126 THE ENTOMOLOGIST. 



NOTES ON THE LIFE-HISTORY OF CHRYSOPA 

 FLAVA, ScopoLi. 



By E. Maude Alderson, F.E.S. 

 (Plate IV.) 



This species is one of our most frequently noticed British 

 Chrysopids. This is in part due to its being a fairly common 

 insect, and in part to its size, it being one of the largest— if not 

 the largest — representative of the family in this country. I have 

 one female which measures 46 mm. in expanse ; and though this 

 is the largest individual specimen I have met with, I have others 

 which measure from 35-37 mm. 



McLachlan, in his " Monograph on the British Neuroptera 

 Planipennia" (Trans. Ent. Soc. 1868, part ii.), says: " C.flava 

 especially frequents trees bordering streams." This is certainly 

 true, but I do not think there is any connection between this 

 species and water, and it is certainly quite as frequently found 

 in gardens and woodlands. 



The only other British species with which C. Jiava is likely 

 to be confounded is C. vittata, Wesmael, and McLachlan has a 

 note that these two have been constantly mixed in collections. 

 They are of about equal size, but C. Jiava can at once be 

 separated by the excised costal margin of the anterior wings. 

 This character, which is constant, can be plainly seen in Mr. 

 Main's photograph. The fore wings seem to rise somewhat 

 abruptly from the thorax, and then at about one-third the costa 

 gives a distinct "dip." C. vittata has a much more rounded 

 costa, and the wings are more " ample " looking. Another good 

 point of difference is the length of the second antennal joint in 

 vittata, which is almost twice as long as, in C.flava. C.flava, 

 also, is of a richer shade of green, and possesses a broad yellow 

 longitudinal line down the whole length of the thorax and abdo- 

 men. C. vittata is also lighter on the thorax, but is more wholly 

 and uniformly pale greenish in colour. 



All my specimens of C. flava I find on examination have 

 been taken during the months of May and June. It must occur 

 throughout the summer, however, as I have notes of ova found 

 during July and August, and Mr. Main writes me that the 

 example photographed was taken so late as August 20th. The 

 very large female mentioned above was caught fluttering among 

 the leaves of a climbing rose, and was evidently searching for 

 aphides, near which to deposit her eggs. She laid thirty-nine 

 ova on July 14th, which hatched out on the 20th of the same 

 month. The ova have their footstalks united into a bundle, 

 as shown in Mr. Main's photograph. Two other groups of 

 ova which I possessed contained sixteen and nine ova respec- 



