CHAPTER V 



SOME WINGLESS INSECTS 



IN an earlier chapter of this book reference has been 

 made to insects, such as most of the aphids or " greenfly ", 

 in which winged and wingless forms may occur, seasonally 

 or otherwise, in the life-history of the same species ; as well as 

 to others, such as scale-insects and certain cockroaches, in 

 which the male is winged while the female is wingless, a con- 

 dition found also in not a few insects which undergo the 

 hidden type of wing-growth, such as the common glow-worm 

 among the beetles, and the notorious "Winter " and " Vapourer " 

 moths. More rarely the male and not the female is the sex 

 destitute of wings. It is of interest to find that among those 

 highly-organized social insects, the ants, the vast majority of 

 members of the enormous families that grow into communities, 

 are " workers " strangely modified, infertile females, all of 

 them wingless ; while among the termites so called " white 

 ants " the wingless workers and soldiers may be modified 

 infertile individuals of either sex. In many families of insects 

 whose members are normally winged, species wingless in both 

 sexes may be found ; earwigs and psocids or " book-lice ' 

 afford examples of this condition. Reference will be made 

 to such in the present chapter, but it is proposed to direct 

 attention especially to certain orders or large groups of insects 

 all of whose members are destitute of wings. 



This wingless condition is frequently the accompaniment of 

 a parasitic mode of life, and a typical example of such wingless 

 parasites is afforded by the lice (Anoplura) an order, possibly 

 allied to the bugs (Hemiptera). Lice (Fig. 89 a) have pro- 

 minent heads with short feelers, and a remarkable suctorial 

 mouth provided with recurved hooks (b), which serve to fix 

 to the host-animal on which the parasite lives and to pierce 

 its skin, and a delicate protrusible tube through which 



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