A pathogenic fungus uses volatiles to entice male flies into fatal matings with infected female cadavers

To ensure dispersal, many parasites and pathogens behaviourally manipulate infected hosts. Other pathogens and certain insect-pollinated flowers use sexual mimicry and release deceptive mating signals. However, it is unusual for pathogens to rely on both behavioural host manipulation and sexual mimicry. Here, we show that the host-specific and behaviourally manipulating pathogenic fungus, Entomophthora muscae, generates a chemical blend of volatile sesquiterpenes and alters the level of natural host cuticular hydrocarbons in dead infected female house fly (Musca domestica) cadavers. Healthy male house flies respond to the fungal compounds and are enticed into mating with dead female cadavers. This is advantageous for the fungus as close proximity between host individuals leads to an increased probability of infection. The fungus-emitted volatiles thus represent the evolution of an extended phenotypic trait that exploit male flies' willingness to mate and benefit the fungus by altering the behavioural phenotype of uninfected healthy male host flies.

A new female-like morph of juvenile male Levant Sparrowhawk (Accipiter brevipes) – sexual mimicry to avoid intra-specific predation?

In migrant Levant Sparrowhawk (Accipiter brevipes) at Eilat, Israel, we noted that juvenile males had two different morphs – the one described to date in literature; and a second, previously undescribed morph, with femalelike barring on the chest and flanks interspersed with tear-shaped elongated spots, giving an overall female-like appearance. Here we forward the hypothesis that explain the evolutionary consequences for the female-like plumage of juvenile males as that of intra-specific sex mimicry developed to avoid intra-specific predation by the larger females.