80 ISew York State College of Forestry 



Plagiognathus sp. II. 



AVanakena and Barber Point, July and August. 



Plagiognathus sp. III. 



Wanakena and Barber Point, July. Knight will discuss this 

 species and the two forms above Avhen he publishes on the genus 

 Plagiognathus. 



Chlamydatus pulicarius (Fallen). 

 Barber Point, August, 1919. 



Family GERRIDAE 

 (jerris remigis Saj^ 



Common, only apterous forms being seen or captured. This 

 insect lives in the coves of Cranbeny Lake, Oswegatchie River, 

 and it often congregates in large num])ers in pools or slow-moving 

 parts of streams. It spends the winter in the mature state. 



Gerris marginatus Say. 



Common. Taken on Crauberiy Lake, Oswegatchie Ixivei' and 

 Bean Pond. This species is a lacustnue and Huviatilc insect. l)ut 

 seems to prefer quiet waters. 



Gerris argenticollis Parshley. 



Taken in the coves of Cranberry Lake with nuirgiiialas and 

 buenoi, 



Gerris buenoi Kirkaldy. 



This is by far the most abundant species of the smaller forms 

 of the genus living in the vicinity of Cranberry Ijake. Its habits 

 and haunts are quite similar to that of G. marginatus. 



Gerris rufoscutellatus (Latreille). 



Very common. Barber Point, Wanakent, Plains, and Conifer. 

 This insect hibernates over winter in the mature form and is 

 among the first of the water-striders to appear in eai'ly spring. 

 The eggs are deposited just beneath the surface film of the Avater 

 upon floating leaves of aquatic plants, small sticks and other 

 objects in the water. They hatch in about ten days or two weeks. 

 In an aquarium the first adults appeared thirty-four days from 

 the time of hatching, but most of the specimens required several 

 days longer to reach the adult state. Like the other members of 

 the genus rufoscutellatus is predaceous and feeds upon small 

 insects, and insects that happen to fall in the Avater and are 

 drowned. Field observations indicate two generations a ywir in 

 the Adirondacks. 



