Performance of Goliath Cockroach Gel against German Cockroach (blattodea: Blattellidae) and a Mixed Population of American Cockroach and Australian Cockroach (blattodea: Blattidae) in the Field

Field studies were conducted to compare the performance of Goliath® Cockroach Gel (fipronil) and a spray treatment of Cislin Residual Insecticide (deltamethrin). These were carried out in Sydney, NSW, Australia against Blattella germanica (L), and Townsville, Queensland, against a mixed population of Periplaneta americana (L.) and Periplaneta australasiae (L). In both studies fipronil (0.05% AI) was applied at two rates. For the German cockroach study the application rate was 1 spot (0.03 g) per m and 3 spots (each 0.03 g) per m. For the American cockroach study the application rate was 1 and 3 spots (each 0.06 g) per m2. The deltamethrin (10 g/l) was applied as a crack and crevice and surface spray treatment. (0.03% AI as a prepared spray). In Sydney there were 10 domestic properties with medium to heavy infestations in each treatment. The duration of the study was 12 weeks and post treatment assessments were made at 3 days, 1 week, 4, 8 and 12 weeks. In Townsville, there were 5 domestic properties in each of the gel treatments and 10 treatments properties treated with deltamethrin treatments. The duration of the study was also 12 weeks. Post treatment assessments were made at 2 and 6 weeks and 12 weeks. Both rates of fipronil gave a similar performance to deltamethrin at the early assessments and were superior at the 4, 8 and 12 weeks. At 12 weeks, the high rate of fipronil achieved a 99% percentage reduction, the low rate a 94.8%, and the deltamethrin spray treatment achieved a percentage reduction of 79.6%. Against a mixed population of American and Australian cockroaches all three treatments achieved control, with both rates of fipronil giving similar results to the deltamethrin spray treatment. At 12 weeks, fipronil at the high rate (3 x 0.06 g/m) achieved 97.8% reduction, deltamethrin spray achieved 88.4% reduction and fipronil at the low rate (1 x 0.06 g/m) achieved 76.1%.