Neuroptera (Lacewings) T. R. NEW Endopterygote, mandibukate Neoptera; antennae multisegmented, filiform, moniliform or variously thickened, usually conspicuous; compound eyes always present; ocelli usually absent; generally two pairs of large, equal or subequal membranous wings, often with numerous cross-veins; main veins usually with 'end-twiggings'; tri- chosors often present. Larvae with distinctive sucking jaws, usually carnpodeiform and free living. Pupation in silken cocoon; pupae decticous. The Neuroptera, or Planipennia, is one of the most archaic described species. The immature stages of Neuroptera groups of endopterygote Neoptera. Adults (Figs 34.1, 2) were discussed by Withycombe (1925) and a synopsis of range from very small insects with a wing-span of about 5 larval forms is given by Gepp (1984). Recent revisions mm to very large forms with wing-span exceeding 150 have considerably improved knowledge of the Australian mm. Although many are cryptically coloured, others are fauna (e.g. Aspock and Aspock 1984, 1985, 1986; brightly coloured and patterned, and many are clothed Lambkin 1986a, b; Mansell 1983; New 1980-89a; Riek with long, dense hairs. Some taxa are very swift fliers 1974b, 1976e), and the biology of the order is reviewed (Ascalaphidae, in particular) but most fly rather slowly by New (1986d). A more extensive, general account of and irregularly and in these the wing-coupling mecha- the order is given by New (1989b). nism, if present, appears inefficient. Sexual dimorphism is generally slight, but is especially marked in some Anatomy of Adult Ascalaphidae in which males have a dorsal abdominal Head (Fig. 34.3~).Usually transverse, orthognathous process (Fig. 34.2~).There are differences in wing shape or more or less hypognathous. Clypeus and labrum elon- between the sexes of some Hemerobiidae and Chrysop- gate in Nemopteridae. Hind margin deeply excavated in idae and the berothid Trichoma. Most lacewings are Ascalaphidae. Compound eyes large, usually bare. Ocelli recognisable by their having the main veins branched (or absent except in Osmylidae, where they are sometimes 'twigged') at the end, and by the way they hold their poorly defined. Antennae multisegmented, usually fili- wings in a steep 'roof' while at rest. form and tapering, pectinate in the male of the non- The Neuroptera is a small order, with a little more than Australian Dilaridae and sometimes longer than wings; 5000 described species. It is represented in all major zoo- scape large, succeeding 1 or 2 segments sometimes geographical regions, usually being more abundant in the enlarged. There is some tendency for both shortening and tropics than in temperate areas. Neuroptera occur broadening to occur, so that the apex is thickened, or throughout Australia. Globally, some of the families are incipiently clubbed in Ascalaphidae and Myrmeleontidae. geographically limited, and many are small, some having More uniform thickening occurs in many Mantispidae, only a few tens of species. The largest families are and enlargement and/or ornamentation of the monili- Chrysopidae and Myrmeleontidae, each with around 2000 form flagellar segments occurs in males of some The Insects of Australia ---------- 9 Fig. 34.1 Chrysopa s. I.sp., Chrysopidae, 6 (im, intrarnedian cell; Psc, pseudocubitus; Psm, pseudomedia). [T. Binder. T. Carpenter] 1 Fig. 34.2 Adults in resting position: A, Psychopsis mimica, Psychopsidae; 8, Glenoleon pulchellus, Myrmeleontidae; C, Drepanacra binocula, Hemerobiidae; D, Megacmonotus magnus, Ascalaphidae; E, Porismus strigatus, Osmylidae; F, Megalithone megacerca, Ithonidae. 34 Neuroptera Coniopterygidae. Mouth-parts simple, biting; maxillary palps (Fig. 34.3~)normally 5-segmented; labial palps (Fig. 34.3~)2- or (more commonly) 3-segmented; ligula reduced to median process, sometimes slightly bilobed, or absent. The apical segment of at least 1 pair of palps is usually enlarged and in some Myrmeleontidae there is a well-defined groove presumed to contain sensilla. Thorax. Prothorax freely movable; generally trans- verse or slightly longer than broad, but relatively longer in many Osmylidae and very long and narrow in Mantispidae (Fig. 34.3~).Mesothorax and metathorax usually well developed, and of similar size (metathorax , reduced in Nemopteridae). Legs. Mostly unelaborated and cursorial, but fore legs strongly raptorial in Mantispidae (Fig. 34.3~)and some non-Australian Berothidae (Rhachiberothinae). Fore coxae often elongate, and with raised setae in some Osmylidae. Hind trochanter apically produced on inner edge except in Myrmeleontoidea. Tibiae with or without apical spur or spurs; femora and/or tibiae rarely expanded and slightly flattened. Tarsi 5-segmented, ending in Fig. 34.3 Head of Dictyochrysa sp., ,Chrysopidae: A, frontal; B, labium, 2 claws except the fore leg of some Mantispidae. The ventral; C, maxilla, ventral. D, head and prothorax of Campion sp., claws may be very long, may have 1 or more subapical Mantispidae, lateral. [M. Quick] teeth and (rarely) are opposable on the tarsus. Some Mantispidae have claws with up to 6 terminal spines. Empodium simple or bilobed. but in many families it appears glabrous at normal mag- Wings (Figs 34.7, 8). Generally 2 pairs of equal or nifications. Males of many Myrmeleontidae have a pos- subequal wings, with full and complex venation. Hind terior clavate projection (axilula pilaris) at the hind wing wings of Nemopteridae (Fig. 34.8~)are very long and base. This is a scent-dispersive surface associated with narrow, and differ markedly from the short fore wings. In thoracic glands. In males of some Nemopteridae there is a Ithonidae (Fig. 34.7~),the hind wing is more expanded in bulla at the base of the fore wing and (sometimes) another the anal region than the fore wing. The hind wing is type of bulla at the base of the hind wing; both have mod- reduced in some Hemerobiidae and Coniopterygidae. ified, silky, probably sensory hairs. Sexual dimorphism is uncommon; males of some Wing coupling is usually simple, and may involve a Chrysopidae and Hemerobiidae have thickened veins and simple frenulum-coupling (as in Hemerobiidae) in which in Chrysopa (Mallada) basalis these form a thickened an expanded jugal lobe at the base of the fore wing cou- pterostigma which is struck on the substrate during ples with a small, basal, costal, hind wing process bearing courtship. Some Osmylidae have a thickened posterior a few enlarged bristles. The jugal lobe is reduced in many spot on the fore wing and 'embossed' areas of wing mem- families and in some of these, thickening of postero- brane occur in some Psychopsidae. In a few families, marginal veins of the fore wing may aid coupling. the number of vein branches and cross-veins is low Coniopterygidae are unusual in that the anterior margin of (Coniopterygidae; Fig. 34.7~;Sisyridae, Fig. 34.76). the hind wing bears hamuli-like bristles, and the fore Many fore wing costal cross-veins occur in all families wing jugal region has a series of hooks. The former link except Coniopterygidae (which have no more than 2) and with the anal region bf the fore wing and the latter with the pterostigma is usually at least indicated and often very the basal length of R in the hind wing, providing firm well defined (Ascalaphidae, Mantispidae). Fusion wing-coupling. between parts of some of the main longitudinal veins is Abdomen. Ten-segmented, with only 9 distinguishable responsible for the very distinctive zig-zagged venation of segments in Chrysopidae, and Sl .generally strongly Chrysopidae (Figs 34.1, 8B, c). reduced. Usually cylindrical, but broadened around small circular spots (nygmata) are sometimes present segments 3-5 in males of Stilbopteryginae (and with the and are presumed to be sensory. They occur between the tergites sometimes ornamented), and males of many posterior 2 branches of the apparent Rs, rarely behind the Ascalaphidae have a dorsal process on segment 2 or 3. posterior branch, and/or basally between Rs and M. The The-terminalia are modified and specialised in both wing margin often has a fringe of hairs or a series of sexes, and the various parts of the genitalia are difficult marginal thickenings (trichosors) each bearing hairs. to homologise between the families. They are discussed There may be 1 trichosor between each pair of veins and by Acker (1960), Adams (1969), Tjeder (1970) and branches around the wing perimeter. The wing veins Aspock et al. (1980) and recent taxonomic papers indi- themselves may be haired and some Berothidae have cate the range of structures present. Apparently only thickened scale-like hairs on some veins. The wing mem- Coniopterygidae retain a true penis. A long ovipositor brane is more or less scattered with minute microtrichia, occurs only in Dilaridae and some Mantispidae (not in F Order Odor 528 The Insects of Australia / Hatching usually occurs through use of a larval ovirup- I tor to make a longitudinal slit, but in many Myrmele- ontoidea this structure is absent and there is a circular 'line of weakness' which enables the 'top' of the egg to be pushed off. Larva. The general form (Figs 34.9-12) is an active, predatory, campodeiform larva, with conspicuous, pro- truding jaws. Rarely, associated with more sedentary feeding habits, a more scarabaeiform larva occurs, as in the subterranean Ithonidae and parasitic Mantispidae. Some ground-dwelling larvae possess long, curved hairs or setae, sometimes grouped on raised tubercles, and those of Nymphes and many Chrysopidae have tangling I filaments, all of which entrap debris on the dorsal surface, aiding concealment. There are well-defined lateral processes on the thorax and abdomen of many Myrmele- ontoidea, and their arrangement has considerable taxo- nomic value. Ascalaphidae, in particular, have heavily ornamented papillae (dolichasters) on the body. Tarsi are I-segmented, and there are nohnally 2 tarsal claws. In some groups of Myrmeleontoidea, the hind tibia and tarsus are fused into a single structure, presumably more efficient for backwards movement. The mandible and maxilla of each side fit together to form a sucking tube.