years in the years of our log.  One of these ended 2019 with a report total only one-third of its ten-year average and individuals total less than a quarter — 23% — its average total (in other words, down 77%).  The other species showed a report total down 60% from its ten-year average and generated a total individual count the lowest ever for the species on our log, only 17% of its average (i.e. down 83%).  

The third loser did slightly better (vs. its own ten-year averages) than the two species above but still was down significantly:  down 55% in reports and down 65% in total individuals. 

Can you think back over your own butterfly explorations last year and your memories of browsing on the log and then divide the group of six into three that had “up” years in 2019 and the three that were “down”?  My sense is this will prove a tough challenge.  Kudos to anyone who sorts all six correctly!  

The list again:

  • Orange Sulphur
  • American Snout 
  • Variegated Fritillary
  • Mourning Cloak
  • Red-spotted Purple
  • Common Wood-nymph

Answer: Up or Down in 2019?

— Jack Connor

Posted in Looking At Our Data | Comments Off on A “Teaser Challenge” for Ten-Year-Averages Report Coming Soon

Updates of Guides to Pollinator Plants & Butterfly Host Plants for South Jersey

Beech plum, Prunus maritima, and bee, in Jesse’s garden, April 23, 2019.

Butterfly gardening time is not all that far away, as all experienced gardeners know.

As of January 16, Jesse Connor has updated her guide to the best pollinator plants in South Jersey and her guide to the best host plants.

See them at the links below:

Jesse Connor POLLINATOR PLANT LIST (January 2020)

Jan 2020 Native Host Plants for BFs

[March 12 2020 Update:  Jesse has tweaked both documents slightly.  For the newest versions go to our banner above.]

Posted in Conservation Action, Eggs, Cats, Chrysalids, Host Plants | Comments Off on Updates of Guides to Pollinator Plants & Butterfly Host Plants for South Jersey

Cape May NABA Count 7-24-19

Participants on Cape May’s NABA Count on July 24 totaled a new record high for dion skippers: 143. This mating pair was photo’d by Steve Glynn in his area of the survey.

Michael O’Brien has kindly shared his Compiler’s report of the butterflies seen on the Cape May NABA Count on July 24 — including four record highs and a new species for the count’s all-time total.  Here’s his report:

Cape May, NJ. Yr. 29, 39.0167°, -74.8667°, center at middle of Maurice Blvd., Rio Grande. See 1991 report for habitats. Imminent threats to habitat: Invasive plants continue to be a problem in this count area, particularly in southern territories.

24 July 2019; 0800-1800 hrs; sun AM 51-75%, PM 76-100%; 67-82°F; wind 5-15 mi/hr. 13 observers in 11 parties.

Total party-hours 58.5; total party-miles on foot 35.

Observers: Cynthia Allen, Jim Dowdell, Vince Elia, Steve Glynn, Chris Herz, Brian Johnson, Sandra Keller, Michael O’Brien, Jackie Parker, Keith Parker, Tom Reed, Pat Sutton, and Louise Zemaitis.

Species:

Black Swallowtail 52,

E. Tiger Sw. 76,

Spicebush Sw. 102,

Cabbage White 214,

Clouded Sulphur 6,

Orange Su. 54,

Cloudless Su. 58, [Record High Count]

Sleepy Orange 3, [New Species for Count]

Am. Copper 4,

‘Olive’ Juniper Hairstreak 22,

Gray Ha. 22,

Red-banded Ha. 40,

Eastern Tailed-Blue 108,

‘Summer’ Spring Azure 75,

Am. Snout 17,

Variegated Fritillary 28,

Pearl Crescent 37,

Question Mark 13,

Am. Lady 44,

Painted La. 19,

Red Admiral 117,

Com. Buckeye 518, [Record High Count]

Red-spotted Admiral 39,

Viceroy 20,

Hackberry Emperor 1,

Appalachian Brown 3,

Little Wood-Satyr 1,

Com. Wood-Nymph 23,

Monarch 167,

Silver-spotted Skipper 144,

Southern Cloudywing 3,

Hayhurst’s Scallopwing 37, [Record High Count]

Horace’s Duskywing 47,

Wild Indigo Du. 1,

Com. Checkered-Sk. 1,

Com. Sootywing 9,

Swarthy Sk. 1,

Least Sk. 123,

Fiery Sk. 7,

Tawny-edged Sk. 1,

Northern Broken-Dash 23,

Sachem 97,

Delaware Sk. 21,

Rare Sk. 3,

Zabulon Sk. 12,

Aaron’s Sk. 8,

Broad-winged Sk. 368,

Dion Sk. 143, [Record High Count]

Salt Marsh Sk. 40.

Total:  49 species, 2972 individuals. Immatures: Black Sw. 3 eggs 22 caterpillars on Fennel, Queen Ann’s Lace; E. Tiger Sw. 1 caterpillar on Tulip Tree; Monarch 6 eggs 2 caterpillars on Common Milkweed, Tropical Milkweed.

Sandra Keller and Chris Herz found this Hayhurst’s scallopwing in their area of  the count.

*********

Want to join this count next year?

Michael notes that next year’s count will be Cape May’s 30th and it will be held on Wednesday, July 15, 2020. Mark your calendars now!

Jack Connor

Posted in Events, NABA Counts | Comments Off on Cape May NABA Count 7-24-19

Milkweed’s True Dependents

The long-horned beetle, Tetraopes tetraophthalmus, here feeding on milkweed flower buds, 6-15-18, probably out-numbers the monarchs in your local milkweed patch.

The milkweed flowering season has peaked now — for common milkweed, at least — and will fade to a close over the next few weeks.  By mid-July or so all those butterflies, moths, bees, wasps, ants, soldier beetles, and flower flies attracted by milkweed nectar will have drifted off to different blooming plants and generally become harder to find.

If  that dispersal seems like a bummer to you, you may want to take a look at Monarchs & Milkweeds (Princeton University Press, 2017) by Anurag Agrawal for a pick-me-up and change of perspective.

Agrawal barely mentions the dozens of nectarers that use milkweeds only for sugar hits.  Some (fewer than you might guess) are important participants in the lives of these plants because they pollinate them.  But most of the insects that draw our eyes to the milkweeds each June and July are more or less irrelevant to their ecology.

In Chapter Seven, “The Milkweed Village” he focuses on ten other insects as dependent on Asclepias as monarchs are.  All have evolved adaptations that enable them to feed on plants whose toxins repel virtually all other herbivores.  Several of the group are, like the monarch, brightly colored and distasteful to most predators.  Also like the monarch, all have developed features, behaviors, and a general ecology so intertwined with Asclepias that they cannot survive without it:  they are milkweed obligates.

That “Milkweed Village” chapter, especially Agrawal’s colorful chart (p. 171) detailing the seasonal sequence of those eleven insects from spring through fall inspired Jesse and me to start a focused exploration of our backyard milkweeds last May.  How many of Agrawal’s cast of characters could we find in our own milkweed village? How would their seasonality in a South Jersey yard compare to his sequence in central New York State?  And could we find any Asclepias specialists that he does not mention?

Two other sources proved as useful as Monarchs & Milkweeds:

“The Story of an Organism:  Common Milkweed” by Craig Holdrege (2010) available at The Nature Institute:

Nature Institute The Story of an Organism Milkweed

Milkweeds, Monarchs, & More: A Field Guide To the Invertebrate Community in the Milkweed Patch (2nd Edition, Bas Relief Publishing, 2010) by Ba Rea, Karen Obenhauser, and Michael Quinn.

Monarch caterpillar, presumably a grandchild of the Mexican over-winterers, 6-10-18.

Three Slightly Different Lists:

The eleven “Village” species described by Agrawal (abbreviated as AA below) include two leps (monarch and milkweed tussock moth), three beetles, two true bugs, one leaf-mining fly, and three aphids that he and his students have studied in central New York.  (He is an entomologist at Cornell).

Craig Holdredge (CH below) focuses more on Asclepias syriaca than the insects it draws,   and his detailed account of the sequence of flowering, the complexities of pollination, the formation and dispersal of seeds, and much else is sure to deepen your appreciation of this amazing plant.  He turns to the insects in the last third of his article and his one-page list of “Milkweed-Specific Herbivores” (p. 17) may be the most useful quick guide to the group that you can find in any of these three sources.  Print it out and you can start your own search for these insects a.s.a.p.  He details ten species for upstate New York, leaving out two of the aphids on AA’s list but including a third lep:  the dogbane tiger moth.

Rea, Obenhauser, and Quinn (ROQ below) have compiled a guide to milkweeds and insects throughout North America – not just the milkweed obligates but also nectarers, predators, parasites, scavengers, and passers-by.  It is a rich compilation, but the three authors do not intend the book to be comprehensive.  It would probably be impossible just to describe the multiple hundreds (thousands?) of species that nectar on milkweeds from New Jersey to California. Still, ROQ’s photos and short descriptions are extremely helpful to anyone trying to study a milkweed patch’s activity.  They identify fourteen milkweed specialists in North America:  seven leps (adding four southern species to AA’s and CH’s lists – queen, soldier, tiger-mimic queen, and a Pyralid moth), the three beetles and two true bugs AA and CH both list, one of AA’s three aphids, and they add a western beetle, Chrysochus cobaltinus, the blue milkweed beetle.

ROQ hint at another possible specialist with four small photos and two intriguing sentences (but no cited reference) on page 38:  “These planthoppers were observed feeding exclusively on milkweed in southeastern Pennsylvania.  The nymphs fed in groups of three to six individuals and began emerging as adults in late July.”  The species (one of fifty-eight in the family Flatidae) is not named, apparently because distinctions in that group are so subtle.

Our Yard’s Milkweeds: 

 Our yard holds two swamp milkweeds (A. incarnata) in the garden; about a dozen individual butterfly-weed plants (A. tuberosa) scattered around the sunniest spots of the yard; and three or four stands of common milkweed (A. syriaca) comprising about a hundred  shoots in total that grow each year in and around a mostly-untended section near our compost bins and flat-bed trailer.

The common milkweeds draw the most diversity by far.   We have not yet found any milkweed obligate feeding on either of the other two species that has not also appeared on our A. syriaca.

Common milkweeds in our yard, perhaps a single clone, 6-30-19.

A Guide To the Villagers:    

The first five species below sequester the cardiac glycosides they ingest from the milkweeds (i.e. store the toxins in their bodies) and so are poisonous to birds and most other predators. Those five plus the swamp milkweed beetle, which apparently does not sequester milkweed toxins, are also brightly colored and conspicuous — to warn potential predators of their identities.  These “aposematic” colors help make all six easy to identify.

Those six species and the others below are arranged from those easiest to find to those that require more focused searches.  All photos come from our backyard in Port Republic either last year (2018) or this (2019).

Young monarch caterpillar leaving a trench it created, 8-12-18.

Monarch, Danaus plexippus:  No reader of this post needs help identifying North America’s most celebrated insect, but if you take up Agrawal’s book, you may be surprised how much you will learn that you did not know.  One of AA’s points is evident above:  monarchs are not immune to milkweed toxins and early in-star cats are especially vulnerable.  Young cats can even be drowned by exuding latex.  They usually feed by “trenching,” as AA calls it — cutting a hole in leaf while carefully avoiding the larger veins as they chew and so minimizing the milkweed’s defensive gushes of latex.

AA notes that, beginning in the 4th instar, monarch caterpillars often notch large leaves at the base of the petiole. “Like digging a circle trench, this may take tens of minutes…cutting, retreating, and wiping away the latex. [Finally] the caterpillar feeds in the absence of the flowing latex.” Photo 6-8-18.

Long-horned milkweed beetles, as  they can be frequently found: the female chews on common milkweed while the male mates with her, 7-19-18.

Long-horned Milkweed Beetle (a.k.a. red milkweed beetle), Tetraopes tetraophthalmus:  Of all the local milkweed specialists, this pretty creature is the easiest to ID and to photo — generally walking around the plants slowly and boldly and flying only short distances.  Adults emerge in early June (late May?) even before milkweed blooms to feed on both leaves and unopened flower buds — but only on A. syriaca.  It may be the most specialized member of the Village, limited entirely to common milkweed.  Tetraopes means “four-eyed,” a feature evident in the photo at the top of the post, one pair of eyes above the antennae and another pair below.   Last year we still had numbers in our  yard nearly to the end of July.   So far, they are even more numerous this year.

Small milkweed bug nectaring on common milkweed, 6-17-18.

Small Milkweed Bug (Lygaeus kalmii): This is the first of the two milkweed look-alike “seed bugs” that both emerge in June.  Adults of this species appeared both last year and this year just as the first common milkweed flowers opened in our yard — around June 10th — and were still present until late August.  AA suggests this species and the large milkweed bug feed on seeds alone; CH lists L. kalmii’s primary food as “sap of common milkweed” and notes it is  “not a narrow specialist”; ROQ  note small milkweed bugs can act “as scavengers and predators…especially in the spring when milkweed seeds, their preferred food, are scarce or non-existent.” ROQ add, “L. kalmii‘s ability to cope with milkweed toxins enables them to prey on other milkweed specific organisms. They have been documented eating each other.”

Young small milkweed bugs cannibalizing one of their own, 8-7-18.  This feeding continued for ten minutes plus.

Large milkweed bug nectaring on common milkweed, 6-24-19.

Large Milkweed Bug, Oncopelius fasciatus:  AA and CH agree that the second milkweed bug of the year is a seed specialist.  ROQ note that it consumes “milkweed plant matter, mature and maturing milkweed seeds, and nectar from milkweed and other flowers.”  In our yard, it has emerged both years for the first time on the same date, June 17, three or more weeks before the earliest seed pods appear.  The only feeding that we have witnessed so far during that period is nectaring.  It does climb up onto the seedpods as soon as they form, and by September it is easily the most numerously visible of all the milkweed obligates.

The adult’s thick black bar running across the wings distinguishes this species from its look-alike seed bug. (L. kalmii shows an orange X across its back.) 8-1-18.

A common scene in fall: clusters of large milkweed bugs huddled together on milkweed leaves, perhaps to maximize their chances of being identified by birds as poisonous (?). 10-16-18.

Milkweed tussock moth caterpillars, 8-24-18.

Milkweed Tussock Moth, Euchaetias egle:  Here’s a creature most butterflyers and milkweed growers know, and some dislike.  It is the last of the obligates to make itself visible each year, appearing in the caterpillar stage in mid- to late-summer (adults are entirely nocturnal). They seem to come just when most of the milkweed leaves in your yard are looking bedraggled and ready to drop to the ground — and in big years they can land a kind of “death-blow” to the last of Asclepias‘s greenery. I think that’s the reason it is sometimes considered a “pest.”  But does it do more total damage to milkweed leaves than monarchs do?  It doesn’t migrate to Mexico, of course,  but it is a native species and needs milkweeds for the same reasons the monarch does.

ROQ note the bright warning colors of the late instar have led to the alternate name, “harlequin caterpillar.”  The two cats in the photo were our first last year and we saw only a  few afterwards — perhaps a consequence of 2018’s tough weather that apparently limited the numbers of many leps.

Swamp milkweed beetle on swamp milkweed stalk, 6-8-18.

Swamp Milkweed Beetle, Labidomera clivicolis:  AA charts this pretty beetle among the earliest of the obligates to appear in his area and the story seems the same in South Jersey.  We saw the first of the year in our yard in late May in both 2018 and 2019, including two  mating on 5-31-18. Like mourning cloaks and angle-wings, they over-winter as adults, often [according to ROQ] “in the shriveled , wooly leaves of mullein plants.”  Apparently, they prefer to feed on swamp milkweed in the wild, hence the name.  In our yard they consume the leaves of both A. incarnata and A. syriaca.  Larvae appeared in June in 2018 and the second brood adults were present into August.

 

Swamp milkweed leaf showing apparent beetle damage, 6-4-18. Like other milkweed feeders, L. clivicolis avoids the larger veins.

Swamp milkweed beetle walking the edge of common milkweed, a frequent activity, 6-24-19.

Milkweed weevil in what seems a typical spot for late-spring brood – in shade under common milkweed leaves, 6-24-19.

Milkweed Weevil, Rhyssomatus lineaticollis:  If you are still following this compilation (is anyone out there?), we have now reached the point when searching and finding grows tougher.  CH calls this creature the seed weevil, although he lists its primary food as “the pith of common milkweed stems.”  AA calls it the milkweed stem weevil, although he notes it feeds “on stems in the spring and seedpods in the fall,” charts it in two different seasons, late May to late June (stem-eating) and mid-August to mid-September (seed-eating), and hints that it might be two separate species.  ROQ’s simpler name, the milkweed weevil, may be best.  In our yard it seems easier to find later in the summer, after seedpods appear.  To find the earlier brood you need to turn over leaves, especially low on the plants, or look deep into the flower clusters.

Larval milkweed weevil. Note flow of latex created by this or another milkweed feeder. 7-19-18.

Adult milkweed weevil of second brood feeding in the open on top of common milkweed leaf, 7-19-18.

Oleander aphids on common milkweeds, 8-7-18.

Aphids, Aphis, sp.:  The milkweeds and aphids story seems complicated. AA lists three species feeding on his milkweeds; CH lists only the milkweed aphid, Aphis asclepiades as a milkweed-specific herbivore; and ROQ, despite the continent-wide breadth of their book, name and illustrate only one, the species above, the oleander aphid, Aphis nerii.  So far that is the only species we have been able to find.

AA spends several pages detailing the ecology of the three species he considers.  Among other things, he points out this is another case where an insect that seems a pest might not be a bad as many of us presume.  One researcher in AA’s lab found that monarch caterpillars growth was enhanced when they fed on leaves previously fed on by aphids.

Dogbane tiger moth under common milkweed leaf, 6-8-18.

Dogbane Tiger Moth (a.k.a. Delicate Cycnia), Cycnia tenera:  AA does not mention this beauty, perhaps because milkweed may not to be its primary food.  CH and ROQ both include it on their lists, noting it feeds on milkweed as well as dogbane.  According to CH, it sequesters cardiac glycosides (also available in dogbane).  He considers the adult “cryptic” and the caterpillar “aposematic.”  We found the adult above early one morning at the beginning of our little project, but have not seen an adult since (a black light might end that problem).  We found our first caterpillar just last week.

Dogbane tiger moth caterpillar on common milkweed, 6-25-19.

Dogbane beetle on common milkweed, 8-1-18.

Dogbane Beetle, Chrysochus auratus:  This gorgeous creature makes none of the lists I’ve been citing here, but BugGuide notes that, although dogbane seems its primary food, it is “also reported in association with common milkweed.”  In our yard it regularly explores common milkweed — flying back and forth from nearby dogbane plants.  And we have once or twice seen it apparently eating Asclepias syriaca.  At the moment, it is far more numerous in our yard than it was during any period in 2018, so I am hoping to document that consumption more certainly.  All sources seem to agree it sequesters cardiac glycosides and shows aposematic colors to warn predators away.  It is too pretty not to keep on the list!

Dogbane beetle apparently feeding on common milkweed, 7-29-19.

Planthoppers apparently feeding  on common milkweed, 6-25-18.  (The waxy threads are a defensive feature.)

Planthoppers, Flatidae, sp:  Our yard list ends with this might-have-been.  These larvae seemed to be feeding on our common milkweed, and they look like those in the photos of the planthopper larvae ROQ describe as “feeding exclusively on milkweed in southeastern Pennsylvania,” and suggest might be a milkweed specialist not yet recognized (p. 38).  We did not find the adults last year and have not yet found the larvae this year….yet!

Final Words:

We would very much like to hear from anyone who has surveyed their plants for these or other milkweed obligates — and from anyone who takes up the chase now.  Corrections are also welcome.

Best of luck to all explorers!

Sincerely,

Jack Connor

PS:  For more from Anurag Agrawal and his monarch and milkweeds adventures, you can go to his website:

Anurag Agrawal at Cornell University

 

Posted in Eggs, Cats, Chrysalids, Host Plants, Links to Research Articles, Milkweed Butterflies, Moths | Comments Off on Milkweed’s True Dependents