APHIDS (HOMOPTERA, APHIDIDAE) OF POTENTIAL IMPORTANCE ON CITRUS IN THE UNITED-STATES WITH ILLUSTRATED KEYS TO SPECIES

In commodities produced by the U,S. in 1990, citrus ranked 16th with a n approximate value of $1814 million (Florida $1316, California $472, Arizona $16, and Texas $10 million). Until recently, the brown citrus aphid (BrCA), Toxoptera citricida (Kirkaldy), was not known to occur i n the citrus-growing areas of Central and North America. However, in 1 991, one alate BrCA was collected in a trap in melon fields in Costa R ica. In 1992, several colonies of BrCA were collected in Costa Rica, D ominican Republic, Haiti, Nicaragua, and Puerto Rico. In 1993, BrCA wa s collected in Cuba and Jamaica. This aphid is still not known to occu r in the continental United States. The citrus industry could suffer s everely with the introduction into the United States of BrCA. As the p rincipal vector of citrus tristeza virus (CTV), BrCA is a threat to un infested Citrus-growing areas of the United States. The pictorial and dichotomous keys and information on taxonomic characters, hosts, and d istribution included in this manuscript will be invaluable tools to th ose surveying for BrCA in as yet uninfested areas.