Pycnoscelus indicus, eggplant

March 2009. A farmer on Guam is having a problem with Pycnoscelus indicus, the burrowing cockroach (formerly known as the Surinam cockroach). The pest is girdling his eggplants. He has tried killing them with malathion but this did not work. It is possible that the population is resistant to organophosphates. Does anyone have any control recommendations?

In response, a member mentioned that with other species of cockroaches, low concentrations of fipronil mixed with peanut butter were extremely effective in controlling OP resistant cockroaches in compost bins. This chemical (fipronil) is also registered for cockroach control in domestic situations – there is a lot of info on the Web if you Google ‘fipronil and cockroach control’. It may be commercially available as an ant bait which might be suitable for the eggplant situation. It was suggested that the manufacturers of fipronil should be contacted for more information.

A similar soil dwelling cockroach occurs in north Queensland which is very destructive on sweet potato tubers and can be encouraged to congregate under wet hessian bags, old carpet or similar material on the soil surface. If the burrowing cockroach behaves similarly, a baiting or targeted insecticide spray could then be used.

Of course, there are issues of registration, safety to non-target organisms and the environment to consider.