1960] 
MacLeod — B oriomyia 
27 
Past experience with numerous types of Neuroptera has indicated 
that when eggs can be obtained from field-collected females, these eggs 
are fertile. The usual procedure for inducing oviposition by such 
females has been to confine the insect in some suitable container. 
Thus Smith ( 1922) was quite successful in securing eggs from females 
of various Nearctic species of C hr y so pa by placing them in lamp- 
chimney cages over growing, aphid-infested plants, the aphids serving 
as food for the female and possibly also as an oviposition stimulus. 
Killington (1937) utilized much the same procedure in obtaining 
eggs from many species of British hemerobiids. 
Although this method was tried by the present writer, the inspec- 
tion of so large a volume for the infrequent eggs supplied by the 
females of B. fidelis proved difficult. In addition, the broadly oval 
wings of this species with their numerous macrotrichiae render the 
insect somewhat clumsy and almost any confined space serves to trap 
the female, the leaf axils of the plants serving especially well in this 
respect. 
A more satisfactory arrangement was found by confining the fe- 
males individually in 75 x 25 mm. cotton-stoppered glass vials. Hu- 
midity was supplied from a small pleget of cotton, dampened with a 
solution of sucrose and water which was placed in the bottom of the 
vial. To obviate the possibility of the female becoming stuck to the 
wet cotton, a cardboard partition was placed between the damp cot- 
ton and the female and this was removed only for a short time each 
day to permit the female to drink. Small nymphs of the aphid Mac- 
rosiphurn liriodendri (Monell) collected from nearby tulip trees 
( Liriodendron tulipifera (L.)) were supplied on a small piece of 
leaf daily. 
Eggs, which were invariably laid on the cotton plug of the ovi- 
position vial, were removed as soon as detected and placed singly in 
40 x 13 mm. cotton-stoppered shell vials. Larvae were supplied each 
day with nymphs of the same aphid as was fed to the adults. This 
food was introduced into the vial on a piece of fresh leaf which 
probably served to maintain a reasonable humidity although no at- 
tempt was made to control or record this variable. Small wads of 
damp cotton were placed in the vials after the cocoons had been spun 
in order to prevent excessive dryness; however, these were not placed 
in vials with larvae in order to eliminate any possibility of the larvae 
becoming trapped and drowning. These rearings were carried out 
in a room open to the usual fluctuations in the summer temperatures 
