Diversity of feeding strategies in adult Mecoptera

Abstract

In this article I review the diet and feeding behaviour of adult scorpionflies in the nine extant families. Members of the Apteropanorpidae and Panorpidae are saprophagous on dead and decaying invertebrates, and the only known eomeropid Notiothauma reedi is also saprophagous on animal matter. Bittacids are predacious on a variety of invertebrates, predominantly insects. Both bittacids and panorpids supplement their diet with a variety of food sources such as nectar, and members of the Nannochoristidae most likely utilise nectar as the primary food source. Adult Panorpodidae are phytophagous, and all species of Boreidae are also regarded as phytophagous, although feeding on invertebrate carrion has also been reported for this family. The diets of the Meropeidae and Choristidae in natural habitats are unknown, although choristids may be saprophagous based on laboratory investigations. Nuptial feeding is a feature of the Bittacidae and Panorpidae, whereby the male provides the female with a food item as a prelude to or during courtship, and the female feeds on it during copulation. Relating head morphology to known diets indicates some patterns. The rostrum is more elongate in those taxa known to feed predominantly on animal matter, and shorter and wider in plant-feeding taxa such as the Panorpodidae. An exception is the predominantly phytophagous Boreidae, in which most species have a long rostrum.