Pitcher-plant mosquito

IUCN Red List

not listed

NatureServe

NR - Unranked

Minnesota

not listed

Pitcher-plant mosquito is a small mosquito. It occurs in the United States and southern Canada east of the Great Plains.

Pitcher-plant mosquito is an inquiline, an animal that lives in the home of another. It is found in bogs, fens, swamps and peatlands—wherever its host purple pitcherplant (Sarracenia purpurea) is found. Having co-evolved with its host, the mosquito completes its entire life cycle in close proximity to the plant.

Unlike tropical pitcher plants that secrete highly acidic, enzyme-rich cocktails to dissolve prey, the purple pitcher plant collects rainwater. This dilutes its digestive enzymes and creates a habitable micro-ecosystem for a variety of organisms. Several of these residents form a mutualistic processing chain.

When an insect drowns, it is first torn apart by “shredders” (midge and fly larvae), that break down the carcass into microscopic particles. This debris triggers a bloom of “decomposers” bacteria and rotifers which feed on those particles. The mosquito larvae act as the “filterers”, using their brush-like mouthparts to sweep the water for bacteria, rotifers, and "insect dust." By consuming these microorganisms, the mosquito helps “clean” the pitcher and converts solid waste into nitrogen-rich ammonia, which the plant can easily absorb.

Adults are small, ⅛″ (3 to 4 mm) in length.

The palps are reduced in both males and females, and the antennae on the male are not feathery (plumose). Males and females cannot be distinguished except by their genitalia.

The upperside of the middle segment of the thorax (scutum), which covers most of the thorax, is covered with broad, flattened, dark scales. The top of the head, the upperside of the abdomen, and the wings, are also covered with dark scales, sometimes with metallic reflections.

The sides of the thorax (pleuron) and the postpronotum are covered with shiny pale scales. The underside of the thorax and abdomen are covered with round, flattened, silvery white scales. There is a sharp dividing line between the dark and light scales, giving the entire body a distinctly bicolored appearance.

The legs are very long. The uppersides of the third and fourth segments (femur and tibia), and of the last part of the leg (tarsus), corresponding to the foot, are covered with dark scales. The underside of the femur, tibia, and tarsus, and all of the first leg segment (coxa), are covered with round, flattened, silvery white scales. The hind legs are held arcing forward high over the body, possibly mimicking antennae.

The larvae are creamy-white and somewhat translucent, often revealing a dark digestive tract. The head has specialized, brush-like mouthparts used to filter microorganisms from the pitcher fluid. The rear segment has large, sausage-shaped anal papillae (gills) used for salt balance. The southern populations has four gills but the northern population has only two. There is a short, blunt, hairy, breathing siphon at the tail.

Size

Total length: ⅛″ (3 to 4 mm)

Similar Species

This is the only mosquito larvae that lives inside Sarracenia purpurea pitchers.

Bogs, fens, swamps and peatlands

Season

Adults: June through fall

Larvae: Year round

Behavior

Females in the north do not drink blood.

Life Cycle

As winter approaches, the larvae enter a state of suspended animation known as diapause. They spend the winter months literally frozen solid within the ice cores of their host pitchers. When the spring thaw arrives, the larvae “wake up” and resume feeding.

Larva Food/Hosts

Bacteria, rotifers, and "insect dust"

Adult Food

Nectar and plant sap