Maggot is the common name of the larval phase of development in insects of the order Diptera (flies). Sometimes the word is used to denote the larval stage of any insects.

Identification

Of the maggots that we find in peoples’ houses, calliphorid maggots are the most common. Calliphorids are also known as blow flies or bottle flies. Maggots are the larval stage of the flies. Fully grown maggots can reach over a half inch in length. Mature blow fly maggots are creamy in color. Maggots have a very typical body shape; the head end is slender and tapers to a point while the rear end is thicker and ends bluntly. The hook-like mouth parts are the only visible part of the head of these flies. The rear end of the maggot has two kidney bean shaped patterns on the end; these are spiracles used for breathing. Spiracles are used to identify the family and species of fly maggots since, superficially, they all look the same. Mature maggots will pupate. The pupa is concealed in a red-brick case called a puparium. These are smaller than the maggot and more circular in shape. Adult blowflies resemble house flies in shape but are often metallic green or blue in color.

Lifecycle

Adult blow flies lay eggs on or near rotting vegetation, manure or animals. Eggs hatch very quickly, and maggots begin to consume the decaying food. Maggots pupate and emerge as adults within a few days, depending on the temperature. Total developmental time from egg to adult can happen as quickly as a week, given good conditions, and depending on the species. They develop and consume food quickly, so much so that when a maggot has matured, it moves away from the food source to digest and prepare for pupation. During this movement away from the food, a maggot can travel quite far, up to 100 yards. This is when people most often discover the maggots as they disperse through a wall and across the living room floor.