202 MAINE) AGRICUI.TURAL E^XPERIMENT STATION. I909. 



cluster contains about 100 eggs. These hatch in 8 or 10 days 

 from the time the Chermes appear on the needle of the pine. 

 The young settle about the new growth of the shoot and pierc- 

 ing the tender tissue with their beaks, suck the sap. Where 

 the infestation is heavy this causes a yellowish and sickly 

 appearance of the new growth which is sometimes thus con- 

 siderably stunted. The young, though exceedingly minute, can 

 be located because they produce a white flocculent waxy secre- 

 tion which makes their presence discernable.* 



The Pine-leaf Chermes is one of those species of plant lice 

 that have alternate "host plants," that is, they pass one stage 

 of their life on one plant and the succeeding stage on another 

 species of plant. 



The winged Chermes that appear suddenly upon the needles 

 of the pine in mid-June have not developed on the white pine 

 but in a cone-like gall common on the Red Spruce and Black 

 Spruce, see Fig. 44. This gall is an abnormally developed shoot, 

 the unusual form of growth being stimulated in. some way by 

 the presence of the Chermes. The young Chermes can be 

 found in these galls by opening the sections of the galls where 

 little reddish brown objects will be seen, — the developing 

 Chermes. 



These galls though sometimes very abundant in Maine are 

 likely to escape notice as they are so cone-like in appearance as 

 to seem to the superficial glance a normal part of the spruce. 

 They were observed by Packard as common in Maine and the 

 plant louse forming them was named abieticolens in 1879, the 

 fact that they were the same species Fitch recorded for the pine 

 needle not being known at that time.t 



* Another much smaller species of plant louse (Chermes pinicorticis) 

 is frequently present on the trunk of the same tree in such numbers as 

 sometimes to cover almost the entire trunk with a white down. 



t This species develops in a cone-like gall on the black and red spruces 

 (in which connection it was named abieticolens in 1879 by Thomas and 

 subsequently merged by error with abietis in 1897), and migrates to the 

 needles of the white pine (in which connection it had been previously 

 named pinifoliae by Fitch in 1858, and merged by error with pinicorticis 

 in 1869). This historical discussion with full reasons for resurrecting 

 this doubly merged species under the original name of pinifoliae, which 

 has been discarded for about 40 years, will be published presently in 

 more technical form by the Maine Agricultural Experiment Station. For 

 the purposes of this economic bulletin it is not necessary to include 

 either detailed descriptions or discussion. 



