MANNEB OF BIBTH OF APHIDIDiE. •"»•'> 



tical to those already described, bui in many such cases the young 

 aphis died before freeing itself from the sac. This was probably 

 due to the fact that the insect lay upon a miscroscope slide instead of 



being held aloof from the bark, as under normal condition-. 



How are other species of Aphididae born? In an attempt to 

 answer this question I have made observations on several species, 

 among which is the apple aphis (Aphis malt Fab.), which will be 

 considered at some length. The birth of this species is similar in 

 all the stages to that of the woolly aphis, except in one or two minor 

 points. The leg-, at least the last pair, are bent back upon them- 

 selves, so as not to extend beyond the abdomen, while being pressed 

 to the ventral surface by the pellicle. When the young has all it- 

 legs free from the sac the mother does not in all cases, a- observed 

 with the woolly aphis, press her offspring down for a footing, but 

 -imply loosen- her hold. Apparently the greater length of leg- in 

 this species makes it unnecessary for the mother to assist her young 

 in thi- way. As soon as the young begin to free their antennae and 

 legs a delicate whitish substance appear- on the tip of the abdomen. 

 as with the other species described. The so-called honey tubes of the 

 apple aphis, and kindred species, are bent toward the extremity of 

 the abdomen and held closely against the body of the insect by the 

 enveloping pellicle. As the vd^ of this membrane passes along over 

 these tubes they bow up. and when the tip- are released they 

 straighten into nearly their normal position. Before the final release 

 of the tube- the delicate transparent membrane, constituting the pel- 

 licle, can be readily seen stretched across the intervening -pace. 

 Owing to the relatively much shorter beak of the apple aphis than 

 that of the woolly aphis, I have not been able to see the waxy, thread- 

 like connection between the seta? and the cast pellicle. If present, th ■ 

 separation probably take- place when the last pair of leg- i- being lib- 

 erated, which would tend to prevent a view of the thread. When the 

 leg- of the apple aphis are free, the discarded pellicle adheres to the 

 tip of the abdomen for a short time, whereupon it i- worked on by the 

 movement- already described. In one instance, however. I distinctly 

 -aw a young aphis deliberately remove the shriveled pellicle from the 

 tij) of its abdomen with its hind legs. 



In all the other species of Aphididae which have been under con- 

 sideration the manner of birth, in every case, was similar to that of 

 those alreadv described. 



Mr. Quaintance remarked that hi- observations a- to the mode of 

 birth of aphides agreed with those of the speaker, lie called atten- 

 tion to the fact of recent statements in literature to the effect that 

 the so-called honeydew of aphides was excreted only from the anus. 



7487— No. <i7— 07 ;'» 



