Karamaouna, F. 1999 . Biology of the parasitoids Leptomastix epona and Pseudaphycus flavidulus; behavioural interactions with the host mealybug Pseudococcus viburni. Ph.D. thesis, London, Wye College. Wye, London

Notes: (Ph.D. thesis, London, Wye College.) Some aspects of the biology and behaviour of the solitary parasitoid Leptomastix epona (Walker) and the gregarious Pseudophycus flavidulus (Brèthes) were studied with a view to obtain some insights into their potential commercial application for the control of Pseudococcus viburni (Signoret), a world-wide distributed mealybug and important pest in protected cultivation and field crops. The rate of development of both parasitoids in large or small hosts increased with a linear trend as the temperature increased within the range of 21 - 31 °C and development was faster in larger compared to smaller hosts of the mealybug at all temperatures. Temperature requirements (lower threshold and thermal constant) of the parasitoids seem to be similar with the host's. Both parasitoid species achieve a greater intrinsic rate of increase (rm) and a shorter doubling time in large mealybugs compared with small ones. However, L. epona produces more female offspring per generation (Ro) than P. flavidulus in large hosts and P. flavidulus is able to double its population faster than L. epona, especially in small hosts. Encapsulation does occur in both parasitoid species in larger and small mealybugs at 26°C. The ability for host discrimination was studied within each species (conspecific) at 0 - 3, 24, 48, 72 or 96 hours intervals after the first parasitization of the host or between the two parasitoid species (interspecific). Conspecific superparasitism by L. epona occurs at all time intervals after the first oviposition but may have a pay-off for the superparasitizing female within 0 - 25 hours. However, conspecific discrimination is possible by P. flavidulus 0 - 3 and 72 hours after the first oviposition and in the early hours may prevent overcrowding of the offspring. L. epona is a superior competitor of P. flavidulus in multiparasitism.