Phenology and interspecific association of Forficula auricularia and Forficula pubescens in apple orchards

The European earwig Forficula auricularia L. (Dermaptera: Forficulidae) has been widely studied as a key predator of pests in temperate regions, but its phenology and behavior may differ in warmer areas such as the Mediterranean. Here we assessed the phenology, aggregation, and interspecific association of F. auricularia and Forficula pubescens Gené, the only two species found consistently in both ground and canopy shelters in Mediterranean apple orchards. In addition to F. auricularia and F. pubescens, three other earwig species, namely Labidura riparia Pallas, Nala lividipes Dufour and Euborellia moesta Gené, were found occasionally. The mature stages of F. auricularia were observed mainly from May to November in tree shelters and immature ones from October to June in ground shelters. Adult individuals of F. pubescens were observed year-round and nymph instars were detected from April to June in ground as well as in tree shelters. The suitability of the current degree-days models for temperate regions was evaluated for the prediction of European earwig phenology in a Mediterranean climate. Regarding interspecific association, F. auricularia and F. pubescens co-occurred in canopies without apparent competition. This study provides useful weekly data about the phenology of the two earwig species throughout the year that can be used to detect the key periods during which to enhance their populations in pip fruit orchards or to control them in stone fruit crops. Furthermore, our results are of relevance for the development of new phenological models of earwigs in Mediterranean areas where nymphs hibernate, a feature that makes current models inaccurate.Funding: This study was funded by the Spanish project Programa Nacional de Investigación y Desarrollo Agrario nº AGL2010- 17486 (AGR) Control integrado de plagas en frutales de pepita y hueso

Enhancing biological control in apple orchards

La tisoreta comuna Forficula auricularia Linnaeus i Forficula pubescens Gené (Dermaptera : Forficulidae ) poden tenir un paper decisiu com a depredadors. Es va observar compatibilitat entre la tisoreta i nematodes entomopatògens (NEPs) i una activitat dissuassòria en larves de carpocapsa Cydia pomonella L. (Lepidoptera: Tortricidae) mortes per NEPs, reduint l’alimentació de la tisoreta sobre cadàvers que contenien nematodes al seu interior. La presència de tisoretes i aranyes (Araneae) es va observar all llarg de tot l’any, però tan sols les tisoretes van contribuir a reduir les infestacions de pugó llanut. Les re-infestacions procedents de colònies subterrànies no resulten ser rellevants en les regions mediterrànies. D’aquesta manera, el control d'aquest pugó cal que estigui dirigit tant cap a les colònies aèries com a les arrels. L'ús d’infraestructures ecològiques pot augmentar el control biològic de plagues, proporcionant un entorn més favorable i aliments i refugis alternatius als enemics naturals. Anacyclus clavatus Desf., Dorycnium pentaphyllium Scop., Erucastrum nasturtiifolium Poiret, Euphorbia serrata L., Hedysarum confertum Desf., Papaver rhoeas L., Trifolium pratense L. a la primavera, i Atriplex sp., Dittrichia viscosa L., Medicago sativa L., Moricandia arvensis L., Salsola kali L., Sorghum halepense (L.) Pers., Suaeda spicata Willd. i Verbena sp. a la tardor poden proporcionar refugi i aliment a les aranyes. Viburnum tinus L., Euonymous japonicus L. fil. i Pistacia lentiscus L. van mostrar resultats prometedors per a augmentar la riquesa i abundància d'enemics naturals.La tijereta común Forficula auricularia Linnaeus y Forficula pubescens Gené (Dermaptera : Forficulidae ) pueden tener un papel decisivo como depredadores. Se observó compatibilidad entre la tijereta y nematodos entomopatógenos (NEPs) y una actividad disuasoria en larvas de carpocapsa Cydia pomonella L. (Lepidoptera: Tortricidae) muertas por NEPs, reduciendo la alimentación de la tijereta sobre cadáveres que contenían nematodos en su interior. La presencia de tijeretas y arañas (Araneae) se observó durante todo el año, pero sólo las tijeretas contribuyeron a reducir las infestaciones de pulgón lanígero. Las re-infestaciones procedentes de colonias subterráneas no resultan ser relevantes en las regiones mediterráneas. El control de este pulgón debe dirigirse tanto hacia las colonias aéreas como a las subterráneas. El uso de infraestructuras ecológicas puede aumentar el control biológico de plagas, proporcionando un entorno más favorable y alimentos y refugios alternativos a los enemigos naturales. Anacyclus clavatus Desf., Dorycnium pentaphyllium Scop., Erucastrum nasturtiifolium Poiret, Euphorbia serrata L., Hedysarum confertum Desf., Papaver rhoeas L., Trifolium pratense L. en primavera, y Atriplex sp., Dittrichia viscosa L., Medicago sativa L., Moricandia arvensis L., Salsola kali L., Sorghum halepense ( L. ) Pers., Suaeda spicata Willd. y Verbena sp. en otoño pueden proporcionar refugio y alimento a las arañas. Viburnum tinus L., Euonymous japonicus L. fil. y Pistacia lentiscus L. mostraron resultados prometedores para aumentar la riqueza y abundancia de enemigos naturales.The European earwig Forficula auricularia Linnaeus and Forficula pubescens Gené (Dermaptera: Forficulidae) may play a crucial role as biocontrol predators. Compatibility between European earwig and entomopathogenic nematodes (EPN) and an earwig deterrent activity in EPN-killed codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) larvae that reduces the foraging of European earwig on insect cadavers containing nematodes was also observed, suggesting compatibility between the European earwig and EPNs was observed. European earwigs and spiders (Araneae) were found throughout the year, but only earwigs contributed to reduce woolly apple aphid infestations. Reinfestations from root colonies are not relevant in Mediterranean areas. The use of ecological infrastructures may increase the biological control of pests, providing a more favorable environment and additional food and shelters for natural enemies. Anacyclus clavatus Desf., Dorycnium pentaphyllium Scop., Erucastrum nasturtiifolium Poiret, Euphorbia serrata L., Hedysarum confertum Desf., Papaver rhoeas L., Trifolium pratense L. in spring, and Atriplex sp., Dittrichia viscosa L., Medicago sativa L., Moricandia arvensis L., Salsola kali L., Sorghum halepense (L.) Pers., Suaeda spicata Willd. and Verbena sp. in fall were observed as native flora useful to provide shelter and food for spiders. Viburnum tinus L., Euonymous japonicus L. fil. and Pistacia lentiscus L. showed promising results in order to enhance abundance and richness of natural enemies