The Rosv Rustic. 81 



POTATO TKSTS. 



The Rosy Rustic {//i/dracia mlcacea) attacking 



Potatoes. 



Amonf^st the numerous enemies iVum wliicli the polaln crop 

 suft'ered during 1902 wei-e the larvie of one of the nocluid mollis 

 known as the l!osy llusiic {Jfydrfrcia micacea). This attack was 

 reported to the liourd of A,Lnieullure from two localities, namely from 

 Winton, Manchester, and from near Wigan, Lancashire, and was also 

 observed pei-sonally. The two notes sent with these larvie were as 

 follows : — 



(1) Enclosed are prubs that have uttiicked and are dcstroyini: a larjje 

 jKitch of jK>tatoes ; will you kindly say what they are and what remedy I 

 can take. 



(2) I herewith send two insects that I have found amon^'st my 

 potatoes. They were looking well to about a week ago. Any information 

 about them will be thankfully received. 



In both cases the caterjiillars were found to be working in a 

 similar way, namely, by tunnelling up the stalks of the potatoes, 

 completely hollowing them out and so killing the haulm. Should 

 this pest become veiy numerous it would Ihj a serious matter, aa 

 remedies are quite out of the question save hand-picking the 

 attacked haulm. These caterpillars are recoitled as feeding in the 

 stems of equisetums, docks, valeiian, but probably attack a variety 

 of other jjlants. 



The larva when mature varies from an inch and a (juarier t<> an 

 inch and a half in length. The back and sides ai"e dull puri»lish- 

 bixtwu, paler on the fii"st three segments and where the segment.s 

 join, the sides and venter aixj of a dull flesh coloiu', the legs pale and 

 the head yellowish-brown ; on the .second .segment is a bnnvn .semi- 

 circular plate broadly margined in front with Idackish-brown and a 

 shiny yellowish-brown ])atch on the anal .segment with a jKjsterior 

 lx)nler of small dark warts ; on the segments ai-e small dark-brown 

 tul>ercular warts each with a Jine terminal hair ; the spii-acles are 

 deep brown and the prtdeg^ pale with black extremities. 



IV'fore pupation the larva Wcomcs a paler dull snu»ky flesh 

 colour all over, with a dusky median doi-sal line. The full-fed stage 

 w reached from the l>eginning to the end of July. During the whole 

 of its life the larva burrows up the haulm and emits a great quantity 

 of green frass ; a round e.xit bole is made in the stem, the fra.ss being 



r, 



