Sept. 1895.] 



INJURIOUS INSECTS AND FUNGI. 



165 



infested with the larva? of the pea beetle, Bruclms pisi, which 

 materially injure and, in some cases, altogether destroy their 

 powers of germination. Some British seedsmen will not buy 

 peas for seed from certain countries, and many object to have 

 peas from these countries in their warehouses, because they are 

 liable to be infested by the pea beetle, which is most difficult to 

 get rid of when it has been introduced. 



This insect has been confounded with another beetle known 

 as Sitones lineatus, whose habits and history are quite different. 

 This latter insect lives in the earth, and does not enter the peas 

 either in larval or in beetle form. In larval form, it attacks the 

 roots of peas and other plants ; in its beetle form, it attacks 

 their foliage, and sometimes, as in the spring of this year, 1895, 

 causes serious injury to the pea-crop. 



Life History. 



The pea beetle, Bruclms visi, is about the sixth of an inch 

 long. It is black in colour, and thickly covered with brownish- 

 grey hairs. Its antennae are red and have eleven joints. The 

 head is long and drooping, and terminates in a short snout, at 

 the end of which is the mouth, furnished with strong jaws. 

 There is a white spot on the lower part of the thorax, and two 

 large distinct black spots upon the end of the abdomen, which 

 is not nearly covered by the wing cases. The legs are reddish 

 in colour, and the hind legs are very stout and long. The 

 beetle can fly for a long time and for long distances. It 

 may be seen flying about pea plants when they are in 

 blossom. When the pods have been formed, the female beetle 

 places long, spindle-formed, yellow eggs upon their surface, 

 fastening them with a sticky substance. A yellow larva with a 

 black head comes from the egg in a few days, and bores 

 through the skin into the nearest pea, and feeds upon its 

 contents, remaining in the pea, it may be, throughout the 

 autumn and winter following. It then changes to a pupa, from 

 which the beetle is soon produced. There is hardly any trace 

 of the presence of the larvae in peas infested in this way, so 

 that, until pupation takes place, it is most difficult to discover 

 whether they are infested. Before this, the larva " cuts a circular 

 hole quite to the thin outer membrane of the pea, thus providing 

 for the future exit of the beetle, which has only to eat through 

 the thin membrane left by the larva. It has been proved that 

 the beetle would die if the larva had not prepared this passage 

 way, and it has been asserted that it will perish if the hole is 

 pasted over with a piece of paper thinner than the hull itself."* 



Some of the beetles emerge from the peas ir. the autumn, but, 

 as a rule, they do not make their appearance until the spring. 

 In fine warm days, in the early spring, they may be seen 

 in sunny windows and on the walls of warehouses and granaries 

 which contain infested peas. As the weaiher becomes warm 



* Insect Life, edited by ProtVssor Riley, Vol. IV., p. 298. 



