Scale and other Parasitical Insects. 307 



troublesome orsoabundantly represented in the Gardens as 

 this. And as regards the several species, the same remarks 

 are true. That mentioned is found to attack several plants, 

 but none to so great an extent as the mango, from which it 

 has derived its name. In form it is flat, and rather acumi- 

 nate, being broader at one end than the other, and of a 

 brownish colour. It affe6ts the under sides of leaves, never 

 apparently the branches. It does notadhere very tenaciously 

 and is best removed by hand washing with soap and water. 

 Lecanium testudo. — A second species, irregular in out- 

 line and dark or black in colour. Compared to the last, 

 the members comprising the colonies are few in number. 

 It is found to attack several plants. Instead of con- 

 fining its ravages to the parenchyma of the leaves, it 

 preys on their ribs, stalks, and also on the branches. The 

 plants on which it is found are the Akee (Blighiasapida)^ 

 the Oronoque tree and other species of Erythrina, Com- 

 bretum laxum &€. Perhaps L, testudo may be looked 

 upon as the least troublesome of this genus. 



Planchonia fimbrtata. — Twigs and leaves of the Akee 

 affefted by scale were sent to Mr. MclNTlRE on which was 

 found this species, accompanied by L. testudo. This, how- 

 ever, is by far the more destru6live of the two, and indeed may 

 be regarded as more destru6live than any yet mentioned. 

 Its mode of attack is similar to that of Z,./^.?^«^^, but it gives 

 the stem or part of the stem, a warted or cankered appear- 

 ance, and if left unchecked greatly arrests the growth of the 

 plant. ItsprincipalhosthereistheAkee,butithas been found 

 as well on the Central American Rubber (Castilloa elas- 

 itca), and also on one or two native trees. Alltheseplants, 

 when it is present, exhibit the same warted and cankered ap- 

 pearance. To remove it a small hard brush is required. 



