Flora and fauna of the Athens County area, and occasionally habitats outside Ohio. Subject matter will consist of both interpretive material and taxonomic issues in plant and animal identification.

Monday, September 5, 2011

Another Insect Walk

Actually this is a combination of several trips I took to find insects. I'd like to start with an interesting find regarding this damselfly. Based on the fact that the top of every abdominal segment is covered in a black-green color, this has to be either a Marsh Bluet or Hagen's Bluet female. Both are found in northern Ohio, but only the Marsh Bluet has been recorded in southern Ohio, and right here in Athens County, so I'm going with that. The genitalia must be examined under a scope to be absolute. Thanks to Tom Schultz of Denison University for mentioning that this is an "andromorph".

Andromorphs are females that mimic males. This female above is not normally blue. To what advantage is this character? Female Odonata take a beating during mating, especially when pursued by multiple males for repeated mating attempts. Regular females not receptive to mating simply fly away and hide. An andromorph female will turn and face males head-to-head in defiance, thereby not exposing her genitalia. This polymorphism is not only morphological, but behavioral. While these females do mate successfully, the gene is less prevalent in populations because males tend to give up on them and stick to the more abundant, normal looking females.

Since we started with a damselfly, let's do another. Both the bright blue and lavender one are the same species. The black marks on the abdomen are arrowhead shaped. Except for a small dot, the 8th and 9th abdominal segment are blue, and the 10th segment (the last one) is black. That narrows it down partially. On the head, the eyespots are connected by a stripe. Most importantly is the back of the thorax. Most damsels have a solid color there, usually black. You will see a blue stripe break up that black, giving it a stripe both on top and on the side. That makes this the Double-striped Bluet, Enallagma basidens.

That split stripe on the side is more evident in this photo of a female. Click to enlarge if you can't see it, then compare it to the solid stripe seen in the first pic on this post. All markings are the same as the male, except for the 8th and 9th abdominal segments now have black, and the 10th does not. That black mark on the 9th segment is shaped differently than any other female damsel. To many people, all these damsels look the same. I've stated it before, and will continue to say that without specimens in hand, or closeup pictures, damselflies are difficult to identify.

In a previous post I talked about the Bee Assassin Bug. I finally found one sitting on Liatris busy sucking away at a honeybee it captured.

Also in a previous post I mentioned that many young grasshoppers can not be identified to species. Luckily this striking pattern is fairly consistent from nymph to adult. This is Syrbula admirabilis. I don't think is has a common name.

Here is the common Northern Walking Stick, Diapheromera femorata. They occur in both green and brown. Most will be turning brown come October when they will be found mating. The male will be on top and is much smaller than the female. During population outbreaks, Walking Sticks can become an insect pest, eating and damaging large areas of oak forests. Walking sticks are in their own order, Phasmida or Phasmatodea, and do not grow wings like mantids.

This Bee Fly is very active at flowers, but when disturbed heads to the ground and tucks its abdomen. This group of Bee Flies are difficult to tell apart. Because the abdominal segments are lined with rows of yellow hair, this is Villa lateralis. If just one row of hair was bright white, it would bee a different species.

Boy, somebody is sending out some powerful pheromones. The False Indigo seed pods were just covered with these. This is Alydus eurinus, a Broad-headed Bug. Looking like Leaf-footed Bugs because of their enlarged hind legs, Broad-headed Bugs are in a separate family. In Leaf-footed, Assassin Bugs, and others, the head is usually much narrower than the thorax. In this family the head is wide, almost the same width as the thorax.

If you look closely, it appears they have multiple eyes like a spider. These are called ocelli. They don't see objects the way their compound eyes do, but serve mostly as light sensing organs. Insects have either 1, 2, or 3 of them, and some insects have none at all.

Freaky-face here is Otiocerus wolfii, a Derbid Planthopper. Planthoppers are related to leafhoppers and treehoppers, and are members of the Hemiptera sub-oder Homoptera. Like all True Bugs, they have piercing-sucking mouthparts. The Homoptera keep their wings folded up like a tent rather than flat like other true bugs. The other difference is Homoptera antennae are very reduced in size. Above the orange mouth palps is an orange antennae base with a thin wire-like antennal segment. Click on it for a closer look.

If you drive around Ohio, you'll see the Black Locust trees along the highways turning a premature brown. They are not dead, but the victim of the Locust Leaf Miner, a black and orange beetle. These leaf miners feed upon the surface layer of photosynthesizing cells. Several years ago in S.E. Ohio, they were virtually on every tree. They're still around here, but not as bad as they once were, though in many places of the state I've seen this summer, they appear to still be a problem.

They do feed on other trees, but Black Locust is their primary host. Trees will re-leaf, and mortality usually only occurs during drought.

Imagine seeing small pieces of leaves, twigs, and silk moving along a leaf. It doesn't look like much in the picture, but this is a Lacewing larvae that camouflages itself with decaying organic matter as it hunts around for a meal.

And what looks like a piece of cotton with bumps like a crown? Another Lacewing larva?  Nope. This unusual thing is the cocoon of the Planthopper Parasite Moth. About a quarter inch long, it's in the same superfamily as the Slug and Flannel moths, but it's biology is different. Instead of feeding on leaves like most caterpillars, the larvae hatch out onto a leaf and wait for Homopteran planthoppers to come by. They will attack Cicadas and Leafhoppers, but are particularly fond of the Fulgorid Planthoppers.

They latch on and begin chewing through the chiton of the exoskeleton. It will feed on the body fluids of the host. They stay on the outside (an ectoparasite) being careful not to kill the host. Upon maturity, the wax covered caterpillar will drop off, form this white cocoon, and hatch into a small black moth.

How would you like to be laying on the ground photographing a leaf, when this "old mans beard" starts crawling over the edge?

If this thing sat and didn't move, it would resemble perfectly a Tiger Moth cocoon. But cocoons don't crawl.

So what is this wispy haired thing? It's the next to last instar of the Black-waved Flannel Moth, Megalopyge crispata. The Flannel Moths, like the Planthopper Parasite above, are also related to the Slug Moths. These caterpillars can sting.

If one looks past all the hair, you can see there really is a caterpillar underneath. I thought I'd have an interesting story to go along with this, but I find there was another answer. When I reached for a branch, I felt an irritation, like that of Stinging Nettle. The only thing I saw under the leaf was this. Two hours later it wasn't itching or burning like nettle, but was throbbing with pain. Four hours later, with my knuckles still numb, I saw a red circle, with a center puncture wound. Must have been a yellow-jacket that got me. I didn't think a caterpillar could inflict that much damage.

Sticking with caterpillars for a minute, I knew this was some type of Prominent. Turns out there are two nearly identical. The Double-lined Prominent and the Variable Oakleaf Prominent. It's not called the Variable Oakleaf (Lochmaeus manteo) for nothing. I think it's this one because the black stripe on the face is bordered by white on BOTH sides, and the yellow and white stripe on the side of the body is often broken up on the Double-lined. The Double-lined usually has more brick red and less green on its back. If you look at Dave Wagner's caterpillar book, nothing I just stated is born out in the pictures. You have to rear the caterpillars to adult moths to be sure.

One of the best finds of the day turns out not to be an insect. With a little help, I found out this Orb Weaver is one of the four Mastophora Bolas spiders in Ohio. The behavior of these spiders is the kind of stuff you see on Nat Geo or Animal Planet. Bolas spiders don't spin big webs. Instead they are able to create a chemical that mimics certain cutworm moth pheromones. Male moths fly in expecting to find a female. Instead the Bolas spider has a trick.

American cowboys use a lasso to rope cattle. In Argentina, the cowboys or gauchos use a Bolas. It is rope with round weights at the end for entangling the legs of livestock. The Bolas Spider spins a rope of silk with a weighted drop of a glue-like substance at the end. It swings it around and grabs the moth, pulling upward while it's stuck on the silk. Farm out!

For the rest of this post, I went out and tried night photography again. Still willing to experiment till I get it right. The top picture is the common pink and yellow inchworm known as the Chickweed Moth, Haematopis grataria. The bottom one is a little tougher to figure out. It's an aquatic Pyralid whose larvae live in water. There are a half dozen genera that have a yellow, black, and blue spotted hindwing. The orange streaks bordered by white, and the two large white circles in the front wing make this Chrysendeton medicinalis.

One of the bigger inchworms in our area is the Large Maple Spanworm, Prochoerodes transversata. The larvae feed on many plants besides maples.

Here's the very same species shot at the same place, only under different light conditions. This specimen is slightly more worn, but you can see the variability within the species. All the white scratch marks in the wing are so noticeable because of the camera flash.

In my Black Fork Bottoms post, I illustrated the Black-horned Tree Cricket. Turns out there are a lot of tree cricket species in Ohio. They are related to our common black field crickets, but Tree Crickets are usually white or green. The red thorax and paired spots on the back make this Neoxabea bipunctata, the Two-spotted Tree Cricket.

There are a group of Tree Crickets that all look like this one. This is either the Narrow-winged or Snowy Tree Cricket. You have to look at the arrangement of black spots found at the base of the antennae. Way too small to be visible in this photo, it's just another example of how the tiniest details are needed for insect identifications.

Katydids, like Tree Crickets are members of the order Orthoptera. This order is the most vocal of all insects, and like songbirds can best be identified by the sounds they make. Unlike songbirds, you have to go out at night to listen for them. Visually, they are tougher to identify. A group of them have dark markings on their back. Based on the shape of the brown spot, I believe this is the Lesser Anglewing Katydid, Microcentrum retinerve. He must have been in some nasty confrontations, one antennae is almost all cut off, and the other is missing entirely.

I'm still not sure which species this is, but I illustrate it for a different reason. If you're going to sing for your mate, you better hope the opposite sex have some good ears. The ears or tympanic organs, are located on the front legs, and appear as holes. Can you imagine during a conversation with someone having to lift your leg and go "what'd you say?"

Many bats are able to zero in on Katydid sounds and find a good meal. In the tropics, there is a species of Katydid that avoids bat predation by tapping out a morse code on branches to attract a mate instead of singing.

1 comment:

  1. Your photo of Villa lateralis dipicts a female filling her "psammophore" or "sand-chamber", an interesting aspect of bee-fly behavior and anatomical adaptation/evolution. (See comments & links under this BugGuide post for more details.)