322 XEW YORK STATE MUSEUM 



Bibliography 

 189 Lintner, J. A. Ins. N. Y. nth Rep't, p. 181-89 

 1S96 Lowe, V. H. N. Y. Agric. Exp. Sta. 14th Rep't, p. 554-58 

 1890 Packard, S. A. U. S. Ent. 5th Rep't, !>. 4^8-3.3 



Yellow spotted willow slug 

 Ptci'onns vcntralis Say 



Greenish black sawfly larvae about %o i"(-h long and witli heart-shaped, yellowish 

 spots on each side, defoliate willow and poplar. 



This species is considered' one of the worst enemies of baslcet willows, 

 particularly in the South because of its producing several generations 

 annually, and even in the North Dr Harris has recorded two broods as 

 occurring in Massachusetts. All kinds of willow with the e.xception per- 

 haps of the weeping willow and species developing into tall trees are 

 injured by these slugs according to Dr Howard. The species and varieties 

 of white willow appear to be preferred, and-yoimg poplars growing in prox- 

 imity to these trees are also damaged, though their older and tougher 

 leaves escape attack. The greatest injury is inflicted on young growth and 

 as a consequence the species may be controlled with arsenical poisons. 

 One of the serious features of injury by this insect is that the willow, after 

 defoliation, produces leaves on side shoots, thus destroying the commer- 

 cial value of the product for basket purposes, since the shoots should be 

 of nearly uniform size throughout their length. 



Description. The early stages of this insect have been described by 

 Dr Dyar as follows : 



Eggs [see Insect Life, i : 36]. In large clusters of flat, semicircular saw- 

 cuts under the lower epidermis, i x 2 mm in size. 



1st stage. Head round, shining black; width .55 mm. Thoracic feet 

 long, spreading, black except at the joints ; segments indistinctly 4-annulate, 

 abdominal feet small, on joints 6-1 1, 13. Body slightly shining, blackish 

 green, subtranslucent ; anal prongs concolorous. 



2d stage. As before. Head .75 mm wide. Body smooth, greenish 

 black, anal prongs black. 



3d stage. Head shining greenish black ; width i mm ; eyes and jaws 

 black. Body scarcely annulate, smooth, shining, obscure blackish olive, 



