A new and easy method of feeding dragonflies in captivity

In summer, large populations of dragonflies, such as Orthetrum sabina, Crocothemis servilla, C. erythraea, Pantala flavescens, contaminata Brachythemis and Diplacodes lefebvrei have been reported actively feeding on insect pests of cotton, rice, maize, Egyptian clover and tomatoes in Pakistan (cf. e.g. M.A. ALL 1983. Studies on population and feeding habits of dragonflies on insect pests of cotton. M. Sc, thesis. U niv. Agric., Faisalabad; — M.A. NAJAM, 1984, Population and feeding habits of dragonflies on insect pests of rice. M. Sc. thesis. Univ. Agric., Faisalabad). Due to their active feeding and large populations in cropped fields, it was thought necessary to evaluate them as biological control agents. For this purpose, the extent of feeding of dragonflies on insect pests of various crops had to be determined under seminatural conditions or in the laboratory. Efforts were made to feed them in both situations but they did not feed due to their captivity. In view of this, it was felt necessary to find some method of their feeding in captivity. Many ways and alternatives were tried for feeding the dragonflies in cages. For example, a single individual, a pair, or many individuals of a species were released separately in laboratory cages (60x46x64 cm) of muslin cloth and field cages (178x118x180 cm) of wire-gauze, and different insect pests of cotton (jassid, aphid, whitefly and thrips) were provided as food on potted cotton plants. In some experiments, water containers were also placed in the cages. In certain cases, the dragonflies were familiarized with the captive conditions continuously for 2-3 days, but in no case did they show any activity and interest in their prey.