Bait Performance on Brown Banded Cockroaches

During the development of cockroach baits, they are typically tested on German cockroaches and American cockroaches. This is perfectly reasonable as they are the key cockroach pests. However, how do they perform on brown banded cockroaches?

Cockroach baits are a core product for use in cockroach management, but how do commercial cockroach baits perform against brown banded cockroaches (Supella longipalpa)? The question was posed as there is a distinct lack of data on bait performance against brown banded cockroaches and indeed often cockroach baits are not tested against them during the product development process.

Brown banded cockroaches may not be as prevalent as the infamous German cockroach, but they are nevertheless a significant pest in domestic and commercial environments. It is clear they have a different biology to German cockroaches from the locations they typically infest – they are a more common pest in warmer climates (greater than 25ºC is preferred), but with lower moisture requirements than German cockroaches, they can thrive in a wider range of locations within the home. It is perhaps dangerous to assume that cockroach baits perform as well on brown banded cockroaches as they do on German cockroaches

A research team lead by Prof. Chow-Yang Lee at the University of Riverside, California has recently evaluated a range of US commercial cockroach baits against the brown-banded cockroach, Supella longipalpa. Laboratory studies using arena and choice box bioassays, the researchers demonstrated that most baits tested exhibited slower kill on brown banded cockroaches than on German cockroaches. Whereas most products delivered 100% mortality (albeit taking longer), two products – Maxforce FC Magnum and Vendetta Plus – were well below 100% mortality even at 14 days post treatment, and the authors believe that these products would be unlikely to deliver satisfactory performance in the field.

Whilst differences in the performance of the active ingredient cannot be excluded, the researchers belief that the different nutritional requirements and food preferences are likely to be the more significant factor in the reduced performance of gel baits. Research has shown that brown banded cockroaches prefer a diet higher in carbohydrates – a 1:5 protein to carbohydrate ratio, with German cockroaches preferring a 1:2 to 1:3 protein to carbohydrate ratio. In addition, with brown banded cockroaches having adapted to drier environments, they also have increased preference for drier food sources.

The researchers flagged two implications for pest managers. Firstly, pest managers should not assume that their “go to” cockroach bait is necessarily the best cockroach bait for brown banded cockroaches (and so may need to try different options) and secondly, that with for brown banded cockroaches, hygiene actions (removing alternative food sources) becomes more important to gain satisfactory control when using baits.