Primer registro en la Península Ibérica de <em>Oobius rudnev</em>i (Nowicki, 1928) (Hymenoptera: Encyrtidae), un parasitoide oófago poco conocido de <em>Cerambyx</em> sp. (Coleoptera: Cerambycidae)

Abstract

Se cita por primera vez a Oobius rudnevi (Nowicki, 1928) (Hymenoptera: Encyrtidae) de la Península Ibérica y el sur de Europa usando huevos centinela. El parasitoide se detectó en julio de 2016 en tres dehesas en Extremadura (SO de España), localizadas en Almendral (La Jara) y Mérida (La Serrana y Parque Natural de Cornalvo). O. rudnevi parasitó tanto los huevos de Cerambyx cerdo Linnaeus, 1758 (su único hospedador conocido hasta la fecha) como los de C. welensii (Küster, 1845), lo que supone una nueva asociación hospedador-parasitoide (C. welensii-O. rudnevi). El porcentaje de parasitismo se mostró bastante variable entre sitios y fechas (rango 0–93%), con mayor prevalencia en C. cerdo que en C. welensii. Nuevos estudios se desarrollan en campo y laboratorio para explorar la ecología, comportamiento y potencial parasitario de O. rudnevi en las dehesas mediterráneas de quercíneas.

Female delayed mating has a limited impact on the reproductive output of Cerambyx welensii, a synovigenic longhorn beetle

“…Mated females of Cw wander over the host trunk and main branches, probing the bark repeatedly with the ovipositor, looking for suitable bark crevices and pruning wounds to lay eggs (Torres‐Vila et al, 2016). It follows that if females cannot dedicate the necessary time to properly locate each egg (a form of time limitation), then eggs laid could suffer increased mortality as they remain more exposed to inclement weather or to attack by predators and egg parasitoids, mainly the encyrtid wasp Oobius rudnevi (Nowicki) (Torres‐Vila & Fusu, 2020; Torres‐Vila et al, 2021).…”

“…Mated females of Cw wander over the host trunk and main branches, probing the bark repeatedly with the ovipositor, looking for suitable bark crevices and pruning wounds to lay eggs(Torres-Vila et al, 2016). It follows that if females cannot dedicate the necessary time to properly locate each egg (a form of time limitation), then eggs laid could suffer increased mortality as they remain more exposed to inclement weather or to attack by predators and egg parasitoids, mainly the encyrtid wasp Oobius rudnevi (Nowicki)(Torres-Vila & Fusu, 2020; Torres-Vila et al, 2021).In conclusion, Cw females have evolved physiological adaptations to overcome significant mating delays and maintain a high reproductive output, and even the oldest females can reproduce and reach a significant fecundity. Even so, mating delay could still have negative fitness consequences due to collateral factors such as early predation or egg-laying time limitation, which deserve additional studies.…”

When a threatened species becomes a threat: a key to reading the Habitats Directive based on occurrence and distribution of Cerambyx cerdo L. in Mediterranean urban and peri‐urban areas

“…Measures to be performed must firstly consider low-impact control actions such as pruning and removing part of the trees highly attacked by GCB. Management of natural enemies such as the egg parasitoid Oobius rudnevi (Nowicki) could also be potentially effective in some situations (Torres-Vila & Fusu, 2020;Torres-Vila et al, 2021). These interventions normally lead to a significant decrease in GCB infestations and reduce drastically the risk of potential damage to citizens by falling branches.…”