Biological response of German cockroaches fed diets containing allopurinol

The acceptability of dietary allopurinol to German cockroaches, Blattella germanica (L.), was assessed. In diet choice tests between rat chow with or without 0.1% w/w allopurinol there were no significant differences in nymphal development, feeding duration, visits or consumption. The LT50 of cockroaches fed a choice of diets was 3 weeks greater (7.88) than those fed non-choice a 0.1% allopurinol diet. Female cockroaches provided a choice of diets aborted a significantly greater percentage of their oothecae (98.6%) than those fed the untreated diet (1.7%). Choice arena tests of 2% allopurinol in rat chow significantly reduced cockroach populations compared with untreated controls. After 6 weeks, populations were reduced by approximately 50%, and 97% after 14 weeks. These results indicate that allopurinol is acceptable to B. germanica as a dietary supplement which could be used in baits for cockroach control.