Insects in an Urban Garden - Diptera
Ottawa Canada

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Aedes excrucians: Woodland Mosquitos are found throughout Canada and are one of our longest-lived species, flying from May through August. A high-power microscope is needed to separate them from the more common A.stimulans. This is a female, her antennae are designed to smell the octenol and nonanal in mammalian perspiration and carbon dioxide from respiration, her proboscis is tipped with a sheathed drill for biting. Length 8 mm. Aedes excrucians female
Aedes sticticus: While taxonomists argue over whether Ochlerotatus is a subgenus of Aedes or a genus in its own right, Floodwater Mosquitos continue to overwinter as eggs and hatch in the spring to bite us. This is a male who lives off plant nectar and doesn't bite, his feathery antennae are used to detect the whine of a female's wings, his long palp to smell her pheromones. Length 8 mm. Aedes sticticus male
Agromyza: The larvae of tiny leaf miner flies eat the insides of leaves. Length 2 mm. Agromyza female
Anopheles punctipennis: This is one of the most common mosquitos in North America and was a major vector of malaria here during the building of the Rideau Canal. Body length 6 mm. Anopheles punctipennis female
Archytas californiae: These large tachnid flies are parasites of many crop pests, including forest tent caterpillar, fall webworm, tomato fruitworm, corn earworm and cutworms. Body length 11 mm. Archytas californiae male
Bibio xanthopus: March flies have split eyes; perhaps one set is optimized for detecting predators, the other for mates. Adults are short-lived, most existing solely to reproduce. Their larvae eat grassland plants and roots. Body length 9 mm. Bibio xanthopus male
Bombylius major: This bee fly lives off nectar, in my case Forsythia blooms; it can hover in front of a flower to feed with its long proboscis. Wing span 20 mm. Bombylius major
Borophaga: Nothing is known about these flies - their life must be unusual to result in such powerful leg muscles. Length 2.7 mm. Borophaga
Calliphora vomitoria: This blow fly feeds on decaying meat and feces both as adult and larva. Length 12 mm. Calliphora vomitoria
Camptomyia: This gall gnat's head is literally all eyes! At 300 µm diameter, it overshadows the rest of the face. As the name implies, the larvae of these flies produce galls. Length 2 mm. Camptomyia female
Chaoborus punctipennis: The larvae of Phantom Midges eat small zooplankton at night and migrate down to cold dark water during the day; adults live only a few days. Length 4 mm. Chaoborus punctipennis male
Chironomus: Non-biting midges found near water that feed on sugars such as honeydew. Their larvae are an important food source for fish. This one seems to be intersex. Length 7 mm. intersex Chironomus
Chrysopilus quadratus: A long-legged snipe fly whose larvae live in rotten wood. Length 7 mm. Chrysopilus quadratus
Conarete: A gall midge. Length 1.9 mm. Conarete female
Condylostylus caudatus: It's believed that this fly is a predator of small insects both as adult and as larva. Length 3.5 mm. Condylostylus caudatus male
Condylostylus sipho: Length 7 mm. Condylostylus sipho female
Coquillettidia perturbans: The larvae of this mosquito can breath through the airtubes of aquatic plants so they never need to surface for air. Body length 7 mm. Coquillettidia perturbans female
Cricotopus: Length 7 mm. Cricotopus
Cylindromyia interrupta: The bright white calypteres of this tachnid fly stand out. It parasitizes moths. Length 7 mm. Cylindromyia interrupta
Dasyhelea: These midges are unusual in that they don't bite but only eat nectar as adults. Body length 2 mm. Dasyhelea
Delia platura: Seedcorn Maggots burrow into seeds, hence the name. Body length 6 mm. Delia platura
Dioctria hyalipennis: A robber fly subduing a small wasp for a meal; it's bitten off enough of the wasp's wings that it can no longer fly, but the wasp has bitten several chunks off the fly in return. Diptera length 10 mm. Dioctria
Dolichopus albicoxa: These little flies choose a leaf with a commanding view of the surroundings, then defend a litre or two volume around it. They are highly reflective iridescent green from head to tail, appearing as tiny sparkles over dark leaves, and are the most numerous visible insect in the garden. Length 4 mm. Dolichopus albicoxa
Drosophila immigrans: This tiny fruit fly is attracted to over-ripe or rotten fruit, but doesn't damage produce. Originally from east Asia, it has spread world-wide over the past century. It can only survive Ottawa winters indoors so is rare in the spring; needing only 14 days from laid egg to egg-laying female, it is abundant by autumn. Length 2 mm. Drosophila immigrans
Drosophila melanogaster: This fruit fly, originally from equatorial Africa but now spread world wide, is widely used in genetic studies. Length 2 mm. Drosophila melanogaster female
Eupeodes americanus: The larvae of this syrphid fly feed on aphids and scale insects. Body length 7 mm. Eupeodes americanus
Forcipomyia: These biting midges are found near water; a Taiwanese species is noted for causing exceptionally itchy bite reactions. Length 2 mm. Forcipomyia male
Glyptotendipes senilis: A non-biting midge that lays its eggs in water. Length 4 mm. Glyptotendipes senilis female
Gonomyia sulphurella: This female crane fly is infested with Hydrachnidia water mite larvae. Body length 4 mm. Gonomyia sulphurella female
Harnishia: a group of non-biting aquatic midges with 11-segmented flagellomeres Harnishia complex male
Helophilus fasciatus: Syrphid flies use mimicry to dissuade their enemies, most looking like stinging Hymenoptera as this one does. The adults live off nectar and pollen, larvae are aquatic. Length 14 mm. Helophilus fasciatus male
Hemipenthes webberi: The larvae of this bee fly are parasites on Hymenoptera and Diptera, the adults feed on pollen and nectar. Length 7 mm. Hemipenthes webberi
Heterotrissocladius: These midges resemble black flies but they don't bite. They swarm in large groups of males waiting for a female to appear. Wing span 6 mm. Heterotrissocladius male
Hybomitra: One of the horse flies, it gathers in groups hovering above the ground in shafts of sunlight around the Thuja occidentalis waiting for a female to appear. Hybomitra male
Hydrophoria lancifer: introduced in the 1920s, this fly breeds on dung. Hydrophoria lancifer female
Leschenaultia: This fly hatched in a rearing jar of top soil that included imported cocoa shell mulch. Body length 13 mm. Leschenaultia
Leucophora: or possibly Phorbia, in either case one of the Anthomyiidae - root maggot flies. Length 6 mm. Leucophora female
Lucilia illustris: Blow fly larvae are important recyclers of dead animals; adults can always be found on Solidago once it is in bloom. Some infest living animals, but this one's larvae live solely on dead tissue. Body length 7 mm. Lucilia illustris
Megacyttarus (Rhampomyia): These dance fly females swarm to attract males, opposite to usual dipteran behaviour. Length 4 mm. Megacyttarus (Rhampomyia) female
Merodon equestris: Narcissus Bulb Fly is a European bumblebee mimic that is now found throughout Canada. As an adult it eats pollen; its larvae live on Narcissus and Lilium bulbs. Half a dozen of these were jousting over my garden, two facing each other about half a body length or less, then doing acrobatics keeping their relative position until one couldn't keep up and backed off - fascinating display. When one is caught in a net, it folds its wings back so they overlap then produces a high-pitched whine. Length 12 mm. Merodon equestris male
Micropsectra: A genus of non-biting midges that appear as tiny specks of white fluff when flying. Length 3 mm. Micropsectra male
Nephrotoma ferruginea: This crane fly breeds in the garden. Body length 12 mm. Nephrotoma ferruginea mating
Omisus pica: A non-biting midge. Length 5 mm. Omisus pica female
Paralauterborniella: Non-biting midge whose larvae grow in soft pond sediments. Length 3 mm. Paralauterborniella female
Phyllomyza: The larvae of several species develop in ant's nests. Body length 2.4 mm. Phyllomyza male
Phytomyza aquilegivora: These larvae are mining Aquilegia chrysantha leaves. Body length 1.4 mm. Phytomyza aquilegivora
Platycheirus: This hover fly's eyes cover 360° in all directions. Length 9 mm. Platycheirus female
Poecilanthrax tegminipennis: The larva of this bee fly grow inside Noctuidae larvae. Wingspan 30 mm. Poecilanthrax tegminipennis
Pollenia rudis: The Cluster Fly is an import from Europe that can overwinter as an adult here, so is one of the first flies to appear in spring. It lays eggs in moist soil, then the larvae burrow to find (European) earthworms on which to feed. The bright light tan calypteres and orange prothorax hairs help to identify it. Length 8 mm. male Pollenia rudis
Platypalpus harpiger: The large mid legs of these flies hold their prey while the fly feeds. Length 5 mm. Platypalpus harpiger
Procladius bellus: The larvae of this midge eat detritus in the mud of ponds. It's in the Psilotanypus subgenus. Length 1.7 mm. Procladius bellus male
Procladius: (Holotanypus). The hairy wing shows that it's in a different subgenus than P.bellus. Length 2.5 mm. Procladius (Holotanypus) male
Rhagio mystaceus: Snipe flies suck plant juices or body fluids of other insects; a few feed on animal blood. Their larvae mostly live in decaying wood and eat small invertebrates. Length 7 mm. Rhagio mystaceus
Schwenkfeldina: A Fungus Gnat is regurgitating a drop of stomach liquid - it will suck it in again. This is a common behaviour, but no one really knows why. Length 5 mm. Schwenkfeldina
Sciaridae: Dark-winged Fungus Gnat larvae are common in damp organic soil where they eat fungi and decaying organic matter, occasionally living root hairs. The adults don't eat or bite, only living for a few weeks. This one is trapped in a sticky trap indoors. Length 1.7 mm. Sciaridae
Simulium: A Black Fly - the tarsal claws of this one identify it as a mammal feeder. Length 2.1 mm. Simulium female
Strauzia longipennis: Sunflower Maggots bore in the stems of various plants of Asteraceae, particularly Helianthus annuus, and feed on the pith. Length 7 mm. Strauzia longipennis female
Thricops nigrifrons: These flies eat pollen; their bright orange calypteres stand out. Length 7 mm. Thricops nigrifrons
Tipula paludosa: European Crane Fly adults exist entirely to reproduce and are incapable of eating. Their larvae eat grass roots, as do those of our native Tipula species. Tipula paludosa female
Toxomerus marginatus: This is a common small syrphid hover fly that varies considerably in colour depending on the temperature experienced by the larva. It bobs its flattened abdomen about twice per second to mimic stinging Hymenoptera; its larvae eat aphids and thrips. Length 5 mm. Toxomerus marginatus
Trichocera: These small crane flies fly in colder weather than most others, earning them the nickname winter crane flies. Their larvae live in rotting vegetable matter. Length 6 mm. Trichocera
Zodion cinereum: These flies mimic stinging Hymenoptera, attack them in flight and insert an egg between the wasp's abdominal segments that then grows as an internal parasite of the wasp. Length 7 mm. Zodion cinereum
Zygoneura: Fungus Gnat. Length 1.8 mm. Zygoneura

John Sankey
other insects in the garden

Manual of Nearctic Diptera
DipteraInfo - Diptera forum
A Photographic Key to Adult Female Mosquito Species of Canada