Vol. xxviii] 



ENTOMOLOGICAL NEWS. 



301 



These are the detailed instars and molts of the specimens it 

 was possible to breed to maturity. It is to be noted that these 

 transformations represent an extreme as all conditions were 

 favorable. There was the warmth of summer and an abun- 

 dance of food, even though it changed not at all from day to 

 day. 



Gerris marginatus — Life History. 



No. 1 — Emergence to adult, 24 days 



One of 4.5 ova deposited by one female. 



These life histories give a period of between 33 and 34 days 

 for the full transformations from the egg to the adult, and of 

 between 24 and 28 days for the five nymphal instars. 



Briefly, then, Gerris marginatus has one embryonic, 5 

 nymphal (or if the first tenuous molt be considered a true 

 ecdysis, 6), and one adult, a total of seven instars, which take 

 about a month. This would allow for three broods a summer. 



Feeding Habits of Adult Chrysopidae (Neur.). 

 I have taken adult Chrysopidae (Chrysopa sp.) on flowers with ex- 

 posed nectar: Pastinace sativa, June 15 and 24, 1886; Tiedemannia 

 r'lgida {Oxy polls rigidior) , Aug. 15, 1888. These visits were men- 

 tioned under Neuroptera in Trans. St. Louis Acad. Science 5 : 459. 

 They are not cited by Knuth, Handbuch dcr Bliitenbiologie, III. 2: 469, 

 but visits of a Chrysopa sp. to Yucca whipplei are there recorded. — 

 Charles Robertson, Carlinville, 111. 



