Two animals, a fungus and a houseplant — Part III The Fungus Gnat

Feb 02, 2015 • 9:52 AM UTC

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Microorganisms

laksiyer

Human observer of life. https://sukshmadarshin.wordpress.com

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In the veritable ecosystem of my Bilva plant (see previous posts I , II ), there is yet another set of inhabitants who lives in the soil, and are more of an irritant to the denizens of the household than to the host plant. They often get in your face, or attain moksha (their end) in your morning juice and tomato soup. They are not to be blamed as they only follow odors diffusing from your food probably expecting fungi nearby. I had a rooting garlic pod in water next to the plant (for another experiment) and the stench of the garlic attracted three fungus gnats that met their end in the water. I mounted them on slides and put a tape over for foldscoping. They are extremely delicate and I was a bit rough with them and hence the gnats are damaged in places.

Fungus gnats are classified as Dipterans and like other true flies (fruit flies, mosquitoes and so on) have a short pair of wings called the halteres behind the main set of wings.They are grouped in the Sciaridae superfamily. Their larvae feed on fungal spores or sometimes plants roots, but I suspect mine is associated with a mushroom that occasionally sprouts in the soil. In a sense it contributes to the decay of plant matter and perhaps fertilizes the soil. They are often so tiny that it requires you to look at them under a microscope to identify the species. These are the various anatomical features of the fungal gnat that I observed (pardon my amateur slipups).
1. Head (Antennae): Filiform with 13 flagellomeres. Mouth parts were unfortunately damaged by daft hands.

2. Head (eye) Typically have ocular bridge between eyes (Eyes fused by a bridge of ommatidae) above antenna. I didnt get a good frame for the bridge but the compound eye is really nice.

2. Narrowed neck between head and thorax

Humped thorax

3. Forewing and haltere. Compare the best shot of the wing with the standard Sciaridae wing venation

4. Legs. Fungus gnats are stilt-legged with very long legs and a large coxa.

5. Abdomen

6 . Male terminalia

With that I have exhausted the little I know of insect anatomy. The foldscope is perfect for little insects and will be a great tool for the naturalist. Now there is this curious poem called the Blind men and the Elephant by John Saxe that I learnt as a kid. My description of this gnat reminds me of that poem.. So what is this species of Gnat that resides in my house?
Video of one of the gnats.