common name: a citrus blackfly parasitoid
scientific name: Amitus hesperidum Silvestri (Insecta: Hymenoptera: Platygasteridae)

Introduction - Distribution - Description - Biology - Hosts - Selected References

Introduction

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.

Distribution

Amitus hesperidum has been reported as native to Asia. It is found in Sri Lanka, China (Hong Kong, Szechuen), India, Java, Malaya, Pakistan, and has been introduced into Guam, Venezuela, Mexico, and the United States (Florida and Texas) to control citrus blackfly (Silvestri 1927, Smith et al. 1964, Flanders 1969). In Florida, it was released in Brevard, Broward, Collier, Dade, Highlands, Hillsborough, Indian River, Lee, Manatee, Martin, Monroe, Okeechobee, Palm Beach, Pinellas, Sarasota and St. Lucie counties.

Description

Female shiny black, tiny (0.75 mm long). Antenna 0.65 mm long, 10 segments with the last three closely united and forming a club; wings shiny; hind tarsus 5-segmented. Male similar to female, antenna ten-segmented filiform, scape curved, with all flagellar joints longer than wide and covered with short erect hairs (Silvestri 1927).

female

male

Biology

This species is non-polyembryonic and biparental in reproduction with a sex ratio of 1:1. It lays eggs in all three larval stages of the host, with a preference for the first stage. A female of the citrus blackfly usually produces two, three or occasionally four adult parasites, whereas a male host pupa produces only one. Both male and female parasites can be produced from a female of the citrus blackfly pupa. Amitus hesperidum females have a life span of four to five days, and males live three to four days. Life cycle from egg to adult varies from 45 to 60 days under laboratory condition (T=27°C). In the field, A. hesperidum is well synchronized with the host and has a high rate of reproduction. A female can produce more than 60 offspring; it is very effective with the high density of the citrus blackfly in Florida. However, the female has a poor searching capability and survives only four to five days under field conditions. The parasite population will die out soon after suppressing A. woglumi populations (Flander 1969, Nguyen et al. 1983).

adult parasitoids and their hosts

Hosts

Aleurocanthus citriperdus Quaintance and Baker, A. spiniferus (Quaintance), and A. woglumi Ashby are reported as hosts (Silvestri 1927, Smith et al. 1964).

Selected References

Author: Ru Nguyen, Florida Department of Agriculture and Consumer Services, Division of Plant Industry.
Originally published as DPI Entomology Circular 311.
Photographs: Division of Plant Industry
Project Coordinator: Thomas R. Fasulo, University of Florida
Publication Number: EENY-243
Publication Date: October 2001
Copyright 2001 University of Florida

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