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Home , Antlion, Catacanthus, Catascopus, Ceroplastes, Dinidoridae, Eudalia

5. Evolution and Classification 101

Economic and ecological significance: internally. External wing buds, typical for Some of the exclusively phytophagous stick immature hemimetabolous , appear insects are known to defoliate fruit trees like only during the last larval instar. Guava and tree crops like Eucalyptus, and Economic and ecological importance: Web- therefore have to be considered as pests. and Footspinners mainly occur in the Tropics and subtropics. They live aggregated under loose bark, stones, on the ground or are associated with dung. They are not considered as pests, thus of no economic significance.

5.6.3.14 (Psocids, Bark-, Booklice) [biting wings] General biology: Small, free-living exo- pterygote with large mobile head. The chewing mouthparts bear asymmetrical mandibles. The compound eyes are large or reduced. The long and filiform antennae are composed of 13 to 50 segments. The pro- thorax is small, the legs are slender with 2- or 3-segmented tarsi in adults and 2-segmented tarsi in nymphs. The wings are present, Fig. 5-22: (Web-, Foot-Spinners): reduced or absent. If present, the membranous Notoligotoma sp. ♂ (Notoligotomidae) (repro- wings show reduced venation and are held duced from CSIRO, 1991) roof-wise over the abdomen. The forewings much larger than the second pair of wings. Cerci are absent. Gradual with 5.6.3.13 Embioptera (Web- or Footspinners) relatively short life span. [lively wings] Economic and ecological importance: The General biology: Small, elongate, flattened mostly fungivorous Psocoptera can be exopterygote Neoptera with large, strongly encountered in many habitats, associated with prognathous heads possessing chewing mouth- rotting plant material. However, some parts and noticeable jaws. The eyes are well are common pests of stored products such as developed, ocelli are absent. The antennae are food stuff and can occur in collections, elongate, multisegmented and filiform. The libraries and herbaria, encouraged by poor legs are short and stout with enlarged front storage methods. There they feed on mould, tarsi. The females are wingless, the males cereals, starches, glue and paper, Well known either winged or wingless. Wings, if present, representatives of this are the common are equal, membranous and have reduced booklice Liposcelis divinatorius and Trogium venation. The cerci are one or two-segmented pulsatorium. See fig. 5-23. and asymmetric in males (fig. 5-22). Embio- ptera, also called Embiidna, are so tiny that they are often only recognised by the presence of the tubular galleries which they weave wherever they go. The silken thread is spun by approximately 200 silk glands housed in the enlarged tarsi of the forelegs. The nymphs undergo incomplete development. The immature stages are remarkably similar to the adults, particularly in the wingless species. Fig. 5-23: Psocoptera (Booklice): Myopsocus The wing pads of the winged males develop sp. () (reproduced from CSIRO, 1991) 102 5. Evolution and Classification

5.6 3.15 , like the with a [purely wingless] reduced type of chewing mouthparts: General biology: Minute exopterygote Neo- · like the introduced ecto- ptera with chewing mouthparts and monili- parasites of domesticated poultry Columbi- form, 9-segmented antennae. Alate forms are cola columbae and Goniocotes gallinae blind, winged forms possess compound eyes · occurring on mammals, and distinct ocelli. The tarsi are 2-segmented. and introduced with their respective hosts. Wings, when present, are membranous with Pests on livestock and pets are Bovicola only one or two veins. The wings are shed by bovis on cattle, Bovicola ovis on sheep, adults, leaving only small buds. The cerci are Bovicola caprae on goat, Trichodectes canis short and one-segmented. Females with or on dog and dingo and Felicola subrostratus without . Gradual metamorphosis. on cat

Fewer than 20 species are known, most of Ischnocera and Amblycera were formerly in them occurring in tropical America. Zoraptera the group . do not occur in . Economic and ecological importance: Anoplura (sucking lice) with piercing- Zorapterans live in rotten wood or under dead sucking mouthparts to penetrate the host’s bark, often in ‘colonies’ of a few to a hundred skin and to suck its blood: . The insects feed on small · on pets and livestock like like mites. Linognathus vituli on cattle, L. pedalis and L. ovillus on sheep and L. setosus on dog and dingo 5.6 3.16 Phthiraptera (Lice) · Haematopinidae on ungulates like Haem- [wingless lice] atopinus suis on pig, H. asini on horse, H. General biology: Small, exoparasitic, wing- eurysternus and H. quatripertusus on cattle less, dorsoventrally flattened, exopterygote · Pediculidae on primates like the body Neoptera. The head is sessile or with limited Pediculus humanus, shown in fig. 5-24 B, movement, bearing chewing or piercing- and the head louse P. capitus on man sucking mouthparts, depending on the sub- · Phthiridae with only one sibling species, order. The antennae are 3 to 5-segmented, the human crab or pubic louse Phthirus filiform or capitate and are sometimes hidden pubis. in a groove of the head. The compound eyes Rhyncophthirina with only one known are reduced or absent, ocelli are always species not occurring in PNG. absent. The thorax is small and sometimes Economic and ecological importance: As indistinct, the legs short, stout, but well ectoparasites found only on mammals and developed. The tarsi are 1- or 2-segmented birds, lice are of medicinal and veterinary bearing a single or two claws for clinging to significance. Lice spend their entire life more feathers or hair of the host. Wings are always or less specifically on one particular host. absent. The abdomen has 5 to 8 segments. They prefer warmer, hairy body parts of their Gradual metamorphosis with three instars respective host, eg. the pubic region for the only. There are a few important families in pubic or crab louse Phthirus pubis. The four suborders: minute called nits are firmly attached to Amblycera with a reduced type of chewing feathers or hair of the host and are hard to mouthparts feeding upon shed skin and dried remove. Apart from the fact that lice are a blood associated with wounds of the host: nuisance for the host causing severe skin · Boopiidae found with a few exceptions on irritations, they are vectors for various Australian and Papuan marsupials diseases of man and livestock, especially · found world-wide on wild poultry. For instance the or cooty species of birds and domestic poultry, like Pediculus humanus can transmit typhus and Menopon gallinae other severe diseases in humans. 5. Evolution and Classification 103

during rest in Stenorrhyncha and Auchenor- rhyncha, or lie flat over the abdomen, or are coleopteroid (as in ). The forewings are homogenous, transparent or translucent, membranous in Stenorrhyncha, Auchenor- rhyncha and some other groups. In most Heteropterans, the true bugs, the forewings may be entirely or at portion (corion) of harder consistency than the thinner, trans- parent or translucent and membranous hind- wings (name: different wings, see fig. 5-26). If winged, the wing venation is in general reduced and the base of the wings is separated by a large conspicuous scutellum. Cerci are A B absent. The abdomen of females of many Fig. 5-24: (A) Zorotypus sp. (Zoraptera), (B) species bears a well-developed sheath-like or Pediculus humanus (Phthiraptera: Pediculidae, saw-like ovipositor. Gradual metamorphosis Lice) (reproduced from CSIRO, 1991) with two to seven, commonly five larval instars (fig. 2-37). Parental care occurs in some species (fig. 2-34). 5.6.3.17 (, , like have complex sound producing Scale Insects, Cicadas, True Bugs, etc.) mechanisms, discussed in chapter 3.1.1. A [half wings] fundamental feature of true bugs (Hetero- General biology: Diverse, very small to ptera) is the presence of scent glands or stink medium-sized exopterygote usually winged glands that release an unpleasant deterrent Neopteran insects with piercing-sucking odour when disturbed (chemical defence). mouthparts. The mouthparts consist of a Mimicry by means of imitating , thorns hinged stylet-like beak (proboscis) formed by or other distasteful stink or assassin bugs is mandibles and maxillae (figs. 2-11, 2-13 and common. Hemipteran defence and the mutual- 2-14). The proboscis is held backwards and istic relationships between ants and homo- rested in an anterior ventral groove between pterans like plant lice or scale insects are the coxae when not in use. The mouthparts outlined in chapter 3.2.3 and 4. are absent in adults of some species of aphids Economic and ecological importance: Most () and scale insects (Coccoidea). species are phytophagous sucking on plants. The antennae are usually 3- to 10-segmented, A number of predacious or parasitic species the compound eyes are various and large but feed upon body juices, sucking blood sometimes absent, the number of ocelli varies of mammals or fish, or hemolymph of insects. from two to three. The legs are usually Hemipteran predators of insects play an cursorial and similar. The forelegs of some important role in the natural control of their predacious like are prey populations and are therefore considered raptorial, in aquatic Gerromorhpa adapted as beneficial insects. However, many species for swimming or walking on the surface of are of agricultural, veterinary and medicinal water, others have forelegs or hindlegs significance since they are common and developed for jumping. In females of scale severe ectoparasites of man and domesticated insects (Coccoidea) the legs are reduced or animals or destructive pests of cultivated absent. The coxae are free, the tarsi are 2- to plants. Moreover, many of the pest species are 3-segmented, the pretarsal structures are capable of transmitting diseases. Pest species diverse. Usually two pairs of wings are are indicated with an asterisk and discussed present that are held roof-like over the body in the context of the respective . 104 5. Evolution and Classification

Hemipterans are one of the very diverse insect by some people for its sweetness (‘manna’). orders, divided into more than a hundred Nymphs may produce white waxy secretions families of three suborders Stenorrhyncha, or honeydew. Most species have to be Auchenorrhncha and Heteroptera. The term considered as pests of agriculture because Homoptera (half wings) is also widely used they feed on plant juices. Some transmit viral and comprises the two suborders Stenor- diseases or produce galls. However, some are rhyncha and Auchenorrhncha. suitable as biocontrol agents if their host is a Suborder Stenorrhyncha with four super- weed. Heteropsylla spinulosa for instance is families: used for the control of the giant sensitive plant Mimosa invisa in PNG. Pests of tree · Aphidoidea* (aphids, plant lice, green , crops in PNG are Glycaspis spp. and Cardia- ) Of importance is the family - spina spp. sucking on young shoots of Euca- idae (figs. 5-25 A, 8-7 D) causing considerable lyptus spp., shown in box 6-1 N, O and fig. 6- damage on foliage and roots of agricultural 3 J- L. crops. Some species produce galls. Aphids are small, soft-bodied, winged or wingless · Aleyrodoidea* () Minute insects with long threadlike or short antennae, 2- that might be confused with , as shown segmented tarsi and one pair of cornicles at in fig. 5-25 D. Their wings are covered with the posterior end of the abdomen. Aphids white waxy powder. Immature stages sessile reproduce often by means of parthenogen- and scale-like and sometimes covered with esis. Some species are covered with woolly woolly fibres, shown in fig. 5-25 E. Many fibres. The mutualistic relationships between species cause severe damage of agricultural aphids and ants is discussed in chapter 3.2.3. crops like citrus (fig. 8-7 E).

The sweet secretions of aphids, called honey- · Coccoidea* (scale insects, and dew, sometimes drip onto leaves, offering gall-makers) differ from aphids in respect of good conditions for mould to grow on. The the facts that 1. females are always wingless. blackish stains of mould are then referred to 2. usually only the first larval instar is mobile, as black sooty mould. Aphids show very the other stages are sessile, covered by a soft poor flight performance, usually they depend or tough scale (fig. 5-25 F) or an amorphous on wind for dispersal. Aphids are not very secretion made from wax. 3. the males that diverse in natural habitats in the tropics. This are much smaller than the females have only is because the probability of drifting to a one pair of wings. The legs of sessile forms suitable host tree is minute due to high can be completely reduced. Important families species diversity and low abundance of a are (soft scales, wax scales) particular host species. However, aphids are covered under hard or soft material; Pseudo- quite likely to become pests in monocultures. coccidae (mealybugs) without scales from In PNG the pine woolly aphid Pineus pini wax but with waxy filaments, noticeable (), shown in fig. 6-3 I, is of along the periphery of their body (fig. 8-7 B); economic significance in Pinus caribaea plan- (armoured scales, fig. 8-7 C, F) tations. concealed under hard waxy removable scale · * (lerps, jumping plant lice or and (felted scales). The gall psyllids) Of importance is the family makers cause swellings of plant tissues like , with some members similar to leaves and stem. Larvae and other stages are aphids while others look like the miniature of enclosed in galls where they suck plant juices. cicadas, shown in fig. 5-25 B, but with much Some species are beneficial and useful to longer antennae. Psyllids have strong jumping man. The Mexican coccineal insect Dactylo- legs with enlarged femora. Lerps spin conical pius coccus is used for the production of a red scales (lerps) to shelter underneath, as shown dye for food, drinks and cosmetics. The lac in figs. 5-25 C, 6-3 J and box 6-1 N. The insect Kerria lacca is used for the production sugar lerp Spondyliapsis eucalypti is sucked of the varnish shellac. However the majority 5. Evolution and Classification 105

of species are pests rather than of any benefit · Cicadoidea* Cicadas (fig. 5-25 G) of the to man. In Papua New Guinea’s forestry family Cicadidae are large robust insects of 5 sector, the pink wax scale Ceroplastes rubens cm or more with prominent compound eyes (box 6-1 I) damaged Pinus caribaea and and three distinct ocelli on the back of the mealybugs infested Acacia and Tectona. head. The head bears short, bristle-like Gumtree scales of the Eriococcus antennae. The wings are large and membran- attack a wide range of Eucalyptus in Australia ous and are held roof-like above the body. but are less common and severe in PNG. Females possess a strong, spear-like ovi- The Suborder Auchenorrhyncha comprises positor. Male cicadas have highly developed two infraorders, the and musical and auditory organs which are dis- Fulgoromorpha, having small, needle-like cussed in chapter 3.1.1. The legs of some antennae and almost always 3-segmented adults and nymphs are raptorial, legs of other tarsi. The Cicadomorpha are further divided nymphs fossorial. Females lay eggs in in- into three superfamilies: cisions in bark. The nymphs drop after hatch

A B C

D E F G H

I J K

Fig. 5-25: Hemiptera, Group Homoptera: (A) Meringosiphon sp. (Aphididae, plant lice), (B) Creiis sp. ♂ (Psyllidae, lerps), (C†) Spondyliaspis sp. (Psyllidae, lerps) on Eucalyptus sp., (D†) adult whiteflies (Aleroydidae) on Acacia mangium, (E†) woolly fibres produced by immature whiteflies (Aleyrodidae) on Acacia mangium, (F) Parasaissetia sp. ♀ (Coccidae, scale insects), (G) Froggattoides sp. (Cicadidae, ), (H) spittle of nymphs of spittle bugs (), (I) Sertorius sp. (Membracidae, tree hoppers), (J) Stenocotis sp. (Cicadellidae, leaf hoppers), (K) Scolypopa sp. (Fulgoroidae) (reproduced from CSIRO, 1991; Schneider, M.F. †) 106 5. Evolution and Classification ing, bury themselves in soil and attach to Suborder Heteroptera [different wings]. The rootlets for piercing-sucking feeding. The forewings of true bugs may be entirely or in exuviae of the last nymphal instars can be part of harder consistency than the hindwings often found attached to bark or fence posts. (hemelytra), a feature that distinguishes true The North American species Magicicada sep- bugs from beetles (see also box 5-4). True temdecim has a prolonged subterranean life bugs have dorsal stink glands on the cycle. Only after 17 years the adults syn- abdomen. Most species are herbivorous, but chronously appear in huge swarms, cause there is also a large number of predacious severe damage to trees and make a lot of species. True bugs are divided into over fifty noise. -laying punctures can harm trees, families in eight superfamilies belonging to when cicadas are abundant. the following infraorders: · Cercopoidea* (frog hoppers and spittle 1. Coleorrhyncha bugs) The brownish smaller but robust 2. Enicocephalomorpha saltatorial cicada-like animals have antennae 3. that are inserted between the compound eyes 4. Lepdopodomorpha and possess coleopteroid wings. The nymphs 5. (Amphicorisae) are slender live in self-produced ‘spittle’ shelters, as semiaquatic insects, adapted to life in or on shown in fig. 5-25 H. Some members of the the surface of water. Typically they have very family Cercopidae are pests of cultivated long legs. The tarsi and at least the ventral Gramineae, herbaceous plants and trees, body part is covered with water-resistant hair, causing stunted growth, and during severe buoying the bug. Many species are scavengers infestation, eventually the death of the host. or predators that run quickly on the surface of water to hunt for other insects. Common are · Cicadelloidea* comprise the families the water striders and pond skaters of the Eurymelidae, Membracidae (, family , like Gerris spp. and Limno- fig. 5-25 I) and Cicadellidae (leafhoppers and gonus spp. (fig. 5-26 A) and marsh treaders or jassids, fig. 5-25 J), the latter being the largest water measurers of the family Hydrometr- family of hemipterans. The cicada-like Cica- idae like Hydrometra. dellidae are small, elongate insects with 6. (Hydrocorisae) are mostly wings held roof-like above the body. The hind aquatic, predacious bugs. The short antennae tibiae have one or more rows of small spines. are hardly visible from above. Some species The female leafhoppers possess a strong ovi- like the giant waterbug Lethocerus insulanus positor to cut slits in plant tissues to deposit (, fig. 5-26 C) have raptorial their eggs. The nymphs walk sideways like forelegs for seizing prey such as tadpoles or crabs and some produce honeydew. Charac- fish up to twice the bug’s size. This group of teristic for members of Membracidae is a bugs developed a variety of breathing mecha- grotesque, hump-like, greatly enlarged pro- nisms while under water. Water scorpions like ornamented with ridges, horns or Laccotrephes spp. (fig. 5-26 B) or Ranatra prongs. Many species of Cicadelloidea are spp., both , possess a respiratory destructive to certain crops, not only causing siphon that is pushed up through the surface stunted growth and discolouring the foliage, film. The giant waterbug Lethocerus can but also transmitting plant diseases. remain submerged up to two hours because it · Fulgoromorpha with one superfamily, the carries some air bubbles trapped in the hair- Fulgoroidea* (, fig. 5-25 K) are edged space of its abdomen for breathing. similar in appearance to leafhoppers. Some Back-swimmers belonging to the family have leaf-like wings or bizarre projections of have a keel-like back and use the head. Common pest species of cultivated their feathered elongate hindlegs to swim plants belong amongst others to the families upside-down. Other conspicuous families are , Eubrachyidae, , Derb- the (water-boatmen), Gelastocor- idae and (fig. 6-3 M). idae and . 5. Evolution and Classification 107

A B C D

E F G H I

J K L M N

O P Q R S T Fig. 5-26: Hemiptera, Suborder Heteroptera: (A) Limnogonus luctuosus (Gerridae, water striders), (B) Laccotrephes tristis (Nepidae, water scorpion), (C) Lethocerus insulanus (Belostomatidae, giant waterbugs), (D) Cimex lectularius (, bed bugs), (E) Trilaccus sp. (, plant bug), (F) Stephantis sp. (, lace bugs), (G), (H) Pristhesancus sp. (Reduviidae, assassin bugs), (I) Euander sp. (, chinch bug), (J) Delacampius sp. (), (K) Dindymus sp. (, red bugs), (L) Leptoglossus sp. (, squash bugs), (M†) Nezara viridula last nymphal instar, (N†) Nezara viridula adult, (O) Oechalia sp. (, shield bugs), (P) Megymenum sp. (), (Q) Oncomeris sp. (), (R) Tectocoris sp. ♀ (S) ♂, (T) Scutiphora sp. (, jewel bugs) (reprod. from CSIRO, 1991; Gullan, P.J. & Cranston, P.S., 1994†) 108 5. Evolution and Classification

The following two infraorders are also Assassin bugs are harmless for humans, referred to as Geocorisae (terrestrial bugs) although being pierced is quite painful due to 7. * are bugs that prey on the injected saliva that might cause an other animals, mainly arthropods. A number inflammation of the wound. Assassin bugs are of families are of economic importance: considered as beneficial insects, however they · Bed bugs and relatives suck are not suitable as biocontrol agents due to blood of birds and mammals like bats and their unspecific . humans. The nocturnal bedbugs (Cimicidae) 8. Pentatomorpha* Bugs of this infraorder are small with broadly-oval flattened bodies are called ‘stink bugs’ due to their well and vestigial wings. They possess short developed scent glands, releasing an unp- filiform antennae and a 3-segmented probos- leasant deterrent scent upon disturbance. Most cis. The bed bug Cimex lectularius, shown in species are phytophagous and can cause fig. 5-26 D was introduced into PNG, considerable damage to agricultural crops. Australia and other South Pacific countries Some families are: from Europe. Bed bugs are quite a nuisance · , which include the family causing very itchy and irritating bites, but do . The so-called flat bugs or bark nor transmit any diseases. Exposing the in- bugs are commonly encountered under bark, fested bed and mattress to the sun quite likely usually gregariously, where they feed on eradicates the pest. fruiting bodies of wood-decaying fungi. Many

· Miroidea* typically have a 4-segmented flat bugs are apterous. labium. The plant or leaf bugs (Miridae, fig. · * are phytophagous, with many 5-26 E) are a prominent family of this group being pest species of cultivated plants. Bugs and one of the most diverse groups of true of the family Lygaeidae*, shown in fig. 5-26 bugs. These bugs are small elongate or oval I, are called seed bugs or chinch bugs, and vividly marked. Typically they have a reflecting their feeding habits. The bugs are triangular section called cuneus in the apical small elongate and sometimes colourful. tip of the hardened part of the hemelytra with Ocelli are usually present. In some species two enclosed cells. Most are phytophagous short and long-winged forms can be found. and can become serious pests of cultivated Some feed on seeds and plant juices of plants. Gramineae, causing serious damage of the · Tingoidea* are close relatives of the host. Largidae*, shown in fig. 5-26 J, are Miroidea and possess a 4-segmented labium. similar to Lygaeidae and Pyrrocoridae and The chiefly phytophagous lace bugs (Ting- comprise a number of pest species. Pyrro- idae, fig. 5-26 F) are small flattened bugs coridae* or red bugs are medium-sized to with lace-like wings, a broadly flattened large bugs of rounded to elongate shape with pronotum and bizarre, spiny nymphs. They small heads and large compound eyes. The feed on foliage of trees and shrubs, causing forewings have many-branched veins and defoliation. crossveins. Some species are short-winged. A

· Reduvioidea comprise the predacious number of species cause damage of seeds, eg. of cotton and other crops. See fig. 5-26 K. assassin bugs (name), that can be easily identified by their sickle-like, 3-segmented · * including the Coreidae* (figs. proboscis, shown in fig. 5-26 G, that is not 2-37, 5-26 L) or squash bugs which are ‘parked’ in a ventral groove during rest. The typically large-sized, elongate-oval bugs of head is separated from the rest of the body by brownish colours with strong repellent a ‘neck’. They can produce sound by scraping odours. The membranous part of the hem- the tip of their proboscis along a file on the elytra is many-veined. The hind legs often ventral part of the thorax, as shown in figs. 3- have stout femora and expanded or spined 1 and 3-3. Some have arrays of spines on the tibiae. Squash bugs preferably suck on various forelegs for grasping and holding prey. legumes, Eucalyptus, Cucubitaceae, etc. The 5. Evolution and Classification 109 crusader bug Mictis profana (fig. 6-3 N) can 5.6.3.18 Thysanoptera () be easily recognised by the yellowish cross- [fringed wings] like markings on the closed hemelytra. It General biology: Small, slender, dorso- feeds on shoot tips of Acacia causing them to ventrally compressed exopterygote Neoptera. wilt. Leptoglossus (fig. 5-26 L) and The broad-based head bears asymmetric Pternistria feed on Tectona and Eucalyptus. rasping-sucking hypognathous mouthparts in Members of the family * are brown a cone-like beak on the ventral side of the or grey with long antennae and legs. Many head. The compound eyes are variable from Coreoidea are severe pests of vegetables, almost holoptic (round view) to only three fruits, Gramineae and tree crops. facets in some wingless species. Three ocelli are present in some species. The antennae · * The shield or stink bugs have 4 to 9 moniliform or filiform segments. typically have a large triangular or sometimes the pronotum is conspicuous. The legs are semi-elliptical scutellum that reaches at least slender but have sometimes large tarsal teeth to the apex of the clavus or might even cover and swollen femora. The tarsi are 1- to 2- the whole abdomen. The antennae of adults segmented. The wings are slender and fringed are usually 5-segmented, the feelers of at one or more margins (fig. 5-27 C). Thrips nymphs with 4 segments. Many of the mainly are characterised by a peculiar type of brown or greenish, broadly-oval, medium- development and their metamorphosis is inter- sized to large phytophagous shield bugs of the mediate between complete and incomplete. family Pentatomidae are well known pests in The first two or three immature stages PNG’s gardens. They feed on a variety of resemble the adults, whereas the two to three cultivated plants. The introduced green quiescent, pre-imaginal instars are ‘pupal’ vegetable bug Nezara viridula, shown in fig. stages termed prepupa or propupa (fig. 5-27 5-26 M and N, is the horror of horticulturists. A, B) These ‘pupal’ stages possess wing Other common genera are nigri- rudiments and have probably evolved inde- pes (Plate 3 E), Oechalia (fig. 5-26 O), pendently from the true pupal stage with Oncocoris, Vitellus, Biprorulus, Cuspicona, internally developing wings of the holometa- Eribotes, Glaucias and Alcaeus. Bugs of the bolous insect orders. The relatively small family Tessaratomidae are small to large, order comprises eight families, of which four vividly coloured phytophagous bugs. Some of occur in Australia and probably in PNG. these pests are of economic importance. Oncomeris flavicornis, shown in fig. 5-26 Q, can be commonly encountered in PNG. The small to large Scutelleridae are also referred to as jewel bugs, because of their vividly iridescent or metallic body coloration. The basic colour is mainly green or blue and one quite conspicuous feature is the greatly enlarged scutellum, that covers both pairs of wings. Due to this feature they might be mistaken as beetles. There are some precious jewels amongst the Scutelleridae in PNG, that are desperately wanted by insect collec- tors. The cotton harlequin bug Tectomeris A B C spp. is shown in figs. 2-34, 5-26 R and S. Others are shown on Plate 3 D and fig. 5-26 Fig. 5-27: Thysanoptera (Thrips): (A) T. The small brownish, very active bugs of Teuchothrips sp., , (B) Teuchothrips sp., the family Dinidoridae (fig. 5-26 P) suck on II, (C) Desmothrips sp., adult (reproduced vegetables and are considered as pests. from CSIRO, 1991) 110 5. Evolution and Classification

Economic and ecological importance: There are predacious and phytophagous species of thrips. The predators hunt for mites and small insects under bark of dead trees and in the ground cover. Phytophagous thrips can be often found associated with flowers, where they search for . A number of species are pests of agriculture, inducing galls and other symptoms on commercial crops such as tobacco, onions, beans and fruit trees.

A B 5.6.3.19 (, ) [large wings] Fig. 5-28: Megaloptera (Alderflies and General biology: Medium-sized to large Dobsonflies): (A) Stenosialis sp., aquatic mandibulate, endopterygote Neoptera with larva, (B) Archichauliodes sp., adult (repro- broad and prognathous head. Ocelli might be duced from CSIRO, 1991) present or absent, the compound eyes are large. The multisegmented antennae are long and slender, either filiform, moniliform, 5.6.3.20 Raphidioptera (Camelneck- serrate or pectinate. The mouthparts are of the and Snake-Flies) chewing type, with strong, enormously [fused wings] elongated mandibles in males. The pronotum General biology: Large, mandibulate endo- is large. All legs are similar and well pterygote Neoptera similar to Megaloptera, developed. The tarsi of all legs are 5- but distinguished by their long serpentine segmented and generally with two simple ‘neck’. The prognathous, flat, elongate head is claws. The two pairs of functional, subequal, basally tapering or broad, extremely flexible similarly textured, membranous, large wings and strongly sclerotized. The antennae are can reach a span of 20 to 175 mm. The wings long, multisegmented and filiform, rarely possess many crossveins. The abdomen is moniliform. The large compound eyes are very soft and without projecting cerci. Adult situated laterally and are always present. Megaloptera (fig. 5-28 B) resemble adults of Three ocelli are present or absent, depending the order . The aquatic larvae, on the family. Raphidioptera have chewing shown in fig. 5-28 A, are mandibulate with a mouthparts. The prothorax is elongated and large prothorax, functional legs, paired lateral very mobile, the pronotum shield- or tube- abdominal gills and in some groups with a like. All legs are equal, cursorial, the tarsi are long terminal process. The pupae are active, 5- segmented and bear two very small claws. decticous and exarate, similar to that of some The transparent wings are membranous, sub- Coleoptera. Complete metamorphosis with equal and elongate. Females have a long and long generation time. flexible ovipositor, as shown in fig. 5-29 A. Economic and ecological importance: Complete metamorphosis with decticous Alderflies and dobsonflies are a small order, pupa. About hundred species are described mainly occurring in temperate climates. Since world-wide and divided into two families. larvae as well as adults are predators they are Economic and ecological significance: a significant link in food chains. They dwell Snake-Flies are a small group of diurnal in both lakes and streams, where the larvae predators without economic importance. They hunt for small aquatic animals. The larvae are are restricted to Holarctic forests and can’t be reared and commonly used as baits by found in PNG. The larvae (fig. 5-29 B) occur fishermen. under loose bark where they hunt small insects. 5. Evolution and Classification 111

surface of leaves. The mainly terrestrial larvae usually have well-developed heads, thoracic legs, but lack abdominal legs. The order is divided into about 20 families. Some families are , ( flies, the only family with aquatic larvae), (dust flies), Myrmeleontidae (), , , , , and (green lacewings). Economic and ecological importance: Most adult lacewings and their larvae, called antlions, are predators. Antlions of the family Myrmeleontidae are abundant in very dry sandy, poor soils such as under houses. Their peculiar way of catching prey by the help of a A B funnel-like pitfall trap is described in fig. 4-9. Adults of the most diverse lacewing family Fig. 5-29: Raphidioptera (Camelneck-flies, Mantispidae resemble praying mantids. Their Snake-flies): (A) larval Phaeostigma sp., (B) forelegs are greatly enlarged and raptorial to adult Raphidia sp. ♀ (reproduced from CSIRO, 1991) catch prey. The larvae of sponge flies (Sisyridae) are aquatic and feed on freshwater . In general, Neuroptera are purely 5.6.3.21 Neuroptera (Lacewings, Antlions) beneficial insects. The larval green lacewing [nerve- or net-like wings] signata (Chrysopidae), shown in General biology: Small to large and slender, fig. 8-7 D, is used as a general predator in endopterygote, mandibulate Neoptera. The agriculture for the biological control of orthognathous head bears large, well sepa- aphids, mites, whiteflies, scales, mealybugs rated compound eyes, ocelli are usually and small caterpillars. The specific use for the absent. The mouthparts of adults (fig. 5-30 B) control of one particular pest species how- are of the chewing type. The mandibles and ever, is not yet well established. maxillae of larvae (figs. 4-9 B and 5-30 A) are extended and usually form two distinctive, sickle-shaped sucking jaws for sucking up A body juices of prey through a mandibular- maxillary groove. The long antennae are multisegmented, filiform or moniliform and tapering or variously thickened and longer than those of . The prothorax is freely movable. The legs are usually cursorial, but the forelegs of some species are raptorial. B The tarsi are 5-segmented and usually end in two claws. Adults have two pairs of large, equal or subequal transparent membranous wings, that often have numerous cross-veins. The wings are of diagnostic importance and are usually held over the body during rest. A Fig. 5-30: Neuroptera (Lacewings, Antlions): frenulum is sometimes present for coupling (A) myrmeleontid , (B) adult Glenoleo of wings. Complete metamorphosis. Eggs are pulchellus (Myrmeleontidae) (reproduced from laid on long and slender stalks, placed on the CSIRO, 1991) 112 5. Evolution and Classification

absent or in others so large that they meet above and/or below the head. The number of ocelli varies from zero to three. The well developed antennae are usually 11-segmented, but the number of segments can be reduced to 7 or increased to 30 or more. The length and shape of the antennae are very variable and characteristic for particular families or taxa, therefore very important for the identification of beetles. The antennae may be moniliform, pectinate, serrate, clavate, filiform or capitate (see fig. 2-5) and are often longer in males than in females, eg. in longicorn beetles Fig. 5-31: Lentilburgeroptera: yet unnamed (Cerambycidae). The antennae are usually species (reproduced from Giam, A.N., Hamb, A.K., developed for chemosensation, but might be Noga, T. and Mask, I., in press) modified. They are for instance involved in the gas exchange in aquatic . The prothorax is large and well developed and 5.6.3.22 Lentilburgeroptera almost always free. Together with the head it General biology: Little is known about this forms a distinct fore body, contrasting with peculiar mandibulate insect group, shown in the hind body which consists of the small fig. 5-31. Apparently these insects have an mesothorax, the larger metathorax and the unique feature: the wings are attached to the abdomen. The body is more or less depressed. prothorax and mesothorax, as reported by The mesoscutellum is usually visible from the first-time collectors Giam, A.N., Hamb, above between the elytral bases. The heavily A.K., Noga, T. and Mask, I. The only records sclerotized legs are often gressorial or of the Lentilburgeroptera are from Papua New cursorial, and normally increase in size from Guinea, where they were just recently front to rear. The legs of some species are discovered. The only specimen collected so adapted for jumping, swimming, burying in far is kept in the collection of the Bulolo soil or tunnelling in wood. The tibiae often University College. The family is also possess a comb of spines or a pair of enlarged referred to as Coleolepidorthoptera by the spines (tibial spurs). The number of same authors. These insects are closely tarsomeres is of diagnostic importance and is associated with Lentilburgeraceae (name!). indicated in some identification keys as There are no further data available on the ecology of this order.

5.6.3.23 Coleoptera (Beetles) [sheath wings] General biology: Small to large, hard-bodied, rounded to elongated endopterygote Neoptera. The adults almost always have chewing mouthparts that face forward (prognathous head). The mandibles, when thickened and enlarged, are armed with ridges or teeth-like tubercles (mola). The mandibles of males of some species like Lucanidae are greatly enlarged and are used for combating other males. The compound eyes are usually Fig. 5-32: No chewing of ‘ nut’, but conspicuous and variable, in some species how about betelnut? (photo Hertel, H.) 5. Evolution and Classification 113 tarsal formula. In beetles it is normally 5-5- ever, there is a large number of very colourful 5, indicating that the tarsi of the fore-, mid- beetles, eg. the rose chafers (, and hindleg possess 5 tarsomeres each. Cetoniinae) and jewel beetles (). However, the number of tarsal segments Beetles undergo a complete metamorphosis might be reduced to 4 or 3 in particular pairs with 3 to 5 larval instars. The larvae have a of legs. Sometimes the tarsomeres are fused in distinct head capsule with antennae, chewing such a manner that eg. four tarsomeres might mouthparts and three pairs of thoracic legs, be mistaken as three tarsal segments. but lack abdominal legs in most cases. The Particular tarsal segments of some species larvae or grubs are either scarabaeiform, cam- bear tarsal pads or adhesive setae. The podeiform, eruciform or apod, as shown in terminal pretarsus usually has two claws. figs. 2-42 and 5-33. The pupae are mostly Beetles normally have two pairs of wings adecticous and exarate and rarely obtect, as which can be greatly reduced in some species shown in fig. 2-43. or taxa, eg. in rove beetles (Staphylinidae). General biology: Beetles are the largest The first, mesothoracic pair of wings is group of animals and organisms in general modified into more or less hardened, veinless, with more than 300,000 named species. non-foldable, rigid elytra, which usually meet About 50% of all insect species, 30% of all edge to edge in a straight line at rest and animal species and 24 % of all organisms are partly or wholly cover the hind wings and beetles. In PNG there are probably more than abdomen. The metathoracic wings, when 25,000 species of beetles, making almost 10% developed, are membranous, folded and alone of the world’s total. However, many species used for propulsion in flight. The elytra are are yet to be described. The evolutionary one of the main distinguishing feature success of this insect order is mainly due to between adult bugs and beetles, other differ- the development of elytra protecting the ences are listed in box 5-4. The abdominal hindwings when not in use and allowing the sternites are almost always heavily scle- occupation of cryptic (hidden) habitats by the rotized. Adult beetles can vary in size from adults. The elytra also protect beetles from less than a millimetre up to 10 centimetres. predation and infection by microorganisms. Their coloration can be dark and dull, how Various chemical defence strategies by means of scent glands were developed by many groups. Some of the excreted products simply act as deterrents whereas others are potential lethal poisons: some larvae of leaf beetles A (Chrysomelidae) release the stored deadly poison hydrogen cyanide. Others like the bombardier beetle Pheropsophus verticalis (fig. 5-34 A) possesses a binary weapon: upon disturbance, an explosive mixture of hydrogen peroxide and hydroqinones is ignited in an abdominal combustion chamber. This peculiar defence mechanism is further described in fig. D 4-15. Other effective, non-chemical defence B C strategies are (plate 1 B), Fig. 5-33: Types of beetle larvae: (A) eruci- protective structures, snapping as done by form Paropsisterna sp. (Chrysomelidae), (B) click beetles (Elateridae), dropping, feigning scarabaeiform Anoplognathus sp. (Scarabae- death and many more. Some species of Elater- idae), (C) apodous Trigonotarsus sp. (Cur- idae and Lampyridae, called ‘fire flies’ or culionidae), (D) campodeiform Eudalia sp. ‘glow worms’ have the ability to produce (Carabidae) (reproduced from CSIRO, 1991) glowing light for courtship signalling and 114 5. Evolution and Classification

distinguishing feature adult bug adult beetle mouthparts piercing-sucking chewing first pair of wings sclerotized proximate and first pair of wings form hardened membranous apical part of elytra, covering the abdomen and the forewings (‘half wings’) the hindwings development hemimetabolous holometabolous

Box 5-4: Main distinguishing features between adult bugs and beetles prey-luring. Often both sexes and all stages of 1. the life cycle, even the eggs may glow. The 2. bioluminescence organs can be located 3. : A relatively large group of almost anywhere on the body. During court- highly specialised, mainly predacious beetles, ship, the mobile male emits light. A sedentary having immobile hind coxae. Tarsal formula female responds and thus indicates her 5-5-5. The largest family of this suborder are location. · Carabidae (ground beetles). The nocturnal, minute to large-bodied, very active beetles Economic and ecological significance: Most vary in shape and coloration. Some are oval adult and larval beetles are or whereas others are elongate with either black, predators of other insects. Some beetles are dull, bright or metallic coloured bodies. The scavengers on decomposing organic matter. beetles usually have long, cursorial legs for Usually adults and larvae of the same species running down prey and prominent, strong and have the same feeding habits, eg. both are pointed mandibles. The adults usually have phytophagous. A wide range of beetles is of filiform antennae and large compound eyes. economic importance since they interfere with Due to the predacious character of most adults agricultural and forestry crops, timber pro- and larvae (fig. 5-33 D), some species are ducts, stored products, etc. In the following suitable for the biological control of insect section, families and other taxa of common pests. This family includes the subfamily coleopteran pests are indicated with an Cicindelinae (tiger beetles), which is con- asterisk *. However, beetles do not transmit sidered as a separate family by some authors. any diseases of man or livestock. Due to the Species of this subfamily have large pro- fact that there are many predators, herbivores truding compound eyes. Common genera and and scavengers amongst the beetles, they play species in PNG are Colpodes, eg. C. habilis, an important role in maintaining the eco- Scopodes, Demetrida, the bombardier beetle logical balance in natural systems. Further- Pheropsophus verticalis (fig. 5-34 A), Clivina, more, many host-specific species are in use as Catascopus and the tiger beetles (Cicin- biocontrol agents of insect pests and noxious delinae) Cicindela, Therates labiatus (fig. 5- weeds. Apart from this, many beetles are 34 B), Tricondyla aptera and Megacaphala important for the pollination of plants, as discussed in chapter 4.2.2, mainly by means 4. This is the largest coleopteran of walking on smaller, inconspicuous flowers suborder. Some of the series and families are: such as Umbelliferae. Most of these flowers : release a carrion-like scent that attracts beetles · Hydrophilidae Water scavengers are but which humans find unpleasant. aquatic beetles with predacious larvae and herbivorous adults. The 7- to 9-segmented, The order is divided into more than 500 clubbed antennae of the Hydrophilidae are families, belonging to four suborders. About involved in gas exchange. The beetles are two thirds of the families are believed to generally poor swimmers, since their legs are occur in PNG: not adapted for swimming. The silvery