CAPE COD CRANBERRY INSECTS 



Black-headed Fireworm. 



Fig. 5. Cranberry leaves with fruiting bodies of a fungus (Venturla compacta Pk.) 



olten mistaken by growers for its eggs. Much enlarged. 

 Fig. 6. Larva. Considerably enlarged. 

 Fig. 7. Moth. Much enlarged. (From U. S. Dept. Agr. Farmers' Bui. 860.) 



worms generally take nearly tiiree weeks to mature, but those of the second 

 brood mature in about two weeks. The second brood sometimes works till 

 well into August, even on bogs bared of the winter water in April. 



The Pupa. 



In Massachusetts and New Jersey the mature worms generally leave the 

 vines to pupate on tiie sand or in the trash beneath them. The pupa often is 

 naked but usually is in a light case of silk and sand or fallen leaves. If 

 water happens to be standing under the vines, the worms all pupate among 

 the webbed foliage. They generally do this in Wisconsin, probably because 

 most of the bogs there are poorly drained. The pupa is light brown at first, 

 but it gets almost black iiefore the moth emerges. The pupal period of the 

 first brood is nearly two weeks, and that of the second about a week and 

 a half. 



The Math. 



The moth (fig. 7 and Plate One, lig. 6) is dark grayish brown and so small 

 that it often is mistaken for a fly when in flight. It expands somewhat over 

 three-eighths of an inch. The fore wings are marked with gray-brown and 

 silver-gray l)ands. The female may lay eggs within a day after It emerges. 

 The moths fly little during the day unless it is warm and very cloudy, but 

 they are flushed up easily. At dusk they fly and hover freely just above the 

 vines. 



