74 



Marvels of Insect Life, 



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natives of our own island, and two foreigners that have settled down in certain 

 districts and become naturalized. 



The head is furnished with a pair of long, slender antennae, a pair of compound 

 eyes, but no simple eyes ; and the mouth has the cutting-jaws characteristic of all 

 the straight-winged order. At the hind extremity of the body the two antenna- 

 like tails of the cockroaches and crickets are replaced by a pair of horny processes 

 which take the form of callipers. These callipers differ in size and shape in the 

 different species, and in the two sexes of each species. They are certainly used in 

 the packing up of the wings after use, as Mr. F. Enock has clearly demonstrated in 

 a wonderful series of careful drawings showing every stage of the process. It has 

 been suggested that these callipers are used also for wounding leaves and shoots of 



plants that the earwig may sup the juice, but an 

 Insect that is provided with a good set of cutting- 

 jaws is hardly likely to adopt so roundabout a 

 method, even if the callipers were suitable for such 

 work — which is very doubtful. But there can be 

 little doubt that the mere possession of these 

 organs protects the earwig from some possible 

 enemies. Carried as is usual, with the points 

 somewhat elevated and apart, they look much more 

 formidable than they are, and may produce the 

 impression that they mean business. That the 

 callipers are not intended chiefly for packing up 

 the wings is shown by the fact that they reach 

 their proper development in species that have no 

 wings to pack away ; and there are species in 

 which they are so long that, turned over the back, 

 their tips would reach the earwig's head, but 

 could not possibly touch the wings or wing-covers. 

 Then, too, they appear to be the most variable 

 organs, so far as their size in individuals of the 

 same species goes. In the common earwig 

 difference in length is almost restricted to 

 males, where it ranges from 2^ mm. to 9 mm. 

 have noticed what we think is another way in 

 which these callipers are useful to the earwig — 

 when the Insect is hiding in a dahlia, or other flower, the hinder part of the body 

 with the caflipers open protrudes and produces the effect of a head with wide open 

 jaws ready for attack. It is probable that this attitude may have a protective 

 value in respect of certain of its enemies. This becomes more probable when one 

 looks at the photograph of the shore earwig's callipers protruding from under a 

 stone (page yy). 



It is a common belief that the earwig exists mainly for the annoyance of 

 gardeners, and there is little doubt that much of the damage to plants that is due 

 to other Insects is debited to the earwig. But there is evidence, not only that it 



PJiolo bv] 



Earwig's Pincers. 



[H. Diutin. 



These are the calhpers of the male cominoi) earwig. 

 They differ greatly in size in different individuals, 

 and are sometimes used to assist in packing away 

 the wings. Magnified about twelve times. 



the 

 the 

 We 



