276 Iiisect Pests. 



Not only can this parthenogenesis last for one generation, 

 but in one species at least {A. fasciata) Dr. Osborne (Ent. Mo. 

 Mag., XIX. 97 ; XX. 200 ; XXI. 128) has shown that a third gene- 

 ration may be obtained without any male connection. 



Prevention and Teea.tment. 



The attack of the gooseberry and currant sawfiy is usually 

 fairly persistent. Year after year certain gardens, and even certain 

 parts of a garden, are attacked by these pests. This is when no 

 steps are taken to check the increase of the insects, which, in all 

 cases, pupate in the earth beneath the bushes. From these pupse 

 the adults emerge close to the food plant of their future progeny, 

 and thus can readily deposit their eggs. It is therefore very desirable 

 to check this increase, or to try and exterminate the pests when in 

 their winter quarters. 



This can be done by removal of the earth and pupte. Eenioval 

 of surface soil during the winter and burning it or burying it deeply 

 whilst the fresh soil taken from the hole is placed beneath the 

 bushes, is an excellent plan, and may well be practised when the 

 number of bushes devastated has been small. The earth may also 

 be burnt and soon replaced — all the cocoons thus being destroyed. 

 The earth tehould be removed to a depth of 3 or 4 inches, as the 

 winter is passed by the pupa^ deeper in the earth than occurs 

 during the summer. Where this plan has been employed it has 

 met with success. In regard to the application of caustic substances 

 to the soil, nothing answers better than gas lime, but it is very 

 doubtful if it has much direct effect. Kainit has been employed 

 with very doubtful results. 



Turning the soil over does little good, for the cocoons have to be 

 very deeply l)uried to prevent the adults from forcing their way 

 out of the earth. 



Benefit has resulted from the application of quicklime spread 

 beneath the bushes and deeply dug in the autumn. A plan 

 adopted by certain gardeners is to beat the earth under the bushes 

 that have been attacked early in the spring, so as to make the 

 soil too firm for the insects to pass through when they have hatched. 

 Experiments made have not shown this plan to be of much use, 

 for I found that even when the earth has been beaten much firmer 

 than could be done under ordinary circumstances, the flies managed 

 to force their way out. 



It is too early yet to speak with confidence of the effect of 



