Robber flies are one of nature’s predators. This diverse family of flies, also known as Asiladae, is scattered throughout the world, which could explain some of their diversity. Robber flies have insatiable appetites, and glut themselves on a vast number of insects, including wasps, bees, dragonflies, grasshoppers, and some spiders.
What Are Robber Flies?
Robber flies, or Asiladae, are a subfamily of “true flies.” They belong to the superfamily Asiloidea, which belongs to the suborder Brachycera. There are currently 7,0003 known species of robber flies spread out around the world, with nearly 1,000 species living in North America alone – and more than 100 of those species reside in Florida.
What Do Robber Flies Look Like?
All robber flies share one characteristic: a divot on the top of their head. This divot is located between their prominent, compound eyes. Most robber flies have elongated bodies with tapered abdomens, although some species are long and skinny, much like a damselfly, while others are stout and hairy, mimicking a bumblebee. Adults can vary between 3 mm and 50 mm in size, although most average between 9 – 15 mm in length. Their legs are long and strong in order to aid with capturing prey. Females usually have a slightly broader abdomen than the males of the species. Most robber flies are either brown, gray, or black, although some subspecies are striped like a bumblebee.
What Do Robber Flies Do?
Robber flies are what is known as “opportunistic predators,” meaning they prey on other insects that are available within their environment. Robber flies establish a perching zone, which they use to locate potential prey. Perching zones vary depending on the species, but are usually in an open, sunny area. Robber flies swoop in on their prey mid-flight and inject the victim with their saliva, which contains neurotoxic and proteolytic enzymes and immediately immobilizes their victim as it digests bodily contents. The robber fly then returns to its perch spot, where it enjoys its liquid meal.
Robber flies are distributed all over the world, although some groups are unique to certain regions. Most robber flies live in warm, sandy areas, with a large population (consisting of all four subfamilies) residing in Florida. Some species have adapted to desert climate, and very few have adapted to woodland areas, although those that have tend to stay on the outskirts, near grasslands.
What’s The Robber Fly Life Cycle Like?
Female robber flies lay white colored eggs on low-lying plants, in grasses, or in crevices within soil, bark, or wood. Egg laying habits vary from species to species, although most lay a bunch of eggs at once. Robber fly larvae live in the soil or decaying organisms found within the environment. Larvae are just as predatory as their adult counterparts, feeding on other eggs, larvae, or other soft-bodied insects. They overwinter as larvae, pupating in the soil, then migrating to the surface as adults. It can take between 1-3 years for complete development, depending on the species and environmental factors.
Robber flies are rather intimidating insects to contend with, and if you notice an outbreak of them around your home, you’ll probably want to call a pest control professional.
About the author: Chris is a blogger for a baltimore pest control company. He enjoys writing about the quirkier side of the pest control business with fun and interesting things about insects.