INTKODUCTION. 17 



" It seems the adults take readily to their wing on certain nights,, 

 especially when the moon is bright. Numbers later in the year 

 used to fly into my house of a night, attracted by the lights." 



The tubercular folds in the integument at the sides of the abdo- 

 men appear to be stink-glands, but little evidence is forthcoming 

 on this point. Green found that Elaunon hipartitus, Kirby, when 

 handled, gave off a pungent odour, like that of the Bombardier- 

 Beetle. 



The forceps, which assume such a variety of remarkable shapes, 

 especially in the male, are useful weapons of offence and defence. 

 We have seen (p. 15) how Lahidura riparia uses them to 

 seize its prey. Of Diplatijs, Green writes: — "When food is? 

 offered to an adult Dyscritma [^Diplatys] it usually goes through 

 a curious performance to test its suitability. It takes up its 

 position to one side of and slightly in advance of the object ; then 

 bending its abdomen round to one side, it gives it a sharp nip with 

 its forceps and retires quickly to note results. If the proffered 

 object does not resent this treatment, it is then considered safe 

 and fit for food : but if the victim makes any movement, Di/scritina 

 immediately retires beneath its shelter." 



A number of interesting notes on the function of the forceps of 

 earwigs have been collected by Gadeau de Kerville (05), who shows 

 that they are used as a weapon of offence and defence, but never 

 during the act of copulation. Also, the insects do, occasionally, 

 at all events, use them as a help to fold and unfold their delicate 

 wings and to lift their elytra. Even Forjicula auricularia was 

 observed to do this by Paul Noel, and the same thing has been 

 observed in an unnamed species by Morris. 



With reference to their use as a weapon, the author was 

 startled by a nip of a female Lahidura riparia, which made him drop 

 the creature, and though the forceps did not pierce the tough skin of 

 the human thumb, it would have been a formidable adventure to an 

 insect of its own size. Gadeau de Kerville was nipped by F. auri- 

 cidaria so strongly that blood was drawn, and Commander- 

 J. J. Walker had the same experience in New South Wales, from 

 the largest known earwig, Anisolabis colossea. Baer (04) has 

 recorded that tlie relatively weak A'ptenjr/ida linearis, Esch., in 

 the Argentine Eepublic, is capable of raising a local inflammation 

 by its nip, though the irritation was perhaps caused by septic 

 matter present on the forceps, for no traces of poison glands are 

 known. The author introduced a large bluebottle into a small 

 glass-topped box with a male Lahidura riparia. The earwig by 

 a lightning-like movement, instantly transfixed the fly on one 

 limb of its forceps, and carried it about thus spiked for several 

 hours before devouring it. 



Food. 



Earwigs are probably omnivorous, though chiefly carnivorous. 

 Green was unable to determine the natural food of Biplatys, but 



c 



