CRANBEREY INSECT PROBLEMS. 9 



LATE HOLDING OF THE WINTER FLOWAGE. 



"Where the winter flowage was held until June 1 this method of 

 treating worms on level, shallow-flowed bogs was found successful. 

 It is essential, however, to keep the water just over the tips and to 

 mow or burn any exposed tips. (Fig. 5.) The warmth of the shal- 

 low water causes hatching of the eggs under water and eventual 

 drowning of the small worms. 



On the other hand, a deeply flooded bog is Imown upon which 

 considerable hatching of fireworm eggs occurred after the removal 

 of the winter flowage, June 18. 



After repeated failures in the control of the worms with arsenical 

 sprays, such as arsenate of lead, arsenite of lime and Paris green, 

 and with arsenicals applied as dusts, these materials have been dis- 

 carded in favor of 40 per cent nicotine sulphate. This insecticide has 

 a wide usage for insect pests and recently has been found of value 

 against firewoi'ms. It is not known definitely at this writing to what 

 extent it will be effective where reflowing can not be practiced, but 

 it has given very marked results in conjunction with reflowing. 



For bogs without reflowage two applications are suggested after 

 drawing the winter floAvage May 10. Make one application about 

 May 17 and a second application one week later. 



Preparation of the nicotine- sulphate spray. — The proportions 

 found effective in killing the blackhead fireworms are 1 part of 40 

 per cent nicotine sulphate to 800 parts of water. The material may 

 be used much stronger without causing injury to vines or fruit, but 

 the control of the worms Avill not be appreciably better. The addition 

 of 2 pounds of fish-oil soap aids in spreading the insecticide. This 

 spray should be applied as a moderately fine mist, about 200 gallons 

 being used per acre, and it being borne in mind that it is mainly 

 effective as a contact poison and not as a stomach poison. 



For good results this spray must be applied when the small worms 

 are in or near the tops of the uprights just before growth of new 

 foliage is made. Once the worms become Avebbed up in leaves of 

 the current season, the spray will not be so effective, because it will 

 be impossible to wet many of them at that time. 



YELLOWHEAD FIREWORM.^ 



The yellowhead fireworm is often troublesome in New^ Jersey but 

 is of minor importance at present in other cranberry regions. As 

 an apple pest it is known widely throughout this country. Its 



