324 



REPORT OF STATE BOARD OF HORTICULTURE, 



knees, as well as the tips of the shanks and the feet, blackish. The honey 

 tubes are long, slender and also black, as is the tail. 



The antennse are almost as long as the insect itself, and are six-jointed. 

 The third joint — the first of the long joints — has a series of from six to ten 

 sensory pits, arranged in a line on the outer side. Though it is a somewhat 

 variable matter, seven pits are normal. In a general way, there is a little 

 group of three near the tip, another group of three near the middle, and a 

 single pit near the base. One of the pits near the tip sometimes becomes 

 multiplied into two or three, or one of them may drop out; so, while there 

 may be an actual difference in the number of pits, the general arrangement 

 and appearance remain the same. The single pit at the end of the fifth 

 joint and the little group at the enlargement of the sixth remain as in the 

 other stages. 



The head in this form is distinct from the other segments, and there is a 

 pair of ocelli, one on each side, close to the compound eye. 



Fig. 17— Winged apple plantlouse, much enlarged; single Joints showing sensory pit.s. 

 yet more enlarged. 



The corresponding stage of the wingless type resembles the stem-mother, 

 except in size. It is never more than six-huudredths of an inch in length, 

 and seems proportionately less obese. The antennse are six-jointed, there 

 is a sensory pit at the end of the fifth joint, and a gi'oup of very small pit- 

 tings on the sixth. The honey tubes are proportionately much larger than 

 in the stem-mother, as is the tail. The legs are slender, and have the usual 

 darkening of the tips of the tibiae and of the tarsi. 



May 16, the stem-mothers had practically disappeared, and their wingless 

 descendants had begun to bring forth young. No positive observations 



