Encarsia inquirenda (Silvestri)

Taxonomic placing: Insecta, Holometabola, Hymenoptera, Chalcidoidea, Aphelinidae

Common name: None.

Geographical distribution: The Mediterranean Region.

Hosts: Several armored scale insects (Diaspididae), especially the chaff scale, Parlatoria pergandii and the tropical grey chaff scale, Parlatoria cinerea. It also attacks the olive scale, Parlatoria oleae. In the laboratory this endoparasitoid can be reared on the latania scale, Hemiberlesia lataniae.

Morphology: The female is dark yellow, its size being from 0.6 to 0.9 mm.

Life cycle: Encarsia inquirenda is a solitary endoparasitoid of chaff scales, attacking all immobile stages, including the male prepupae and the females. The egg is inserted through the shield into the host’s body whereon the emerging larva feeds. Parasitized 2nd-stage male nymphs, whose bodies become bloated due the larva’s presence, continue to build their shields, which become rounded instead of elongated. The bodies of parasitized chaff scales gradually turn white, losing their purplish color, and then become mummified. Prior to pupation the larva excretes its fecal matter in the shape of black pellets (”meconia”). The development of the parasitoid is undisturbed by the host’s molts. The adult often emerges through an exit hole in the shield, or by crawling out from underneath. Encarsia inquirenda is thelytokous, requiring about four weeks to complete a generation at 28°C, each female producing about 20 offspring. In the field the parasitoid, which is relatively tolerant to low humidities, has two population peaks, in spring and in autumn, being rare during summer and winter. It attacks its chaff scale hosts mostly on the fruit and leaves, rarely on the wooden parts of the trees, and does not feed on its hosts.

Economic importance: A parasitoid of chaff scales.

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.