New research has found that Australian female mantis can fake fertility to lure mates and then eat them.
Katherine Barry of Macquarie University in Sydney conducted a study on false garden mantis, or Pseudomantis albofimbriata, which is one of the most common species of mantis in Australia.
For the purpose of the research, Barry collected some false garden mantis from various places in Sydney. Barry separated the males and females and split the females in four groups and fed them different diets, ranging in quality from "very poor," "poor," "medium" and "good." Males were then given a chance to mate, but they could find a suitable mate only via the scent released by the females.
Barry thought that the males would be attracted to the group of females who were best fed. As the least fed females were lean, they were less fertile. The researcher thought that this group would attract males the least.
However, Barry found that the least fed mantis attracted more mates. The female mantis produced and released pheromones to sexually lure their mates then ate them. The females used their body resources to produce pheromones. Eating a male can improve body condition by about 33 percent and fecundity by about 40 percent.
"The Femme Fatale hypothesis suggests that female mantids may be selected to exploit conspecific males as prey if they benefit nutritionally from cannibalism," reported the study.
Previous studies of these mantis suggest that females resort to cannibalism only when they are hungry. They mate with their partners if they are in their best body condition. Prior studies also reveal that about 90 percent of female mantis used cannibalism when they were in their worst body conditions. Only 50 percent of such encounters result in the males mating with the female mantis.
The latest study suggests that when female mantis are starving, they will send out deceptive signals that they have eggs and are ready to mate. Even though the study was conducted on false garden mantis, Barry suggests that other species also show the same characteristics.
The study was published in the Royal Society's journal Proceedings B.