LOCUSTS 291 



subsequently serves as a sort of reservoir, by the aid of whiclr tlie 

 Insect can diminish other parts of the body, and after emergence 

 from the capsule, penetrate cracks in tlie earth so as to reach the 

 surface. Immediately after doing this the young Stauronotus 

 moults, the skin it casts being called by Kllnckel an amnios. 

 The cervical ampulla reappears at subsequent moults, and enables 

 the' Insect to burst its skin and emerge from it. 



The process is apparently different in Caloptenus sp'etus, 

 which, according to Eiley, ruptures the egg-shell and works its 

 way out by the action of the spines at the apex of the tibiaa 

 This latter Insect when it emerges moults a pellicle, which Eiley 

 considers to be part of the embryonic membranes. 



Eiley states that a female of Calo2}tenus spretus makes several 

 egg-masses. Its period of ovipositing extends over about 62 

 days, the number of egg-masses being four and the total number 

 of eggs deposited about 100. The French naturalists have 

 recently observed a similar fact in Algeria, and have ascertained 

 that one of the migratory locusts — Schistocerca peregrina — may 

 make a deposit of eggs at more than one of the places it may 

 alight on during its migration. 



It has been ascertained that the eggs of Acridiidae are very 

 nutritious and afford sustenance to a number of Insects, some of 

 which indeed appear to find in them their sole means of subsist- 

 ence. Beetles of the family Cantharidae frequent the localities 

 where the eggs are laid and deposit their eggs in the egg-masses 

 of the Orthoptera, which may thus be entirely devoured. Two- 

 winged flies of the family Bombyliidae also avail themselves of 

 these eggs for food, and a mite is said to be very destructive to 

 them in North America. Besides being thus destroyed in 

 enormous quantities by Insects, they are eaten by various birds 

 and by some mammals. 



Most of the Insects called locusts in popular language are 

 members of the family Acridiidae, of which there are in different 

 parts of the world very many species, probably 2000 being 

 already known. To only a few of these can the term Locust be 

 correctly applied. A locust is a species of grasshopper that 

 occasionally increases greatly in number, and that moves about in 

 swarms to seek fresh food. There are many Orthoptera that 

 occasionally greatly increase in numbers, and that then extend 

 their usual area more or less ; and some Acridiidae multiply 



