Marcb, 1911.] 49 



NOTES ON CHRY80PA DORSALIS, Burm. 



BY E. MAUDE ALDERSON, F.E.S. 



Plate I. 



On July 28tli, 1909, I received through the kiuduess of Mr. 

 itmore, of King's Lynn, three living examples of Chrysopa dorsalis, 

 Bunii., one J* and two $ ? . In the letter accompanying the insects, 

 Mr. Atniore informed me that the species was attached to Scotch fir, 

 so my first care was to provide them with a sprig of this tree, on 

 which to oviposit. The stem of the shoot was passed through a hole 

 bored in the bottom of a large chip box, resting on a vessel containing 

 water, and a glass jar, inverted over the top, formed a makeshift 

 vivarium, highly suitable for observation. 



The insects on lieing liberated from the chip boxes, in which they 

 had travelled, became extremely active, fluttering up and down the 

 sides of the glass jar. One of the females, however, c^uickly settled 

 down amongst the fir " needles," and I had hopes, by the careful way 

 i which she examined them, that she was selecting a suitable position 

 for her eggs. In this I was not disappo ,3d, as by the next morning, 

 July 29th, a single glistening green egg had been laid, whilst a careful 

 scrutiny with the lens revealed several abortive attempts at oviposition, 

 the stalks of the eggs being present, but no more ova. I removed the 

 " needle " on which the single ovum was laid, for fear of accidents, 

 and awaited results, hoping for more ova next morning. To my 

 intense disappointment, however, the next day found the ovipositing 

 female dead, and also the only male. 



All my hopes were now centred in the one tiny green atom, and it 

 was with considerable relief that I saw it begin to change colour on 

 the second day, and not shrivel up, as I half dreaded it would do. 



A new anxiety, however, now arose — the question of food. Mr, 

 Atmore had distinctly stated that C. dorsalis was attached to Scotch 

 fir, and therefore presumably to those Aphides affecting the genus 

 Pinus. With these I was quite unacquainted, and, moreover, the 

 nearest fir trees were a mile or more away. The larva hatched out on 

 August 6th, and in some trepidation I offered the common Rose aphis, 

 Siphonophora rosm, Reaumur, but my doubts were soon set at rest, for 

 the aphides were accepted without any hesitation, and I subsequently 

 found such distinct species as Cliaitopliorvs saZicivoms, Walker, Rhopa- 

 losiphnm mjmplieese, Linn., CalHjjterus coryli, Goetze, and PhyUapliis 

 fagi, Linn., equally relished. The young larva continued to flourish, 

 and on August 10th apparently effected its first change of skin. The 



