(1st Place) The affects of proper application on cockroach gel bait performance

German Cockroaches (Blattella germanica) remain one of the most challenging indoor pest species to manage. This is particularly concerning, given their ability to transmit pathogenic microbes and produce metabolites that trigger allergies and asthma. Management is often complicated due to the limiting number of insecticides labeled for use indoors and the ubiquitous resistance to pyrethroids. While cockroaches remain challenging to manage when using traditional spray-based residual insecticides, insecticidal gel baits remain an extremely effective management strategy. Cockroach gel baits are composed of a gelatinous matrix which attracts and induces feeding, and an active ingredient which causes mortality after consumption. Gel baits carry many advantages over traditional pyrethroid-based residual sprays, including their low mammalian toxicity, but it is still unclear how long gel baits remain effective following application. To investigate this, multiple gel baits were aged for up to 6 months (24-hours, 1 month, 3 months, 6 months) at multiple humidities (15%, 40%, 80%) and evaluated in two-choice assays against multiple populations of German cockroaches. Our results indicated that gel baits remained palatable and effective for up to 6 months, with consumption reducing gradually the older the bait is. The susceptible population consumed less bait than the field populations, but achieved full mortality sooner. Consumption of baits also reduced with lower humidity levels, however, mortality remained high. These results indicate that gel baits can be effectively used for extended periods of time, reducing the need to re-apply baits unless consumed.