OF WASHINGTON, VOLUME XV, 1913. 57 



deliver at least 55 pounds of locust eggs. In this way a total of 

 629,882 pounds of eggs were collected. 



Achetidoe (Gryllidce) . 



In this family are several species frequently noted in economic 

 literature. The mole cricket of the West Indies, Scapteriscus 

 didactylus Latr., is excessively injurious to tobacco, sugar cane and 

 various other crops in Porto Rico. It is present in various islands 

 of the West Indies, and occurs in South and Central America and 

 in Mexico. Its presence in the southern United States is a well 

 established fact. 



Gryllotalpa a/n'ccma Beauv. is recorded from Asia, Africa, Australia 

 and New Zealand. In Uganda and Formosa, it is said to be ex- 

 tremely injurious to rice. Oecanthus pellucens Scop, occurs in 

 southern and central Europe, western and central Asia. It punc- 

 tures grape canes and stems of other plants like our 0. nigricornis. 



Acheta bimaculata DeG., in Formosa, is very injurious to young 

 vegetation of various kinds, especially cotton, tea, etc. 



THYSANOPTERA. 



There are many species in this order which have shown them- 

 selves in the United States and elsewhere to be formidable enemies 

 of crops, as Euthrips pyri, E. citri, and Thrips tabaci. The habits of 

 these insects, in some cases, are quite favorable to their dissemina- 

 tion from one country to another, and numerous species are already 

 widely scattered over the world. 



Limothrips denticornis Haliday occurs general!}' over Europe, and 

 infests oats, barley, and various fruits. L. cerealium Haliday, the 

 so-called corn thrips, is distributed over all Europe. It is con- 

 sidered by Uzel as one of their more destructive species, injuring 

 corn, wheat, oats and grasses, the attack causing the grains to 

 shrivel and become abortive. Heliothrips hcemorrhoidalis Bouche*, 

 a species which Bouche thought to be native to America, is widely 

 distributed over Europe and occurs in Australia. It is destructive 

 to numerous plants, and is one of our more injurous forms. H . rubro- 

 cinctus Giard, the cacao thrips, is spread over the West Indies, 

 where it is one of the prime enemies of cacao, attacking the pods, 

 tender shoots and foliage. It also injures the cushew, guava, 

 mango, etc. and is recorded from Uganda. The insect has recently 

 made its way to Florida. 



Thrips communis Uzel, in Bohemia, injures potatoes and beets, 

 where it is regarded as quite destructive. T. flava Schr. injures 

 blossoms ot pear, apple, plum, cherry, etc. and occurs on vegetables. 

 In England, this species with T. physopus L. are known as pear 



