Resource dependence of male mating tactics in the scorpionfly, Panorpa vulgaris (Mecoptera, Panorpidae)

Males of Panorpa vulgaris used two resource-dependent mating tactics: (1) offering dead arthropods and (2) offering salivary masses during copulations. Males had to be well-fed in order to produce salivary masses. There was no forced copulation as has been described in other Panorpa species. Because of competition for dead arthropods, copulations at baits were more frequently disturbed and were shorter than those in which the male offered a salivary mass. In the field the ability of males to use the non-territorial salivary mass tactic was restricted by food limitations. Only large males of the first of the two generations of the year were capable of employing the salivary mass tactic. They achieved long copulations before females began ovipositing, and so had the best chance of being successful in sperm competition.