THE CANADIAN ENTOMOLOGIST. 180 



LIFE-HISTORIES OF NORTH- AMERICAN WATER-BUGS. 



IIV J. R. 1)E LA TORRE I'.UENO, NEW YORK. 



At every turn, since beginning my studies in the aquatic Hemiplera 

 some four years ago, my attempts to verify some observation liave been 

 balked by the extreme meagreness of the information on tlie subject 

 running all through the field of entomological literature. This lack is far 

 more noticeable with regard to the immature stages of the Cryptocerata 

 and of the aquatic and semi-aquatic forms of the Gymnocerata. As a 

 result, my general work has been in the neglected field of investigations in 

 life-histories and habits, rather than in the more commonly accepted form 

 of labour on classification and systematic phylogenetics. During this 

 period a number of partial experiments, more or less unsuccessful, were 

 made, until in the past year, 1905, four species were completely worked 

 out in the full life-cycle from the ovum to the mature Hemipteron. In 

 the following pages will be given in quite a little detail the results of my 

 experiments in raising Belostoma fltcmijiea^ Say, Banatra qiiadridcntata^ 

 Stal., Microvelia americaiia^ Uhler, and Alicrovelia pulchella ? Westwood 

 (Uhler). 



I. 



Life-history of Belostoma fluminea^ Say. 



It is a familiar fact to all collectors of the Hemiptera, that in a 



rumber of the genera of the family Belostomatidce (the genera Be/osto?na, 



Latreille, Abedus, Mayr, Diploiiychus^ Laporte, and Hydi-och'ius, Spinola), 



the ova are borne on the back, covering the hemelytra. Uhler^ records 



this fact without committing himself as to the sex of the bug, but for long 



(in fact, from the very beginning of entomology until within not more than 



six or seven years) it was held that the egg-bearers were females, and that 



the ova were deposited on its own back by each female. Authors have 



even gone to the extent of describing the process at length, going into 



details of " a long protrusile ovipositor which the insect can extend over 

 her own back."' 



This absurdity has had a large circulation, although how so fiat and 

 broad an insect could carry concealed within itself a necessarily bulky 

 organ such as that imagined, has not to my knowledge been satisfactorily 



1. Standard Natural History, Insects, p. 25S. 



2. Leon Dufour, Essai Mong-raphique sur les Belostomides, Ann. Soc. Ent. 

 Fr., 1863, Vol. Ill, p, 378. Diminock, Belostomida? and other Fish-destroying- 

 Bugs, Ann. Rep. Fish and Ciame Comm., Mass., 1886, p. 71. Comstock, Intro- 

 duction to the Study oi Insects, 1888, p. 189 ; Manual for the Study oi Insects 

 1899, p. 131 ; Insect Life, 1899, p. J33. 



June, 1906 



