The highly variable colors and patterns of the skiff moth are hypothesized to mimic senescent/necrotic lesions on leaf surfaces. They often have paired white spots that are thought to mimic the eggs of the tachinid fly, a parasite that enters the caterpillar after hatching. These “egg mimics” are hypothesized to work by dissuading flies that may attempt to avoid depositing eggs on victims that were previously parasitized.
These guys remind me of the tornado chasing vehicles that were on those TV shows about a decade ago.
This one was photographed on my wife, Sarah’s finger at Shaw Nature Reserve.
Finally, I was able to photograph the adult during National Moth Night this summer.
In my anecdotal experience of hunting for slug caterpillars over a six to eight week period this summer, the Nason’s slug (Natada nasoni – Hodges #4679) was by far the most abundant that I came across. This was particularly true in the drier, oak/hickory/pine hillsides of Hickory Canyon N.A. in Sainte Genevieve County.
This species is able to retract its spines, elongating them to their fullest with any notion of danger. These guys have pretty substantial spines and because the cats were so abundant, I found I was accidentally stung a few times while lifting vegetation. This was not a pleasant experience.
I really enjoy the colors and patterns this species displays.
The image below was one that I had previsualized and worked a good bit on to get it right. I used my plamp to hold the leaf and attached the plamp to a dead limb to position the leaf high enough to get the leaf and caterpillar back lit by the sun. I then used just a bit of flash to illuminate the ‘face’ of the caterpillar and the underside of the leaf. In cases where I removed the leaf to get a photo, I always placed the leaf securely back on the same plant.
The next slug to make your acquaintance is the Red-crossed Button Slug. This species is quite similar to one or two others as both larvae and adult, but given that most lists I have seen from Missouri list this one and not the others, I am pretty confident in this ID. This species lacks the stinging, protective hairs, going instead with a more camouflage approach of looking like a bit of leaf blight as it passes over leaves of oaks, hickories and quite a few other known woody, deciduous host plants.
The image above gives a glimpse into how the slugs get around – on a substance described as liquid silk. See the winding trails?
Here I caught one in the act. From what I’ve read, slugs leave distinctively shaped (indented) frass that is different from that of other caterpillars. I didn’t pause long enough to investigate.
Finally, the adult slug moth is pictured above. Slug moths are strongly attracted to lights and, from what I have read, are often some of the first species to show up when setting up a light and sheet/trap. I have a theory that this may be why I find many less slug caterpillars the closer I look near St. Louis. Although I found very similar habitats with the same composition and numbers of sapling oaks and hickories (the favored host plants), the closer I came to the city the number of slug caterpillars dropped significantly. Perhaps the city lights are sucking in the adults before they are able to reproduce? Probably a too simplistic idea, but it is a trend I noticed. It could just as well be due to fragmented habitat and overall less habitat available the closer one gets to the city.
While searching for arthropod subjects to photograph on Steve’s property, we decided to check the compost/midden pile and found something completely unexpected.
These beetles were crazy to watch – super speedy while flipping their gold-tipped abdomens over their backs in display. These guys yield even more support to my contention that the vast majority of ideas used in the sci-fi genre (particularly the creature-features) were taken from somewhere within the natural world.
This tiny and speedy ichneumon wasp, which I am calling a Theronia species, has been hanging around my patch of wild strawberries for a couple of months. If I am close to correct in the identification (with more than 100,000 described ichneumons, how close could I be?), then this species parasitize tent caterpillars along with a number of other lepidopterans.
“I cannot persuade myself that a beneficent & omnipotent God would have designedly created the Ichneumonidæ with the express intention of their feeding within the living bodies of caterpillars …”
I was thrilled when I took my camera inside from shooting in my wildflower garden on a past summer day and identified this hymenopteran as a Bee Wolf. Philanthus gibbosus (Family Crabonidae) is what I am calling this one. Bee Wolves get their name from doing what you expect, feeding primarily on bees. These solitary wasps will load their brood chambers with pretty much any bee or wasp smaller than themselves that they can catch as a provision for a single egg they deposit prior to sealing the chamber shut. Some taxa have specific bees they prefer to catch and this can aid in identification. This poor thing was quite beaten up as you can see in the photograph below. Missing a few legs, it probably escaped a bird or larger insect, and was not happy to have me and my camera in its face. In the photo above I captured it doing a rapid vibration of its wings, something I read that these guys are known for doing as a communication. I can’t imagine what she may have been trying to tell me…
I believe the insect below to also be a species of Bee Wolf, but have not yet been able to put a name with this one. I photographed this one having a drink in a wet area of Shaw Nature Reserve early one morning.