You probably have seen an insect that looks like a mosquito but with much longer legs and a bit bigger body. Many call these insects mosquito eaters but their real name is crane flies and mosquitoes actually aren’t their main source of nutrition.
Crane flies are Tipulidae family insects that can be found all around the world from tropics to mountains, although the widest diversity of species can be found in tropic climates. That’s why these flies are called differently all around the world, for example in the United Kingdom they are commonly referred to as daddy longlegs, but in other places crane fly have acquired names like mosquito hawk, may fly, whapper and, of course, mosquito eaters.
The adult crane flies have a very slender body with long legs that can be from 0.079 up to 3.9 inches (2 – 100 mm) for some species living in the tropics. And because the build of these flies isn’t very proportional, they are not good fliers. In fact, they often wobble when they fly and fly in unregular patterns, which makes it quite easy to catch them.
Although the most common name for crane flies is mosquito eater, adult crane flies don’t prey on mosquitoes. Adult crane flies are actually physically incapable of killing mosquitoes. The main source of sustenance for crane flies is flower nectar. The nickname mosquito eaters probably comes from the fact that some larval crane flies feed on mosquito larvae, but it also is only occasionally. Moreover, the adult crane flies also don’t bite humans, so other than their annoying sound, they are harmless to us as well as mosquitoes.
However, these long-legged flies are harmful to plants, which is why they have acquired an agricultural pest status in many countries. Crane flies often live in the very top layers of the soil and therefore eat the roots of the plants and sometimes even the leaves of the plants that are growing in this soil. And that can not only stun plant growth but even kill plants altogether.
So even though the mosquito eaters aren’t mosquito eaters at all, in fact, they are more of a fly than a mosquito, and even though they don’t bite us as mosquitoes do, they can be harmful to plants and therefore still are pests that need to be eliminated. Just as their nickname counterparts.
The lifecycle of a Crane Flys
The adult crane fly carries matured eggs around which when fertilized by the male during mating, are deposited in a wet soil. There isn’t any motherly care here unlike what is obtainable with vertebrates like birds and mammals. It just pushes out the eggs through its ovipositor and flies off.
When the eggs hatch within a week or two, the larvae commonly referred to as leatherjackets make their way to any growing plant. It is at this stage of development that a crane fly is most destructive. The leather jackets which are worm-like creatures with numerous hairs latch onto the roots or shoot of a plant, deriving their nutrient from this part of the plant. This affects the growth and the quantity of produce recovered from the plant.
The larva continues its feeding habit in a manner similar to that of a mosquito – it feeds at night and rests in the daytime. This might be considered as a defense mechanism against preying insects which abound during the day.
During the winter season, the larva goes into hibernation. This period is their resting phase and gets the leatherjacket ready for its imminent transformation. Once the cold season is at its end, the larva builds itself a cocoon within which it hides and undergoes metamorphosis. And then once the season is favorable and the weather is warm again, the adult crane fly emerges from the cocoon and goes on to play its own role in nature. If the crane fly which comes out is a male, it helps the female in fertilizing the eggs. Crane flies don’t live very long. Their entire lifecycle ends in about two weeks!
The thickness of the outer covering of the larvae of crane flies is responsible for their odd name – leather jackets. Besides the nature of their covering, this stage of crane fly’s life can be identified by its cylindrical shape with narrow ends. This is completely different from what’s seen in the larva of a mosquito.
Since there are thousands of crane flies species, there are a few changes in the larval stage of development. These differences are not focused on physical appearance but location. While some adapt successfully to living on land, others find the water conducive to their activities. They can be seen in swampy areas seeking a potential food source.
Do Mosquito Eaters Possess Any Ecological Benefits?
And while the larva of a crane fly is known to cause immense damage to plants, they actually do provide some ecological benefits as well.
For those species which live on land, their biological activities have been shown to improve the soil structure. They also increase the organic matter content of the soil. The larvae of certain species of crane flies are capable of eating other harmful insects including the dangerous ones like the mosquito. Again, this is why one of the names associated with crane flies is mosquito eaters.
The adult crane fly feeds on nectar though some might not eat anything at all. But they all provide a source of food for other animals like amphibians, reptiles, and some fishes. This provides some form of balance in a food chain. And makes sure that mosquito eaters aren’t just useless insects flying around and annoying us.
So here you have it, a little intro to crane flies aka mosquito eaters. Despite the fact that they actually don’t eat mosquitoes (their larvae sometimes do), these flies are still pretty interesting creatures that are worth learning more about. Because if we know more, we can better understand the insects, differ them from mosquitoes and other pests and know not to harm them when we see one.