Fig. 5-46: Diptera (Flies): (A) Leptotarsus Imperatorius (Tipulidae), (B) Simulium Sp
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5. Evolution and Classification 131 A B C D E F G H I J K L M N O P Q Fig. 5-46: Diptera (Flies): (A) Leptotarsus imperatorius (Tipulidae), (B) Simulium sp. X (Simuliidae), (C) Atrichobrunnettia sp. C (Psychodidae), (D) Orfelia sp. X (Mycetophilidae), (E) Trichophthalma spp. (Tabanoidea), (F) Leptogaster sp. C (Asilidae), (G) Comptosia lateralis C (Bombyliidae), (H) Heteropsilopus sp. X (Dolichopodidae), (I) Eristalis sp. (Syrphidae), (J) X stalk-eyed fly Achias sp. (Platystomatidae), (K) Achias sp. C (Platystomatidae), (L) X antlered fly, (M†) larvae of Creatitis capitata (Tephritidae), (N†) pupa of Creatitis capitata (Tephritidae), (O†) adult fruit fly Creatitis capitata (Tephritidae), (P) Musca sp. X (Muscidae), (Q) Sarcorohdendorfia sp. C (Sarcophagidae) (reproduced from CSIRO, 1991; Hill, D.S. and Waller, J.M., 1988†; photos Schneider, M.F.) 132 5. Evolution and Classification wild as well as domesticated mammals, living The femora sometimes have a row of setae or amongst the feathers or hair of their host. The stout bristles on the outer surface. The adults flies are of economic importance since they have two pairs of functional, subequal infest livestock like sheep, horses and cattle. membranous wings that are folded roof-like A number of these pests are introduced. or flat above the body during rest. The wings show poor cross-venation. A wing coupling mechanism (frenulum) is present. Body and wings are densely covered with hairs and occasionally with groups of scales (fig. 5-47 B). The aquatic larvae have well developed chewing mouthparts, peg-like antennae, compound eyes, functional thoracic legs, one pair of abdominal prolegs and abdominal tracheal gills (fig. 5-47 A). The free living caterpillar-like larvae build fixed protective A B shelters or portable cases shown in fig. 5-47 C-G to protect their soft, membranous and pale abdomen. The shelters are spun from silk incorporating grains of sand, small stones, diatoms, algae, bits of twigs and other materials. Each species seems to have its own characteristic shelter, allowing it to be used for the species identification. Silken threads are also used by the larvae as an anchoring line in strong currents and for the construction of nets to capture food particles from the C D E F G water current. The larvae use a wide range of food sources, some are herbivores, others are Fig. 5-47: Trichoptera (Caddis Flies): (A) predators, piercing, scraping, filtering or aquatic larva of Baliomorpha sp., (B) adult of swallowing their food. Most species prefer Stenopsychodes sp., portable larval cases of cool running waters. The pupae are exarate (C) Tasimia sp., (D) Tascuna sp., (E) Oecetis with strong mandibles for biting their way sp., (F) Plectotarsus sp., (G) Antipodoecia sp. through the pupal case. The pupae are hidden (reproduced from CSIRO, 1991) inside the protective structure made by the last larval instar. Caddis flies undergo complete metamorphosis. The insects are one 5.6.3.28 Trichoptera (Caddis Flies) of the largest aquatic orders. The largest [hairy wings] families of caddis flies are the Hydrobiosidae, General biology: Small to medium-sized, Ecnomidae and Leptoceridae. endopterygote neopteran insects that are closely related to Lepidoptera. The mouth- Economic and ecological significance: The parts of adults are poorly developed and aquatic larvae of caddis flies play an suitable for imbibing liquid food only. The important role in the food chain of freshwater compound eyes are usually well developed, ecosystems, however larvae of some the ocelli mostly absent or rarely 3 or 2 ocelli herbivorous species cause damage to young present. The antennae are long and slender, rice plants or ornamental water plants like multisegmented and mostly filiform. The legs water lilies. Trichoptera larvae are very are strong and slender with 5-segmented tarsi sensitive to pollution, therefore they are used and two terminal claws. The tibiae sometimes as indicator organisms for the assessment of possess long spines or are fringed with hairs. water quality. 5. Evolution and Classification 133 Hesperiidae. Head, body and appendages like antennae, proboscis, wings and legs are clothed with usually overlapping pigmented scales. The large legs are usually well developed in adults and adapted for walking. The mid- and hind tibiae usually have one or two pairs of spurs. The forelegs of some Papilionoidea and the hindlegs of some Hepialidae and Geometridae might be reduced. The tarsi are 5-segmented with a pair of articulated, curved terminal claws. The two pairs of large membranous wings are covered on both surfaces with two layers of A B overlapping, broad and flattened scales, as Fig. 5-48: Lepidoptera (Moths and Butterflies): shown in fig. 5-48 B. The iridescent physical (A) view of a butterfly head showing the colours of the scales are due to the structure partly hidden proboscis, (B) scales of a butter- of the scales and are caused by interference fly wing (photo Schneider, M.F.) of light. The wings are absent or non- functional in females of a few species. The wing venation, only visible when the scales 5.6.3.29 Lepidoptera (Moths and Butterflies) are removed, is of diagnostic importance. [scale wings] Different types of wing coupling mechanisms General biology: Small to large, endo- (frenulum, fig. 5-49) are usually present in pterygote Neoptera with robust and elongated moths but lacking in butterflies. The frenulum bodies. The mouthparts bear a proboscis and holds together fore- and hindwings and in are of the siphoning-tube type, rarely with general results in a better flight performance chewing mouthparts in adults. The proboscis of the moths. During rest, the wings are or haustellum (fig. 2-17) is coiled when not folded roof-like above the abdomen or out- in use and might be completely or partly spread in most moths, and raised back to back hidden in dense scales at its base as shown in above the body in most butterflies. Sound fig. 5-48 A. The head has two prominent producing and tympanal organs are present on compound eyes and lacks a median ocellus or the abdomen of some groups. Lepidoptera is without ocelli. The antennae are 3- always lack cerci. Females of nocturnal segmented and variable in shape and are species possess dermal, abdominal sex either flagellate, pectinate, ‘clubbed’ as in pheromone glands. The male and female most butterflies or ‘hooked’ as in the genitalia are of diagnostic significance. Fig. 5-49: Different types of wing-coupling mechanisms (frenulum) between the fore- and hindwings of Lepidoptera; for abbreviations see fig. 2-21 (reproduced from CSIRO, 1991) 134 5. Evolution and Classification The larvae called caterpillars (figs. 2-42 and bear sclerotized hooks (crochets), that are of 5-50) have 10 visible abdominal segments, diagnostic importance. The larval head and chewing mouthparts, are eruciform, mostly body is covered with sensory setae which are peripneustic and rarely holopneustic. Usual- a useful tool for identification. The hairs of ly the hypognathous or prognathous head is particular caterpillars, eg. of Lymantriidae heavily sclerotized. In most species the and Limacodidae can cause severe irritations labium bears a silk gland (spinneret) for of the skin when touched. Coleopteran larvae spinning a cocoon or shelter. The antennae are are most often confused with those of short and 3-segmented. Each thoracic segment Lepidoptera. The difference however, is that has one pair of 5-segmented legs, that might caterpillars almost always have at least one of be reduced or lost in some species. False legs the following features: (prolegs) can be present on the abdominal · a median labial gland developed into a spinneret segments 3-6 (ventral prolegs) and segment · paired adfrontal ridges 10 (anal prolegs). Terminally the prolegs · crochet-bearing prolegs on S3 to S5 or S6 and S10 F A G H B I C D J E K Fig. 5-50: Larval Lepidoptera (Butterflies and Moths): (A) Danima sp. (Notodontidae), (B) Phalaneoides sp. (Noctuidae), (C) Mnesamplea sp. (Geometridae), (D) Opodiphtera sp. (Saturniidae), (E) Psilogramma sp. (Sphingidae), (F) Carthaea sp. (Carthaeidae), (G) Cephrenes sp. (Hesperiidae), (H) Papilio sp. (Papilionidae), (I) Delias sp. (Pieridae), (J) Euploea sp. (Nymphalidae), (K) Ogyris sp. (Lycaenidae) (reproduced from CSIRO, 1991) 5. Evolution and Classification 135 vigorously. This can be compared with an attempt to glue dusty surfaces. Many noc- turnal moths like Sphingidae, Arctiidae and Noctuidae can ‘hear’ ultrasound produced by bats, one of the moths’ major natural enemies. Bats use their ultrasonic radar system for orientation during the night, like an aircraft uses its radar system during low visibility. Apart form this, bats use ultrasound for locating their prey, especially moths. As soon as a moth hears an approaching bat, it drops, in most cases out of the reach of the bat. Another effective defence mechanism of the larvae of some Papilionidae caterpillars such A B as Troides oblongomaculatus are eversible Fig. 5-51: Pupal Lepidoptera (Butterflies and stink glands (sing. osmeterium) located Moths): (A) decticous, exarate pupa, (B) dorsally between head and thorax. When the adecticous, obtect pupa (reprod. from CSIRO, 1991) caterpillar is disturbed, the osmeterium pops out, as shown on plate 2 I, releasing an unpleasant, deterrent scent. Hairy caterpillars, The pupae are rarely decticous, usually causing skin irritations, are generally refused adecticous and obtect (figs. 2-43 and 5-51). by predators. Such stinging hairs can be found Usually the pupae of moths are housed in a on caterpillars for instance of Anthelidae, silken case spun by the caterpillars, whereas Limacodidae, Lymantriidae and Arctiidae the pupae of butterflies are naked. Butterflies (fig. 4-13 B and plate 2 C, D). Camouflage is and moths undergo complete metamorphosis. very common, especially in Geometridae and The evolutionary success of the Lepidoptera Noctuidae (fig. 4-11, plate 1 A, E, F).