[5] COLLECTING AND PRESERVING SCALE INSECTS COCKERELL. 



Coccidse. Even India has received but the most meager attention, 

 although the Ceylonese species have just lately been carefully stutlied 

 by E. E. Greeu. We know nothing of the scale insects of Arabia, Persia, 

 Afghanistan, Turkestan, etc., Japan, until lately, had no coccid records, 

 but some collecting recently done there has yielded excellent results, 

 the majority of the species being new. 



The islands of the Indian Ocean, Madagascar, and the whole of trop- 

 ical Africa are practically unexplored for Coccidte. 



Thus, to sum up, it may be said, in the first place, that the Coccidfe 

 are by far the most abundant in the Tropics; and in the second, that no 

 part of the Tropics has been anything like carefully examined for them, 

 except Jamaica, Antigua, Trinidad, and Ceylon.* There is thus a vast 

 field left for investigation, compared to which the investigated por- 

 tions of the earth are uttei-ly insignificant, 



II. Plants on which Coceidce are found. — Ooccidae are found principally 

 on trees and shrubs. Herbaceous plants in temperate regions, which 

 die down in winter, support Aphididir and Aleyrodidae, but very rarely 

 Coccidse. The reason of this is obvious, since the stationary females 

 would perish when the infested parts of the plant died. Nevertheless, 

 there are some root-inhabiting coccids of great interest, and others 

 which occur on perennial grasses and similar plants. Some, also, are 

 found in the nests of ants. Mr. Newstead has lately taken the trouble 

 to examine such situations in England, with the result of finding sev- 

 eral entirely new and very interesting species. Mr. G. B. King, col- 

 lecting in Massachusetts, has been even more successful. 



Of temperate-region trees and shrubs there are many which have 

 yielded Ooccidpe. The various species of oaks are especially worth 

 examination, while mention must be made of the willows, poplars^ 

 roses, ashes, elms, birches, pines, spruces, and all the rosaceous trees 

 cultivated for fruit. While in the Tropics the leaves of trees are 

 much infested, in temperate regions the smaller branches and twigs 

 will be found to bear most of the scale insects. Evergreens, however, 

 will exhibit species of Diaspinaj on the leaves. 



Going somewhat farther south, the native shrubs and perennial her- 

 baceous plants will show a fair coccid fauna. In the Mesilla Yalley 

 the Atriplex canescens is extraordinarily prolific in coccids, presenting 

 six species, all of difl-erent genera. I have come to regard it as a 

 probable rule in this region that every native shrubby plant will 

 show at least one coccid, though there are several on which none have 

 yet been found. The mesquite, Frosojns, has yielded good coccids in 

 New Mexico, Arizona, and Jamaica, but in each region the species are 

 diflferent. Thus it is evident that collecting should be carefully done 

 at various points in the range of a likely plant; even the Mesilla Val- 

 ley, New xVlexico, and Tucson, Arizona, have very different coccid 



* Professor Townseiid has lately collected with care in Tabasco, Mexico, but the 

 collection has not yet been studied. 



