Osservazioni sulla bioetologia della Dioryctria pineae (Stgr.) (Lepidoptera: Phycitidae) e sul suo parassitoide Elachertus geniculatus (Ratz.) (Hymenoptera: Chalcidoidea)

Abstract

OBSERVATIONS ON THE BIOETHOLOGY OF Dioryctria pineae STGR. (Lepidoptera: Phycitidae)

AND ON ITS P ARASITOID Elachertus  geniculatus (RATZ.) (Hymenoptera : Chalcidoidea )

Dioryctria pineae is an insect pest to pine cones of different species of Pinus (Pinus halepensis, P. pinea, P. pinaster). It is also present in Southern Italy where it has two generations a year, while in Centrai ltaly it only has one.

The first adults fly into the field during March-April and lay eggs on macrophyllous and pine cones. Larvae enter the cones and feed on fertilized ovules which are destroyed. When the larvae are mature they pupate in the soil and the adults of the first generation emerge from June to August.

Some larvae from the second generation develop in the pine cones partially destroyed by the former generation and the mature larvae overwinter in a cocoon in the soil and pupate in the following spring. A small percentage overwinters as last instar larva in dry pine cones.

Three parasitoids have been collected: Elacbertus geniculatus which parasitized up to 24% of last instar Iarvae of Dioryctria pineae during June-July, Apanteles dioryctriae, less frequent respect the previous one and only one sample of Temelucha decorata (Hymenoptera: Cremastinae) from one pupa of the D. pineae.

We have been growing E. geniculatus continuosly on larvae of Galleria mellonella in laboratory.