190 PROTECTION OF WOODLANDS. 



ish longitudinal lines along the sides of the front rings of the 

 thorax, and a yellowish dot on each side of the back of the head, 

 is a species of less frequent occurrence. 



The only preventive or annihilative measure of any practical 

 use against wood-wasps is to cut out without delay any sickly or 

 injured stems, and thus keep the woods as clean as possible by 

 thinning and proper supervision. 



C. CRICKETS (Gryllidse). 



91. The Mole-cricket, Gryllus gryllotalpa (Gryllotalpa vulgaris). 

 (Vide Plate IV. fig. 24) 



This well-known insect, easily distinguishable through its 

 strongly developed claw-like legs, formed like a mole's for digging, 

 belongs to the order of Orthoptera, and has only an imperfect 

 metamorphosis. 



The wingless larva already resembles the fully developed 

 insect, whilst this is still more the case with regard to the 

 chrysalis, which only differs from the imago by having merely 

 rudimentary in place of completely developed wings, and crawls 

 about and feeds like both larva and imago. 



The pairing-time is in June, when both sexes entice the other 

 by means of a chirping underground. After impregnation the 

 female deposits her ova, up to the number of about 200, and 

 in size about as large as a grain of hempseed, inside a nest 

 formed by a hollow clump of earth about the size of a fist, 

 cemented with a kind of slime, and lying about 3 to 4 inches 

 below the surface of the soil. 



After about 2 or 3 weeks the larvae make their appearance ill 

 July, being at first of a whitish colour, but becoming darker later 

 on, and soon wander throughout the soil in search of food. After 

 hibernating under the surface of the soil, and making several 

 changes of skin, they develop into imagines during the following 

 spring. It is well worthy of note that the female cricket watches 

 carefully over the opening of the nest containing her young, but 

 at the same time also actually devours a large number of her 

 progeny. 



The food of the mole-cricket is for the most part animal, an< 

 in this way it may to a certain extent be useful. But in its 



