Wednesday, May 25, 2016

Nursery Web Spider

The nursery web spider (pisaurina mira) is a common spider found throughout the United States and Canada, but is more common in the Eastern portion of its range. They are large spiders with a leg span well over 2 inches. They are highly variable in coloration and may be tan, yellowish or gray. There is a darker midline stripe that runs from the eyes through the cephalothorax and across the abdomen. The stripe on the abdomen is outlined in white. The eyes are distinctive in identifying this species. The bottom row of eyes are in a straight row, and the upper row of eyes have a deep upward curve. They rest with their front legs close together, outstretched in front of them, like pictured above.

I encountered one of these spiders on my front porch the other night and it behaved in a very strange manner. It literally bounced, or hopped in a very erratic, rapid fashion and hid underneath the step to our hot tub. I coaxed it out and it hopped a few feet away and when I moved in front of it, it stopped and then raised one hind leg. It repeated this behavior several times.....hop...hop...hop....stop, then raise a leg. Not sure why it acted like that, if it was some bizarre defense behavior, or if this was an odd behavior that this particular individual exhibited for some unknown reason.

You will find these spiders near woodland edges, in open grassy fields, meadows and near man-made structures. They are wandering spiders and actively seek insect prey. They may also be found near lights at night, and one could assume these are the opportunistic hunters.

Mating takes place while suspended from a dragline of silk that the male uses to approach the female.  The male will bind the front legs of the female together with silk then offer her a fly. If she accepts the fly; mating will take place. During copulation the female will devour the fly instead of the fly is most likely a decoy to distract the female while he passes his genetics on. After mating, the female will produce an egg sac that she carries around with her in her chelicerae. When the egg sac is ready to hatch, she will create a nursery web in a low lying bush or in tall weeds. The egg sac will be placed safely inside the nursery web where the spiderlings will emerge. The spiderlings will remain in the nursery for a week or so while mom stands guard protecting them from predation.

The name "Pisaurina" is the feminine version of Pisaura, and "mira" is Latin for astonishing or wonderful. Eugene Simon bestowed this name upon the spider in honor of Pesaro River in Italy.

Sunday, May 22, 2016

Brown Rove Beetle

While flipping rocks today at the farm I found this large rove beetle. At first I thought it was the Gold & Brown Rove Beetle (Ontholestes cingulatus) and tentatively ID'd it as such on Facebook. My good friend Eric Eaton over at Bug Eric corrected me and supplied the correct ID as the Brown Rove Beetle ( Platydracus maculosus). He assured me that these two beetles are often mistaken for each other. I must admit they do look very similar. The P. maculosus is larger and often found under leaf litter, rocks, logs, carrion, etc. whereas O. cingulatus will be found more often in or around fungi. Both may occasionally be found near lights at night.

The Brown Rove Beetle is common throughout much of the United States, but especially in the east. It will also be found in parts of Canada. They are dark brown covered in golden hairs, with a series of darker spots that run down the center of the abdomen. They have blue underwings that give them the appearance of a wasp when in flight. Their wings are short and barely extend onto the abdomen. They are sometimes mistaken for earwigs and at least superficially they resemble them.

Pictured above right is an
earwig for comparison
When alarmed they will curl the tip of their abdomen up and over their back and move erratically to escape potential threats. They move rapidly and are often very difficult to photograph and this one was no exception. It took quite awhile to manage a couple of decent images before I finally gave up and it disappeared underneath another rock.

As larvae and adults they use their strong pincher-like mandibles to feed on other insects especially fly larva, and should be considered beneficial to humans for the pest control they provide. They are also one of the insects collected at crime scenes to aid in determining the time of death of a corpse as they are attracted to carrion and will feed on the fly larva also attracted to rotting flesh. One could say they are opportunistic hunters.

Tuesday, May 17, 2016

Lance Wolf Spider

One of the things I love most about this time of year is all the insects and spiders that are out and about, or sometimes hiding under rocks, logs and debris. Tonight while flipping stepping stones I encountered this wolf spider. It sat still long enough for me to take a few pictures so I could go back later and identify it. I find wolf spiders quite frequently around my yard and they are always welcome as the apex hunters they are. This one however was new to me, but I finally identified it as the Lance Wolf Spider (Schizocosa avida). They are found throughout the United States, but are more common in the Eastern portion of the country. These spiders are common and are usually found in fields, meadows, pastures and backyards where there is plenty of places for them to hide out during the day, such as under stepping stones. They may also be encountered in forested areas as some people have reported. According to the authors of "Spiders of the Eastern United States" they are frequently found in swimming pools where they drown or may become caught in the pool filter.

These are large spiders with a legspan around 2 inches or more. Legs are not banded and may be gray, brown or yellow. The body is light brown with a blond stripe down the carapace that extends to the abdomen where it opens to form two stripes that will surround a darker lance-like mark where the spider gets its common name.

Like all wolf spiders they do not form webs to capture prey, instead they wander around seeking insects to capture. They do not chase down insects, but rather sit and wait for prey to come within striking distance. Wolf spiders have excellent eyesight like most wandering spiders and are able to see prey as it approaches, once an insect is within striking distance the spider will rush out and overtake the unfortunate victim and inject venom. Like all spiders the hairs on their legs are also extremely sensitive and may also play a part in sensing nearby prey. If the insect is small it will be eaten right away. If the prey is on the large size there may be a wrestling match until the spider can overpower the insect. The spider will hold its prey in place with her powerful legs, and deliver a fatal bite. Venom acts quickly to begin dissolving the soft tissue inside the body of the insect, so that the spider can slurp it up like an insect-slurpee. Crickets, grasshoppers, beetles and other larger insects make up the largest portion of their diet. They will also eat other wolf spiders, including those of their own species.

Maturity is reached in May and mating takes place in June. Males die shortly after mating, females live until the first freeze. The female will lay a drag-line of silk near where she is waiting for prey. This drag-line is easily detected by males of her species and plays an important role in mating courtship. A male wolf spider is able to follow the drag-line to the female and may be able to coerce her into mating. He will wave his legs and will use stridulation on leaf litter to show his interest in making her his mate. If she is interested she will accept his overtures and not use him for her next meal.  She will form an egg sac sometime in the early or mid-summer. She will dig a burrow that she will hide out in and look after the egg sac. When the urge to hunt overtakes her, she will attach the egg sac to her spinnerets located at the tip of her abdomen, and carry it with her while she hunts. Her egg sac will contain up to 200 eggs and will hatch sometime late in the summer or early fall. The spiderlings will crawl onto their mothers abdomen where she will look after them for a short period of time until they are ready to disperse and be on their own. Spiderlings may remain in the area where they were born, still others will climb to a vantage point and balloon on air waves to new locations. Those that survive predation by other spiders and insects will overwinter as juveniles and in the spring begin the cycle all over again.

Saturday, May 14, 2016

Marbled Fungus Weevil

While outside walking around my yard yesterday evening I noticed a weevil clinging to the side of our metal garage. I tried photographing it, but could not get the photos to come out, so I moved the weevil to a blade of grass and snapped a few pictures.

Beyond being a weevil, I had no idea what this beetle was. I posted the picture to facebook and in no time my good friend Eric Eaton at Bug Eric was able to ID it as a fungus weevil. That gave me a place to start in getting a positive ID to species and I began my search on In no time I found a perfect match of Marbled Fungus Weevil (Euparius marmoreus). They range throughout the Eastern United States to Montana and also Arizona.

Weevils in the family Anthribidae are classified as the fungus weevils, they typically have longer antennae than other weevils. Most antennae of weevils have elbows, but the fungus weevils do not. This sets them apart and aids in identification. The marbled fungus weevil is blotchy in appearance in shades of tan, brown and gray. There is a black eyeline from the snout, along the side of the face to the elytra. They are relatively small at 3 to 8 mm in length.

As adults they feed on fungus, and decaying plant matter. As grubs they feed within decaying logs, trees and other wood, especially elm.This one was hanging out on the side of our garage no where near any rotting or decaying wood. So it was a little out of its normal environment, and I'm not quite sure what it was after there, unless it was warming in the sun for some reason.