RHYNCOTA. ■ 39 



adult form devour numbers, the larvae of the Lace- 

 wing Fly {Chrysopa vulgaris) — but it is not common 

 enough to be of much service — and the larva of the 

 pretty two- winged Si/rphus. But the combined effects 

 of all these are not equal to those of some of the 

 Hymenopterous Ichneumons, which often occurring in 

 enormous quantities do eminent service in the destruc- 

 tion of Plant-lice. The turnip crops in many of the 

 midland counties, including Shropshire, suffered fearfully 

 in the year 1865 from the attacks of various insects. 

 The effects of the destructive work of the Aphis in the 

 months of August and September of that year, were 

 most remarkable. Crops that had survived the turnip- 

 beetle ("Fly") and the fat caterpillars of two moths, 

 A gratis segetum and A. exclamationis, were suddenly 

 attacked by countless myriads of Aphis, chiefly of the 

 species A. brassica?. In a few days that which promised 

 so well was liopelessly blighted ; the leaves first curled 

 and puckered inwards, then withered and died; the 

 smell arising therefrom tainted the air far and wide 

 with a peculiar offensive odour. Scarcely a green 

 turnip field was to be seen for miles around ; nothing 

 but dead leaves, which in the distance, gave to the field 

 rather the appearance of a brown fallow than a crop of 

 Swedes. Towards the middle of October an avenging 

 army of other insects came in myriads ; the turnip 

 fields swarmed with them, your clothes were covered 

 with them. They were but tiny creatures, no larger 

 than the Aphis, about Ij line in length and 2j in 

 expanse of wing. The insect in question was the 

 Aphidius (Trionyx) rapco of Curtis, one of the Ichneu- 

 monidce, whose offtce it is to pierce the bodies of the 



