Colorado Beetle. 89 



pass the winter in the i)upal stage, whidi, however, is api)arently 

 exceptional. 



This secondary method of jiassin*;,' the winter makes tlie insect 

 more difhcult to cope with when it makes its appeanince in a new 

 country, and sliouhl be borne in mind in the destruction of any future 

 colony that is found. 



The number of beetles that appeared this year (1002) was not 

 large, but sufficient to show that they can well survive our winter, 

 even umler such uufavouniblc circumstances as existed on the plots 

 at Tilbury. 



Fi-om specimens in the National collection it seems that there are 

 thi-ee closely-related species of Dor^/pliora, namely, Z>. niulcccmlincata, 

 Stal; D.junda, Germ. ; and D. mdanothorax, Stal. The fii-st-named 

 has black legs, but otherwise resembles the Colonuhj Beetle. 

 D. mclanothorax has an entirely dark thorax, not yellow with black 

 sp«»ts and centml mark, as seen in the Colorado Beetle. D. juncta, 

 known as the Bogus Colorado Beetle, has two of the black lines on 

 till' wing cases very closely united, forming almost one broad single 

 line. 



There is a fourth species in the collection, D. mnltitccniata, 

 Stal, but there seems to Ixj no diftereuce between it and D. nndcccm- 

 lincata. 



The only specias likely to lie confounded with the potato i)est is 

 D.jvncta in its larval stage; but it can easily be told when young by 

 Wing much paler than (hrem/incata, and when adult by having a pale 

 liead instead of a black one ; its eggs also differ, being wlute instead 

 of omnge. 



The Ileports sent to the Boanl of Agriculture on visits paid to the 

 infested plots are appended. 



First Report on Colorado Erctlc Outhrcok at Tilhury. 



The potato |)lots in the allotuK-nts in Tilbury Dockyanl were visited on 

 Au«:ust I'ind, I'.iol. 



The Colonido Bc-etle {Doryphora lO-Uneata) was fnuud to )>' present. 

 The Ixx'tles wea* not at all numerous, not more than two dozen being 

 ol>served. 



They Wire, howevir, very active, and briM-ding w;us going on. Larvai 

 n all sUiges were found and thnr l«it«lies of ova. 



The beetles 8ecmc<l to Ix- limited to alwiit fifty yanls of thf alJotnientR, 

 the end nearest the station In-ing <|iiitc free from the jx-st. A single 

 RiKH'imen w;is also found on the Nigiiusjmde. None wtre d»'t<H'tc<l in the 

 rough lurbiigi- surrounding the jilot/^, a likely place to Imrlwur hilxTuatore 

 durini: the winter. 



The beetles showed great vitality, but the damage, although noticeable 



