Wednesday, December 15, 2021

Life in a Looper

Last month, Barb put some cuttings from her Swedish ivy, Plectranthus australis, in a vase on top of our piano. The plant is in the Lamiaceae or mint family. A few days later we found frass all around the base and spotted this looper caterpillar crawling along the leaves. 

We identified it as a soybean looper, Chrysodeixis includens.  It is found all over the western hemisphere and even the Galapagos.  It is a soybean pest but its diet includes a number of plant families including Lamiaceae above.

A few days later it had wrapped up a leaf in silk and formed a pupa.  We sealed the pupa in a baby food jar with a dampened little piece of paper towel to raise the moth for confirmation. When we returned to town a week later we found the leaf/pupa case seemingly intact and the jar filled with 200-300 little 1.5 mm winged creatures.   
Our best guess is these are parasitoid wasps, probably in the superfamily Chalcidae.

The silk case around the leaf had these wasps on the outside but none inside or on the pupa as seen below. Without a microscope I wasn't able to get any better photographs than this one. I kept the jar of wasps until Barb ruled that the household Statute of Limitations had run out and the dead bodies were committed to the kitchen drain.

There are over 22,500 known species of Chalcid wasps (who keeps track of them?) and most are under 3mm in length, the smallest being 0.14 mm! Most are parasitoids of insect species ranging from lepidoptera (butterflies and moths), flies, bugs and beetles, and even a few spiders. Ours probably emerged from the caterpillar pupa although I can't see the exit holes and none are inside the silk web.

Wasps all outside the silk enclosure

I am holding on to the pupa until spring in the unlikely possibility it wasn't the source of the wasps. Don't tell Barb.

Sunday, December 12, 2021

Long-legged Fly

Last May I got this photograph of a long-legged fly from Courtney Reece of the WOLF School.  We now have "research grade" confirmation on INaturalist that it is Condylostylus longicornis, possibly the most wide spread species in its genus, found from the US down to Paraguay and even Polynesia!

Head on - Ken Schneider CC
Long-legged flies range in size from 1 to 9 mm and are usually a shining metallic color ranging from green to blue to bronze. They are generally characterized by their slender bodies and long legs.

They are commonly found in moist woodland areas.  Larvae develop in wet to dry soil and pupate in cocoons made up of soil particles cemented together. The larvae are predators, feeding on soil or bark-dwelling invertebrates.  Adults mate after elaborate and unique behavior, involving the males displaying their legs to the female.  Bugguide

Long-legged flies belong to the family Dolichopodidae (try saying that three times rapidly!) which has thousands of species worldwide.  Typically they have large, prominent eyes and a metallic cast to their appearance.

"Long-legged flies (Figure 1) are small (1-9 mm), but easy to recognize because of their metallic green, blue or gold coloration, slender body shape, and not surprisingly, rather long legs! Often you can find them scurrying about on vegetation in the sunlight during the day. They are excellent fliers, but usually run or fly short distances from leaf to leaf when disturbed, making them a lot of fun to observe in your own backyard!"

They are considered beneficial for pest control, feeding on small arthropods, including other flies, thrips, aphids, mites, springtails, leafhoppers, whiteflies, beetle larvae, and even termites! They will carry their prey around with them in flight as they secrete digestive enzymes into it and ingest the liquefied contents (similar to spiders). Ohioline.osu

Ready to pronounce Dolichopodidae? Here you go! 

Sunday, December 5, 2021

Jumping Spider

I saw the little quarter inch cutie in the back of my truck with a pile of firewood.  It moved carefully with a few tiny steps, typical of a jumping spider (JS, family Salticidae) which will reserve its leaps for dinner or defense.  Although it was only a quarter inch long, I could make out the little hairs covering the body and legs. When challenged they may face the danger and back away in short spurts.  

When a JS makes its jump it usually leaves a silk thread to dangle from if needed.  When I bumped it with a stick it jumped and hung from the thread as I nudged it into a bug box.  A few hours chilling in the refrigerator let me get a good facial photograph.

JS can be recognized by their eye pattern. All jumping spiders have four pairs of eyes, with the anterior middle pair being particularly large.  They have binocular vision that allows them to measure the distance to their prey, necessary when they pounce on a victim.  The small pair on the top of their head seen above gives them 360 degree vision to movement with a slight turn of the head.


You have to love the face of my jumping spider.  Spiders have mouth parts called chelicerae and on JS species they are often metallic blue-green.  These function like fingers, the upper portion fixed and the lower flexible. They can contain glands for the toxic fluid to paralyze prey and manipulate their dinner.

There is a lot more to like about jumping spiders.  For one thing, you can play with them, getting them to chase a laser light as shown in many Youtube videos.  As described in this Atlantic article, their eyes are shaped like little telescopes, a tube with a lens at each end just like Galileo created.  "Only three groups of animals have similar eyes: falcons, chameleons, and jumping spiders."

Bug Lady* describes the advantages of their hirsute body and legs:

"JS’s are relatively short-legged. Each leg ends with many tiny hairs, and each of those tiny hairs is further split into many more hairs, and each of those hairs is equipped with an “end foot.” With all those mini-feet, jumping spiders can boldly go where no spider has gone before—like straight up a pane of glass with the end feet gripping, just like a climbing wall, the “imperfections” in the glass."

There are an estimated 5,000 species of JS and mine doesn't have enough distinctive features to identify it further. The good news is that they can make the identification for mating.  As in many other spider species, sex is dangerous as the female may decide that the first meeting is going to be a "dinner" date.

*Bug Lady's blog has a lot more interesting details of JS at this link.