184 



of destrovers. So complete and so rapid was the destruction in some 

 Sstances^ that a Mhole field was found, in two or three days. to pre- 

 sent only an assemblage of skeletonized leaves ; and thxs too whea 

 the turnips had attained a considerable size. ,• , u^ 



The insect whose proceedings have been thus bnefly ^o^^^d be- 

 longs to the Hymenopterons family TenthredimdcE ; it is tjie ^<Ja^^« 

 Centifol-KB, a species first noticed by Panzer. Mr. \ arrell desenbes 

 the perfect insect and the caterpiUar ; and then recurs to the damage 

 effectedby the latter. By their repeated broods the devastation wa^ 

 continued for so long a time that even the third sowmg did not m all 

 caSrescape destruction ; and itwas not until the occurrence of the 

 hea' VS in September, terminating the unusuaUy dry summer. 

 thatihe mischief ceased. The destruction of the leaves caused. in 

 mSt nstSices, the loss of the root also ; and where the leaves suf- 

 Sred fmm the attacks of the black caterpiUar, but not sufhciently to 

 occasion the death of the plant, the turnip itself became Fthy and 

 of litrte value. It has become necessary, Mr. YarreU statės, to im- 

 port the root largely from the Continent to supply the deficiency of 



'""'linemedial measures adopted on a former visitation we the 

 turnSg into the infested fields of a large number of ducts^į° 

 S3v devoured the caterpillars as they were brushed from the 

 Paves by a boy with a long pole ; the passing of a hea^T roUer over 

 the Sound at night, when the caterpUlars ^vere at their feed; ąnd 

 the ftrewrnfof qui k lime by broad cast over the fields. rene^-ing 

 lt as often^ it was disperseŽ by the wind. The atter mode was 

 generaUy considered as the most eflfectual preservative. 



