21 



This species is often very abundant, sometimes completely cover- 

 ing the bark of the host-plant. Repqrts of trees having been killed 

 by this insect are not infrequent. Various authors have given willow 

 and cottonwood as food-plants of C. salicis-nigrae and Prof. Osborn 

 has taken it on poplar. In the Department of Agriculture are 

 examples on Salix alba, S. nigra, S. alba var. camellia, Cornus 

 pubescens, C. asperifolia, Balm of Gilead and Russian poplar. In 

 addition to these I have received specimens on Liriodendron 

 tnlipifera from Dr. James Fletcher, Cornns stolonifera and C. sericea 

 from Mr. A. H. Kirkland, Ccanothus from Mr. Alex. Craw and on 

 Amelanchier canadensis from Mr. G. B. King. 



This species passes the winter in the egg stage, about seventy-five 

 eggs occurring under each scale, according to LeBaron. The same 

 author observed the " deep-red " young larvae hatching on May 8. 

 Professor Lugger has seen the eggs hatching about the first of June, 

 but the difference in time is probably due to difference in locality or 

 variation in season. There is no published statement of the num- 

 ber of broods of this insect and I have never had an opportunity of 

 studying its habits. We are entirely without information, also, as to 

 the appearance of the male insect. 



A few remarks on the names given to this insect seem desirable 

 and will explain my reasons for retaining the name sa/icis-mgrae. 

 Professor Comstock was the first to consider our species identical 

 with the European salicis, but his conclusions were based on only 

 two lots of specimens from this country. Had his series been more 

 extended his conclusions probably would have been different. Sev- 

 eral years before, LeBaron described the insect as new under the 

 name of Mytilaspis salicis, apparently unaware of the fact that this 

 specific name was preoccupied. Early in my studies on this genus 

 it became evident that the true European salicis had not been dis- 

 covered in this country, and that it was necessary to give a name to 

 our American insect. It must be admitted that Walsh's description 

 is very incomplete and applies equally well to several other allied 

 species, but, as far as I know, this is the only species in the group 

 which occurs in Illinois, the state from which Walsh described his 

 species, with the exception of corni which is smaller and confined to 

 Cornus. Walsh's type of the species is lost, probably having been 

 burned with the rest of his collection in the great Chicago fire. The 

 only other species now known from which Walsh's description could 



