Antennal sensilla of seventeen aphid species (homoptera: Aphidinae)

Antennae of the 4 nymphal instars and the alate and apterous virginoparous adults of pea aphid (Acyrthosiphon pisum (Harris)) were studied. Differences in antennal morphology as well as distribution and description of antennal sensilla are given. The first 2 nymphal instars possess 5 antennal segments, the others have 6. Total number of sensilla remains constant from second nymphal instar through adult. Scanning electron micrographs of sunken uniporous pegs of primary sensoria on segment 6 and openings to rhinariellae on segment 2 are presented for the first time. Comparisons are made of adult antennal characteristics of 17 species of aphids from 5 subfamilies. Microtrichia are absent from secondary sensoria, except in Drepanosiphinae and in 2 species of Aphidinae. Microtrichia are present around primary sensoria except in subfamilies Chaitophorinae and Lachninae. Thick walled hairs with enlarged tips are found in Drepanosiphinae and in the tribe Macrosiphini of Aphidinae. A new multiporous sensillum is described from members of the subfamily Drepanosiphinae. It is suggested that some of these antennal characters may aid in tracing phylogenetic relationships. © 1978 Pergamon Press Ltd