Category Archives: insects

Camel Crickets

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They are called camel crickets, cave crickets, spider crickets, or sprickets. Among the places they live are in damp basements and garages. They are harmless. There are 150 different species of them in North America, Entomology Today reports. Until recently, the site says, the camel crickets found in basements and garages were native species. But no more.

A citizen science project by researchers at North Carolina State University found that 90 percent of the camel crickets observed by the researchers or reporting citizens were greenhouse camel cricket (Diestrammena asynamora), a non-native species from Asia long known in greenhouses, but not in basements.

To make things even more interesting, photographs of camel crickets sent from the northeastern US appear to depict Diestrammena japanica, which hadn’t been formally reported in the US before.

Entomology Today article.
NC State University Camel Cricket project site.
Journal article on the project.

 

Moth Week Resources

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moth weekNational Moth Week is July 19 – 27. While most state wildlife departments struggle to include invertebrates of any kind in their program, if you are looking for educational opportunities, this one is as worthy as any. The week was founded and promoted by Friends of the East Brunswick Environmental Commission (and, yes, that’s in New Jersey).

Fine the National Moth Week website here.
And, of course, there’s a Facebook page.

The Nature Conservancy is celebrating National Moth Week.
It’s list of moth-related activities is here.
And a blog post with more background is here.

Can Roadside Weeds Save the Monarch?

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Monarch_butterflyThe number of monarch butterflies wintering in Mexico has plummeted in the last two years. Many factors are involved, but widespread use of glyphosate (an herbicide) is one cause that’s under human control.

The development of genetically modified plants that resist glyphosate is often sited as one of the causes of monarch butterfly decline. Because agricultural fields can now be liberally covered with the chemical, the little patches of milkweed that once thrived on on the edges of farm fields throughout the Midwest are now gone, taking the monarch caterpillar’s food source with them.

The Los Angeles Times reports that the Natural Resources Defense Council has filed a petition with the US Environmental Protection Agency asking that glyphosate not be spread on highway margins and utility rights of way to allow milkweed to grow there, as long as human safety isn’t compromised. It also asked that farmers establish glyphosate-free zones in their fields.

Read the entire article in The Los Angeles Times, here.

Photo: Monarch butterfly, Mark Musselman, USFWS

Worse Year for Monarchs

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Monarch_butterflyDepending on where you live, you may have noticed it in autumn. There were very few monarch butterflies around. It wasn’t unexpected. Numbers were low last winter in Mexico, and the weather over the summer didn’t favor the hatching of new monarchs.

World Wildlife Fund, Mexico’s Environment Department and the Natural Protected Areas Commission just announced that the numbers of monarch butterflies overwintering among the Transvolcanic mountains of central Mexico are the lowest since they started keeping records back in 1993. They measure the butterflies in the number of hectares that they cover in the park. This winter they covered 0.67 hectares. At their recorded high, in the winter of ’95-’96 they covered over 20 hectares.

Why, oh, why, do you ask? At one time the forest where the monarchs roost over the winter was being cut down, but that problem seems to have been solved. Climate change is in the mix. But the big problem, according to MonarchWatch, at the University of Kansas, is that herbicide tolerant (HT) crops have removed milkweed from a part of the country vital to the monarchs’ migration: the Midwest.

Read the report from MonarchWatch, here. It includes all the details on the HT crops theory.
Read the Associated Press news story in SF Gate, here.

Photo: by Mark Musselman, courtesy US Fish and Wildlife Service

Invasive Ladybug Packs A Secret Weapon

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Harmonia_axyridis01The multicolored Asian ladybug, also known as the harlequin lady beetle or ladybird (or just Harmonia axyridis), carries a fungal parasite in its blood that doesn’t seem to cause it much harm, but is deadly to the native ladybugs of Europe and North America.

That’s why the Asian ladybug has been such a ferocious competitor to native ladybugs, a paper in last week’s issue of the journal Science found. Scientists have long known that where Asian ladybugs are introduced, native ladybugs disappear, but they weren’t sure why. It seemed that the invasive species was out-competing the natives somehow. The new study explains why.

A fungus in the same genus infects honeybees.

Read the article in Science, here. (Subscription or fee required to see the entire article.)
Read the AAAS ScienceShot, here.Here’s the Guardian article, which I ignored at first because it focuses on European ladybugs. (The North American natives are in the same boat.)
Here’s the Los Angeles Times article on the same paper.

Fly away home, indeed.

Photo: ©entomart, just some of the many varieties of the multicolored Asian ladybug

Insecticide in Surface Waters

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Twelve_Spotted_Skimmer The news is not that imidacloprid is toxic to dragonflies and snails. The chemical is an insecticide after all. No, the surprise in the paper published in PLoS ONE is how much of the stuff was found in surface water. It was enough to kill off 70 percent of the invertebrate species in some places, including mayflies, midges and molluscs.

The Guardian had the story.

Further, the loss of those species might be affecting birds that are aerial foragers, which have been in decline in North America [PDF]. (Well, the molluscs aren’t feeding aerial foragers, but they are the most endangered taxa in North America anyway.)

The study took place in the Netherlands, but if anything imidacloprid use is more widespread here. Food for thought if you are concerned with mysterious declines in dragonflies, molluscs or aerial foragers.

The point of the study was actually to research honeybee decline. Imidacloprid is a neonicotinoid.

Read The Guardian story here.
Read the PLoS ONE story here. (It’s open access, of course.)

Photo: Twelve-spotted skimmer by Rick L. Hansen, courtesy US Fish and Wildlife Service

Butterfly Heads and Tails

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Great_purple_hairstreak_on_Common_dogbaneRecently published research from the Florida Museum of Natural History’s McGuire Center for Lepidoptera and Biodiversity provides experimental confirmation that the thing that looks like a second head on the back wings of some hairstreak butterflies does indeed protect the butterflies from predators, as has long been guessed.

The surprise was what predator it provided protection from. The conventional wisdom has said that adaptive coloration protects butterflies from birds, the researcher, Andrei Sourakov, says in a University of Florida press release. But this research showed that  the fake heads were very successful at deterring jumping spiders — which easily took down other butterflies without fake heads on their hind-wings.

This may not be much help in day-to-day wildlife management, but it is a cool piece of research, and with several hairstreaks endangered or threatened at the state level, you never know when you’ll be writing up a hairstreak management plan.

The University of Florida press release.
The open access Journal of Natural History paper.

Photo: Great purple hairstreak by Dr. Thomas G. Barnes/University of Kentucky, used courtesy of the US Fish and Wildlife Service

Chagas Disease in South Texas Wildlife

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chagas bugChagas disease, spread by kissing bugs or reduviid bugs is a scourge in South America, has the potential to cause heart failure. The symptoms can be chronic and go on for years.

Until recently, the disease and the insects that carry it were rare even in northern Mexico, but recently, says a report on the KABB Fox News TV station in San Antonio, Texas, the number of the kissing bugs found in south Texas has increased sharply.

More to the point, the piece says, a recent survey by Texas A&M researchers found that 60 to 80 percent of the mammals trapped on public land have been found to be infected by the disease. The animals trapped include feral hogs, white-tailed deer, wood rats, rabbits and raccoons.

Watch or read the piece on the KABB website, here.

More on Chagas disease at PubMed Health, and
probably more than you want to know, unless you have it, from the Centers for Disease Control

Photo: A kissing bug of the type that carries the parasite that causes Chagas disease, courtesy of the Centers for Disease Control

Monarch Pops Plummet

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Monarch_butterflyThe Washington Post reports that the monarch butterfly population wintering in Mexico has shown a drop in six of the last seven years. “…There are now only one-fifteenth as many butterflies as there were in 1997,” the article says.

Journey North reports that this year’s population is lowest since record-keeping began.

Drought and herbicides that have killed off milkweed, which the monarchs require as host plants — particularly in the Midwest, are thought to be the main contributors to the decline. While populations have rebounded after drops, the overall trend is down, down, down.

Read the Washington Post article here.
Read an Associated Press article here.
The Journey North Facebook page is here.

Photo: Monarch butterfly by Mark Musselman, used courtesy of the US Fish and Wildlife Department.

Bumblebee History

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cleptoparasitic beeOther native bee populations in the Northeast are holding up better than bumblebees (genus Bombus), a new paper in the Proceedings of the National Academy of Sciences reports.

The study looked at over 30,000 museum specimens spanning 140 years. It found that species richness of bees in the region declined weakly overall. However, three species declined sharply, all the the genus Bombus. The study also showed that there were significant shifts in species abundance over time, with 29 percent of the species decreasing and 27 percent increasing.

Unfortunately, the bees that showed the greatest increase were exotic species. Also doing well were southern species on the northern edge of their range.

In a EurekAlert press release, lead author Ignasi Bartomeus is quoted as saying, “Environmental change affects species differentially, creating ‘losers’ that decline with increased human activity but also ‘winners’ that thrive in human-altered environments.”

The scientist found that the more vulnerable species tend to have larger body sizes, restricted diets, and shorter flight seasons.

Read the EurekAlert press release here.
Read the PNAS abstract here. (Access to the paper requires a subscription or a fee.)

Photo: The cleptoparasitic bee Coelioxys sayiis is widely distributed in North America and parasitizes Megachile leaf-cutter bees. This photo was taken in Prospect Park in Brooklyn, N.Y. by John Ascher, of the American Museum of Natural History. Used courtesy of AMNH.