Entomology 3rd edition - C.Gillott - Chapter 10

10 The Remaining Endopterygote Orders 1. Introduction The six remaining endopterygote orders dealt with in this chapter are quite distinct from those that form the panorpoid complex. Of the six, the order Hymenoptera appears most isolated phylogenetically and is sometimes considered in a distinct superorder, the Hy-menopteroidea, perhaps the sister group to the panorpoid complex. Except for the Strep-siptera, whose affinities remain unclear, the remaining orders are then tentatively united in a neuroptero-coleopteroid group (see Chapter 2, Section 3.2). Some authors include the Mecoptera and Raphidioptera as suborders within the order Neuroptera. 2. Megaloptera Synonyms: Corydalida, Sialoidea (in order Neuroptera sensu lato) Common names: alderflies and dobsonflies Large, soft-bodied insects; head with chewing mouthparts, elongate antennae, and large com-pound eyes, three ocelli present (Sialidae) or absent (Corydalidae); two pairs of identical wings with primitive venation and large number of crossveins, abdomen 10-segmented without cerci. Larvaeaquaticwithchewingmouthpartsandpairedabdominalgills.Pupaedecticousandexarate. Representatives of this small (300 species) order are found especially in temperate regions, though their distribution is discontinuous. Some 43 species have been described from North America, about 25 from Australia, and 3 from Britain. Structure Adult. AdultMegalopteraaregenerallylargeinsects,withmembersofsomespecies having a wingspan of about 17 cm. Their prognathous head carries well-developed compound eyes, long multisegmented antennae, and chewing mouthparts [including enor-mously elongate mandibles in some male Corydalidae (Figure 10.1C)]. Three ocelli are present in Sialidae but absent in Corydalidae. The thoracic segments are well developed and freely movable; the pronotum is broad. All legs are similar. Four membranous wings occur, with all of the major veins and a large number of crossveins present. The wings lack 297 298 CHAPTER 10 FIGURE 10.1. Megaloptera. (A) An alderfly, Sialis mohri (Sialidae); (B) Sialis sp. larva; (C) a male dobsonfly, Corydalus cornutus (Corydalidae); and (D) Corydalus sp. larva. [A, B, from H. H. Ross, 1937, Studies of Nearctic aquatic insects. I. Nearctic alderflies of the genus Sialis (Megaloptera, Sialidae), Bull. Ill. Nat. Hist. Surv. 21(3). By permission of the Illinois Natural History Survey. D, from A. Peterson, 1951, Larvae of Insects, By permission of Mrs. Helen Peterson.] a pterostigma. The wing-coupling apparatus is of the jugofrenate type. The abdomen is 10-segmented and lacks cerci. The structure of the internal organs is poorly known. The alimentary canal has a mediodorsalfoodreservoir;sixoreightMalpighiantubulesarepresent;thenervoussystem is primitive with three thoracic and generally seven abdominal ganglia; females have a varied number of panoistic (Corydalidae) or telotrophic (Sialidae) ovarioles. Larva and Pupa. Larvae are elongate and in some species may reach a length of 8 cm. The prognathous head is well developed and carries chewing mouthparts. The thorax bears three pairs of strong legs, the abdomen seven (Sialidae), or eight (Corydalidae) pairs of gills. Pupae are decticous, exarate, and not enclosed in a cocoon. Life History and Habits Adult Megaloptera are generally found in the vicinity of streams or in other cool, moist habitatswhere,duringtheday,theyrestonvegetation.Theyprobablyfeedverylittleandare generally short-lived. Reproduction appears to be entirely sexual and eggs are attached, in batchesofseveralhundredtoseveralthousand,tostones,vegetation,etc.,usuallynearwater. Larvae are aquatic and predaceous. Development in most species is completed in a season, but in some large forms it may take up to 5 years. Larvae pass through 10–12 instars and when mature leave the water and burrow into soil or moss or under stones where pupation occurs. Before emergence pharate adults wriggle to the surface of the pupation medium. Phylogeny and Classification Fossil Megaloptera are known from as early as the Upper Permian and probably had a common ancestry with the Raphidioptera and/or Neuroptera in the Upper Carboniferous. ThecladisticanalysisofAspo¨cketal.(2001)indicatesthattheMegalopteraandNeuroptera are sister groups. Corydalidae, including larval forms, are known from the Lower Creta-ceous, and representatives of modern genera occur in Eocene Baltic amber. Extant species areplacedinasinglesuperfamilySialoidea,whichincludestwofamilies,SIALIDAE(alder-flies)(Figure10.1A,B)andCORYDALIDAE(dobsonflies)(Figure10.1C,D).Probablyless than 100 species of Sialidae occur, of which perhaps about one half have been described. The family is cosmopolitan. Corydalidae, with about 150 described species, are not found in Europe or North Africa. 299 THE REMAINING ENDOPTERYGOTE ORDERS Literature The biology of Megaloptera is described by Berland and Grasse´ (1951). Kristensen (1991), Aspo¨ck et al. (2001), and Aspo¨ck (2002) discuss the phylogenetic position of the order.KeystoNorthAmericangeneraaregivenbyEvansandNeunzig(1984),toAustralian families by Theischinger (1991), and to British species by Elliott (1996) and Plant (1997). Aspo¨ck, U., 2002, Phylogeny of the Neuropterida (Insecta: Holometabola), Zool. Scripta 31:51–55. Aspo¨ck, U., Plant, J. D., and Nemeschkal, H. L., 2001, Cladistic analysis of Neuroptera and their systematic position within Neuropterida (Insecta: Holometabola: Neuropterida: Neuroptera), Syst. Entomol. 26:73–86. Berland, L., and Grasse´, P.-P., 1951, Super-ordre des Ne´uropte´roides, in: Traite de Zoologie (P.-P. Grasse´, ed.), Vol. X, Fasc.l, Masson, Paris. Elliott,J.M.,1996,BritishfreshwaterMegalopteraandNeuroptera:Akeywithecologicalnotes,F.W.Biol.Assoc. Sci. Publ. 54:1–68. Evans, E. D., and Neunzig, H. H., 1984, Megaloptera and aquatic Neuroptera, in: An Introduction to the Aquatic Insects of North America, 2nd ed. (R. W. Merritt and K. W. Cummins, eds.), Kendall/Hunt, Dubuque, IA. Kristensen, N. P., 1991, Phylogeny of extant hexapods, in: The Insects of Australia, 2nd ed., Vol. I (CSIRO, ed.), Melbourne University Press, Carlton, Victoria. Plant, C. W., 1997, A key to the adults of the British lacewings and their allies (Neuroptera, Megaloptera, Raphid-ioptera, and Mecoptera), Field Stud. 9(1):179–269. Theischinger, G., 1991, Megaloptera, in: The Insects of Australia, 2nd ed., Vol. I (CSIRO, ed.), Melbourne University Press, Carlton, Victoria. 3. Raphidioptera Synonyms: Raphidiodea, Raphidioidea (in order Neuroptera sensu lato) Common name: snakeflies Large insects similar to Megaloptera but distinguished by elongate “neck”; head with chewing mouthparts, bulging compound eyes, and elongate antennae; thorax with two pairs of identical wings; abdomen 10-segmented, cerci absent, females with elongate ovipositor. Larvae terrestrial with chewing mouthparts. Pupae decticous and exarate. Recent members of this order, which comprises about 210 described species, are found only in the Northern Hemisphere, mostly between 35◦ and 50◦ N. About 100 species occur in Europe, mostly in the Mediterranean region but including 4 in Britain. Some 30 species are in central Asia, and 21 in southwestern North America. In the southern part of their range they are found at higher altitudes (up to 3000 m). Structure Adult. Snakeflies resemble Megaloptera but may be distinguished by the elongate “neck” formed from the prothorax and narrow, posterior part of the head. The prognathous 300 CHAPTER 10 head carries a pair of bulging compound eyes, chewing mouthparts, and long, multiseg-mentedantennae.Threeocelliarepresent(Raphidiidae)orabsent(Inocelliidae).Thewings are identical, and have a primitive venation of many crossveins, and a pterostigma. Females have a long hairlike ovipositor. The internal structure is not well known. The crop has a dorsal food reservoir, and there are six Malpighian tubules. The central nervous system includes three thoracic and eight abdominal ganglia. The testes each comprise 12 follicles, the ovaries each about 40 telotrophic ovarioles. Larva and Pupa. Larvae are elongate and have a prognathous head with chewing mouthparts. The thoracic legs are all identical. The abdomen lacks appendages. Pupae are decticous, exarate, and closely resemble adults. Life History and Habits Adult Raphidioptera are diurnal and may be found on flowers, foliage, tree trunks, etc. where they prey on soft-bodied arthropods, especially aphids and caterpillars; they also eat somepollen.Alongcourtshipprecedesmating,afterwhichthefemalelaysseveralhundred eggs, in batches of up to 100, in cracks in the bark of trees, etc. Larvaeoccurunderloosebark,especiallyofconifers,wheretheypreyonotherinsects. Larval development usually takes 2 years or more, and there are 10 to 15 instars. Mature larvae form a cell in which to pupate. Pupae may actively move about until eclosion. Phylogeny and Classification The Raphidioptera probably separated from their sister group Megaloptera + Neu-roptera (Aspo¨ck et al., 2001) in the Upper Carboniferous, though fossils are not known before the Early Jurassic (supposed pre-Jurassic specimens have now been reassigned). Though Recent species occur only in the Northern Hemisphere, fossil snakeflies have been found in Early Cretaceous deposits in Brazil. Eocene Baltic amber includes species assignable to the two extant families. Recent members of the order are included in a single superfamily Raphidioidea, containing two families, RAPHIDIIDAE (155 species) (Figure 10.2) and INOCELLIIDAE (20 species). The families have similar world distribu-tions, but within each family species generally have limited distributions. North American species are restricted to three genera, Agulla and Alena (Raphidiidae) and Negha (Inocelli-idae) (Aspo¨ck, 1986). Literature Aspo¨ck (1975) and Aspo¨ck (1986, 1998, 2002) describe the biology of Raphidioptera. ThephylogeneticrelationshipsoftheorderarediscussedbyAchteligandKristensen(1973), FIGURE 10.2. Raphidioptera. A snakefly, Agulla adnixa (Raphidiidae). [From D. J. Borror, D. M. Delong, and C. A. Triplehorn, 1976, An Introduction to the Study of Insects, 4th ed. By permission of Brooks/Cole, a division of Thomson Learning.] Kristensen (1991), Aspo¨ck et al. (2001), and Aspo¨ck (2002). Aspo¨ck (1975) deals with the North American species, and Plant (1997) with the British species. Achtelig, M., and Kristensen, N. P., 1973, A re-examination of the relationships of the Raphidioptera (Insecta), Z. Zool. Syst. Evolutionsforsch. 11:268–274. Aspo¨ck, H., 1986, The Raphidioptera of the world: A review of present knowledge, in: Recent Research in Neuropterology (J. Gepp, H. Aspo¨ck, and H. Ho¨lzel, eds.), Graz (published privately). Aspo¨ck, H., 1998, Distribution and biogeography of the order Raphidioptera: Updated facts and a new hypothesis, Acta Zool. Fenn. 209:33–44. Aspo¨ck, H., 2002, The biology of Raphidioptera: A review of present knowledge, Acta Zool. Acad. Sci. Hung. 48(Suppl. 2):35–50. Aspo¨ck, U., 1975, The present state of knowledge on the Raphidioptera of America (Insecta, Neuropteroidea), Pol. Pismo Entomol. 45:537–546. Aspo¨ck, U., 2002, Phylogeny of the Neuropterida (Insecta: Holometabola), Zool. Scripta 31:51–55. Aspo¨ck, U., Plant, J. D., and Nemeschkal, H. L., 2001, Cladistic analysis of Neuroptera and their systematic position within Neuropterida (Insecta: Holometabola: Neuropterida: Neuroptera), Syst. Entomol. 26:73–86. Kristensen, N. P., 1991, Phylogeny of extant hexapods, in: The Insects of Australia, 2nd ed., Vol. 1 (CSIRO, ed.), Melbourne University Press, Carlton, Victoria. Plant, C. W., 1997, A key to the adults of the British lacewings and their allies (Neuroptera, Megaloptera, Raphid- ioptera, and Mecoptera), Field Stud. 9(1):179–269. 301 THE REMAINING ENDOPTERYGOTE ORDERS 4. Neuroptera Synonym: Planipennia Common names: lacewings, mantispids, antlions Minute to large soft-bodied insects; head with chewing mouthparts, long multisegmented anten-nae, and well-developed compound eyes; two pairs of identical wings present, most species with primitive venation and veins bifurcated at wing margins; abdomen 10-segmented, cerci absent. Larvae of most species terrestrial with suctorial mouthparts. Pupae decticous and exarate, en-closed in a cocoon. The order includes about 6000 species and is represented in all world regions though is more diverse in warmer climates. About 335 species have been described from North America, 620 from Australia, and 66 from Britain. Structure Adult. Adults range in size from a few millimeters to several centimeters. Members of most species are soft-bodied, weakly flying insects whose head carries a pair of well-developedcompoundeyes,long,multisegmentedantennae,andchewingmouthparts.Ocelli areabsentexceptinOsmylidae.Inmostspeciesthelegsareidentical,thoughinMantispidae and some Berothidae the forelegs are large and raptorial. The four wings are membranous, about equal in size, and generally have a primitive venation. In Coniopterygidae, however, the number of longitudinal and crossveins is much reduced. The abdomen is 10-segmented and lacks cerci. Internal structure is poorly known. A dorsal crop diverticulum occurs in some groups, and there are six or eight Malpighian tubules. Three thoracic and seven abdominal ganglia are present. Females have polytrophic ovarioles. Larva and Pupa. Larvae have a prognathous head with suctorial mouthparts. Each mandible is sickle-shaped and grooved on the inner side. The lacinia is closely apposed to ... - tailieumienphi.vn