THE CANADIAN ENTOMOLOGIST. 17& 



is what he did : First, he rubbed the first pair of legs together, that is, the 

 tarsi and tibipo, and then each leg rubbed the other all the way down to 

 the tarsi, much as a man washes his hands and arms. Then the middle 

 leg of one side was vigourously rubbed against the hind leg, and then 

 against the front. Then, with the front legs, the antennae were rubbed 

 quite vigourously, but always from the base to the tip, so as ntn to disturb 

 the tactile hairs which all point in that direction. The middle legs were 

 bent under, and the sternum and abdomen rubbed with the tibife. The 

 minuteness and (juick motions of the bug caused many points to be 

 missed, but this is the process in its essentials. The reason for the use of 

 the tibiae is that all are furnished with a comb at the distal end, running 

 crosswise of the leg. 



In common with all tlie other Gerrids, Microvdia americami displays 

 the phenomenon of apterousness, but in a very marked degree. Ordinarily, 

 all ihe examples of Microvelia americana taken, or to be seen in collec- 

 tions, are wingless, but at times it is possible to get a few winged 

 individuals in sheltered si)ots, under the overhanging banks of streamlets 

 principally, or in exceptional seasons or situations. Thus, in the summer 

 of 1907, there was a great abundance of winged individuals of normally 

 apterous species to be found in the streams about White Plains, N. Y. 

 Then I secured some dozen or so, seven in one limited area of perhaps 20 

 or 30 feet on one August day. 'i'he next summer, also in August, no less 

 than 15 winged were taken in a. roadside drinking trough, which was fed 

 by a cold stream flowing from a hillside in a pasture. They were gathered 

 in large numbers at the inlet end of the trough, where the water ran 

 coldest. In the tropics the winged individuals are more abundant, as 

 Westwood notes in his introduction, where he says Hope possessed a 

 large number of Microvelia pnicheiia from St. Vincent, almost all winged. 



Distant, in Hemiptera of British India, notes that Green has taken in 

 Ceylon Microvelia singalensis in an acetylene moth trap. I have never 

 got any of our species at light, but doubtless the fact will be recorded by 

 some fortunate investigator in due time. 



This little bug does not appear to be as amorous as its larger 

 relatives of the Gerrijice. According to the classification, of Gadeau de 

 Kerville, of the ways of mating in Hemiptera,* it comes under 

 " accouplement par superposition," as in the Gerrince, and, in fact, in all 

 the water-bugs I have observed. I was able to observe the act in some bred 



8. 1902, Bull. Soc. Ent. Fr., No. 4, p. 68 



