OVIPOSITIONAL BEHAVIOR OF MACROLOPHUS-CALIGINOSUS (HETEROPTERA, MIRIDAE) ON TOBACCO-LEAVES

The ovipositional behaviour of the mirid predator Macrolophus caligino sus Wagner, a potential biological control agent of glasshouse pests, was studied in detail using a modified video camera technique. In the laboratory, females laid their eggs in the leaves of tobacco plants. T hey remained generally motionless on the main veins of the leaves, rai sed their body, folded the rostrum towards the thorax and extended the ir ovipositor when selecting a site in which to oviposit. The oviposit or was inserted into the plant tissue by a downward and forward thrust of the body and contractions of the abdominal muscles. After a period of immobility, the ovipositor was retracted and the insect's body and organs returned to their initial positions. This behaviour was preced ed and followed by extensive rostral exploration of the oviposition si te. In most females the same area was explored before and after egg-la ying and the ovipositor was inserted approximately in the middle of th e selected area. The sequence and pattern of ovipositional behaviour v aried between females.