228 Miss A. L. Embleton on the 



harbour tliem under their webs iu folded leaves, etc., where, 

 safe from the attacks of parasites and enemies, they in- 

 crease and multiply inordinately." He thinks the popu- 

 lar theory that wind carries scale insects from tree to tree 

 is fallacious to a great extent, but that there is an indirect 

 action of the wind, due to the influence it exerts upon the 

 flight of insects and otlier winged animals which transport 

 Coccid/e; this applies with particular force to spiders whose 

 webs are carried in the direction of prevailing winds. 



Hubbard's brief observation in his paper on "Insects 

 affecting the Orange," suggested the experiments con- 

 nected with insects and spiders conveying the pest, which 

 I carried on last year with Mr. C. Warburton, as to the 

 modes of dissemination of the black-currant gall-mite 

 {E')'io2')hyes \_Phytopt'Us\ onbis)* Here it was found that 

 spiders, Aphida3, Coccinellid larvae, and, indeed, any pass- 

 ing creature, carried the mites in considerable numbers 

 from bush to bush. 



Thus it appears probable that, in a state of nature, 

 CoccidiB are largely disseminated by the agency of other 

 insects. The males are active on the wing, and if a single 

 female Avere transported by an insect to another tree, a new 

 colony would in this way soon be established. This mode 

 of dissemination, and the observations I have related 

 as to the crawling of the young on inanimate objects, are 

 clearly of considerable significance in connection with the 

 quarantine operations that I have referred to as being 

 carried out in different parts of the world. For the creatures 

 may be imported on merchandise or by insects as well as on 

 plants. Neither should it be forgotten, that if a pernicious 

 scale be once introduced and then all other importations 

 be prevented, then the parasites that may be contained in 

 the scales are excluded. To avoid this, a knowledge of the 

 marks by which parasitized scales can be distinguished 

 from others, is really essential in the carrying out of the 

 quarantine regulations. 



Fortunately for the prospects of the cultivator, it some- 

 times happens that in places where noxious insects have 

 been introduced, some native insect may bo ready to take 

 up the work of control that is performed by other 

 destroyers in the original country. Marlatt f in his recent 



* Liun. Soc, London, xxviii, pp. 366-378, pis. 33. 34. 

 ■f Proceedings of the Thirteenth Annual Meeting of the Associa- 

 tion of Economic Entomohjgists, 1902, p. 45, 



