354 ' NEW YORK STATE MUSEUM 



deep. The plates and spines are as in the adult; the chitinous processes 

 are subequal and similar to those in the adult though of course smaller; 

 the ventral glands wanting, ventral thickenings parenthesis-shaped ; 

 anus and transverse thickenings as in the adult. The dorsal pores are 

 fewer than in the adult but are plainly of the same general arrangement, 

 with two or three at the first incision, a row from the second incision 

 consisting usually of three pores and the lateral row with about six 

 running up to the lateral transverse thickening. There are usually one 

 or two pores still laterad of this and generally two or more to represent 

 the basal angle group. This is closely similar to the second stage of 

 A. a n c y 1 u s, but may be distinguished in carefully prepared specimens 

 by the absence of the fringing plates which characterize the latter. 

 Usually the difference in the general shape of the lobes and the deeper, 

 narrower incisions of A. perniciosus and A. f o rb e s i will dis- 

 tinguish the second stages of these two species from those of A. 

 ostreaeformis to one at all familiar with these forms. 



SCALE INSECTS, COCCIDAE, IN NEW YORK STATE 



This list of 78 species gives some idea of the number of scale insects 

 farmers, horticulturists, nurserymen and those interested in greenhouses 

 have to contend with. It also has value in that it indicates about what 

 forms may be found on certain plants in the state, though the list of food 

 plants of a number of species could undoubtedly be considerably 

 increased by farther collecting. Those occurring on any one plant can 

 easily be ascertained by referring to the index, where the species are 

 listed under the names of the plants on which they may be found. 

 Many of these scale insects are not injurious, but there are also a number 

 of pests of considerable importance. This list is largely based on pre- 

 vious records, and many additions would undoubtedly result from special 

 collecting. An effort has been made to exclude unreliable records. 

 Some of the earlier determinations on which records depend may be 

 erroneous, but it is almost impossible to eliminate this source of error. 



It is a pleasure to acknowledge the assistance of several coworkers in 

 the preparation of this list. Messrs Comstock, Howard, King, Lowe, 

 Parrott, Pettit and Slingerland have very kindly called my attention to 

 overlooked records, given suggestions as to the synonymy, and also 

 placed at my disposal their own unpublished notes. 



