32 REPORT OX INJURIOUS INSECTS FOR 1907. 



Clean cultivation is all-important in dealing with this pest. In the 

 early part of the year it lives on charlock and other cruciferous weeds, 

 later passing on to cabbage and turnip crops. It is most important that 

 all such weeds should be destroyed. Further, all infected cabbage 

 stalks and turnip peelings should be burnt, and not allowed to rot in 

 heaps on the ground. 



I have not yet had an opportunity of experimenting with Apterite 

 on this pest, but I think it will be found an effective remedy. 



THE TURNIP SEED WEEVIL. 



Ceuthorhynchus assinrilis, Payk. 



A Staffordshire correspondent forwarded Turnip seed badly in- 

 fested with the larvae and pupae of this tiny beetle. 



Seed merchants know it as a most destructive pest, for pods 

 which have been attacked, contain few, if any perfect seeds. 



In a sample of seed sent, the fat, yellowish- white larvae were 

 present ; also cocoons composed of agglutinated seeds, inside each of 

 which I found a pupa. 



This beetle attacks other cruciferous plants in a similar manner. 



Seed known to be attacked should be fumigated with bisulphide 

 or carbon (See p. 56). 



THE PINE WEEVIL. 



Hylobius abietis, Fabr. 



The insect is one of the commonest, and at the same time, one 

 of the most destructive to pines we have in this country. Personally, 

 I have no experience of it apart from pine, but it is known to attack 

 other conifers, as well as oak and other trees. 



LIFE- HISTORY. 



The beetles swarm from May to June, and breed on to September. 

 The eggs are deposited on the stumps and roots of the pines. 



They hatch out in from fourteen to twenty-one days, and, until 

 well on in the autumn, form their characteristic burrows ; passing the 

 winter at the end of these burrows. During the first year they feed 

 upon the bast and sapwood ; so that, so far as the larval stage is 

 concerned, they do little damage. Pupation takes place late in the 

 following spring, in the roots or stump, and the perfect insect appears 

 from May to September. 



Those \vhich emerge in the spring gnaw the bark of the young 

 plants, thus allowing the resin to exude. In some cases the trees 

 become almost completely peeled. 



During the winter, the adults hibernate in hollow stumps, amongst 

 dead leaves, under stacks of \vood, etc. 



