Biological parameters of "Xylotrechus arvicola" females, an insect pest in Iberian Peninsula vineyards

Aims: Xylotrechus arvicola is an important pest in vineyards of the Iberian Peninsula. The action of X. arvicola larvae, associated to the spread of fungi, causes direct and indirect damage in the vineyard. Biological parameters from wild (captured in the field) and laboratory females (reared in the laboratory) were investigated to provide more information about the pest-control measures. Methods and results: The pre-laying period, post-laying period, longevity and egg laying parameters (fecundity, viability and number) were evaluated in wild and laboratory females. Both female groups (wild and laboratory) needed a short pre-laying period, which was longer in wild females. Laboratory females, whose larvae were reared on artificial diet, had the greatest fecundity during the 1st two egg layings. Wild females showed the greatest fecundity and viability of eggs during the 1st egg laying; these fecundity and viability rates decreased over time with the next egg layings, whereas in laboratory females, fecundity and viability decreased faster. Wild females had the greatest percentage of viable eggs in the 1st six egg layings (44.11% in the 1st and 11.15% in the 6th), reaching a maximum number of 18 egg layings in laboratory. Conclusions: These results suggest that the diet satisfies larval nutritional requirements, increasing production of laboratory females´ eggs (greatest fecundity in the 1st two egg layings). Nevertheless, this artificial diet may lack certain essential nutrients that would increase the viability of eggs. Significance and impact of the study: The host, a woody plant, would provide these essential nutrients when the larvae of wild females are developing in the field, these wild females being able to perform successive egg layings in laboratory with a high viability of eggs.