Mx' 



Lw 



Fig. 94, — Diagram of mouth-parts of 

 Orthopterous insect. 



i86 INJURIOUS AND USEFUL INSECTS 



functional in adult. Antennae long. There are two pairs of 

 membranous reticulate wings, the hind pair larger and folded 

 fanwise. Larva aquatic. 



Order Orthoptera (cockroaches, grasshoppers, crickets). 



Mouth-parts biting. There 



^ ; ^^^ are usually two pairs of 



^^ ^-ii. Lbr wings, which often differ in 



texture, the fore pair being 

 ' jMn firmer, and serving as wing- 

 covers, the hind pair folded 

 fanwise. 

 Mxf Order Corrodentia (book- 

 lice, bird-lice). Mouth biting. 

 There may be two pairs of 

 membranous and few-veined 

 wings, but they are often 

 wanting. 



Order Thysanoptera or Physopoda (thrips). Mouth-parts 

 adapted for piercing and sucking, with palps. There are two 

 pairs of long, narrow, membranous wings, fringed with long 

 hairs. A resting-stage in some species. 



Order Rhynchota or Hemiptera (bugs, water-boatmen, 

 aphids, scale-insects, lice). Mouth- 

 parts suctorial, with a jointed 



beak or proboscis (labium), which (^ aj^ ^^ Lbr 



encloses piercing styles ; no palps. 

 There are usually two pairs of 

 wings, which may be similar or 

 dissimilar. Male Coccidse undergo 

 complete transformation, with a 

 resting-stage. 



° ° Fig. 95. — Diagram of mouth-parts 



of bug. 



Section III. Holometabolic 

 — i.e. undergoing complete transformation. There is a 

 resting-stage, during which the insect rarely moves about, 

 and never feeds. The wing-rudiments develpp within in- 

 ternal pouches, and do not appear externally till the larval 

 skin is cast. 



Order Neuroptera (lace-flies, alder-flies, scorpion -flies). 

 Mouth-parts biting. There are two pairs of equal, similar, 

 membranous, closely reticulate wings. 



tw 



