320 



REPORT OB^ STATE BOARD OF HORTICULTURE. 



Fig. 8— Stem-raotlier: fifth 

 from the egg; euhirged. 



stajre 



The honey tubes have changed to some 

 extent. They are now longer than one body 

 segment, taper a little to the tip, and are 

 there squarely cut off. They are slender 

 tubes or cylinders, rather than, as before, 

 fleshy processes through which tubes are car- 

 ried. The terminal segment is yet more 

 prominent, and the embi'yos are seen to be 

 well developed inside the body. 



By April 30 all the eggs were hatched, 

 and on May 2 no more larvae in the first stage 

 were noticed : all had molted at least once, 

 and a large number were in the fifth stage 

 ready to reproduce. 

 These "stem-mothers," as they are called, are about .08 of an inch long, 

 bright green in color and almost pear-shaped. They have no wings nor 

 traces of such organs, and are not sexually developed, i. e. 

 they are neither males nor fully-developed females, but 

 forms that reproduce their kind without sexual union. 

 This is called parthenogenesis or, sometimes, agamic re- 

 production. It is a common occurrence among the plant 

 lice, and accounts in part for their great powers of multi- 

 plication, every individual being capable of bearing 

 young. 



Though the body of this stem-mother is very large, the 

 legs, antennae and honey tubes are much more slender, all 

 the parts being better defined. The eyes are now brown 

 in color, the facets numerous and small, and the honey 

 tubes exceed two body segments in length, being also 

 brown. Except that they are longer and more slender, 

 the feelers do not dift'er from those in the preceding 

 stage. This is the only series of breeders in which the 

 feelers have only five joints. 



In this stage the tips of the tibia;, or shanks, and the tarsi, or feet, are 

 blackish, a little color character which is present in all the reproducing- 

 forms of this species and absent in all the larval stages. The last body seg- 

 ment has become developed into a dark-brown, tail-like process, and this is 

 another feature of the adult stage in all the series. 



May 3, the first young of the second brood were seen, and this draws 

 attention to another peculiarity of these insects : they bring forth their 

 young alive and ready at once to feed. For this reason we call them vivi- 

 parous. . 



From the eighteenth of April, when the eggs hatched, to the third of 

 May, when the specimens coming from the eggs first produced young, is 

 a period of fifteen days, Avhich may be assumed as the average length of 

 time required for this first brood to come to maturity. But as egg-hatching 

 did not cease until April 28, it would be May 13 before all the specimens had 



Fig. 9 — Antenna, 

 honey tube and 

 tarsus of stein- 

 mother; very 

 much enlarged. 



