Category Archives: Beetles

A Little Weevil House

Key Words: masting, Curculio, Quercus, mast seeding, acorn weevil, diapause

I picked up these acorns (Quercus sp.) when I visited my folks recently in Texas. They have several oak trees on their property and there was an abundance of acorns all over the ground this year, so I brought a few home with me in a ziplock bag. I like acorns. My mom used to draw little faces on them and I had acorn “people” to play with when I was a child.

Acorn “person”

I also found a very cool bug under one of those oak trees while I was there. This strange looking creature is one of the Nut and Acorn Weevils (Curculio sp). It has an extremely long snout. When you find out how this weevil uses it to DRILL, you may be amazed. The adult female weevil will use this drill on her very long snout to make a hole in those acorns!

Nut and Acorn Weevil (Curculio sp).
Nut and Acorn Weevil (Curculio sp).
Nut and Acorn Weevil (Curculio sp).

Keep reading. It really is amazing.

A female weevil will make a hole in the acorn so she can put her eggs inside it!

Hole drilled by Nut and Acorn Weevil

Because I like word games, I thought I’d point out to you that rearranging the letters in the word weevil will make the words “we live?” Well, those eggs hatch into baby weevils who LIVE in a little house that is an acorn (and sometimes in other nuts too). Some folks call them grubs or worms. They are actually the larvae of the adult weevil mom who selected the acorn for her nursery.

If you are assessing this situation from an agricultural perspective (say that nut is a pecan), invested in harvesting a profitable crop, you might be feeling very worried. Sometimes the worry may indeed be justified, but in many cases, like with these acorns, the tree has evolved a strategy to deal with occasional waves of weevils and other insects we consider pests. In actuality, they are just utilizing the resources of the tree like we do when WE (the humans) eat the nut or fruit.

Larvae of Nut and Acorn Weevil (Curculio sp).

I’m going to name the trees’ strategy of dealing with this bug FEAR NO WEEVIL. However, the actual scientific moniker for this strategy (and it applies to other pests and adverse weather stressors as well) is MASTING. The word mast has been used since way back in the Middle Ages to refer to the acorns and seeds of forest trees that drop and accumulate on the ground. It comes from Old English, mæst. Essentially, masting is an ecological term referring to the highly variable and often synchronized periodic cycles of fruiting/seeding in the reproductive processes of trees (both forest and fruit trees).

How is it a strategy for circumventing the deleterious affects of pests? Well, the idea is that in some years, bumper crops of nuts and seeds are produced in order to satiate the predators, so some are left to germinate and continue new generations. In this particular case, you could think of it as the oak trees sacrificing some of their offspring to the weevil gods. When there are more acorns than there are adult female weevils, some of those acorns will escape the weevil drill and makeover into little bug nurseries.

In reality, this relationship is much more complicated. In some cases, acorns parasitized by only a few weevil larvae will germinate, while those acorns with many larvae will not. The trees’ bumper crops of seeds and nuts will also cycle with years of low production, where resources are scarce for the weevil (and other organisms). Nature is incredibly dynamic though. Studies show some species of weevils have adapted a counter mechanism to circumvent the trees’ strategy of masting. It’s called prolonged diapause. This means these weevils are able to sleep longer (more than one year) as they develop in order to synchronize adult emergence with years when the trees’ seed/nut production is high.

If you are interested in reading more about the history and MYSTERY of masting, I encourage you to delve into the literature I’ve listed in the references below. It’s quite fascinating – especially going back in history to the link between masting and pannage. Way more than I can cover here. Check it out.

References

Baldwin, M. 2021. Pigging out in the forest: the Common of Mast (Pannage) in Britain https://www.wildlifeonline.me.uk/blog/post/pigging-out-in-the-forest-the-common-of-mast-in-britain

Bugguide 2021. Curculio. https://bugguide.net/node/view/6682

Higaki M (2016) Prolonged diapause and seed predation by the acorn weevil, Curculio robustus, in relation to masting of the deciduous oak Quercus acutissima. Entomol Exp Appl 159:338–346. https://doi.org/10.1111/eea.12444

Jefferson, R. 2006. Why Are More Acorns Falling? Excessive Drops of Nuts from Oak Trees Is Part of Normal ‘Mast Year’ Phenomenon. Scientific Times. https://www.sciencetimes.com/articles/33795/20211006/why-more-acorns-falling-excessive-drops-nuts-oak-trees-part.htm and https://youtu.be/EQ748TZcuqs

Jesse, L. No date. The dark side of collecting acorns. Plant and Insect Diagnostic Clinic. Iowa State University Extension and Outreach. https://www.extension.iastate.edu/news/2007/sep/072107.htm

Koenig WD. 2021 A brief history of masting research. Phil. Trans. R. Soc. B 376: 20200423. https://doi.org/10.1098/rstb.2020.0423 Koenig, W. D., & Knops, J. M. H. (2005). The Mystery of Masting in Trees: Some trees reproduce synchronously over large areas, with widespread ecological effects, but how and why? American Scientist93(4), 340–347. http://www.jstor.org/stable/27858609

Nut Leaf Weevil

I found a’nutter weevil! They’ve been everywhere this week! Looks like this may be the Nut Leaf Weevil (Strophosoma melanogrammum). These weevils feed on the leaves of broad leafed shrubs. I saw it on a chunk of rotting alder. It was pretty small and tough to photograph in low light. Probably about 3.2 mm in size. San Juan Island, WA October 13, 2021.

Strophosoma melanogrammum 

Facebook Fail

The social media giant we all have become overly dependent on in recent years, had a big, giant F-A-I-L today. The entire site was down. I couldn’t share bug photos or look to see what crazy or amazing things my friends had been up to. I also couldn’t watch the fabulous video of the frog and bearded dragon that I’ve been replaying over, and over, and over because it’s so DARN cute! You can find it on Tik Tok if you can’t find it on Facebook.

In the void, I resorted to the fail safe backup. It’s called E-mail. I really feel old because I actually remember how we communicated before the advent of cyberspace – handwriting letters that you put a stamp on and eventually were delivered by USPS.

So, in my email, I actually had received two nice bug pictures I want to share with you. Victoria Compton (who is running for Friday Harbor Port Commissioner btw) sent these to me. The first, a caterpillar, is going to turn into my favorite moth, Lophocampa roseata or the Rosy Amelia Moth. The 2nd, is a ground beetle in the family Carabidae (Scaphinotus marginatus) – also sometimes called the Margined Snail-eating Carabid Beetle.

Happy Bug Viewing! Thanks for checking these out and thanks for sending the photos Victoria! You have my vote. 😉

Lophocampa roseata moth caterpillar

Scaphinotus marginatus Carabid beetle

Links to read more about these two bugs

Lophocampa roseatahttps://buggingyoufromsanjuanisland.com/2018/10/02/lophocampa-roseata-rosy-aemilia/

Lophocampa roseata https://bugguide.net/node/view/247272

Scaphinotus marginatus https://bugguide.net/node/view/327898

Twenty-spotted Lady Beetle (Psyllobora vigintimaculata)

Twenty-spotted Lady Beetle (Psyllobora vigintimaculata) on daisy. This tiny ladybug almost went unnoticed when I was watering flowers the other day. It wasn’t easy to get a photo and she crawled down headfirst into the flower bud. I suppose she was feeling shy!

After reading a bit more about these, I discovered the best place to look for them is at the base of skunk cabbage in early spring. AND, this is the best part. Later in the season, these little beetles switch to plants that have powdery mildew. They eat it. Definitely a garden friend!

Twenty-spotted Lady Beetle (Psyllobora vigintimaculata) on Daisy – May 30, 2021 San Juan Island, WA
Twenty-spotted Lady Beetle (Psyllobora vigintimaculata) on Daisy – May 30, 2021 San Juan Island, WA

References/Further Reading

https://bugguide.net/node/view/39631

https://www.researchgate.net/publication/233687670_Biology_and_Co-Occurrence_of_Psyllobora_vigintimaculata_taedata_Coleoptera_Coccinellidae_and_Powdery_Mildews_in_an_Urban_Landscape_of_California

Northern Carrion Beetle – Thanatophilus lapponicus

This is a Northern Carrion Beetle – Thanatophilus lapponicus, one of the carrion beetles in the family Silphidae. The origin of the name Thanatophilus is from Greek thanatos (θανατος)- “death” + philos (φιλος)- “loving, liking” (Bugguide.net, 2003-2021).

Northern Carrion Beetle (Thanatophilus lapponicus)

Death is part of a biological process that can be unsettling for many of us. That said, death makes way for new life. This past February, a small fawn died on our property.

February 17, 2021

We left the body where it lay. First the eagles came, then a pair of ravens. I believe a fox visited too (tracks in the snow).

Bald Eagle 2.18.2021

Fox (?) tracks in snow

Over the course of the past 12 weeks, I’ve found some very cool bugs developing in the carcass, even now in the bits of hide and bones that remain.

Did you know?

There is actually an entire field of scientific study (Forensic Entomology) where time of death of a body can be estimated by the presence and developmental stage of certain insects involved in the decomposition process. This is called determining the Post Mortem Interval or PMI. Forensic entomologists can aid law enforcement in crime investigations by surveying for species of arthropods on a corpse, and determining stages of development and feeding behavior of the arthropods present (Barnes, 2000).

Carrion beetles in the family Silphidae fall into two subfamilies: the Nicrophorinae and Silphinae. While both feed on the remains of animals, the Nicrophorinae or Burying Beetles are associated with smaller corpses like birds, mice, voles, etc., weighing under 300g, while the Silphinae utilize larger cadavers (Watson & Carlton, 2005). This preference or niche, makes them ideal for investigations related to human death or death of larger species of wildlife (as in poaching or other crimes against animals).

Northern Carrion Beetle (Thanatophilus lapponicus)
Northern Carrion Beetle (Thanatophilus lapponicus)

From Ratcliffe, 1996.

Distribution. Thanatophilus lapponicus ranges broadly throughout Canada and Alaska, across the norther United States from coast to coast, and south to Southern California, Arizona, and New Mexico (Anderson and Peck 1985, Peck and Kaulbars 1987). It is also found in Northern Europe and Asia (Hatch 1928, Schwaller 1982).

Remarks. Thanatophilus lapponicus is readily identified because of the presence of a row of small tubercles on each of the elytra intervals (Figs. 31-32, 62); it is the only silphid in North America with this distinctive form of elytra sculpturing.

https://museum.unl.edu/file_download/inline/1bde566e-27c3-4c55-9345-59057400e350

The larval stage was described by Dorsey (1940) , and a brief synopsis was given by Anderson and Peck (1985). The larva of this species is characterized by a dark brown to black color on the dorsal surface, urogomphi that are about two times the length of the 10th abdominal segment, and antennae with a large sense cone on the second segment (as in Fig. 40).

Anderson and Peck (1985) reported that individual females lay about ten eggs in the soil surrounding a carcass. The egg stage lasts 5-6 days, the first instar about 7 days, the second instar 8-10 days, and the third instar 10-12 days. While Anderson and Peck did not observe pupae, they did note that T. lapponicus is a cold-adapted species that occurs at higher elevations in the western Mountains of North America. It is often the only silphid present in some of these areas. Thanatophilus lapponicus shows a strong preference for open areas (Anderson 1982c).

Clark (1895) observed extensive predation on fly larvae by adult beetles.

Size. 9-14mm

Time of Year Seen. March-October

References:

Anderson, R.S. and Peck, S.B. (1985) The carrion beetles of Canada and Alaska. The insects and arachnids of Canada, part 13, 1–121.

Barnes, S. 2000. Forensic entomological case study and comparison of burned and unburned Sus scrofa specimens in the biogeoclimatic zone of northwestern Montana. Graduate Student Theses, Dissertations, & Professional Papers. 4655. https://scholarworks.umt.edu/etd/4655/?utm_source=scholarworks.umt.edu/etd/4655&utm_medium=PDF&utm_campaign=PDFCoverPages

Bugguide.net. https://bugguide.net/node/view/37875

Ratcliffe, B.C. 1996. The Carrion Beetles (Coleoptera: Silphidae) of Nebraska. Bull Univ. Nebr State Mus 13:1-100 https://museum.unl.edu/file_download/inline/1bde566e-27c3-4c55-9345-59057400e350

Watson, E., & Carlton, C. 2005. Succession of Forensically Significant Carrion Beetle Larvae on Large Carcasses (Coleoptera: Silphidae). Southeastern Naturalist, 4(2), 335-346. Retrieved April 27, 2021, from http://www.jstor.org/stable/3877967

TreeHugger Soldier

This little guy got into my pants yesterday! 😁 What is it? This is a Treehugger Soldier Beetle (Dichelotarsus piniphilus) in the family Cantharidae or soldier beetles ( because their wings resemble military uniforms). More interesting though is the Greek translation of Cantharis or κανθαρισ, translating to ‘blister beetle.’

Treehugger Soldier Beetle (Dichelotarsus piniphilus)


I’m pointing this out because this little Treehugger got confused yesterday and when it was hugging my leg and my pants were hugging back a bit too tightly, it either bit me or exuded some of the defensive chemicals that they use to repel would-be predators . In either case, I was fine aside from a bit of a temporary stinging sensation.

Treehugger Soldier Beetle


This species is common in the west. Surprisingly, very little is known about the life histories of these beetles. I’ve spotted them on nettle this time of year. Adults are known to feed on insects (including aphids), nectar, and pollen.


I wondered if there is some uptake of the chemical constituents of the nettle to produce the defense secretions in the beetle, either via consuming pollen from the nettle, or via feeding on another insect feeding on the nettle. A literature search failed to yield any supporting information, though I did find an older publication listing insects found in association with nettle. Quite a few were some of our lovely Lepidoptera, so you might want to leave those nettle patches instead of clearing them away 🦋

Treehugger Soldier Beetle

Read more here:


https://bugguide.net/node/view/279953?fbclid=IwAR2meHyQsnxdeb94MKL3YEpRMWo29-4oBmuSsru0M5nkX_aaMDN_Vxe639I


https://biologicalsurvey.ca/ejournal/ph_25/ph_25.pdf


https://en.wikipedia.org/wiki/Cantharidin

Bill the Beetle, aka Zeke the Greek

I thought I’d post about something new I discovered today when reading about the Darkling Beetle species Zophobas morio.  These are beetles that some folks will know by the common name for their larval form, Superworms.  

First off, the beetle I’ll be using as my representative here is named “Bill.” I discovered Bill one day in my bin of feeder roaches for my Bearded Dragon (Drago).  When I first met Bill, he was a weird waxy, mummy-looking mutant lying motionless amongst the frass (roach poo) at the bottom of the plastic bin. 

He almost got dumped into the trash, but I gently picked him out recognizing the wax museum-like form as the pupal stage of some sort of bug.  It definitely was NOT a roach since roaches have hemimetabolous development.  This means their intermediary stages or nymphs, basically look like mini replicas of their adult parents. 

Zophabus morio, “Bill”

Bill didn’t stay red for very long and in fact, the next day he was pretty BLACK.  While investigating a bit about the meaning of his scientific or Latin name, I couldn’t find much in the entomological references I checked.  I delved a bit deeper and came up with this and thought you might find it interesting.  

In Greek, Zophos refers to “black” or “black darkness of the nether world.”  Mori refers to “death.”   

I think I like the name Bill if he’s going to hang out on my kitchen counter, but maybe for Halloween he can be scary Zeke the Greek, herald of black death of the netherworld.  

Bill is also going to be a family member for about as long as Drago.  I’m not sure how my husband will feel about this.  He asked me when I got Drago how long Bearded Dragons live.  I said “about 15 years with good care.”  Wow!  That means we will be in our 60’s.  

Drago was 3 when he came to live with us in March 2020, so if he lives to be 15, I will be the very old age of 68.  Well, BILL can live for about the exact same amount of time!  FIFTEEN years.  That’s right!  I read it here -https://sciencing.com/superworm-life-cycle-5347598.html

Bill in his habitat

If you’re interested in a pet beetle like mine, here’s a link to a care sheet. They are easy to keep, low maintenance, and don’t bite! https://beta-static.fishersci.com/content/dam/fishersci/en_US/documents/programs/education/technical-documents/data-sheets/carolina-biological-darkling-beetle-data-sheet.pdf

Thanks for reading! 🐞🦋🐝🐛🐜🦗🦟

Aphodiine Dung Beetle – October 21, 2020

I found this tiny (approx 4.5mm) Scarab yesterday when I went out to pick the remaining few tomatoes in the garden. It came in with me just long enough to get a few photos so I could attempt an ID. If I’d kept it long enough to realize what I had, I might have tried for better pics. Instead, I returned it to a sunny spot outdoors and let it go about its business in the garden.

After an internet search, I came up with a preliminary ID to subfamily Aphodiinae, but I believe this specimen to be in the tribe Aphodiini and possibly (Agoliinus sigmoideus). This is where my frustration begins as I definitely need my specimen back for further examination in order to confirm. For now, we’ll leave it at Aphodiinae.

The Aphodiinae are dung beetles that feed on detritus and more. Bugguide references the work of Skelley (2008) and states, “many feed on dung, some are detritivores, psammophiles, saprophages, inquilines with ants or termites, or may potentially be predators; adults with reduced mandibles are suspected to feed primarily on bacteria or yeast-rich fluids in dung or decaying materials.”

Reading about dung beetles in general, I came across an interesting publication in Biological Control that examined how some species of coprophagous dung beetles can reduce the contamination of bacteria like Escherichia coli in agricultural systems when flies, livestock, or wildlife are present. Aside from providing other important ecosystem services like feces removal and nutrient recycling, the aspect that they also help with food safety by reducing harmful bacteria is another reason we need to invest in organic agricultural systems that do not rely on harmful pesticides, fertilizers, and herbicides which alter the natural biological processes at work. In short, nature does it best!

Aphodiini San Juan Island, WA 10.21.2020
Aphodiini San Juan Island, WA 10.21.2020
Aphodiini San Juan Island, WA 10.21.2020

References

Bugguide.net – https://bugguide.net/node/view/13137

Skelley P.E. (2008) Aphodiinae. In: Generic guide to New World scarab beetles

Key to genera of New World Aphodiini (Scarabaeidae: Aphodiinae) http://unsm-ento.unl.edu/Guide/Scarabaeoidea/Scarabaeidae/Aphodiinae/AphodiinaeTribes/Aphodiini/Key/AphodiiniK.html

Nicrophorus Burying Beetle Powerpoint – Grave to Cradle

The links here are for a project I worked on in grad school about Burying Beetles. I was having some trouble getting the code to share it on WordPress, so if you have trouble viewing, let me know. Powerpoint link is via OneDrive at https://1drv.ms/b/s!AnuXRWM_ynxHcba_40yxFvTJCgw?e=toCNNE but I also have it on Slideshare.net at https://www.slideshare.net/CyndiBormann/burying-beetles-powerpoint?qid=e930baf4-87e9-4553-a366-0044098db422&v=&b=&from_search=1

The Three Banded Lady Beetle (Coccinella trifasciata subversa)

Coccinella trifasciata subversa on clover

I found my first Three Banded Lady Beetle (Coccinella trifasciata subversa) this morning in the patch of clover in front of my home. At least I believe it is the subspecies ‘subversa’ according to the information I found online and referencing the distribution map. While I did not find much information about this particular species pertaining to life in the Pacific Northwest, I did find that according to the Lost Ladybug Project, this species (Coccinella trifasciata) is considered a species of greatest conservation need in the state of New York.

Coccinella trifasciata subversa on clover Photo by Cynthia Brast-Bormann San Juan Island, WA 07.06.2020
Distribution map of Coccinella trifasciata subversa

So, because I’m interested in Lady Beetles and conservation, I submitted my photos today to the Lost Ladybug Project. They’re keeping records of sightings and I believe it’s important to collect and share data that help us understand more about the lives all of all the amazing critters we share the planet with.

If you see a Lady Beetle you are interested in knowing more about, take a look at the Lost Ladybug Project here – http://www.lostladybug.org/index.php

If you have time, check out my Facebook Page, Bugs of the San Juan Islands at https://www.facebook.com/buggingyoufromSJI/

Thanks for reading! 🐞🐞🐞

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