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Scale insects. Scale insects are attacked by the para- 

 sitic Hymenoptera, which have habits very similar to those 

 of the egg parasite mentioned above. The eggs ot Jhe para- 

 sites are deposited within the body of the scale insector 

 under its protective covering, and the young grubs which 

 hatch Prom these eggs tVr<| upon the tissues of the body of 

 t lir scale insect. <>r upon the eggs or young. 



Only a few species of West [ndian scale parasites are 

 known; and the exact extent of their usefulness lias not 

 been determined, in the case of most oi: the scale insects, 

 t lie amount of control which maybe exerted by an insect 

 of this kind is well illustrated in the case of the black scale 

 of cotton, or the Hibiscus shield scale, as it is called. 



The black scale of cotton was a very serious pest in Bar- 

 bados, in 1905 and 1906. About that time its parasite began 

 to develop very rapidly, and for the past two or three years 

 the attacks of the parasite on the black scale have so com- 

 pletely checked its host that no serious outbreaks of black 

 scale on cotton have been reported. 



When'scales are seen with smair "round holes in them 

 it is a sure sign that the parasites have been present, have 

 completed their life-cycle, and have emerged. It rn^iy be 

 taken as a safe supposition that many other scales which do 

 not have the holes in them are parasitized and that the 

 holes will appear when the parasites are full-grown and 

 make their escape. 



Scale insects are also attacked by predaceous enemies 

 lady-birds, both in the larval and adult stages, attack the 

 young crawling larvae of many species of scales. The larva 

 of the lace- wing ny has a similar habit of feeding on the 

 young of scale insects, and it is likely that these insects play 

 an important part in the control of scale insects. 



The caterpillar of a small moth feeds upon certain of 

 the larger shield scales, and birds have been observed when 

 they appeared to be eating scale insects. It is not likely, 

 however, that these two last-mentioned natural enemies 

 exert very much control over the abundance of scale insects. 



Parasitic fungi are among the important natural 

 enemies of scale insects in the West Indies. The red-headed 

 fungus, the black fungus, and the shield scale fungus all 

 have a wide distribution throughout the West Indies. 



