JO REPORT ON INJURIOUS INSECTS FOR 1905. 



INSECTA. 

 SPRINGTAILS. 



Collembola. 



Looked at from the point of view of the economic zoologist, 

 the Springtails have until quite recently been regarded as of little 

 or no importance. During the past year, however, large numbers 

 have been sent in by different correspondents, and I have examined 

 numerous cases where, if they were not the primary cause of injury, 

 they played the part of seconders in a very able manner. 



All the species of this order are small, wingless insects present- 

 ing numerous points of zoological interest. I must here, however, 

 confine my remarks strictly to their economic importance as. 

 destroyers of various plants. 



Curtis* mentions a species of Sminthutus (S. solani] as feeding 

 upon the parenchyma of the green leaves of the potato, and states : 

 " In Nova Scotia the crops of turnips and cabbages are principally 

 destroyed, whilst in the seed leaf, by some Smynthurus, the size of 

 a pin's head, and nearly globular. It hops with great facility by 

 means of its forked tail, and may be found on every square inch 

 of all cultivated ground, but it is not plentiful on new land." He 

 also alludes to a Podura (P. -plumbed, Linn.) being abundant in 

 February, 1846, skipping about the rotting potatoes. 



Miss Ormerodt records injury to the leaves of turnips by 

 Sminthurus luteus. 



Guthrie states that he learned from Professor H. E. Summers, 

 State Entomologist of Iowa, that a species, probably belonging to 

 Achorutes, was so abundant in the soil containing seeds, and kept 

 it so thoroughly worked up, as to give the little plants no chance 

 to root, and that many died. 



Theobald** records certain Collembola damaging orchids; and 

 again a species of OrcheselM^ ; also a species of Lipura damaging 

 the roots of cauliflowers and celery. 



Carpenter** has also recorded Achorutes Armatus, A. longis- 

 pinus, and Lipura ambulans damaging bean seeds. 



In March last a correspondent forwarded from Solihull, roots 

 of cauliflowers covered with specimens of Lipura ambulans, Linn. 

 The plants were badly attacked with " Finger and Toe " disease, 

 caused by a fungus (Plasmodiophora brassicae]. This species is 

 extremely common in decaying vegetable matter, but I have not 

 met with a case where they have attacked healthy plants. 



The same .species of Lipura was later sent in from some nursery 

 gardens near Birmingham on Narcissus bulbs, which had been 



* Farm Insects, p 432. 



t Rpt. Ob*. Inj. Insec's for 1(304, p. no. 



\ The Collembola of Minnesota, 1903, p. 4. 



** First Rpt. Econ. Zool., 1903, p. no. 



tt Second Rpt. Econ. Zool.. 1904, p. 75. 



\\ Ibid., p. 158. 



$t Proc. Assoc. Econ. Biol., 1905, vol. i, p. 14. 



