Aphytis hispanicus (Mercet)
Taxonomic placing: Insecta, Holometabola, Apocrita, Hymenoptera, Chalcidoidea, Aphelinidae.
Geographical distribution: The Mediterranean Basin, Central America, Texas, California, Taiwan.
Hosts: Several (Diaspididae), especially chaff scale, Parlatoria pergandii Comstock and tropical grey chaff scale, Parlatoria cinerea Hadden. In the laboratory the parasitoid can be reared on the latania scale, Hemiberlesia lataniae (Signoret).
Economic importance: A parasitoid of chaff scales.
Morphology: The female is yellow, its size being from 0.6 to 1.0 mm.
Adult of Aphytis
Life cycle: Like other members of its genus, Aphytis hispanicus is an ectoparasitoid of armored scale insects. The 2nd-stage nymphs, young females and scale prepupae are sometimes attacked, but the ovipositing females are the preferred stage for parasitization. The eggs are deposited through the shield on the host’s body; due to the fact that when molting the shields of these scales adhere to their bodies, the parasitoid can deposit only between molts. Its emerging larvae feed on the scales and prior to pupation they excrete their fecal matter in the shape of black pellets (”meconia”). The pupa is free, its eyes changing from colorless to red to green, providing an indication of its age. The adult often emerges through an exit hole in the shield, or by crawling out from underneath. A. hispanicus is a uniparental thelytokous species, requiring about a fortnight to complete a generation at 28°C, each female producing about 24 offspring. In the field this solitary parasitoid has two population peaks, in spring and in autumn, being rare during summer and winter. It attacks its chaff scale hosts mostly on the leaves, less on the fruit and very seldom on the wooden parts of the trees, and does not feed on its hosts.
References
Gerson, U. 1967. The natural enemies of the chaff scale, Parlatoria pergandii Comstock, in Israel. Entomophaga 12: 97-109.
Gerson, U. 1968. The comparative biologies of two hymenopterous parasites of the chaff scale, Parlatoria pergandii. Entomophaga 13: 163-173.
Rosen, D. and DeBach, P. 1978. Species of Aphytis of the World (Hymenoptera: Aphelinidae). Israel Universities Press, Jerusalem.
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