How Big Do Flies Get?
WouterFlies are one of the most common insects, and they range in size from tiny to fairly large. A typical adult fly is between 1/8 and 1/4 of an inch in length. It has four black stripes on its thorax and a sponging mouthpart. These insects are most common during the summer months.
The larva is the main feeding stage of the fly. On hatching, first-instar larvae are about two millimeters long. They grow to a length of about five millimeters before shedding their skin. In the second and third instars, larvae grow to a diameter of around 15 to 20 millimeters before wandering off as pre-pupae. Larvae are distinctive because of their posterior spiracles. These spiracles allow the larvae to breathe.
In addition to nectar, adult flies feed on various types of plant materials. Their eggs are usually laid in leaves or stems, where they feed on plant matter. Adult flies are capable of “spitting” onto dry foods to gain extra nutrients. Because of this, some flies may contaminate food that humans consume. Fly larvae may even suck blood from vertebrates as food.
Adult cluster flies, or house flies, can grow as large as 1/2 inch. They are black or gray and lack golden hairs. Their wings are nearly fully overlapped when at rest. They are common in the northern part of the US and many other countries. During cool months, they will cluster inside homes.
