18 



(13.) Lecanium hesperidum>, Linn. (The Common Shield-Scale.) 



Diagnosis. — Scale brownish or yellowish, oval in outline, somewhat 

 convex, smooth and more or less shiny. The young are produced 

 alive. 



Distribution. — This is perhaps the most widely distributed of all 

 scale insects, the distribution having been brought about, of course, by 

 human means. In the West Indies, it occurs in Kingston, Jamaica ; 

 elsewhere it is known from Mexico, the United States, Europe, South 

 Africa, Chili, Australia and New Zealand. 



Food- plants. — As might be expected from its distribution, its food- 

 plants are various. In Jamaica it has been found on mango, an orchid 

 (Stelis sp.) and Hippeastrum equestre. In other countries, on orange, 

 ivy, rose, myrtle, &c. 



Destructiveness. — Although well known as one of the more injurious 

 scale-insects elsewhere, it appears to be rare in the West Indies, and 

 of little economic importance. Why this should be, it is hard to say ; 

 it cannot be that it does not flourish in the tropics, as at Vera Cruz, 

 Mexico, it appears to do very well. 



Enemies. — In the United States it has several Chalcidid parasites, 

 namely Coccophagus lecanii, Fitch, C. cognatus, How., G. vividus, How., 

 C. flavoscutellum, Ashm., Encyrtus flavus, How., Eucomys bicolor, How., 

 and probably others. According to Prof. F. M. Webster, E. flavus is 

 especially efficient in keeping it in check. 



(14.) Lecanium termination, Ckll. (The Broad Shield-Scale.) 

 Diagnosis. — Somewhat over \ inch long, very similar to L. hesperidum, 

 but broader in proportion to its length, and ornamented with radiating 

 blackish bands. For fuller details see Journ. Inst. Jamaica, Vol. 1, 

 p. 254. 



Distribution. — Known from Kingston, Jamaica, and Vera Cruz, 

 Mexico. Specimens may be obtained in the Marine Grardens, Kingston. 



Food-plants. — In Jamaica on the so-called almond ( Terminalia) ; in 

 Mexico on a liliaceous plant not identified. 



Destructiveness. — Not at present known as a seriously harmful species, 

 but may become so ; as the great difference between its two known 

 food -plants indicates that it will very likely feed on a variety of things 

 like L. hesperidum . 



(15.) Lecanium Unguium, Dougl. (The Long Shield-Scale.) 



Diagnosis. — It resembles L. hesperidum, but differs from it in the 

 opposite way from the last, being longer in proportion to its breadth. 

 It shows radiating blackish streaks, much as in L. terminalia. 



Distribution. — Originally found on hothouse plants in England, but 

 apparently a native of the West Indies. It occurs in Jamaica and 

 Antigua, and Mr. Maskell records what he considers to be the same 

 species from the Fiji and Sandwich Islands. 



Food-plants. — Very various, Acacia, Anona, Myrica, Averrhoa, Spa- 

 th&phyllum, &c. Mr. Barber found it infesting pigeon peas in Antigua. 

 Mr. Newstead sent me specimens from Euphorbia in an English hot- 

 house. 



Destructiveness. — Apparently a rather serious pest in the West In- 

 dies, and from its almost omnivorous habits, liable to become more so. 

 It is, however, a most singular thing with regard to this and the last 



