Sex Pheromones of Noctuid Moths. Xxii. the External Morphology of the Antennae of Trichoplusia ni, Heliothis zea, Prodenia ornithogalli, and Spodoptera exigua1,2

Abstract

The antennae of the noctuid moths Trichoplusia ni (Hubner), the cabbage looper; Heliothis zea (Boddie), the corn earworm; Prodenia ornithogalli Guenee, the yellow-striped armyworm; and Spodoptera exigua (Hubner), the beet armyworm, are setiform with many flagellar segments. Eight types of sensilla occur on the antennae of all 4 species: Bohm bristles on the scape and pedicel; and on the flagellum, sensilla chaetica, 3 types of sensilla trichodea, sensilla coeloconica, sensilla styloconica, and ear-shaped sensilla for which the name sensilla auricillica (singular auricillicum) is proposed. The general pattern of numbers and distribution of these sensilla is similar in all 4 species. Sexual dimorphism is not marked. Except in H. zea males (but not females), which have some type 1 trichodea in rows on the basal half of the flagellum, sexual differences appear as slight variations in the number and distribution of the sensilla.