LONG-TERM MANAGEMENT OF A POPULATION OF AUSTRALIAN COCKROACHES (PERIPLANETA AUSTRALASIAE) IN A TROPICAL PLANT HOUSE IN THE UNITED KINGDOM USING THE JUVENILE HARMONE ANALOGUE (S)-HYDROPRENE

Abstract:
The long-term management of a population of Australian cockroaches, Periplaneta australasiae, causing serious damage to valuable plant species in a United Kingdom tropical plant house, was achieved using a juvenile hormone analogue. (S)-hydroprene was applied as a ULV cold mist every three or four months for three and a half years and the cockroach population was reduced by 81%. Deformity in adults, indicative of juvenile hormone effect, increased from 1.0 % to 52 % by the end of the trial and exceeded 80% on several occasions during the trial. More females than males showed deformity and female deformity was not always indicative of sterility. The hydroprene treatment had a strong impact on age structure of the cockroach population, with the proportion of small nymphs reduced from 32% of the total nymph catch prior to treatment to 1% at the end of the trial. Cockroach damage to the plant collection became insignificant within approximately one year of the start of treatment and the hydroprene treatment had no negative impact on the effectiveness of the biological control programmes employed in the plant house to manage other plant pest species.