The growth of Tipula larvae with particular reference to the head capsule (Diptera: Tipulidae)

Abstract

Larvae of Tipula paludosa, under favorable conditions of temperature, food, and photoperiod, grow continuously throughout the first three larval stages and into the fourth. At 21 °C and 16 h light: 8 h dark regime, larval growth slowed markedly after about 20 days into the fourth stage, but imaginal leg and wing bud development continued for more than another 50 days. The invaginated portions of the larval head capsule show the same pattern of growth as the rest of the body. It is proposed that hemicephaly and restricted sclerotization allow tipulid larvae to grow to large size with relatively few molts, but that molting is necessary to increase the size of the feeding apparatus.