THE MARCHING OF THE LARVA OF THE MAIA 

 MOTH, HEMILEUCA MAIA. 



WM. S. MARSHALL. 



In the autumn of 1901 while collecting along the marshy 

 shore of Lake Wingra, near Madison, I noticed many specimens 

 of the maia- or buck-moth, HcinUcnca uiaia, flying low over the 

 marsh. Both males and females were present, and many of the 

 latter, having settled, were laying their eggs on the grass. These 

 were placed in a somewhat irregular set of spirals closely packed 

 together so that when they hardened, the grass could often be 

 pulled away leaving the eggs stuck together and forming a short 

 tube. The process of oviposition and the arrangement of the 

 eggs has been described by Riley ' and copied by Packard. 2 



Without having any definite plans in view I collected a great 

 many of the eggs most of which I put in a cold place, but a few 

 I left in an open bottle in my room. One morning I noticed on 

 the neck of this bottle a black mass which was found to be a 

 group of young caterpillars ; they had evidently hatched but a 

 short time before. Later in the morning I again looked at the 

 eggs and found that more had hatched ; all io the first bunch, 

 having in the meantime left the bottle, were marching in a line 

 on the table. Again, later in the day other groups were seen, 

 and in nearly every instance, each group had formed a line 

 marching in a regular procession and following the leader which- 

 ever way he turned. I placed some large sheets of paper on the 

 table ; upon these the different groups were soon marching, and 

 could be much more easily seen than when upon the darker 

 table. I now, with a pencil, knocked the leader away from one 

 line and was surprised to see the next in the line, now the leader, 

 stop when he reached the place occupied by the first leader prior 

 to his removal. Here he stopped and raising himself upon his 

 prolegs moved the anterior part of his body to and fro as if he 



1 Riley, C. V., "Fifth Missouri Report," p. 128. 



^Packard, A. S., " Insects Injurious to Forest and Shade Trees," Washington, 

 1890. 



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