412 THE CANADIAN ENTOMOLOGIST 



habitat, under the shaggy bark of the shell-bark hickory (i/ic^orta 



ovata), the ants do not allow them to remain any great length of 



time where they are born, but are transferred by them to the 



terminal or lateral twigs of hickory shoots at the base of the tree, 

 or are transferred to similar situations on the old tree itself, where 

 the bark is tender, such as occurs at the junctures of the leaf 

 petioles with the twigs or at any abrasion or crevice in the bark, 

 and here they are guarded and attended by a few of the ants which 

 watch with all the dexterity and aggressiveness they possess. Here 

 they remain until fall, feeding on the sap, and are "herded" by 

 the ants when cold weather sets in, probably being taken into their 

 nests where they hibernate, or possibly some few crawl under the 

 bark and into crevices of the older bark where they pass the winter 

 in these locations. In early spring, as soon as warm weather 

 comes to stay, the larva? are transferred by the ants to the tree, 

 under the hard protecting bark, where they commence feeding 

 and growing. They apparently become full-grown and mature 

 by about the middle of July in this latitude, for adult females 

 were examined on the 12th July and they were full of embryos. 

 The first larva? were observed on the 28th July, and they continue 

 to lay eggs up to the middle of September (1915) and probably 

 even later. 



This is the largest Psendococcus of which the writer knows, 

 and its size and host plant are enough for ready identification. 

 This scale insect is invariably attended by certain common black 

 ants and the Coccida? are generally in groups of two or three, but 

 sometimes as many as ten are grouped under a slab of bark only 

 six inches in diameter. This gregariousness in habit probably 

 occurs because the ants can collect an abundance of "honey-dew" 

 from the colony without any great difficulty, thus saving time and 

 energy on the part of the ants. As many as fifty ants have been 

 observed encircling one female adult, and as many more were 

 crowding around to get their meal of secreted fluid. When dis- 

 turbed by the removal of the bark, the ants would run around 

 frantically with the tips of their abdomens elevated and their 

 mandibles extended, making a most formidable appearance. The 

 Coccids are generally located between the b^rk and wood where 



