Systematic Coarse, 15 
same methods of treatment. Throughout India there are a large 
number of other Acrididw, which partake more or less of the migra- 
tory habits of locusts and often do a great deal of damage to crops. 
They are too numerous, however, to make it possible to consider 
them in detail in this work. 
Generally speaking, it is only in seasons of drought that locusts 
multiply excessively. This indicates that a dry soil is favourable to 
them and that the extension of irrigation and forests is likely to 
tend in the long run to diminish their ravages. 
Locusts are very subject to parasites, and the number which are 
devoured each year by birds is enormous, while unsuitable climatic. 
conditions, and specially damp, seem to be peculiarly fatal to them. 
Acridium peregrinum is known to suffer from two dipterous parasites, 
one of which attacks the egg and the other the mature insect. A 
Carabid beetle (Colosma orientale, Hope) devours vast numbers of the 
wingless larve, while the Rosy pastor starling (Pastor roseus) works 
almogt incredible havoc amongst the flights. The Decean locust 
( Acridium suecinctum) is said to suffer from parasitic mites and 
Nematode worms, and there seems reason to believe that disease is also 
prevalent. 
Locusts have been shown to be capable of being dealt with effective- 
ly in India by artificial means, but the greatest activity and energy 
is necessary. The old locusts can be killed when they are numb 
with cold in the early mornings. The eggs can be collected by hand 
in vast numbers ; while much can be done in the way of beating the 
winged locusts off the crops, thus compelling them to feed on grass 
and other vegetation of small value. ‘These means should all be 
employed, but the most effectual mode of fighting the pest is by 
destroying the young wingless larve. In the case of Aeridium 
peregrinum, these can be destroyed in millions by driving them into 
lines of trenches or burning straw, long lines of screens three feet 
high, made of cloth with a narrow band of slippery waxcloth along 
the top, being most useful for guiding the insects into the traps. 
In the case of Aeridium suecinctum, which refuses to be driven in this 
manner, the best thing has been found to be collecting the insects by 
dragging bags, made of stout cloth, over the crops in such a way as 
to catch the young locusts. 
In the School Museum isa specimen of Acridium peregrinum, also an 
illustrated diagram which gives its life history in detail, The students 
should examine these carefully. ‘They should also sketch one or two 
Acridide in their note-books. 
Locustid@" (Tree-crickets).—These insects are much like Acridide, but 
‘ T¢ is unfortunate that the name Locustid@ should be applied to a group of insects 
other than what are popularly known as “locusts.” The usage, however, is so well estab- 
lished that it would be difficult to change it without producing further confusion. 
