WHITEFLIES (ALEYRODIDAE) ATTACKING CITRUS IN SOUTHERN TEXAS WITH NOTES ON NATURAL ENEMIES

Five species of whiteflies (Aleyrodidae) were found on citrus in southern Texas: Aleurocanthus woglumi Ashby, Aleurothrixus floccosus (Maskell), Paraleyrodes citri Bondar, Dialeurodes citri (Ashmead), and D. citrifolii (Morgan). Parasite records for this area were Amitus hesperidum Silvestri (Platygastridae) and Prospaltella opulenta Silvestri (both Encyrtidae) attacking A. woglumi; Eretmocerus sp. near paulistus Hem. (Encyrtidae), Amitus sp., and Prospaltella sp. attacking A. floccosus; and Prospaltella sp. attacking P. citri. Predators recorded were Delphastus pusillus (Le Conte) (Coccinellidae) feeding on A. floccosus; D. pusillus and Nephaspis amnicola Wingo (Coccinellidae) feeding on P. citri. A pathogenic fungus, Aschersonia aleyrodis Webber, was found attacking D. citri.

EFFECTS OF FLORIDA CITRUS PEST CONTROL PRACTICES ON THE CITRUS BLACKFLY (HOMOPTERA: ALEYRODIDAE) AND ITS ASSOCIATED NATURAL ENEMIES

The postbloom and summer sprays recommended in Florida commercial citrus cultures for management of insect and mite pests and phytopathogenic diseases caused a significant (P < 0.05) reduction of citrus blackfly, Aleurocanthus woglumi Ashby, infesting urban dooryard citrus. There were no observed adverse chronic effects on populations of the parasite Amitus hesperidum Silvestri, or the predator complex consisting of spiders, chrysopids, and coccinellids attributable to the chemical treatments. The absence of chronic pesticide-induced interference with biological control agents was interpreted as an indication of the potential for development of integrated control strategies against A. woglumi should this insect invade commercial citrus areas in Florida.

Citrus Blackfly Parasitoid, Amitus hesperidum Silvestri (Insecta: Hymenoptera: Platygasteridae)

Amitus hesperidum Silvestri is one of the most effective parasites of the citrus blackfly, Aleurocanthus woglumi Ashby. This parasite was described by Silvestri in 1927 from Aleurocanthus citriperdus in Hong Kong and Singapore (Silvestri 1927). It was collected in India and introduced into Mexico for controlling citrus blackfly (Smith et al. 1964). Because of the success in Mexico, it was imported into Texas (Summy et al. 1983) and Florida (Hart et al. 1978) to suppress the population of citrus blackfly in these states. This document is EENY-243 (originally published as DPI Entomology Circular 311), one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: October 2001. EENY-243/IN511: A Citrus Blackfly Parasitoid, Amitus hesperidum Silvestri (Insecta: Hymenoptera: Platygastridae) (ufl.edu)

HERBERT D. SMITH’S OBSERVATIONS ON CITRUS BLACKFLY PARASITES IN INDIA AND MEXICO AND THE CORRELATED CIRCUMSTANCES

In Mexico during the spring of 1950, four imported species of parasitic Hymenoptera (Amitus hesperidum Silvestri, Prospaltella smithi Silvestri, P. clypealis Silvestri, and P. opulenta Silvestri) were placed on populations of their natural host, the citrus blackfly, Aleurocanthus woglumi Ashby. Their artificial distribution and establishment throughout areas in which the host species was extremely abundant and the observed adjustment of each to its host, to its competitors, and to distinctive regional environments revealed physiological and ecological factors that determined the dominance of one species over another. These factors and the circumstances of their occurrence during 1948 to 1953, inclusive, as reported by Herbert D. Smith, Entomologist of the United States Department of Agriculture, are reviewed and amplified.