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if not to enter more íull\' into a discussion of their distribu- 

 tion, food-habits and life-histories. To do this would, however, 

 require more time and space than are at our disposal just at 

 present. Already there are more than one hundred distinct 

 species of these insects known to exist, and careful collecting 

 would undoubtedly add as many more. 



Next to the destructive or migratory species, on account of 

 its great size and powers for llight, should be mentioned the 

 "Langosta Negra" ( Tropidacris cvistata Linn.). This insect 

 although principally a tropical species is found in small num- 

 bers in several of the mountain-provinces. It usually lives 

 in wooded districts where it feeds upon the leaves of trees and 

 shrubs. Being a good flier it sometimes joins paraneiisis when 

 mangas of the latter fly by. Hence the occasional reports 

 which circulate to the effect that locust-mangas are led by 

 kings or queens. While very large, this insect is exceeded in 

 size by a couple of other species of this and an allied genus 

 which are also natives oí tropical x\merica. The}^ never ap- 

 pear in numbers sufficient to cause much damage. 



The, large, green, short-winged locust shown at fig. 3, on 

 plate 27 is known by the name Elceochlora viridicata Serv. 

 It sometimes, as reports say, becomes quite abundant on the 

 camps of several of the pampa provinces where it eats the 

 grasses. The male insect differs from his mate in being very 

 much smaller and in having fully developed wings (See pla- 

 te 27, fig-. 6). Not long since a female was captured and 

 156 fully developed eggs taken from her hoáy. 



Several of the smaller insects figured in the accompanying 

 plates also increase so as to do harm to camps. These are 

 members of the genera Diclirophis and PnyadicJiropliis. 



The insect figured at 2 on plate 27 is inclined to migrate at 

 times. It is also quite abundant all over the Republic north 

 of Bahia Blanca. In color it is green with red spots and bands 

 on head and legs. Its hind wings are delicate blue. The name 

 by which it is known to entomologists is Zouiopoda tavsata. 



Still other locusts like those shown at 1, 4, 5, in Fig. 27 are 

 sometimes among the injurious kinds. The RJwuialea slo//i'i 

 is interesting because of the habits possessed by the saltonas. 

 They invariably go in droves or herds varying in number 

 from a couple of dozen to several thousands. They are also 

 very conspicuous, being shining-black marked with red spots 

 and bands. The voladoras also retain the social habit to a 



