﻿272 THE ENTOMOLOGIST. 



insects destructive to agriculture and forest were dealt with by 

 many delegates appointed by our Colonial and by foreign Govern- 

 ments. The paper read by Sir Daniel Morris on behalf of Mr. 

 W. A. Ballou (Imperial Department of Agriculture), "Some 

 Entomological Problems in the West Indies," demonstrates 

 beyond dispute how an intimate knowledge of the life-histories 

 of insects may be put to practical uses, and how by the intro- 

 duction of the natural parasite of an immigrant pest the attacks 

 of the pest may be controlled and even defeated altogether. For 

 example, in the sugar-canes of Barbados a root-boring weevil, 

 Dia^repes abhreviatus, has become a pest ; in St. Kitts termites, 

 ? Termes flavipes, have attacked the ripening stalk ; in Barbados 

 the red maggot. Perry condyla gossypii, in Antigua the flower-bud 

 maggot, Contarinia gossypii, and in all the cotton islands except 

 Barbados the leaf-blister mite, Eriopliyes gossypii, have done 

 great injury to the growing plants, but by the destruction of old 

 plants at the end of the season, and picking off and destroying 

 infested leaves, a satisfactory crop has been ensured. Yet the 

 control of some of these pests by their natural enemies has 

 proved even more effective. In Barbados black-scale, wiiich 

 wrought widespread havoc, is now completely controlled thereby. 

 By the use of the shield-scale fungus the scale insects, which are 

 accompanied by the black blight, have been much reduced. In 

 St. Vincent the cotton worm, Alabama argillacea, has been sub- 

 jected successfully to several predacious insects, especially the 

 •' Jack Spaniard," Polistes annularis. 



The question of international action to check generally the 

 importation of pests was raised in the discussion of Mr. A. G. L. 

 Eogers's paper on "The Necessary Investigation with relation to 

 Insect and Fungus Enemies of Plants, Preliminary to Legis- 

 lation." Mr. Ptogers pleaded for the consideration and establish- 

 ment of principles upon which such action might be made 

 feasible. So far, he said, regulations of the kind, while hamper- 

 ing international trade, had in no case been successful in 

 preventing the introduction of disease, the truth being that 

 the pest had anticipated the law. But the real cause of the 

 failure is due to ignorance of the conditions under which the 

 pests spread rapidly enough to become a serious danger, and of 

 their distribution throughout the world ; experience proving it 

 impossible to foretell which species will fail to establish them- 

 selves, and vice versa. Thus, although the potato moth is 

 harmless in Italy, it became a pest when introduced into India ; 

 while several Continental pests have failed to establish themselves 

 in England. A close study of the pest in the mass, and of 

 the aggregate injury caused by a" congregation of destructive 

 insects in their maximum intensity, would prove the most useful, 

 and each country should be invited to compile a black list of 

 those present in sufficient numbers to be characterized as 



