.4.] Locusts. 11 1 



Generally speaking, the life circle of a loeast extends through one 

 year, in which period it passes through its various stages of egg, young 

 wingless larva, active pupa, and winged adult which lays the eggs that 

 are to produce the next generation, the only recorded exception being 

 Acridium, peregrinum, which is believed to pass through two generations 

 in the year in India. 



The eggs are laid in little agglutinated masses in holes which the 

 female bores with her ovipositor in the ground. In temperate climates 

 the eggs are usually laid by the end of summer, and the parent locust 

 dies before the winter commences, the eggs remaining in the ground 

 during the winter months, and hatching out in the following spring. In 

 sub-tropical countries, where there is but little winter, the winged locusts 

 live on through the cold season and do not die off until the following 

 spring, when they deposit their eggs. In this ease the eggs hatch after 

 lying in the ground for about a month. In both temperate and sub- 

 tropical regions alike, the young wingless locusts, on emerging from the 

 eggs in the spring or early summer, feed voraciously and grow rapidly 

 for one or two months, during which period they molt at intervals, 

 finally developing wings and becoming adult. The adult locusts fly 

 about in swarms, which settle from time to time and devour the crops. 

 The damage done by locusts is thus occasioned, first, by the young wing- 

 less insects, and afterwards by the winged adults into which the young 

 transform after a couple of months of steady feeding. 



The following are the chief species of locusts found in different parts 

 of the world other than India : — 



Pacliytyius migratorhis, the chief migratory locust of Europe, occurs 

 especially in Eastern Europe and Southern Russia, also in Central Asia, 

 Siberia, North China, Japan, Fiji Islands, New Zealand, North Australia, 

 Mauritius, Madeira, and possibly in South Africa, very little, however, 

 being known about its distribution in the Southern Hemisphere (Mc 

 Lachlan : article Locust, Encyclopaedia Britannica). It may be looked 

 upon as the chief locust of the temperate zone, excluding America. An 

 elaborate account of this species in South Russia is given by Koppen 

 (Horae, Soc. Ent. Ross, iii, pp. 89 — 246 ; reviewed in Zool. Eecord, 1867, 

 p. 457). From eggs laid in the autumn the larvae hatch in the spring 

 (April and May), and molt four times before they become adult. The 

 larvae band themselves together and move in search of nutriment, feed- 

 ing chiefly on graminae, and doing a vast amount of damage. The 

 imagos emerge about July, copulate soon afterwards, and oviposition 

 extends from August to October. Each female copulates and oviposits 

 about three times, at intervals of about a month; each time laying from 

 50 to 90 eggs, in a hole bored by her horny ovipositor in the soil. This 

 hole is about 1 \ inches deep and is lined with frothy matter, which hard- 



