65 



NOTES ON THE BEHAVIOR OE THE COLORADO POTATO BEETLE 

 IN GREAT BRITAIN. 



(Leptinotarsa [Donjphora] (Jeceiulineata Say). 

 By Fred. V. Theobald. 



Wye Court, Wye, England. 



The advent of the Colorado potato beetle into Great Britain in 

 1901 gave rise to grave apprehensions, which, judging from its behav- 

 ior during its stay on our shores, were certainly not unfounded. 

 For once the country was prepared to deal drastically with this 

 unwelcome intruder, for a bill had been passed by both Houses of 

 Parliament in 1877 by means of Avhich the existing board of agricul- 

 ture has power to take over land infested with the Colorado potato 

 beetle so as to insure its eradication. The necessity of this measure 

 was amply shoAvn during 1901 and 1902 when the " spearman " ^ was 

 present in this countr}^ 



The few notes I made on the general behavior of this beetle during 

 its stay with us may not be uuAvelcome to those in whose land it 

 flourishes, and of interest to others into whose country it may any 

 day be imported. I believe the British invasion is only the third 

 that has occurred in Europe, the two previous outbreaks having 

 occurred in Germany some years ago. 



The beetle was reported to the officials at the board of agriculture 

 m August, 1901, as being present in some allotments in Tilbury 

 Dockyard. On the 22d of that month I visited the dockyard and 

 found the beetles very active and full of generative vitalit}^ They 

 were not numerous, some two dozen or more only being observed, but 

 many more had evidently been at work and some had been collected 

 and killed. At this time they were depositing eggs, and I found 

 larvae in all stages of development. At a glance one could see that 

 the beetles had been at work some time; probably the colony had been 

 there some months before it was detected. The potatoes v^^eve 

 uoticeably defoliated, but mainly, it seemed, by the larvse and not by 

 the adults. The beetles did not seem to take wing, but w^ere most 

 iictive, craAvling about in the bright sunshine. I never saw one take 

 Aving in the open, but those I brought aAvay for further observation 

 became most active in the breeding cages, frequently using their rosy 

 wings and dashing up against the glass of the cages. Later I noticed 

 them in my garden taking short flights under their muslin tents. 



The land where this colony had taken up its abode Avas treated in 



« A name sometimes given to the Colorado potato beetle, based on tbe old 

 generic term Doryphora. 



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