Outbreaks of a disease^ sometimes wipe out the second brood on many bogs. 

 If spraying is contemplated or in progress, it is well to watch for this, for 

 the epidemic may make treatment unnecessary. The general abundance of the 

 fungus that causes the disease may be learned by leaving fifty of the worms in a 

 moist chamber^ over night. By morning the fungus will appear on most of the 

 diseased worms as a fluffy white mold, and around them as a ring of white spore 

 dust. Professor W. H. Sawyer, Jr., found this fungus absent or inactive on the 

 bogs with fireworm infestation notably resistant to control but generally abundant 

 on other infested areas. He found further that the bogs on which it is scarce are 

 generally large, welhmanaged areas that have been flooded, sprayed, and resanded 

 regularly. Evidently it is killed out, directly or indirectly, by late-spring or 

 summer flooding or by spraying or sanding, for no evidence has been found that 

 fall flooding or the winter flood, even when it is held late, affects it. The fungus 

 passes the winter in the form of resistant spores among the chaff^ on the bog floor. 



Moderate infestations of this fireworm must be treated as though they were 

 severe. Even slight ones should be given due attention, especially on large bogs. 

 They should be treated at least once during the season. 



Yellow-Headed Fireworm^^ 



This pest never harms bogs that are flooded completely during the winter 

 on Cape Cod and seldom does elsewhere, for the wintering moths cannot endure 

 submergence. It is attacked by parasites much more than the black-headed fire- 

 worm. They do not reduce the first brood much, but they decimate the second 

 so that, however severe the infestation, the first brood of the next year seldom 

 does much harm. There are two broods in Massachusetts, three in Iowa and 

 Wisconsin, and three or sometimes four in New Jersey. 



Distrihiition and Food Plants 



This fireworm is known widely as an apple pest throughout the United States 

 and southern Canada. It also feeds on pear, plum, rose, huckleberry, swamp 

 blueberry, glaucous willow, and sweet gale. It is worse as a cranberry pest in New 

 Jersey than elsewhere. It is much less generally destructive on the Cape than the 

 black-headed fireworm. 



Character of Injury 



The small worms of the first brood feed on the old leaves at first, usually 

 sewing the surfaces of two adjacent ones together and working between them. 

 Otherwise this species works much like the black-headed fireworm (fig. 8), 

 but it tends to gather more uprights into its web (fig. 9) and often does more 

 intensive injury, not only browning the bog but often leaving only bare up- 

 rights in the fall. The worms work in the berries and score them as black- 

 headed fireworms do (fig. 10). 



Description and Seasonal History 

 The moths that appear in the fall (Plate One, fig. 4) are reddish gray, but 

 they gradually lose the red tinge and become slate color. li They are small but 

 considerably larger than those of the black-headed fireworm. They winter on 



* Caused by Entomophthora sphaerosperma Fres. This fungus also attacks other insect 

 species. Prof. Sawyer grew it abundantly on various culture media. He did his field 

 work on this disease in cooperation with (the Cranberry Station at East Wareham and 

 studied it further in the Laboratories of Cryptogamic Botany at Harvard University. At- 

 tempts to control this fireworm by distributing the culture-grown fungus in a spray or 

 otherwise were unsuccessful. 



8 A clear smooth tumbler inverted over a glass plate and containing a little moist cotton 

 is handy for this. 



10 Peronea niinuta (Rob.). 



11 Form Cinderella Riley. 



[11] 



