A Blistery Spring Day

I walked down the road last Tuesday (April 9, 2019) with my husband.  It was late afternoon and although it rained a bit earlier that morning, the sun was peeking out.   The wind wasn’t blowing, but it was soon to be a Blistery Spring day!

If you know any entomologists, you’ll understand rule #1 about going on ANY walk is to take a collection jar and a camera.  Last week, I failed to do this and missed an opportunity to identify and document this very cool bumble bee mimicking fly (genus Laphria ~ a bee-like robber fly).  This time I made certain to take my phone.  Sure enough, at the bottom of the hill, I see a black beetle crawling about on the chip-sealed road.  Fortunately, I refrained from my very bad habit of grabbing things with my bare hands. This is one beetle you do NOT want to pick up!  It was a BLISTER BEETLE.

Lucky me! I came home with some great photos and some video footage instead of a dermatological eruption that would have landed me in the doctor’s office.  I left the beetle in the road to continue whatever it was doing.

Back at home, I used my reference books to compare the photos and video I took of the beetle and narrowed down an ID to the genus Meloe.  I would need more help figure out the species.  I sent some photos off to Merrill Peterson at WSU with the suggestion that it might be a male Meloe niger.  Merrill wrote back that he thought it was M. strigulosus, but hard to confirm with only a photo.  He agreed it was indeed a male.

Meloe niger Black Meloe Blister Beetle

Meloe strigulosus (male)

You might ask how one goes about determining whether a particular beetle is male or female.  Often, as in this case, the male antennal segments are larger or varied in shape from the female.  This beetle’s antennae had a distinctive kinked platform on their fifth segment.  I would learn later that this kinked part enables them to grasp the antennae of the female during mating.

Meloe strigulosus (male)

Meloe strigulosus photo by Cynthia Brast April 9, 2019 Three Corner Lake Road San Juan Island, WA

Antennae

kink in antennal segment of M. strigulosis (male)

Merrill also sent me a link to what I will refer to as the Blister Beetle bible.  Published in 1970, this research was compiled by the legendary systematics entomologist, John D. Pinto, currently professor emeritus at U.C. Riverside with Richard B. Selander.  Hopeful, I sent off my photos in an email to Dr. Pinto and felt really privileged when I got an almost immediate response.

According to Dr. Pinto, the specimen I photographed was indeed a male Meloe strigulosus.  If you’re interested, you can read “The bionomics of blister beetles of the genus Meloe and a classification of the New World species”by linking here https://archive.org/details/bionomicsofblist42pint  Aside from the wealth of information published in this book, I love the artistic rendering of the female beetle on the cover.

Screen Shot 2019-04-15 at 11.53.12 AM.png

Illustration from Pinto and Selander’s “The bionomics of blister beetles of the genus Meloe and a classification of the New World species.” 

According to Dr. Pinto, there are 22 species of Meloidae in North America.  They are named Blister Beetles because they release a toxic terpenoid blistering agent called cantharadin when they are threatened or handled.  Sometimes people call them “Oil Beetles” because it’s oily. You can find the chemical profile of cantharadin here ~ https://pubchem.ncbi.nlm.nih.gov/compound/cantharidin#section=Drug-Indication

Curiously, this toxic secretion has been utilized to treat various medical conditions.  Among these was the topical application of the “oil” to treat rheumatism or to remove warts and lesions of Molluscum contagiosum, a contagious, viral infection of the skin (https://www.mayoclinic.org/diseases-conditions/molluscum-contagiosum/symptoms-causes/syc-20375226).  Cantharidin is also famously known for its use as an aphrodisiac (Spanish Fly).   This substance was historically used as a treatment for hydrophobia (rabies).  Male beetles were preserved in honey, mixed with other equally toxic ingredients then administered in an attempt to cure the patient. Maybe dying from cantharadin poisoning was less traumatic than dying of rabies.

Blister beetles are economically important because they contaminate alfalfa hay and they are highly toxic to livestock, especially horses.  There are instances where a horse has died from ingesting just ONE beetle. According to this Colorado State Extension publication (https://extension.colostate.edu/topic-areas/insects/blister-beetles-in-forage-crops-5-524/), just the release of cantharadin oil from the beetle can contaminate the hay.  Although reports of cantharadin poisoning in livestock are rare in the West, here’s one case where someone’s goat became very sick from ingesting hay contaminated with cantharidin ~ https://www.vetmed.ucdavis.edu/news/uc-davis-veterinarians-discover-blister-beetle-toxicity-goat

Another interesting fact about these beetles is that the larvae are phoretic parasites of solitary bees and grasshopper egg pods.  The first instar larvae, called triungulins” crawl onto flowers to await a visiting bee, then hitch a ride back to the nest where they will consume the pollen, nectar, and even the bee larvae.  Check out this link from National Geographic to view some extraordinary images of bees covered with blister beetle larvae ~ https://www.nationalgeographic.com/animals/2018/09/bees-blister-beetles-evolution-parasites-pheromones-news/

This was the first blister beetle I’ve seen on San Juan Island, but I do know of one other sighting by San Juan County Land Bank steward, Doug. M. from April of 2016.  I sent the photo of Doug’s beetle to Dr. Pinto as well and this was his reply, “Very likely M. niger – tho the photo is a little fuzzy for positive ID.”  Doug’s photo of the “likely” M. niger below.   

Meloe niger 2016-04-07 14.38.37

Meloe niger Mount Ben, San Juan Island, WA, April 2016                                                                     Photo by Doug. M. San Juan County Land Bank

 

If you’d like to read more about the particular species of blister beetle I found, I’m including the taxonomic key and geographic distribution data from Dr. Pinto’s book below.

                                               Meloe (Meloe) strigulosus Mannerheim


 Direct Key To The New World Subgenera of Meloe

Key to New World Subgenera of Meloe

Key to New World Subgenera of Meloe Pinto and Selander, 1970

 

 

Direct Key to the New World Subgenera page 104.

Direct Key to the New World Subgenera of Meloe page 104 Pinto and Selander, 1970

 

Key to Groups

Key to Groups p. 124

Key to Groups Bionomics of Blister Beetles Pinto and Selander, 1970

Direct Key to Groups page 157

Key to Groups Bionomics of Blister Beetles Pinto and Selander, 1970

 Geographic distribution

Geographic.distribution of M. strigulosus  p. 159

Geographic Distribution of Meloe strigulosus Pinto and Selander, 1970

Larval Key Meloe strigulosus

Larval.key.1

Larval key Meloe strigulosus Pinto and Selander, 1970

Larval.key.2

Larval key for M. strigulosus Pinto and Selander 1970

 

Antennal illustrations for male Meloe strigulosus, Figure 125 a. Dorsal view of segments V-VII, and b. Posterior view of segments V-VII

Male Antennae

Male antennae M. strigulosus Pinto and Selander, 1970

 

 

Antennal illustrations for female Meloe strigulosus, Figure 140

Female Antennae

Female Antennae M. strigulosus Pinto and Selander, 1970

 

 

References

Bittell, J. 2018.  Sex, Lies, and Grappling Hooks: How Parasitic Beetles Trick Bees. Animals Weird and Wild. National Geographic.  https://www.nationalgeographic.com/animals/2018/09/bees-blister-beetles-evolution-parasites-pheromones-news/

Hafernik, John and Saul-Gershenz, Leslie. 2000. Beetle larvae cooperate to mimic bees. Nature. 405. 35-6. 10.1038/35011129.

Kinney, K.K., F.B. Peairs and A.M. Swinker. 2010.  Blister Beetles in Forage Crops. Colorado State University Extension Publication 5.524. https://extension.colostate.edu/topic-areas/insects/blister-beetles-in-forage-crops-5-524/

Mayo Clinic. Mulluscum contagiosum. https://www.mayoclinic.org/diseases-conditions/molluscum-contagiosum/symptoms-causes/syc-20375226(accessed on Apr. 16, 2019)

National Center for Biotechnology Information. PubChem Database. Cantharidin, CID=5944, https://pubchem.ncbi.nlm.nih.gov/compound/5944 (accessed on Apr. 16, 2019)

Peterson, M. A. 2018. Pacific Northwest insectshttps://www.amazon.com/Pacific-Northwest-Insects-Merrill-Peterson/dp/0914516183

Pinto, J.D. and R.B. Selander. 1970. The bionomics of blister beetles of the genus Meloe and a classification of the New World species. Illinois Biological Monographs 42: 1-222.  https://archive.org/details/bionomicsofblist42pint

Piuser, J. 2017. UC Davis Veterinarians Discover Blister Beetle Toxicity in Goat. U.C. Davis Veterinary Medicine.  https://www.vetmed.ucdavis.edu/news/uc-davis-veterinarians-discover-blister-beetle-toxicity-goat

Quinn, M. Blister Beetles of Texas. Texas Beetle Resources. http://texasento.net/TXMeloidae.html#Meloe  (accessed on Apr. 16, 2019)

 

 

 

 

 

 

Scanning Electron Images of a Cerambycid Beetle

Yesterday I had the extreme good fortune to be able to use the scanning electron microscope (SEM) at University of Washington’s Friday Harbor Labs (San Juan Island).  We put a Cerambycid beetle under the SEM and “WOW,” the photos were phenomenal!  Here’s a few for you to see.  Below is a photo of the beetle’s compound eye.  Just think of all the information each of those facets receives and processes.

IMG_7528

Cerambycid beetle compound eye, imaged under scanning electron microscope at Friday Harbor Labs, San Juan Island, WA

Next, you see an image of the beetle head.  It shows the antennal insertion points, the compound eyes, frons, clypeus, labrum, mandibles, and bristly setae.

IMG_7526

SEM anterior, dorsal view of cerambycid head.

If you’re interested in learning more about the morphological features, here’s a pretty good diagram below for reference.

morph12

image from http://www.faculty.ucr.edu/~legneref/biotact/bc-51b.htm

The last image for you is of the beetle’s tarsi (the foot).  This is an important identification feature for many insects.  Imagine that!  When I was working on my masters degree from the University of Florida, I had an amazing taxonomy professor who was an expert on Coleoptera (the beetles).   He created identification keys for Florida beetles and you can take a look at them here:  http://www.entnemdept.ufl.edu/choate/beetles.pdf IMG_7525.JPGWell, I’m looking forward to using the SEM again and my next imaging will hopefully include the sponging mouthparts of a fly.   Stay tuned!

Xestoleptura crassipes on Pearly Everlasting (Anaphalis margaritacea)

Xestoleptura crassipes

Flower Long-horned Beetle (Xestoleptura crassipes) on Pearly Everlasting (Anaphalis margaritacea)

Suit of Armor

Ironclad beetle - Zopheridae

Ironclad beetle Phellopsis porcata

Yesterday’s “Word of the Day” on my new Facebook Page https://www.facebook.com/buggingyoufromSJI was “ Thanatosis.”  Thanatosis is a behavior otherwise known as “playing dead!” Here’s an insect I found on the roadside the other evening, doing exactly that. Only about 15mm long, it was amazing to even recognize it as something other than a piece of bark.

What is it? This beetle is in the family of Ironclad beetles known as the Zopheridae. It is a species called Phellopsis porcata, one of only two North American species in the genus Phellopsis. Little is known about this cryptic beetle, a bumpy, and bark-like “armored soldier.” It is camouflaged from view in what remains of our old-growth forests. This beetle does not fly, so as habitat disappears, so will the beetle. We may never know the entire scope of its role in our forest ecosystems unless these areas are protected.

What do we know about P. porcata? Researchers have documented the behavior of thanatois or playing dead to escape predation, and in the Pacific Northwest, this species feeds on fungi and is associated with western hemlock trees (Tsuga heterophylla).

 

Ironclad beetle - Zopheridae

Here’s a great online diagnostic tool that can help with identifying Ironclad beetles. This links to the page I used to help with the genus Phellopsis: http://coleopterasystematics.com/ironcladid/IroncladID-Phellopsis.html .   Look for these cool beetles when you take your next walk in the forest!

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Working Checklist of San Juan Island, WA Coleoptera

This is a checklist I’ve put together of the Coleoptera of San Juan island. Beetles with (*) asterisks are those I have actually seen, photographed, or have in my collection. It is a work in progress!San Juan Island – List of Coleoptera 2016 by Cynthia Brast

 

 

Meditations from San Juan Island and the story of Jerry the June Beetle (Polyphylla decemlineata)

Last year I had to put together a collection of insects for my graduate course at the University of Florida.  In this photo, I have a Ten-lined June Beetle that I pretty much stole away from a robin that was after it.  The beetle came home with me and I’m sorry to say I put it in the freezer and later added it with the rest of the bugs that eventually got me an “A”.

A few days ago, a friend called me up.  “Would you like another June Beetle?”  he asked.  I drove over to pick it up and afterwards, took a few photos with my new macro lens, fixed up a nice plastic box insect habitat and thought I’d take a few days to decide what to do with it next.

Daily, I peeked into the box.  Not sure what to feed it, I thought a little about whether my June Beetle might be hungry.  Yesterday though, when I looked into the box, I found him buried into the grass.  What was most noticeable to me was the fact that his antennae which had been upwards directed, were now pointing down.  He looked depressed – like he’d just accepted the fate that had come his way.  No! I thought to myself….I can’t keep him locked up like this.  So, grabbing my camera, I took my June Beetle (now named Jerry) outside.  I carefully took him out of the box and set him on a branch propped against a rock.  The sun was shining and warm and almost instantly, he perked up.  Those antennae started to rise, then waved around and spread open into intricately designed fans that were getting signals only he could interpret.

I snapped away with my camera, enjoying the experience of watching life come into him.  It wasn’t more than maybe five minutes and “Jerry” June Beetle decided to try his wings.  His first attempt to take-off failed.  So did his second….but he got it right on the third try and I watched amazed as he lifted into the air.  He rose almost directly upward and as he reached about 20 feet, he circled over me twice before heading over to the big Douglas Fir tree in my yard.  Freedom was his!  And me?  Well, I have come full circle.  You can learn so much more from observing a creature in its natural habitat than in captivity.  Thank you “Jerry” June Beetle.  It was nice making your acquaintance.  🙂

See more of Jerry and his transformation below! fullsizeoutput_958fullsizeoutput_955

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Thank you for setting me free! Love, Jerry the Ten-Lined June Beetle

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