68 The Irish Naturalist. April, 



economic bearing. Yet it has well justified Prof. Miall's 

 remark that the transformations of insects of agricultural 

 importance are fully as interesting as those of any other 

 insects. The first stage larva of Hypoderma^ with its 

 relatively immense mouth-hooks and strong spiny arma- 

 ture, adapted for boring through the skin of cattle, differs 

 so markedly from the smootli second-stage maggot found 

 in the gullet-wall that the life-history might be regarded 

 as approaching the hypei metamorphosis that characterises 

 some Coleoptera. In the latter order besides the oft-quoted 

 cases of larval differentiation among the Meloidae it is well 

 to recall the less marked but highly interesting instances 

 afforded by the Bruchidae — a family of economic im- 

 portance on account of the injury done by them to peas 

 and beans. Here, as Riley and Howard have shown, ^ 

 there is a first-stage larva, provided with legs and a 

 pronotal spiny process, which bores its way through the pod 

 and enters the developing seed within which the legless 

 grubs of the later stages feed. 



During my previous Presidency of this Club, more than 

 twenty years ago, my visit with some of the members to 

 the Mitchelstown Cave led me first to take an interest in 

 those lowly wingless insects, the springtails or Collembola, 

 several blind species of which are included in our Irish 

 cave fauna. At that time beyond a few observations there 

 was nothing to show that the insects had an}/ economic 

 importance, and the severely practical man might have 

 thought that an entomologist, in devoting daj^s and months 

 to their systematic study, was hopelessly wasting his time. 

 During the present century, however, it has been found 

 both in Ireland'^ and in Britain* that several kinds of 

 Springtails are very harmful to roots and other imderground 

 plant structures, to fallen fruit, and to fohage. It is reason- 

 able to suppose that the comparatively sudden rise of the 

 Collembola to importance as injurious insects is not due to 



'^See Carpenter and Hewitt, Irish Nat. vol. xxiii., 1914. PP- 214-221. 

 and Sci. Proc, R. Dublin Soc, vol. xiv., igi^, pp. 268-290. 

 ^Insect Life, vol. iv., 1892, pp. 297-302. 



^Carpenter, Ecov. Proc, R. Dublin Soc, vol. i. (1904, pp. 251-3). 

 *Theobold, " Report on Economic Entomology for 1910 " (pp. 111-127) 



