scorpion fly

A common North American species, also found in Europe, is also called a scorpion fly.

They reach this conclusion by analogy with the mating behavior of the genus Panorpa, or scorpion fly.

Transvestism Male Scorpion flies steal the nuptial gift of other males.

This species infects the scorpion fly (Panorpa communis).

In fruit flies, katydids, and scorpion flies, nuptial gifts contain substances that reduce a female's receptivity to additional matings.

They also note that sexual coercion of females by males occurs in many other animals, including the scorpion fly, an insect Dr. Thornhill has studied extensively.

Direct benefits include nutritional resources to be used by females, donation of foods to mates, males offering prey to the female, seen in scorpion flies and dance flies.

In their own work, they have shown that female scorpion flies can detect a male with symmetrical wings either visually or simply by sniffing the chemical signal - the pheromone - he emits.

With his colleagues Karl Grammer and Steven Gangestad, Dr. Thornhill is trying to apply the evolutionary principles they have developed in their work on scorpion flies and other species to people.

These biologists have gathered evidence from studies of species as diverse as zebra finches, scorpion flies, elk and human beings that creatures appraise the overall worthiness of a potential mate by looking for at least one classic benchmark of beauty: symmetry.

Although female Panorpa flee from males without a nuptial offering (escaping about 85 percent of the time) and resist forcible copulation - and lay few eggs when they are raped - such coercive mating is "in no way an abnormal or 'aberrant' behavior" for male scorpion flies.