What Kind of Insect is That!? – Part 3

What Kind of Insect is That!? – Part 3

In this blog series, we look at some very odd insects that you may encounter in Illinois. In this first blog, we explore: Robber Flies, Assassin Bugs, and Garden Spiders.

Robber Flies

These bugs are a unique kind of fly in the family Asilidae. There is a diverse number of species within this family (approximately 1,000), all of which are notorious for their predatory nature. Their diets consist of a variety of other arthropods including wasps, dragonflies, bees, grasshoppers, some spiders, beetles, butterflies, and even other flies. Robber flies can measure in at about a half an inch in length, allowing them to take on this variety of prey. Their abdomens are elongated and tapering, with a hump-backed appearance near their heads. They are typically gray, brown, or black in color, and are covered in bristle-like hairs. Due to their habits of eating other pests, robber flies are not considered pests themselves. In fact, there has actually been some consideration of programs being enacted to attempt to use robber flies in biological control programs aimed at curbing pest infestations. However, there have not been many studies on this yet and it may be years before we see such a program actually being implemented.

Assassin Bugs

True to their name, assassin bugs are predatory insects that are highly proficient at offing other arthropods. Some of their common victims include bees, flies caterpillars, aphids, and more. There are actually a variety of different species of assassin bugs, and some take their murderous tendencies a step further by even indulging in the blood of their victims. Assassin bugs measure about an inch long and are often black, grey, or brown. In Illinois, you may come across any of the following assassin bugs: the conenose, the masked hunter aka. kissing bugs, the black corsair, or the wheel bug. While these weird-looking insects may only be a true danger to plants and other arthropods, they’ve been known to deliver very painful bites and can even be vectors of some diseases (for examples, the Chagas disease). As such, it is recommended that you stay a safe distance away from any assassin bugs you may come across and seek medical advice in the case that you are bitten.

Garden Spiders

There may be a host of different kinds of spiders that occupy gardens, but true garden spiders stand out among the rest. With a striking color pattern of black and yellow stripes and their legs often positioned in a star-like stance, these arachnids truly make a statement with their appearance. At the largest, garden spiders can measure in at approximately 1.1 inches (28 millimeters). Garden spiders are considered orb-weaving arachnids, which means they create webs with circular structures. While most spiders have two claw-like structures on each foot, garden spiders have three, allowing them to create more complex web designs. Garden spiders are typically non-aggressive towards humans but can deliver painful venomous bites if they feel threatened. Luckily, these bites do not cause much, if any, harm to humans or pets. As these arachnids have a tendency to infest gardens, they are considered pests in Illinois. If you happen to come across these striped spiders in your yard, give us a call today and we would be more than happy to send them packing!

Citations

Finn, E. M. (2018) Robber Flies – Asilidae, University of Florida Department of Entomology & Nematology. Available at: https://entnemdept.ufl.edu/creatures/beneficial/flies/robber_flies.htm (Accessed: June 14, 2021). Laura (2015) These 9 Bugs Found In Illinois Will Send Shivers Down Your Spine, OnlyInYourState. Available at: https://www.onlyinyourstate.com/illinois/bugs-il/ (Accessed: June 9, 2021). Mahr, S. (no date) Robber Flies (Asilidae), University of Wisconsin-Madison. Available at: https://hort.extension.wisc.edu/articles/robber-flies-asilidae/ (Accessed: June 14, 2021). Merchant, M. (2016) Wheel bugs and other assassin bugs, Texas A&M Agrilife Extension. Available at: https://citybugs.tamu.edu/factsheets/landscape/others/ent-1003/ (Accessed: June 14, 2021). Post, S. (no date) University of Illinois, Illinois Natural History Survey. Available at: https://www.inhs.illinois.edu/outreach/spotlight/assasin-bugs/ (Accessed: June 14, 2021). Yellow Garden Spider (no date) The National Wildlife Federation. Available at: https://www.nwf.org/Educational-Resources/Wildlife-Guide/Invertebrates/Yellow-Garden-Spider (Accessed: June 14, 2021).