462 



AN INTRODUCTION TO ENTOMOLOGY 



Certain earwigs possess stink-glands, which open through tuber- 

 cles situated one on each side near the hind margins of the second 

 and third visible abdominal segments; from which, it is said, 

 they can squirt a foul-smelling fluid to 

 a distance of three or four inches. 

 These tubercles are represented in 

 Figure 543. 



The sexes can be distinguished by 

 the smaller size of the forceps of the 

 female, and by the fact that in the 

 female there are distinctly visible only 

 six abdominal sterna, while in the 

 male there are eight. 



In some earwigs the two efferent 

 ducts of the reproductive organs open 



separately. ^'f-A^^-T^n" 



rr^-u " X 1 • • 1 1 ^1 Labia pidctielLa 



ihe metamorphosis is gradual, the burgessi,ma.\e 

 young resembling the adult in form, (From Rehii 

 and the wings developing externally, and Hebard.) 

 The female is said to brood over the 

 eggs, but to abandon the young soon after they are 

 hatched. 



The order Dermaptera was established by 



Latreille in 1831, and again by Westwood in 1839 



under the name Euplexoptera. This later name has 



been used by many authors, including the writer ; but 



the older name should be adopted. The species of 



the world have been monographed by Burr ('11). 



Earwigs are cosmopolitan insects, and are easily transported by 



commerce; consequently exotic species are liable to be found near 



seaports; and some such species have become established in this 



country. 



The order is a comparatively small one ; only about four hundred 

 living species have been described, and these are mostly tropical or 

 semi-tropical. The native and the exotic species that have become 

 established in America north of Mexico number together only fifteen; 

 among these are the following. 



The seaside earwig, Anisoldbis marUima. — In this species both pairs 

 of wings are wanting, the antennae are 24-jointed, and the length of 

 the body is from 18 to 20 mm This earwig is found along the coast 

 from Maine to Texas. 



The ring-legged earwig, Anisoldbis anniilipes. — This is also a 

 wingless species. It differs from the preceding in that the antennas 

 are only 15- or i6-jointed, the body is about half as long, and the legs 

 are ringed with fuscous. Its range does not extend as far north as 

 that of the seaside earwig, but it extends farther inland. 



The little earwig. Labia minor. — In this species the body is thickly 

 clothed with fine yellowish pubescence. It is a small species, the body 

 measuring only from 4 to 5 mm. in length. Figure 538 represents the 

 male, natural size and greatly enlarged; and Figure ."540, the female, 



Fig. 540. — Labia 

 minor, female, 

 and end of ab- 

 domen of the 

 male. (From 

 Lugger.) 



