Colorado Beetle. 89 



pass the winter in the pupal stage, which, however, is apparently 

 exceptional. 



This secondary method of passing the winter makes the insect 

 more difficult to cope with when it makes its appearance in a new 

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

 colony that is found. 



The number of beetles that appeared this year (1902) was not 

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

 even under such unfavourable circumstances as existed on the plots 

 at Tilbuiy. 



From specimens in the National collection it seems that there are 

 three closely-related species of Borypliora, namely, D. ^mdccemlineata, 

 Stal ; D. juiida, Germ. ; and D. melanotJwrax, Stal. The first-named 

 has black legs, but otherwise resembles the Colorado Beetle. 

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

 spots and central mark, as seen in the Colorado Beetle. D. juncta^ 

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

 the wing cases very closely united, forming almost one broad single 

 line. 



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

 Stal, but there seems to be no difference between it and D. undecem- 

 lineata. 



The only species likely to be confounded with the potato pest is 

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

 being much paler than decemlineata, and when adult by having a pale 

 head instead of a black one ; its eggs also differ, being wliite instead 

 of orange. 



The Pteports sent to the Board of Agriculture on visits paid to the 

 infested plots are appended. 



First Report on Colorado Beetle Outbreak at Tilbury. 



The potato plots in the allotments iu Tilbury Dockyard were visited on 

 Aiigust 22nd, I'JOl. 



The Colorado Beetle {Dorijphora 10-Uneata) was found to be present. 

 The beetles were not at all numerous, not more than two dozen being 

 observed. 



They were, however, very active, and breeding was going on. Larvas- 

 n all stages were found and three batches of ova. 



The beetles seemed to be limited to about fifty yards of the allotments, 

 the end nearest the station being quite free from the pest. A single 

 specimen was also found on the Nightshade. None were detected in the 

 rough herbage surrounding the plots, a likely place to harbour hibernators 

 during the winter. 



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



