Life History and Habits

Adult scorpionflies are most frequently encountered in cool, shaded locations, especially among low vegetation, though a few species occur in semidesert habitats. They can fly actively when disturbed, though they normally rest on grass, under leaves, etc. Adult Panorpidae feed mostly on dead soft-bodied arthropods (including insects caught in spiders' webs); they also eat nectar, pollen, and fruit juices. Bittacidae, by contrast, are insect predators, catching their prey either in flight or by hanging under vegetation till it comes within range. In members of both of these families much of the food of females is provided in the form of a nuptial gift by a male during courtship (see Chapter 19, Section 4.2). The food item may be an arthropod recently obtained by the male or a mass of saliva secreted from the male's greatly enlarged salivary glands. Adult Boreidae feed on mosses, and members of other families may be herbivorous, saprophagous, or carrion feeders. To 241

attract females, male panorpids and bittacids secrete pheromones from glands on the pos-

r , • , , • i 11 i "i • \ thepanorpoid terior abdominal segments. Visual signals (wing movements and abdominal vibrations) oRDERS

are also important in close-range courtship interactions in these and other (non-pheromone-

producing) mecopteran families. Eggs ofbittacids are dropped randomly; those of panorpids and choristids are laid in batches in moist depressions in the ground. Boreidae deposit eggs singly or in small batches in soil adjacent to moss rhizoids. The egg stage may last from as little as a week up to several months in species where there is an egg diapause. Larvae are saprophagous, carnivorous, or moss-feeders and pass through four instars before entering a quiescent prepupal phase, usually in an earthen cell. The length of the prepupal phase is varied and may include a diapause. The pupal stadium usually lasts 14-50 days. Most species are univoltine; some are bivoltine; and boreids take 2 years to complete a generation.

Phylogeny and Classification

A rich array of mecopteralike fossils is known from the Lower Permian, and the modern consensus is that this includes a few genuine Mecoptera. By the Upper Permian, and extending through the Jurassic, the order was abundant and diverse. Some Upper Permian scorpionflies from deposits in Australia and Siberia are assignable to the extant family Nan-nochoristidae, while representatives of some other modern families appear in the Lower Jurassic. Recent Mecoptera are arranged by Willmann (1987) in two suborders, containing nine families whose possible evolutionary relationships are shown in Figure 9.1.

FIGURE 9.1. Proposed phylogeny of the extant Mecoptera. [After R. Willmann, 1987, The phylogenetic system of the Mecoptera, Syst. Entomol. 12:519-524. By permission of Blackwell Scientific Publications Ltd.]
Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

Get My Free Ebook

Post a comment