THE CANADIAN ENTuMOLOGIST. 191 



From four or five batclies of ova lunnbering about 200 all told, three 

 adults were obtained, which took respectively 43, 53 and 54 days to 

 arrive at maturity, from the date of oviposition, the last being unduly long 

 in the last nymphal instar. It is, therefore, evident that several broods 

 are possible in the course of one summer. There are five nymphal 

 instars, or seven altogether in the full life-cycle from the egg to the adult. 

 The adults overwinter, burying themselves in the mud of their haunts, and 

 they may sometimes be found in warm days in early spring*"' all covered 

 with mud and lethargic, perched on some rock on the shore, in the sun. 

 ()vij)osiiion begins in the spring, and continues through the summer. It 

 is not unusual to fmd in August the ad.ilt male with freshly-deposited 

 ova, in company with all the nymphal instars, at one and the same time 

 aid place. I have found egg-laden males as early as the middle of May, 

 and as late as the end of August. The last date would allow the young 

 to arri\ e at maturity by the first week in October, before the weather got 

 too cold. Active adults have been secured as late as the middle of 

 October, and partly torpid ones on a cold day in early November. 



Belostonia fluniinea is, in common with all water-bugs, a predaceous 

 carnivore, feeding on the juices of insects and snails, and very probably 

 of such small or weak vertebrates as it can overpower. In times of stress 

 it will feed on its own nymphs, which in turn are not averse to preying on 

 each other when hungry, which is always. In my aquaria they are fed 

 flies, which are put in alive, but their sufferings are over as soon as they 

 are seized. The bug apparently injects some paralyzing poison into its 

 victims. Ordinarily, the prey is seized by the raptorial anterior pedes, 

 and at times all three pairs are employed to hold fast some powerful 

 insects or large victim, such as a snail. 



This water-bug's favourite haunts are muddy-bottomed ponds, where 

 it lurks among the weeds at the bottom. Sometimes it is found in little 

 bayed-in places in streams, where there is a back-water, with grasses 

 growing into it from the banks, or from the bottom. On one occasion a 

 single individual was found under a stone on the pebbly banks of the 

 Rahway River, near Cranford, N. J. 



Belostoma also is parasitized by a water mite, but it does not appear 

 to be injured in any way by its guest. 



Both the adult and the nymph obtain their air supply from the 

 atmosphere, by piercing the surface with the terminal abdominal segments 

 In the adult there is a broad pilose band at each side of the abdomen, 



6. March 21st, in one instance. 



