PTE RA  .

Order: Coleoptera . Biting mandibles; second maxillae very intimately fused . Pro-thorax large and free . Fore-wings modified into firm elytra, beneath which the membranous hind-wings (when present) can be folded . Cerci absent . Four or six Malpighian tubes . Larva campodeiform or eruciform . Pupa free . Includes the beetles and the parasitic Stylopidae, often regarded as a distinct order (Strepsiptera) . (See COLEOPTERA.) Order: Mecaptera . Biting mandibles; first maxillae elongate; second maxillae completely fused .

Prothorax small . Two pairs of similar, membranous wings, with predominantly

longitudinal neuration . Six Malpighian tubes . Larva eruciform . Pupa free . Cerci present . Includes the single family of Panorpidae (scorpion-flies), often comprised among the Neuroptera . Order: Trichoptera . Mandibles present in pupa, vestigial in imago; maxillae suctorial without specialization; first maxillae with lacinia, galea and palp . Prothorax small . Two pairs of membranous, hair-covered wings, with predominantly longitudinal neuration . Larvae aquatic and eruciform .

Pupa free . Six Malpighian tubes . Cerci absent . Includes the caddis-flies . See NEUROPTERA, among which these

insects were formerly comprised . Order: Lepidoptera . Mandibles absent in imago, very exceptionally present in pupa; first maxillae nearly always without laciniae and often without palps, or only with vestigial palps, their galeae elongated and grooved inwardly so as to form' a sucking trunk . Prothorax small . Wings with predominantly longitudinal neuration, covered with flattened scales . Fore-wings larger than hind-wings . Cerci absent . Four (rarely 6 or 8) Malpighian tubes .

Larvae cruciform, with rarely more than five pairs of abdominal prolegs . Pupa free in the lowest families, in most cases incompletely or completely obtect . Includes the moths and butterflies . See LEPIDOPTERA . Order:

Diptera . Mandibles rarely present, adapted for piercing; first maxillae with palps; second maxillae forming with hypopharynx a suctorial proboscis . Prothorax small, intimately united to mesothorax . Fore-wings well developed ; hind-wings reduced to stalked knobs (" halteres ") . Cerci present but usually reduced . Four Malpighian tubes . Larvae eruciform without thoracic legs, or vermiform without head-capsule . Pupa incompletely obtect or free, and enclosed in the hardened cuticle of the last larval instar (puparium) .

Includes the two-winged flies (see DIPTERA), which may be divided into two sub-orders: I . Orthorrhapha: Larva eruciform . Cuticle of pupa or puparium splitting longitudinally down the back, to allow

escape of imago . Comprises the midges, gnats, crane-flies, gad-flies, &c . 2 . Cyclorrhapha: Larva vermiform (no head-capsule) . Puparium opening by an anterior " lid." Comprises the hover-flies, flesh-flies, bot-flies, &c . Order: Siphonaptera . Mandibles fused into a piercer; first maxillae developed as piercers; pips of both pairs of maxillae present ; hypopharynx wanting . Prothorax large . Wings absent or vestigial . Larva eruciform, limbless .

Includes the fleas . Order:

Hymenoptera . Biting mandibles; second maxillae incompletely or completely fused; often forming a suctorial proboscis . Prothorax small, and united to mesothorax . First abdominal segment united to meta-thorax . Wings membranous, fore-wings larger than hind-wings . Ovipositor always well developed, and often modified into a sting . Numerous (20-150) Malpighian tubes (in rare cases, 6-12 only) . Larva eruciform, with seven or eight pairs of abdominal prolegs, or entirely legless . Pupa free . Includes two sub-orders-- I . Symphyta: Abdomen not basally constricted .

Larvae cater-pillars with thoracic legs and abdominal prolegs . Comprises the saw-flies . 2 . Apocrita: Abdomen markedly constricted at second segment . Larvae legless grubs . Comprises

gall-flies, ichneumon-flies, ants, wasps, bees .