In tree fruit pest management, most monitoring and mating disruption technologies are based on pheromones that female insects release to attract males. For example, sex pheromones are used to lure male codling moths to traps or in order to mimic females and confuse the males to reduce their chances of finding females to mate with.
But in some insects, such as the brown marmorated stinkbug, it works the other way around. Females are attracted to a pheromone released by the male.
“That gives us the question: Why would a female risk moving around responding to chemical cues and burning up energy to find a male?” says Dr. Peter Landolt, research leader at the U.S. Department of Agriculture laboratory in Yakima, Washington. “You would expect that she would just park it and let males search for her.”
There are reasons for this, which Landolt is proposing to explore in more detail in the hope of developing more powerful monitoring tools and, ultimately, attract-and-kill strategies for the brown marmorated stinkbug. Male stinkbugs transfer nutrients to females during mating, so he believes that females respond to the male pheromones to find food, good egg-laying sites, and male-produced nutrients, as well as mating opportunities.
The brown marmorated stinkbug is somewhat attracted to the pheromone of a different species, the brown-winged green stinkbug, which is available commercially as a trap lure. However, Landolt said its performance for monitoring has been disappointing.
Landolt plans to research the sex attraction responses of female brown marmorated stinkbugs and hopes to identify the pheromones and kairomones (chemicals given off by the plant) involved. He’ll look for associations between the male pheromone and plant kairomones and identify those that enhance the attraction.
All of this will help in the development of a powerful trap that can be used to improve detection of the pest and timing of control measures and to determine the risk to crops. Eventually, it might lead to an attract-and-kill approach, he said.