7 The Plecopteroid, Blattoid, and Orthopteroid Orders 1. Introduction This chapter deals with the following 10 orders: Plecoptera, Embioptera, Dictyoptera, Isoptera, Grylloblattodea, Dermaptera, Phasmida, Orthoptera, Zoraptera, and the recently established Mantophasmatodea. Members of these orders can be distinguished from other exopterygotes. | 7 The Plecopteroid Blattoid and Orthopteroid Orders 1. Introduction This chapter deals with the following 10 orders Plecoptera Embioptera Dictyoptera Isoptera Grylloblattodea Dermaptera Phasmida Orthoptera Zoraptera and the recently established Mantophasmatodea. Members of these orders can be distinguished from other exopterygotes the hemipteroid orders Chapter 8 by the following features generalized biting mouthparts wing venation usually well developed with numerous crossveins though less netlike than that of Paleoptera cerci present terminalia of male may be asymmetrical and reduced many Malpighian tubules and generalized nervous system with several discrete abdominal ganglia. However as discussed in Chapter 2 the existence of these common features should not be taken as confirmation that these orders constitute a monophyletic group. 2. Plecoptera Synonyms Perlaria Perlida Common name stoneflies Moderate-sized to fairly large soft-bodied insects head with long setaceous antennae weak mandibulate mouthparts well-developed compound eyes and two or three ocelli thorax almost always with two pairs of membranous wings sometimes reduced hind pair in most species with a large anal lobe venation frequently specialized legs identical and with a three-segmented tarsus abdomen of most species terminated by long multiannulate cerci females lacking a true ovipositor males without gonostyles and phallic organs on abdominal segment 9. Larvae aquatic generally resembling adults except for presence of a varied number of tracheal gills. More than 2000 species of this very ancient order have been described including just over 600 from North America about 30 from Britain and 200 from Australia. Though the order has representatives on all continents except Antarctica most families have a rather restricted distribution. 147 148 Structure CHAPTER 7 Adult. The plecopteran head is prognathous and bears a pair of elongate multian-nulate antennae well-developed compound eyes three rarely
