Predatory beetles can detect ant egg-laying sites
Research has found that predatory beetles are able to detect the unique alarm signals released by ants that are under attack by parasitic flies and use them to guide their search for safe egg-laying sites.
In an article published in the journal Ecology and Evolution, researchers from the University of Michigan show that pregnant beetles intercept ants’ alarm pheromones, which let them know that it is safe to deposit their eggs.
Azteca instabilis ants patrol coffee bushes and will emit a chemical signal when under attack by phroid flies. The findings, which may have practical implications for pest management on coffee plantations, are the first documentation of a complex cascade of interactions mediated by ant pheromones, according to the authors.
Phorids are a family of small, hump-backed flies resembling fruit flies. The parasitic phorid flies that attack Azteca ants lay their eggs on the ant's body. Fly larvae develop inside the ant's head, which falls off when the adult fly emerges. Phorids need to see movement to detect individual ants; therefore moving ants, rather than stationary ones, are their targets.
Needless to say, the ants do their best to avoid becoming phorid-fly victims. When the flies attack, the ants release a phorid-alert pheromone to warn other workers in the vicinity. In response, nearby ants enter a motionless, catatonic state and overall colony activity declines by at least 50 percent. This effect can last up to 2 hours.
U-M ecologist Ivette Perfecto said: "This research shows that there are very complex ecological interactions that are involved in population regulation, and when the population of concern is a potential pest species, understanding those interactions is key to the long-term sustainability of pest control strategies.”