Stuck in the Caterpillars’ Web: A Half-Century of Biocontrol Research and Application on Gregarious Lepidopteran Pests in Europe

Unraveling multiple layers of collective behavior outside the well-known isopteran and hymenopteran societies was a tall order for scientific community, especially in case gregarious juveniles Lepidoptera. Often protected with solid silk shelter, devoid reproductive division labor or conventional forms parental care, caterpillar aggregations have rarely been considered terms economic importance. Of over 60 European communal species, 24 can be associated voracious feeding habits, thus irruptive pestilential, depending on extent severity. This review retrieves 59 cases biocontrol against Hyphantria cunea (Drury), Euproctis chrysorrhoea (L.), Malacosoma neustria Thaumetopoea pityocampa (Denis Schiffermüller), T. processionea (L.) Yponomeuta malinellus (Zeller) classifies them predefined research application subcategories. The percentage-wise distribution utilized explored agents projected at 35.59% favor parasitoids predators. Falling between fundamental applicative disciplines, biocontrol, its early days, built global reputation being underreported. To provide guidance future regarding group, functional trait-based concept used this study is complemented preliminary outcome assessment.