Friday, July 1, 2016

75 Common Arkansas Insects (continued)

False Crocus Geometer, Xanthotype urticaria

I don't know what these attractive moths have done to deserve their notorious name. And, to tell the truth, I don't know anyone who has seen a genuine Crocus Geometer. But whatever the false one's personal morality, it is an often seen, pretty, day-flying, almost always mating moth. Once you spot a pair lying in the grass at your feet, you will not forget it, nor, once you hear it, will you forget its unfair name, associated as it is with the basest treachery.

Rock-loving Grasshopper, Trimerotropis saxatilis

Grasshoppers, with a few exceptions, are the grazing animals of the insect world, the things that everything else eats. Therefore evolution has pushed them, not towards better weapons, but towards better evasion tactics. Camouflage is one of them, and this grasshopper is one of the supreme examples. It flourishes on lichen-covered limestone glades, its pattern imitating the shapes and colors of the lichen to perfection. People who have noticed this grasshopper spontaneously call it "the lichen grasshopper."

Fruit Fly, Rhagoletis sp.

Another (and very common) defense for a weaponless creature is to pretend to be something dangerous. Here is a particularly clever example: The wing markings make this look astonishingly like a jumping spider, a very fierce big-game hunter, walking in the other direction. In fact when being stalked by a jumping spider this fly has been seen to walk backwards towards the spider, actually making the spider back off and seek some other target. Here is a typical jumping spider for comparison.

Striped Hairstreak, Satyrium liparops

There are half a dozen or so species of hairstreaks in Arkansas, small, pretty, fast flying butterflies that almost always land with their wings closed up above their head, so that you see the wings' underside. There are various patterns on the wings, but they usually feature large red or blue spots, and "tails" at the end of the hind wings. As a sort of nervous habit, they constantly slide their hind wings back and forth against each other with the effect that the tails seem to be waving up and down. The blue and red spots resemble eyes, the tails are very like waving antennae, and that's their trick. A spider or a bird that wants to catch a butterfly goes for the head, that being the quickest way to disable it. But mistaking the big eyes and the waving tails for the front end, they make their grab, and the butterfly escapes in the other direction. This has been photographed in the case of jumping spiders, and the back ends of healthy active butterflies often have a beak-shaped rip.

 Glowworm, Phengodidae, Phengodes sp.

Glowworms always sound like mythical beasts, something in soppy songs, but here one is, in the middle of a huge outbreak of flat-backed millipedes. This is the larval form of a beetle, and it could be an actual larva, but it could also be an adult female, which sexually matures, mates, and lays eggs retaining its larval form, only the male metamorphosing into a beetle form.

Another oddity: Millipedes are so poisonous nothing eats them, that is, except glowworms, and glowworms feed entirely on millipedes. Here is the glowworm attacking a millipede it is about to devour.

Of course, you have to see a glowworm at night to see its third oddity, from which it takes its name.