Life History of Paracantha gentilis (Diptera: Tephritidae)

Abstract

The life history of Paracantha gentilis Hering in southern California is described. This stenophagous tephritid reproduces in the capitula of native Cirsium thistles. Courtship and mating behavior are described from field and laboratory observations. Territorial and courtship behavior of males and the morphological characters involved in possible male pheromone emission are described and illustrated, as are the oviposition behavior and reproductive morphology of females. Egg clutch sizes ranged from one to 13 eggs, with a maximum of six clutches per capitulum. Larvae fed gregariously within stage-specific niches. Pupariation occurred in the capitula, from which adults emerged in mid-June through early July. After emergence, most adults probably disperse to higher elevations to feed until autumn, then return to lower elevations and reproduce the following year. Limited reproduction also occurs in late-formed capitula or in capitula of alternate Cirsium hosts.