New York Agricultural Experiment Station. 479 



each elytra; the ten-spotted lady-bird beetle, Megilla maculata 

 DeG. This species is red with ten black spots on the elytra. 



Plant lice are also preyed upon by syrphus fly larvae. A photo- 

 graph of a common species, natural size, is shown at Plate XXVI, 

 fig. 11. The egg, attached near the base of an opening apple 

 leaf bud, is also shown, enlarged to about four times natural size. 

 These larvai suck the juices from the bodies of the plant lice, thus 

 quickly causing their death. When full grown the larva forms 

 an oblong green or brown puparium, larger at one end, and 

 usually attached to the under surface of the leaf. In a few days 

 a two-winged fly emerges. This is the mature insect which lays 

 the egg. 



Another species of syrphus-fly larva which has been much more 

 common on the plum trees during the past season than the spe- 

 cies referred to, is smaller and of a yellovv'ish brown color. 

 Specimens which appeared to be about full grown were measured 

 July 20. The average dimensions were 2.4 mm. by 0.78 mm. 

 Eggs were also found on this date. They were pearly white, 

 oblong, slightly oval, rounded at each end and measured 0.87 mm. 

 by 0.33 mm.; the shell brittle, and sculptured with heavy parallel, 

 longitudinal lines of a dull white crossed by oblique parallel lines 

 of the same shade. Every attempt to breed this species in the 

 laboratory failed and neither pupae nor the mature insects were 

 observed. The larvae were very abundant. From May until Octo- 

 ber a few of them could be found upon almost every infested leaf. 

 Frequently they were entirely hidden from view by the large 

 number of plant lice and the white powdery substance with 

 which the lice are dusted so that the only indication of their 

 presence was the brown, shriveled skins of the dead lice. It is 

 probably within bounds to say that these larvae destroyed nearly 

 forty per cent of the plum lice in the Station orchard last season. 



There are still other kinds of. insects which feed upon plant 

 lice. Among them the most common are the aphis lions. These 

 ferocious creatures are the larvae of delicate winged Insects 

 known as the lace- winged flies. The mature insects are very 

 dolicate and liav^ finclv voincd irvfi'u wings The eggs are 



