372 PROTECTION AGAINST INSECTS. 



Locusts are plant-eaters, and feed chiefly on the produce of 

 fields and meadows, but also on the foliage of broadleaved 

 trees and shrubs, especially when they come in swarms, and 

 they can then be extremely hurtful. 



The commonest European species is Pachytyhis migratorius, 

 L., and its area of sub-permanent distribution is from lat. 40 N. 

 in Portugal to 48 in France and Switzerland, and rising east- 

 wards to 56 in Eussia, Siberia, N. Japan. Its area of occa- 

 sional distribution is wider, and it has visited England and 

 Scandinavia. It is also found in S. latitudes in New Zealand 

 and Australia, and in Mauritius and Africa. Only an occasional 

 visitor to India. 



Acrydium peregrinum is permanent in Africa and tropical 

 Asia, especially India, and occasionally visits the South of 

 Europe, and in 1869, was found over a large part of England. 



1. Pachytylus migratorius, L. (Migratory Locust). 



a. Description. 



Imago 35 to 48 mm. long (<?), 42 to 55 mm. long ( ? ), 

 coloured greenish, or brownish; pronotum produced into a 

 blunt point in front ; wings yellowish, or pale brown, almost 

 transparent, slightly darker at the tips; chest with white 

 hairs ; hind femora bluish on their inner side, with a black 

 ring in front of the joint ; hind tibiae yellow. 



Larva with broad brown bands on the front part of the 

 back, and wingless until it has moulted four times. 



b. Life-history. 



The eggs are laid in the ground 3 to 4 cm. deep, in groups 

 of 70 to 80, and as the ? die immediately after laying, their 

 dead bodies lying on the ground show where eggs have been 

 laid. 



c. Relations to the Forest. 



Locusts devour chiefly agricultural produce, sometimes 

 appearing in such countless swarms as to leave nothing green 

 over many square miles of country. South Russia, with its 

 extended grain-producing plains, is specially liable to this 

 scourge, and so is Hungary. Its permanent home appears to 



