FIRST SURVEYS ON AGRILUS SPP. (COLEOPTERA: BUPRESTIDAE) INFESTING HAZELNUT IN NORTHWESTERN ITALY

In the last few years, severe attacks of wood-boring beetles, belonging to the genus Agrilus (Coleoptera: Buprestidae), have been reported in the hazelnut growing area of Langhe (Piedmont, NW Italy). Similar attacks had been observed and attributed to the species A. viridis, larvae of which can cause shrivelling of hazelnut branches with their strong wood-boring activity.
Therefore, in 2006-2007, research was addressed to identify the Agrilus species present in the hazelnut agroecosystem of our region, to assess rate and harmfulness of their attacks, and to evaluate efficacy of egg-parasitoids, with the aim to implement effective and environmentally-friendly control tactics.
From May to August, sampling was carried out in hazel groves using yellow sticky traps, and by visual inspection of branches to collect adults and egg-patches, respectively.
Seven Agrilus species were sampled: three only occasionally and four more frequently; among these last species, the most abundant and widespread was A. olivicolor. Adult beetles were always captured from May to early August, showing a long flight activity in the hazelnut agroecosystem.
Egg-patches were collected starting from May, and larvae emerged from late May to mid-July.
An egg-parasitoid, Oobius zahaikevitshi (Hymenoptera: Encyrtidae), was obtained from egg-patches in both years; in 2007, the parasitisation rate fluctuated from 8 to 58% of total field-collected egg-patches in the surveyed hazel groves.

VII International Congress on Hazelnut

M. Corte, S. Moraglio, L. Tavella

wood-boring beetle, field surveys, life-history, egg-parasitoid, Hymenoptera Encyrtidae

https://doi.org/10.17660/ActaHortic.2009.845.82