Sunday, July 23, 2017

Leafy Cobweb Spider

Leafy Cobweb Spider (Theridion frondeum) are beautiful spiders that are rarely seen because of their diminutive size. Females measure between 3-6 mm and males between 3-3.5 mm. Aside from the fact that they are tiny, they also hide out in leaf litter on the forest floor on at the edge of forests in fields, making them even harder to spot. When they do "hang out" in a bush or shrub, it is usually on the underside of a leaf that has been curled up. All of these things combined makes for one difficult spider to find. The one photographed here was found quite by accident. I actually spotted the bright red of the ladybug first and then discovered the spider next to it. Obviously the spider is responsible for the demise of said ladybug.
The leafy cobweb spider is highly variable in color and some experts claim you can collect numerous specimens from within a particular area and all will look enough different to make you think you've found entirely different species. Typically however they are creamy white, to greenish yellow with various dark brown-black line or blotches. There are specimens that lack the dark marks and are solid in color. The head is light in color with dark lines. Legs are also light colored with dark spots. I think their legs look like they are wearing little black shoes on the tips.

There are over 600 known species Worldwide within the Theridion genus, making them one of the largest groups of spiders. This particular species is found from Southern Canada, southward to Alabama and west to North Dakota.

Females make an egg sac in late spring that hatches sometime in early August. She will place the egg sac within a curled leaf and guard it. Once the spiderlings hatch she will remain with them for a short period time. This maternal care helps protect her offspring from predation. After several molts the young spiders will spend the winter as sub-adults and emerge in the spring to finish their lifecycle into an adult spider.

These are truly one of the most beautiful little spiders I've ever encountered. If you would like to find one, try sifting through leaf litter on the ground and who knows what surprise creature may turn up.

Friday, July 21, 2017

Picture-Wing Fly

This picture-wing fly (Tritoxa incurva) in the family Ulidiidae are Sometimes referred to as the "Gas Mask Fly" and from the looks of that face it is easy to understand how it earned that nick-name. They are common throughout the Central and Eastern portions of North America.

Very little seems to be known about them and there is even less information available about them. Reportedly the larvae feed on organic matter as all fly larvae in the family Ulidiidae are known to do. They are found in meadows, fields and rural areas where flowers occur. It is not clear what their preferred food is as adults, but most likely flower nectar since they are known to be found where flowers are blooming.

Flies in this family are often mistaken for fruit flies, or in the case of the one pictured here, my husband tried to convince me it was a deer fly. In his defense, we had just returned from the farm north of where we live where he was surrounded by biting deer flies. I am guessing he still had that bad experience on his mind when he spotted this fly on my car after we returned home. I even went along with his ID and felt very sheepish when I asked about it's identity on a Facebook insect group page and was told it was a picture wing fly. I REALLY DID KNOW THAT! It seems I fell under the "It has to be a deer fly" spell.... same as my husband.

These small flies (6-8mm) are rusty-red in color and have strongly patterned black and clear wings. Look for them May through October in areas where flowers are. Also may be found at lights at night, at least they are around here.

Sunday, July 16, 2017

Snowberry Clearwing Moth

Snowberry Clearwing Moths (Hemaris diffinis) are sometimes referred to as Hummingbird Moths and Lobster Moths, which are both colorful local names for these moths, which to some must superficially resemble the creatures they are nick-named after.

They are common throughout the Eastern United States, east of the Continental Divide and may be found anywhere there are flowers to nectar at and host plants to lay their eggs upon. Caterpillars feed on dogbane, dwarf bush honeysuckle, snowberry and honeysuckle. With the over abundance of invasive honeysuckle in much of Missouri, the feeding habits of these little caterpillars can only be appreciated.

These day flying moths hover at flowers and behave much like tiny hummingbirds as they unfurl their proboscis and sip nectar. They carry pollen with them as they visit flowers, making them somewhat important pollinators. While they prefer to fly around during the day, they will sometimes continue to be active at dusk if food sources are plentiful

These beautiful moths are bumblebee mimics which may afford them some protection from predation as many animals that would feed on moths may not tackle something that can fight back with a painful sting. Although once a predator learns of the dubious trick they will readily dine on them. Caterpillars are also susceptible to predation and use camouflage to blend in with the plants they feed on to help avoid hungry birds and other predators.

There is another moth in this genus also found locally and often mistaken for the snowberry, it is the Hummingbird Clearwing (Hemaris thysbe). The snowberry, pictured here always has black legs. Otherwise they are very similar with yellow and black furry bodies and mostly clear wings border in reddish-brown with black veins.

After mating, females will lay eggs on the host plant and once the caterpillar finishes growing it will drop or crawl to the ground and burrow into the soil where it will pupate. There are two generations in Missouri, but in colder climates further north there is only one generation.

As you visit your backyard flower gardens keep an eye out for these buzzing moths as they fly past you looking for flowers to sip nectar.

Monday, July 3, 2017


Peusdoscorpions, are a type of arachnid that superficially resemble true scorpions. They lack the stinger and are much, much smaller at only 0.08-0.31 inches in length. Although there is a species, Garypus titanius that may reach lengths up to 1/2 inch. Large by pseudoscorpion standards to be sure.
Body is flattened and pear-shaped and many people mistake them for ticks when they first spot them. In fact the one photographed here was discovered by my daughter when she was unwrapping a wedding gift. I heard her make a comment "oh look, we got a tick with this gift." I looked and discovered it was not a tick, but a pseudoscorpion.

The abdomen of pseudoscorpions have twelve segments and is made up of a protective substance called chitin. They are born looking very much like the adult and go through 3 instars, or molts, before reaching adult size. They may have 2, 4 or no eyes at all. Even those with eyes do not see well and do not rely on eyesight to find prey. Instead they use very sensitive hairs on their legs and pinchers. When a prey item brushes against them they are able to move quickly and grab dinner! Venom glands are located in the pincher-like claws that they use to inject venom into their prey. They are completely harmless unless you are booklice, mites, small flies, ants, or the larvae of carpet beetles and clothes moths. The venom works to dissolve the tissue of their insect prey so this little predator can slurp the insides out like a tiny insect slurpee.

Because of their tiny size they are rarely seen by humans, but they may occasionally show up in homes where you are likely to find them in bathrooms, kitchens and laundry rooms. They seem to prefer moist areas and in the wild you will likely find them in woodlands hiding up leaf litter or wood piles. Being tiny and lacking wings can make it difficult to move from one location to another and to spread your genes around. They have conquered this potential problematic dilemma by hitchhiking on various beetles, and thus are carried from one location to another via the beetle buses they grab a seat on. All of the best travel options serve dinner and these beetles are no exception. Often covered in mites that can drain the beetle, the pseudoscorpion finds itself attached to a flying all-you-can-eat-buffet. This symbiotic relationship benefits both the beetle and the tiny hitchhiker. The beetle gets rid of the mites and the pseudoscorpion gets dinner and transportation. (Ivory Marked Beetle pictured has a pseudoscorpion attached to it).

Some species of pseudoscorpions will even mate on these flights, giving a whole new perspective on the "mile high club."
Males form a packet of sperm called a spermatophore that he deposits on the ground (or the back of a beetle), and then grabs the female with his pinchers and drags her across it so that she will take his sperm up inside her body. Other species push the sperm inside their mates. Females may mate with numerous partners and can retain the sperm of each. She will become impregnated when she is ready to reproduce. She can produce up to 40 offspring and will provide maternal care for them by carrying them on her back and washing them with her pinchers.

The first known fossils of pseudoscorpions date to 380 million years ago. Their body shape has changed very little since they first appeared. Aristotle was the first person known to have described them and  most likely encountered them in the vast amount of papers and books at his disposal They are sometimes referred to as Book Scorpions because they are often found in books and piles of paper where they are feeding on booklice.

They are completely harmless to humans and cannot sting or bite us. Their habit of feeding on insects and tiny arachnids, like mites, that can cause significant damage makes them hugely beneficial to us. You will most likely never find more than one or two every once in awhile, but should you be encountering them in large numbers you may have a moisture problem or a large population of prey items they like to feed on. those issues should be addressed, rather than outwardly killing these tiny arachnids by using chemicals.