Incorporation of pyriproxyfen in a German cockroach (Dictyoptera: Blattellidae) management program

Pyriproxyfen (Nylar), a juvenile hormone analog (JHA), and acephate were used in a German cockroach, Blattella germanica (L.), management program. Monthly applications of acephate for 6 mo reduced nightly trap catches from 24.68-25.25 to 4.46-5.31 at 2 mo, and trap catches averaged 1.49-8.04 from 2-6 mo. After acephate applications were discontinued, trap catches increased from 6.86 at 7 mo to 28.08 at 12 mo. Pyriproxyfen was applied at months 0, 3, and 6. Monthly pyriproxyfen treatments were applied from 7 to 11 mo because, at month 6, only 21.00-27.30% of adults had wing twisting (one effect of pyriproxyfen exposure). These monthly applications resulted in 74.55-78.53% of adults with twisted wings in the German cockroach population at 12 mo. Trap catches in apartments treated with pyriproxyfen aerosol were significantly lower at 7, 8, 10, and 12 mo after the initial treatment than those that did not receive JHA treatment. At 7-12 mo, the pyriproxyfen residual spray did not significantly reduce German cockroach populations, but trap catches were consistently lower. German cockroach populations were sampled for 1 yr (from 13 to 24 mo) after pyriproxyfen applications were discontinued. Compared with those in apartments treated with acephate, trap catches in apartments treated with pyriproxyfen were significantly reduced from 12 to 18 mo after the initial treatment. At 18-24 mo, trap catches in apartments treated with pyriproxyfen aerosol were consistently lower than those treated with acephate, but these differences were not significant.