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S u m m u r y Experimental observations a r e recorded on the bionomics of Damaliniu ovis on the sheep and in tlitro.The optimal conditions for in-vitro rearing of D. ovis a r e 36.50C. and 70-90 per cent, relative humidity when a mixture of skin scurf and baker's yeast is used as food. Under these conditions the life cycle closely approximates the estimated life cycle on the sheep. The incubation period is 9-10 days; the three nymphal instars a r e completed in 7, 5, and 9 days respectively; the preoviposition period is approximately 3 days, making a cycle of 34 days from egg to egg. The lice and their eggs a r e very susceptible to t h a n g e s in temperature.The areas of heaviest infestation are along the mid-dorsal line and down . the sides of the sheep. Individual sheep differ considerably in their susceptibility to artificial and to natural infestations. Sheep in poor condition tend to have the heaviest infestations. which a r e 'etained throughout the year. There is a pronounced seasonal fluctuation in populations of D. ovis, the heaviest infestation occurring in the period from J u n e t o September.

This chapter focuses on the various transgenic approaches in the control of dipteran livestock pests and lepidopteran crop pests based on the sterile insect technique.

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In 1985 the Department of the Environment/Welsh Office commissioned the ’South Wales Desk Study - Mining Subsidence’. This project was to develop a method for preparing Development Advice Maps giving advice to planners and developers on abandoned shallow mining. The pilot area for this study was centred in Ebbw Vale and supplemented by a detailed review of mining subsidence throughout the whole of South Wales. Subsequent to this study a follow on project was undertaken in 1991 in the Borough of Islwyn. The purpose of the study was to confirm the methodology developed during the first study and produce Development Advice Maps which could be introduced into the planning process at Islwyn Borough Council. Maps were introduced into the planning system with planning guidelines and were monitored for 15 months. The monitoring period has indicated that the Development Advice Maps, drafted in accordance with the procedure developed from the South Wales Mining Desk Study, are generally reliable.This paper discusses the method of preparation of Development Advice Maps in South Wales and proposes a strategy of risk management with which to appraise potential mining subsidence.