Satyrization

A "satyr" is any male that successfully mates and reduces the reproductive success of a female of a different species or population. We sought to model the interaction of such potentially intermating species that are initially isolated in space but come to occupy overlapping niches. [...] Species extinction may result from reproductive competition (satyrization) alone.

Collectively, these data are supportive of the Ae[des] albopictus satyrization hypothesis; but, much work must be done for a definitive answer to the very important question of whether sex peptide asymmetries are highly influential in satyrizations.

Although there is some evidence to support the occurrence of this mechanism, also known as satyrization, in natural populations of ticks and tsetse flies (Ribeiro 1988), its importance as a population reduction mechanism among mosquitoes remains unsubstantiated.

Sterility caused by cross-mating between Aedes albopictus and Aedes aegypti (a process known as satyrisation) may have initially contributed to the observed competitive reduction of Aedes aegypti by invasive Aedes albopictus in many areas of Florida.

Additional experiments demonstrating transfer of labelled semen from A[edes] albopictus males to A. aegypti females and low production of viable eggs of females housed with conspecific males, following exposure to A. albopictus males, confirm higher incidences of satyrization than expected, based on heterospecific insemination rates. We conclude that frequencies of satyrization based on detection of interspecific sperm in spermathecae may underestimate the impact of this form of reproductive interference.

Quantifying satyrisation by assessing interspecific sperm in spermathecae underestimates the capacity of male A[edes] albopictus to reduce the fitness of virgin female A. aegypti.

US researchers have added another piece to the puzzle that is satyrisation, one of the most complex aspects of the mosquito world. It only occurs in mosquitoes, in fact, but is of increasing interest as mosquito-borne diseases emerge as problems worldwide. In Greek mythology a satyr is a lusty fertile woodland deity, but satyrisation is the opposite. It occurs when the male of one species mates with the female of another, but instead of producing a hybrid, the result is no offspring at all. In fact, the unfortunate female is rendered sterile. Satyrisation is also the mechanism by which introduced mosquito species displace native mosquito species, particularly island endemics.

In several areas where Aedes aegypti (L.) (Diptera: Culicidae) and Aedes albopictus (Skuse) (Diptera: Culicidae) have come in contact following successful invasions, Ae. aegypti have been rapidly displaced by Ae. albopictus. Recent work has confirmed that mating interference, in the form of satyrization, is likely a driving factor in these competitive displacements. However, in sites of sympatry, Ae. aegypti females evolve resistance to satyrization, and in the laboratory, satyrization-susceptible Ae. aegypti can evolve resistance within a few generations of cage exposure to Ae. albopictus.