A Two-Year Survey of the Melon Aphid, Aphis gossypii Glover, on Crop Plants in Hawaii

Abstract

Vegetable and flower farms on Hawaii and Kauai islands were surveyed over a two-year period to determine the distribution, abundance, phenology, and parasitoids of the melon aphid, Aphis gossypii Glover. Aphids were common on all crops sampled except luffa (Luffa acutangula L.). Populations were generally low (<2 aphids/cm2) and were relatively stable at all sites, including wet (windward) and dry (leeward) locations. Lysiphlebus testaceipes Cresson was the most common parasitoid attacking the aphid, although it was not abundant and was hindered by high levels of hyperparasitism. Four new natural enemies of melon aphid are recorded for the first time in Hawaii: the newly introduced aphidiid parasitoid Aphidius colemani (Viereck); the fungal pathogen Neozygites fresenii (Nowakowski) Batko [Zygomycetes: Entomophthorales: Neozygitaceae]; the parasitoid wasp Aphelinus varipes (Foerster) [Hymenoptera: Aphelinidae]; and a parasitic fly, Endaphis maculans (Barnes) (Diptera: Cecidomyiidae).