164 MAINE AGRICULTURAL EXPERIMENT STATION. 1917. 



emerged August 13. Full grown larvae were again found on Au- 

 gust 27 among the same species of aphid. 



In 1917, on June 29, Mr. R. K. Fletcher and the writer found 

 a number of larvae among Myzus cerasi (Fab.) on cultivated 

 cherry and among Phorodon humuli (Schrank) and Rhopalosi- 

 phum nympheae (Linne) on cultivated plum. These varied from 

 larvae but recently hatched to full grown, all of which showed 

 the characteristic pattern described above, the younger larvae 

 however being lighter in color. Pupation of these larvae began 

 July 8th. The type female emerged August 2 from a puparium 

 formed July 24. 



There thus appears to be at least two generations of this 

 species annually, one occurring as larvae chiefly during June, 

 the other occurring in the larval stage chiefly during August. A 

 one-fourth grown larva was taken among Myzus cerasi (Fab.) 

 on July 14, indicating that the generations are somewhat irreg- 

 ular. 



The larva does not appear to be much restricted in its choice 

 of food, the known hosts representing four different genera. 



It is a species offering considerable possibilities in the con- 

 trol of aphids affecting the stone fruits and its ability to live on 

 aphids of other hosts is at least an advantage in the maintenance 

 of the species. 



The larvae are to be found on the under, infested, side of* the 

 leaves of the trees mentioned and also on the smaller twigs. 

 With the green of the leaf as a background or when removed 

 from their natural surroundings, their colors make them quite 

 conspicuous. But when surrounded thickly by aphids or, more 

 especially, when wound around a small infested twig they are 

 quite inconspicuous. When I first found the larva on an unin- 

 fested twig, in which situation they appear to pupate, I was 

 strongly impressed with its resemblance to the droppings from 

 a bird. 



Puparium (Fig. 10, B). Length about 7 mm., exclusive of the poste- 

 rior respiratory organ which may project half a millimeter farther or be 

 directed more dorsad. Maximum width 3.25 mm., maximum height 2.75 

 mm. The anterior half is irregularly globose, the puparium somewhat 

 suddenly depressed about mid-length, the posterior half remaining flattened 

 much as in the larva. It is interesting to note that this depression, or lack 

 of inflation, begins at the point on the seventh larval segment where the 

 white adipose mass gives way to the black area of segment six. The pu- 



