Mini Robber Flies

I cut a couple of medium sized Black Walnut trees that were growing on the edge of a small prairie patch beside the house.  The trunks were about four inches in diameter, so after stripping off the branches, I left them in the lawn beside the barn to cut up for firewood.  When I returned from adding the branches to the brush pile, I found the logs being used as a perch and hunting platform by a swarm of small Robber Flies.

Robber Flies come in all sizes, but it’s usually the large species that get all of the notice.  Being extremely tiny doesn’t keep these guys from being quite attractive and interesting.  Sunlight on the transparent wings produced a shifting pattern of pastel purple, blue and green.

These are predators that feed on other small insects.  Each log had dozens of flies taking advantage of the slight elevation above the lawn grasses to watch for passing prey items.  When you’re that small it doesn’t take much of a rise to put you well above the action.

Prey of the day appeared to be small leaf hoppers.  The hoppers were so small that I couldn’t even see them in the air.  The Robber Flies with their super sized eyes had no such trouble.  Each quick trip out from the log resulted in another capture.

A variety of leaf hopper species were being captured.  Unfortunately, I couldn’t identify them with any more accuracy than I could the Robber Flies. 

I watched the Robber Fly action for quite a while.  The flies would eat the select portion of the leaf hoppers and then drop the remains before heading out for another capture.  I didn’t want to disturb the action, so I left the logs where they lay.  I’ll finish cutting them up some other day.

Unexpected Tiger Moth Caterpillar Hunt

Last year, this patch of Butterflyweed at the back of my vegetable garden supported a large population of Unexpected Tiger Moth larvae, Cycnia inopinatus, which are an endangered species in Ohio.  According to the literature, the larvae should have pupated at the base of the plants and the late spring hatch of adult moths should have laid their eggs on this clump of plants.  I’ve been making casual observations of the flowers in hopes of finding more larvae, but have seen none.  I decided a more thorough search was in order.

Larvae begin their lives feeding on the blooms, so I began to search flower by flower.  The larvae coloration trends towards bright orange, so they can easily hide among the flower clusters.  Examination from the top revealed no larvae.

Examination from the side revealed no larvae.

Examination from below revealed no larvae.  There was no sign of feeding or of fras anywhere on the plant.  I have to conclude that there are no larvae there. 

I did find many other neat animals making their homes on or otherwise using the Butterflyweed.  This jumping spider wasn’t at all curious about me and did its best to escape my sight.

Soldier Beetles, Chauliognathus marginatus, were busy at the flowers.  I would guess they were after nectar.  Each had its head buried down in the flower and was not moving.  Apparently the black on the wing covers can be quite variable in this species.  All of those I found last week on the Indian Hemp had black patches that extended the full length of the wing cover.  These just have black tabs.

Bees were the most frequent visitors to the Butterflyweed.  The Honeybees moved slowly from flower to flower.  They must have been taking every drop of available nectar.  Since they are not a native species, but don’t cause any particular problems, Honeybees have no status in the Blue Jay Barrens management plan.

A couple of these small green bees left the flowers and took sweat from my hands as I moved foliage aside in my search for larvae.  I’ve found these same bees on about every flower species I’ve looked at during the past week.

This bee was the most active of the different species I observed.  Its head would just pass low over the flower as the bee crawled across the bunch.  This looks like the same species that I saw swarming back in March.  Oddly, I didn’t find any butterflies visiting the Butterflyweed.

I’ll keep watching for the Tiger Moth larvae.  The Butterflyweed is still producing new clusters of flower buds, so suitable larvae food will be available for quite some time.  Hopefully the plants will once again support a good population these unusual larvae.

Ground Cherry Leaf Beetles

There are several species of Ground Cherries, genus Physalis, growing at Blue Jay Barrens.  I’ve been watching a few specimens with plans of photographing each when it reached its prime.  All are very similar, with most differences being associated with leaf shape and the degree of hairiness.  Yellow, bell like flowers are typical of all.

The fruit develops inside a thin walled pod.  It’s not uncommon to have flowers and nearly mature fruit on the same plant and that’s the condition I’ve been watching for.

My latest check showed flowers and developing fruit, but most of the leaves and some of the flower buds had disappeared.  This wasn’t the scene I had been hoping for.

It wasn’t hard to discover the cause of the leaf loss.  Beetle larvae were hard at work eating everything except the stout stem.  The larva is that of a leaf beetle and looks very much like that of a Three-lined Potato Beetle.  Several species have larvae of similar appearance, so it’s hard to be positive at this stage.  The interesting thing about this guy is the bit of protective camouflage it carries on its back.

A chain created from the larva’s feces runs up the back and almost to the head of the tiny creature.  The mass of feces definitely makes the larva less visible and may even make the larva less palatable.  It’s also possible that a grabbing type predator may come away with a bunch of feces instead of a larva.  However it works, there must be some survival advantage for this behavior to have developed.

The size of the feces mass varies between individual larvae.  It seems that the feces could be easily dislodged, but there is some type of projection in the center of the back that appears to act as an anchorage for the feces chain.  The larvae made for an interesting diversion, but all of those feces nuggets were once the leaves I was hoping to photograph.  I guess I’ll have to look around for some more plants.

Small Milkweed Bug

The Butterflyweed is in full bloom and the bright orange flowers have attracted a collection of Small Milkweed Bugs, Lygaeus kalmii.  When I was in school, I raised Milkweed Bugs by the bucketful for the entomology lab, but I prefer to see them individually in the wild.

Milkweed bugs are seed eaters known for their ability to eat milkweed seeds right through the thick seed pod wall.  Their long piercing mouth parts are highly effective at reaching those hidden seeds.  The fact that an adult is present this early in the season, suggests that they are not totally dependent on seeds for their sustenance.

This individual was busily probing the base of the flowers.  The target may have been nectar or material from the ovary.  This species visits many species of milkweeds, but its coloring seems especially suited to the Butterflyweed.

It’s fortunate that the bugs can survive on other milkweed components besides the seeds.  It’s going to be awhile before any seed pods are available.

By the time seed pods form, these adults will be laying eggs and preparing to raise a family.  If they are successful, seed pods may be completely covered by orange and black nymphs.  Milkweed bugs are attractive and fascinating creatures.  I hope to see a lot of them this year.

Little Fish

The drought has reduced the creek flow to a tiny trickle, but every pool and shallow riffle is full of little fish. 

Pools are small and in some areas the riffles have gone completely dry.  At a glance there is no apparent life in the pools.  A closer examination reveals an abundance of creatures, but all are young and tiny.

The overall color of the fish closely matches that of the creek bottom.  If it weren’t for their shadows, it would be hard to notice the fish.  Once you begin to follow those shadows, it becomes obvious that the pool is full of fish.

The fish cruise constantly and investigate the slightest movement in the water.  When the fish prosper, other organisms suffer.  Even these small fry are effective predators.  No insect larvae can be found anywhere on the creek bottom.  Streamside Salamander larvae, which should be abundant at this time of year, are completely absent.  Small fish begin by eating the gills of the salamander larva and then proceed to pick the body clean.

These fish are too small to identify without actually collecting a sample.  Creek Chubs and Blacknose Daces are the only species that I’ve found spawning in the creek so far.  They move upstream early in the spring when the water is high,  spawn in a gravelly location and then move back downstream as the creek flow begins to subside.  From earlier experience, I’m guessing these to be Blacknose Daces.

Water Strider nymphs compete with the fish for floating food items.  Both are alert for anything that strikes the surface.  The current drought is causing these pools to shrink in size every day.  Unlike many of the other creek dwellers, fish must have a constant supply of open water.  They don’t have the ability to live beneath a wet rock to await the return of their pool.  If we don’t get back into a rainy pattern, most of these fish won’t survive.

Onosmodium Insects

The larvae I was monitoring in the False Gromwell flowers have disappeared.  This doesn’t surprise me, because it is the normal conclusion whenever I try to follow caterpillar development in the wild.  Larvae often move to new parts of the plant as they grow and some even move to new plants, so there’s a chance they are alive and well in a different location.  They may have represented some small species and have already pupated.  I suspect they may have been eaten.  If I was able to find them, they should have been easy to discover by some caterpillar predator.

Those larvae may be gone, but something has deposited a bunch of new eggs in the flower whorls.  Maybe these are from the Onosmodium moth I’ve been looking for.

The Onosmodium plants are performing exceptionally well this year.  Many may top four feet once their flower stalks have completely extended.  While searching for my missing larvae, I took the time to examine a few other residents of the Onosmodium plant.

Some insects are found on a plant because of developmental requirements that can only be satisfied by a particular plant species.  Other insects are there just because the plant is a convenient resting place.  The host plant for this Elegant Grass-Veneer moth is grass, which is found in abundance in the prairie areas in which the Onosmodium grows.  To be fair, I have to admit that these moths were so abundant that they were probably resting on every plant in the area.  I couldn’t move without causing a few to take flight.

Small, black beetles were on all of the Onosmodium plants.  Most were doing like this fellow and struggling to negotiate the hairy stalks. 

Fireflies are another insect that just use the plant as a convenient resting structure.  Here is a Photinus species displaying one of the more comical insect faces.  This is a common species responsible for much of the low level flashing seen on summer evenings.

Bumblebees are common visitors to Onosmodium flowers.  Most were carrying impressive masses of pollen.  I often see bumblebees spend the night on nectar plants, so I’m not sure how often they actually return to the nest or how long it has taken to accumulate all of that pollen.

Southern Cloudy Wings were frequent visitors to the Onosmodium flowers.  Most nectar gathering insects tend to concentrate on a single plant species that offers an abundance of flowers.  When blooms fade on that plant species, the insect will begin visiting the next most abundant nectar source.  This habit benefits the plant by increasing the odds that flower visitors will be carrying the right pollen for that plant. The Southern Cloudy Wings consistently passed by other nectar producing species in order to reach the next patch of Onosmodium.

I found many insects in early developmental stages.  The best I could do in identifying this fellow was to determine it to be some type of Hemiptera that is not an aphid.  It was fairly fast moving and continued to evade my observation.

Small flies were particularly abundant on the Onosmodium.  This Rivellia species systematically traveled the plant leaf-by-leaf until I inadvertently scared it off.  It rarely paused and I have no idea what the object of the search may have been.

These two flies were doing a dance on the flower’s exerted style.  One fly would shift its body to one side and the other would match the maneuver.  The body shifts continued for a while and then one fly took off.  As with so many things I observe, I can’t explain the why behind the behavior, but that doesn’t make it any less fun to watch.

Eastern Snout Butterfly and Some Other Puddlers

Dry weather continues and the pond has made its transformation into a mud hole.  Open water is gone, but the area is still attractive to a wide range of wildlife species.  The most noticeable are the butterflies that come to claim water and minerals from the soupy mud.

The Eastern Snout Butterfly, a species uncommonly seen around here, has come to the mud in record numbers.  Normally I only get to see one or two of this species each year.  On this day there were at least a dozen scattered across the mud flat.  This guy has a profile that is unmistakable.  You don’t have to be very close to recognize the squared off back edge of the wings.  It looks like someone snipped them off with pinking sheers.

On the front end is the snout formed by super long labial palps.  If you’ve ever seen one of these butterflies, you’ll never fail to recognize it.

You don’t even have to get close for an accurate identification.  This is the first time I’ve seen this species at the pond, but I’m not surprised they’re here now.

The host plant of the Snout Butterfly larvae is the Hackberry.  This Hackberry growing at the edge of the pond has just gotten large enough to support a colony of Snouts.  I’m going to have to trim this tree back to keep it out of the electric lines, but I hope it will serve for many years as a nursery for Snout Butterflies.

Total butterfly numbers continue to be lower than normal.  I keep wondering if the severe storms and flooding we had earlier are partly responsible.  Even so, several other species joined the Snouts on the mud.  These four Clouded Sulphurs remained as a group as they moved from place to place about the pond bottom.

There were several skippers about, all Wild Indigo Duskywings.  These were all dark, crisply patterned individuals that must have just recently emerged.  As they age, colors fade and scales are lost, making some of the skippers very hard to identify.  It’s nice to see them in such prime condition.

Pearl Crescents were represented by a single individual.  I’ve been seeing them around, but their numbers are much lower than normal.

Eastern Tailed Blues are around in good numbers.  This species is normally very common, but its small size causes it to be overlooked by many people.  Fortunately, it’s tolerant of close approach, so you can slowly work yourself in close for a good look.  I’m hoping that butterflies will become more numerous of summer progresses.