It's that time of year when I take my Forest Entomology students out to dig through leaf litter, tree bark, and old fallen logs. I have posted on forest insect pests in the past, but today it's more about interesting critters we found that are not necessarily pests. Logs like this give obvious clues there has been a lot of activity here.
False Mealworm Beetle,
Alobates pennsylvanica. These are members of the Tenebrionidae family, known as Darkling Beetles. Mealworms, commonly sold in pet stores as herp food belong to this family. The beetles are all black. The purple iridescence is simply reflected light. These beetles are found under bark where they search for other insects to feed on.
At first glance this looks like nothing more than one of those common Scarab beetles we lump into calling May Beetles. You know, the ones that crash into your screen door on warm summer nights. But you have to look closer. Why is this beetle scavenging under the bark of pine trees? Turns out it's the
Pine Darkling Beetle,
Uloma punctulata. The elytra have many "punctured" marks on the back.
Like the previous beetle, it too is a Tenebrionidae. This family is what I call the "dumping grounds" for beetles that don't seem to fit into any of the larger, more familiar groups. One clue for this beetle family is the
11 segmented antennae.
Crawling among some nearby Daffodils were these black and red beetles. These are
Red-necked False Blister Beetles,
Asclera ruficollis. They are pollen feeders.
They are small elongate beetles with rather soft elytra. This species is recognized by the bumps on the red pronotum or thorax. Though not true Blister Beetles, they do emit a noxious fluid that can burn if you have an open cut.
Now there's a strange looking critter. Three pairs of legs tells us it's an insect for sure. I've heard these described as looking like an Armadillo. This is a Firefly larvae. Yes, a Lightning-bug.
Stretched out you can see the black and white antennae, head, and thoracic region. This Firefly belongs to the genus
Pyractomena. Some larvae of certain species can produce the yellow glow we are all familiar with in the adults. These and Net-winged Beetle larvae (Lycidae) look nearly identical. I don't work with larvae, so I'll try to explain the difference the best I can.
You have to look underneath. To my understanding, if this was a Net-winged Beetle, those dark marks on both the middle and sides of the abdomen should go all the way down
on all body segments. On this larva, the last abdominal segments are white. This is where the light producing organs are located. If there is a better way to separate them, I'm all ears.
This Trilobite looking insect is another Lightning-bug larva of the genus
Photuris.
Nothing funnier than watching people pull over a piece of bark, then jump three feet! Common under tree bark is the
Fishing Spider or
Nursery-web Spider, Dolomedes tenebrosus.
From the menacing to the almost microscopic. This eight-legged creature is an Arachnid.
Pseudoscorpions are minute predators that search through wood and soil for Springtails and other small insects to eat. Based on the body shape, the length of the pincers, and the bulging Popeye-arms behind them, this is probably a Wyochernes pseudoscorpion in the family
Chernetidae. To go any further on identification, you have to examine them under a scope.
Here's one backing up into a defensive posture. That's a Dandelion leaf for a size perspective. Those bulges behind the claws do contain a venom, but they are harmless to us. The claws are technically referred to as
pedipalps, simply modified mouthparts.
Garden Centipede,
Lithobius forficatus. Centipedes are predators in the class Chilopoda.
Skinnier ones like this are known as
Soil Centipedes. They are common under leaves and logs. They belong to a group known as
Geophilus.
Millipedes are in the class
Diplopoda. They have two pairs of legs per body segment. They are scavengers. This gray/black millipede has a pointy tooth at the end of the body. You can't see it in this picture, but that makes this an introduced European species known as
Ophyiulus pilosus. Thanks Derek. I hope to spend some time this summer with Derek Hennen from the
Normal Biology blog who works with both these classes. Hopefully I'll be able to put up a more detailed post on millipedes and centipedes one day.
While I was shooting plants this weekend, I also went digging under rocks and leaves for aquatic life. I didn't have to try hard to find this mated pair of
Water Striders,
Aquarius remigis, darting across the water surface.
Sitting under water is what looks like a meaningless bunch of sticks. This is actually a
Caddisfly home, sewn together with silk. Sticks are commonly used in the family Limnephilidae, genus Pycnopsyche. I found several other families of these, and soon as I get a few more of them, I'll do a post on Trichoptera cases.
Lifting up rocks can produce a few surprises, that is if things don't jump off and swim away. This is an
Ephemeroptera nymph, better known as a
Mayfly. Look for the three tails, or
caudal cerci. These Heptageniids are known as
Flat-headed Mayflies.
Plecoptera insects are known as
Stoneflies. They have three shields or plates on their back, and only two tails. (One was missing on this specimen). Most prefer fast moving, clean water streams with high dissolved oxygen content. Many are used in aquatic ecology as water quality indicators.
The mottled back of this critter sure helps him blend in. Only the yellow tail caught my eye. Of course if it's swimming, it's easy to spot.
Two-lined Salamander,
Eurycea bislineata. So named for the two dark stripes along the side. The amount of yellow on the belly and back will vary. Next to the Red-backed, this is the most common species at this site.
Don't confuse these with snail eggs, many of which are white, but laid in rounded clusters. This flattened look is a batch of Two-lined Salamander eggs. When exploring streams, always remember to turn logs and rocks back to the position you found them.
By far the best part of the day was when this critter swam out from under a rock. Too large for a Dusky, this broad tailed species was noticeably pink at both ends. It has to be a
Spring Salamander,
Gyrinophilus porphyriticus. It has been a decade since I taught the class where we cover these, so it's been that long since I've seen one.
Larval forms lack the red color of adults, but the bright pink gills are a clue. I never collect these, even for class, they are too uncommon.
On adults, there is a yellow line from the nostril to the eye. This is absent in the immatures. There has always been a recorded population of them here, so it's good to see they are still around.
