KEY TO THE EGG MASSES OF NORTH AMERICAN MALACOSOMA 



1. Egg mass laid as a helical band which completely encircles a 



small twig as in figure 108 2 



Egg mass laid as a clasping mass which may appear to nearly 

 encircle a twig as in figure 109, or which may be laid as 

 a partially encircling mass (fig. 110), or which may be 

 laid as a nearly flat mass on a larger branch or small trunk 



(fig. Ill) 4 



2(1). Egg mass not covered by spumaHne (fig. 106) . tigris, p. 102 



Egg mass covered by spumaline of some kind 3 



3(2). Spumaline pale, transparent, yellow, and containing approx- 

 imately one large bubble per &gg (fig. 107); on oaks. 



constrictum constrictum, p. 93 



constrictum austrinum, p. 99 



Spumaline dark brown and containing numerous small bubbles 



(fig 113); on many hosts disstria, p. 84 



4(1) Spumaline rich dark brown with many bubbles of various 

 sizes; egg mass usually laid so it nearly encircles small twigs 

 (fig 109), but sometimes laid only partially encircling a 

 branch (fig. 110), or even laid as a nearly flat mass near the 

 base of the trunk of a small tree (fig. Ill); distribution — 

 east of the central Great Plains and south from southern 

 Canada to the Gulf of Mexico (fig. 2) . . . americanum, p. 1 1 1 

 Spumaline medium brown, tan, gray, white, or rich dark brown ; 

 if rich dark brown, then the bubbles are all quite small and 

 uniform in size, or the spumaline often appears to be some- 

 what collapsed and nearly without bubbles; distribution — 

 west and north of the area outlined above, and only slightly 



overlapping 5 



5(4). Spumaline rather tough, usually not easily scraped off" the 

 eggs unless it is very dry; full of small, rather uniform-sized 

 bubbles; color usually white or cream (fig. 117), or dark 



brown (fig. 114) incur vum and subspecies, p. 169 



Spumaline weaker, rather easily scraped off the eggs in most 

 cases; full of various sizes of bubbles or somewhat collapsed 

 and nearly without bubbles as in figure 115; color gray 

 (fig. 116), gray-brown, tan, medium brown (fig. 105) or dark 

 brown (fig 112) .... calif ornicum and subspecies, p. 123 



83 



