3S1 



inally infests the upper surface of the k'aves, but also occurs on the fruit 

 of the Orauge. Morgan, as quoted above, records it from Dictyosper- 

 inurn. 



HABITS AND HABITAT. 



The Kufous Scale is extremely abundant at Kingston; but at INFon- 

 eague I found it more rarely ; and at Mandeville, nearly 2,000 feet above 

 sea level, it was not to be seen, and the oranges and cocoanuts, so far 

 as observed, were free from scales. This immunity in the mountain re- 

 gions has been attributed,* no doubt correctly, to the damp and com- 

 parative coolness, a hot and relatively dry climate being necessary for 

 their favorable existence. 



It is also to be observed that while some palms, on which there are 

 no other Diaspina'^ are so badly infeste<l that the surfaces of the leaves 

 are in places absolutely covered by scales; others, which support Inch- 

 naspis, Aspidiotus palmce (n. sp., Ckll. MS.), A. Jicus, I>iaspis, or Chio- 

 naspis, are less preyed upon by A. (irtwidatua. It is not always a 

 question of want of room, as some of these species do not cover the 

 leaves in the manner of the Rufous Scale, but there seems to be a form of 

 natural selection at work, so that Mhen one species has obtained a foot- 

 ing on any given tree, another has difiiculty is establishing itself. This 

 may serve to account for the fact that although J^. articulatusis common 

 in Barbados, and Cocoanut is one of its known food-x^lants, some badly 

 infested leaves of Cocoanut from there show no J., ((rticulatu.s, but quite 

 different species. In Kingston, some palms are, one might say, smoth- 

 ered in A. articnlatus; while others, which support different kinds in 

 addition, are on the whole less severely attacked, notwithstanding the 

 greater number of species infesting them. In this way, it seems possi- 

 ble that a si)ecies of Coccidie might be indirectly beneficial by keeping 

 off another species more destructive thau itself. 



REMEDIES. 



The remedies usually employed for other species of Diaspince will be 

 appropriate for A. artieulatus; but as it infests so great a variety of 

 plants it will be more difficult to control than others, which, like A. 

 2)((bna\f arc apparently confined to one. I learn from I'rof. Riley that 

 it has never yet been detected in the United States, and as it is a very 

 undesirable insect, due measures should be taken in order that it may 

 not be accidently imported. Whether it exists throughout the West 

 Indies remains to be ascertained. From its occurrence both in Barba- 

 dos and Jamaica, this might be expected, but it must be remembered 



* See Journ. Imt. Jamaica, Vol. 1, p. 48, (1892). 



t The difference of taste between some closely allied species of insects is very re- 

 markable. A. palmw seems confined to Cocoanut, but A. rapax, a very close ally, 

 lives on many different plants. In Lepidoptera Deilephila Uneata is almost omnivor- 

 ons, vrhereas D. euphorbia- eais one species of Euphorbia only, I believe. 

 771— J^o. 11 3 



