The contribution of floral resources and honeydew to the performance of predatory hoverflies (Diptera: Syrphidae).

摘要: Abstract Hoverflies with predatory larval stages are important natural enemies of aphids and other pests in field crops. Many adult hoverflies actively visiting feeding on flowers, indicating that pollen nectar resources for them. The scarcity suitable flowers intensified agriculture is therefore likely to limit their effectiveness as biological control agents. In this study Episyrphus balteatus we quantify how permanent temporal availability affects survival reproduction, assess what extent aphid honeydew can substitute floral resources. Our results show cabbage ( Brevicoryne brassicae ) strongly enhances hoverfly the absence Less be expected, when available, supplementation still generates additional survival. A sucrose solution (as mimic nectar) increases longevity relative water only, similar honeydew. Flowers buckwheat Fagopyrum esculentum ), permanently providing both pollen, further also supports egg production. Feeding during a 6 days pre-ovipositional period allows females produce eggs week thereafter, survive another 2 weeks, they store benefit from these nutritional substantial time. This suggests only occasionally need commute between patches oviposition (e.g., crop) at border field). Honeydew, locally sufficiently high levels, may used by restore energy demands, thereby postponing search Cage experiments present suppress growth colonies Brussels sprouts.