Chironomids: That thing that hits your face when you ride your bike along the riverbank

March 5th, Keichitsu (the awakening of insects), when the cold is still severe.
The first insect to wake from its long winter sleep around this time is the chironomid.

The undisputed lead-off hitter among insects

　When you are riding your bike along a riverbank, have you ever had a huge swarm of small, black, cloud-like insects suddenly appear right in front of your face? That is surely a "chironomid".　In Osaka, every year in early March, groups of chironomids appear, fluttering about as the
lead-off hitters of the insect world. Almost all of those in the swarm are adult males. They form a group called a "midge swarm" over a landmark that stands out from its surroundings, waiting for females to fly into it. They move from landmark to landmark, sometimes forming swarms over cars or people's heads.　If you find yourself with a swarm hovering right above you while walking, try moving slowly toward something like a sign or a billboard that is slightly taller than you. You can
move the midge swarm onto that!

The very fleeting life of a chironomid

　Chironomid larvae are familiar creatures that live in water, from clear streams to dirty water, in various rivers and gutters. They were named "chironomid" (yusurika in Japanese) because of the way the larvae wiggle their bodies in the water.　Although they are closely related to "mosquitoes," many species have no mouthparts and
do not bite or suck blood. The lifespan of an adult chironomid is very short; once they emerge, they do not feed, they search for a mate, hurriedly lay eggs in the water, and die within a week at most, making them very fleeting creatures.

There are many types of chironomids. They can even swarm in massive numbers!

　There are a great many types of chironomids, with 15,000 species known worldwide and about 2,000 in Japan. They range from tiny ones that can pass through window screens to those over 1 cm long, and they come in various colors such as black, brown, and green.　Since they don't suck blood, they seem harmless, but because they sometimes
swarm in massive numbers, they can cause nuisances such as covering walls or piling up in heaps of dead bodies, and in rare cases, they can cause allergies.　They are most common from early summer to autumn, but in warmer regions,
some type of adult chironomid is always emerging from March to about December.　The peak of their emergence often lasts for about a week. After a while, they can disappear as if they were never there.

How to prevent chironomids from entering

　Normally, hanging a "Mushi-Konazu Plate Type" between the inside and outside of your home is effective in preventing flying insects from entering, but in the case of massive swarms, products that can be sprayed on walls and window screens are useful. To prevent chironomids from sticking to walls and window screens or entering your home, "Mushi-Konazu Screen Spray" "Mushi-Konazu Screen and Window Glass Spray" are recommended. They block insects from entering through window screens!

　If lights are attracting chironomids, it is also effective to keep curtains tightly closed at night or turn off outdoor lights. Also, you can kill them by spraying an insecticide such as "Iya-na Mushi Kincho-ru" directly on the insects.　However, as long as no measures are taken in the water areas where chironomids live, they will continue to emerge, so
community-wide efforts are often necessary.

Chironomids are creatures that clean the water

Chironomidae larvae grow by eating pollutants in the water, and as the adults fly away from the water, they help clean the water. Furthermore, because the larvae and adults serve as food for other creatures, and their remains return to the soil to provide nutrients for plants, they play a very significant role as members of the ecosystem.
While they can sometimes be an annoying swarm to humans, Chironomidae are essential and important beings that this planet cannot do without.