Unraveling the Roles of Solitary and Social Web-Making Spiders in Perennial Ecosystems: Influence on Pests and Beneficials

Abstract

The results show that the orb-weaver spiders, Neoscona theisi and Cyrtophora citricola, occurred in both guava and citrus agroecosystems, and their prey primarily comprised a wide diversity of insect pests. In contrast, the sheet web-constructing social spider, Stegodyphus sarasinorum, occurred only in the citrus agroecosystem and preyed mainly on the beneficial insects, particularly the pollinators, including the Asian honeybee, Apis cerana, along with the predaceous ladybird beetle, Coccinella septempunctata, damselfly, Agriocnemis femina, and the ant, Camponotus compressus. Field observations revealed that the beneficial insects caught and captured by the social spiders comprised mainly the flower-visiting insects of ornamental and weed plants growing in the vicinity of the fruit trees. N. theisi preyed predominantly on pests of paddy (Nephotettix nigropictus, Oxya nitidula), wheat (Rhopalosiphum padi), citrus (Papilio demoleus) and guava (Bactrocera dorsalis) and to a lesser extent on damselflies, houseflies, and ants. C. citricola with smaller orb webs preyed upon N. nigropictus, R. padi, M. domestica, C. septempunctata, and C. compressus. Except the guava pest, B. dorsalis, the pests of paddy and wheat from the infested crops cultivated in the nearby ~ 500-m distant located farm were attracted by the streetlights and were preyed upon by the arboreal spiders. The results highlight the significant role of orb web spiders in the suppression of insect pests of crops and also provide direct evidence of the negative role of social spiders as predators of the Asian honeybee, A. cerana, and other beneficial insects.