NATURAL CHECKS OF COTTONY MAPLE SCALE. 51 



after making several futile attempts to gvt its inaii(lil)ic iiiuler the 

 side of the scale. Avoiild Hiiallyaive it up and attack another specimen. 



The great number of scale insects destroyetl by the coccinellid and 

 its hirva can only be realized when we consider the large number 

 of eggs deposited by the Pulvinaria. At INIontclair, Avhere these 

 insects and beetles were most numerous, between 500 and 1,000 young 

 scales were counted on each of several leaves and there were many 

 leaves just as badly infested; l)ut after tlie coccinellid had completed 

 its work not a leaf could be found with more than a dozen scales set 

 on it. while most of the leaves showed still fewer. 



In looking over the long series of beetles bred from larva? it was 

 found that there were some variations in both the males and females 

 in size and markings. The majority of the specimens were black in 

 color, with the single reddish spot on the disk of each elytron, but a 

 few examples were found Avhich showed an extra smaller red spot 

 near the tip of each elytron. This latter is in all probability the 

 form which was originally described by Olivier as signafa, while the 

 form with the reddish spots, which occurs niost commonly, is the 

 one Say described later as hinotata. Olivier's name, therefore, has 

 precedence and should be the one by which the species is designated. 



It is interesting to note also that while in 1905 this species was 

 found almost exclusively feeding on the Pulvinaria and only occa- 

 sionally attacking Pseudococeiis aeeris Sign., just the opposite has 

 been true the past season (1906). The insect has been found where- 

 ever PseiuIococeiiH aceris occurred, but only in small numbers attack- 

 ing the Pulvinaria. This is due in part perhaps to the fact that the 

 latter insect has not been so abundant. Apparently the Pulvinaria is 

 the favorite food of the coccinellid, but being nnable to secure a 

 sufficient amount of this, it attacks the Pseudococcus and other 

 species. , 



Although the beetle and its larva did such etfective work in Mont- 

 clair in checking the scale, there were other places where it had not 

 been so abundant, and consequently a much larger number of scales 

 set and developed in those localities. 



On July 24, when, at New Brunswick, I examined some leaves 

 fairly well set with young Pulvinaria, I found that a few of them 

 were parasitized and, except for their smaller size, appeared pre- 

 cisely like the parasitized forms of the hibernating females. Upon 

 inspecting the infested trees in other localities I found that conditions 

 were similar — a few examples parasitized in every case. An examina- 

 tion of the latter showed larvae and pupae similar to those of the para- 

 site of the hibernating form. Within a day or two adults of the 

 latter made their appearance both in the laboratory and out of 



