The Green Mosquito: Chironomid Midge

Male Chironomid Midge on Hare's Tail Grass (or the Bunny Tail Grass, Lagurus Ovatus)

Yellow Chironomid Midge on Lagurus Ovatus.

Yellow Chironomid Midge

The Big Swamp Wetland, Bunbury is a great place for bike riders. It is my favourite place to ride. My bike rides are made more interesting by the different insects I spot. This was one of them. It was so tiny that I could only see it with my macro lens. It looked like a mosquito, but green in colour. It was clinging on to the Hare's Tail Grass. The bright green body against the pale green Hare's Tail Grass was a standout. The plumose antennae on top of the feathery weed was a pretty sight to see through the lens. Not to mention the tiny iridescent wings! The yellow midge with bright yellow head contrasting the green body with black oval eyes did not have the feathery plumose antennae as prominent as the green midge (making me think it could be a female, due to lack of plumose antennae).

There were a group of them clinging on to the weed, basking in the sun. The sun worked against me to take a good picture but the insects were still enough for me to find an angle to shoot. I love those times when the insects pose for me!

This is the Chironomid Midge, also known as the Green Midge. It is a non biting midge related to the notorious biting midges (Ceratopogonidae). The resemblance to mosquitos is because they belong to the same suborder of Nematocera (characterised by thin, filamentous, segmented antennae) and to the same infraorder Culcimorpha. The mosquitos branch off into the superfamily Culicoidea and midges branch off into the superfamily of Chironomidae. 

I am not sure what genus or species the one I photographed belongs to. Apparently there are so many obscure species of Chironomidae that it needs cytogenetic confirmation using their Polytene Chromosomes*. Genetically interesting fact about Chironomidae is that the Polytene Chromosomes were first discovered in the salivary glands of these midges (Balbiani in 1881) much before the hereditary pattern was studied in fruit flies. The salivary glands of chironomids are still used for the study of polytene chromosomes.

Chironomids are ecologically important. Many species of Chironomids adapt easily to anoxic conditions in polluted water. The larvae are red due to haemoglobin content which helps them get as much oxygen from the toxic environment. The abundance of Chironomids indicate low biodiversity in the ecological system due to presence of high level of pollutants. Chironomids are the food for fish and many aquatic organisms. The presence of midges in Western Australian wetlands is supposedly a nuisance for people's outdoor activities. This is because they are attracted to and cluster around UV light sources. They are small enough to pass through fly meshes. 

Location: Big Swamp Wildlife Park, Bunbury, Western Australia

(seasonal fresh water wet land)

Season: Spring (October)

Order: Diptera  

Suborder Nematocera

Infraorder: Culicomorpha

Superfamily: Chironomoidea

Family: Chironomidae 

*Polytene Chromosomes are formed through repeated DNA replication without actual cell divison hence they are easily identified by banding patterns. The pattern inversions and deletions help in species identification.

References: BugGuide, Wikipedia, Public Health WA, MDFRC.ORG.AU, www.armadale.wa.gov.au