388 APPLIED BIOLOGY 



fleas had wings because embryo fleas show the beginning of 

 wings. Hence, such degenerate insects are not apterans, 

 but belong in a higher order. 



Orthoptera. Name means straight wings, referring to main 

 veins of the wings, or to the way they fold together. Ex- 

 amples : grasshoppers, crickets, katydids, stick-insects, 

 cockroaches, mantis, earwig. Two pairs of wings, similar 

 to those of grasshopper. Mouth-parts for biting. At least 

 10,000 species are known. 



Netted-winged Insects. Old books recognize an order 

 Neuroptera for all insects which have two pairs of netted- 

 veined wings like the dragon-fly and May-fly ; but study of their 

 other organs and especially of their embryonic development 

 has shown that dragon-flies, May-flies, termites (often called 

 white ants), and others with netted wings are not similar 

 except in their wings. The netted-veined wings are found 

 on insects now grouped in five or six orders. However, the 

 beginner cannot do better than to use the popular name 

 " netted-veined," and for further information consult the 

 larger books on insects for descriptions of Neuroptera and 

 other orders of insects which exhibit this kind of wings. 



Hemiptera. Name means half wings, referring to the fact 

 that in some of these insects about half the wing next to the 

 body does not show distinct veins. Examples : all true bugs, 

 cicadas, squash-bug, box-elderbug, " stink-bug," chinch- 

 bug, parasitic lice, bed-bug, water-bug, cochineal bug, plant- 

 lice, scale-bugs. Four wings, overlapping when folded. 

 Mouth-parts for piercing. Incomplete metamorphosis. 

 About 20,000 species. 



Lepidoptera. Name means scale-wings, referring to over- 

 lapping scales. Examples : butterflies and moths. Two 

 pairs of wings, covered with flat or hair-like scales. Mouth- 

 parts for sucking. Complete metamorphosis. Butterflies 

 usually fly in daytime and have slender antennae with knob 

 or club at end. Moths are nocturnal and have feather-like 



