BLUEBERRY INSECT CONTROL 



Though It Is true that many of the newer cultivated blueberry plantings In 

 Massachusetts are not seriously troubled with Insect problems, such Is not the 

 case In many of the older plantings. The kinds of Insects that are known to 

 infest blueberries at some time or other are quite numerous, but fortunately only 

 a few are of enough Importance to require the use of Insecticides. In 

 Massachusetts these are cranberry frultworm, cherry frultworm, blueberry maggot, 

 Japanese beetle, and cranberry weevil. Several other species are encountered and 

 are occasionally troublesome, such as fall webworms and Datana worms which feed 

 In groups and sometimes defoliate Individual bushes. Sucking Insects such as 

 heath splttlebug, plant bugs and leaf hoppers are minor drains on bushes and the 

 sharp-nosed leafhopper has the added distinction of spreading the stunt disease 

 virus of blueberry. Also troublesome at times are stem galls, stem borers, and 

 scale Insects. 



Brief descriptions of these Insects and the damage they cause is contained 

 In Massachusetts Extension Circular #240, "Blueberry Growing", and the control of 

 the most important is outlined in the "Pest Control Chart for Cultivated Blue- 

 berries" which is revised and reissued regularly by the Massachusetts Cooperative 

 Extension Service. Some additional thoughts and recent developments is the 

 excuse, if any, for this brief write-up. 



Much trouble and grief later on can be avoided during the pruning operation 

 while the plants are dormant. Stem galls should be removed and disposed of in 

 such a manner that they can not emerge and relnfest bushes the following spring. 

 Canes infested with stem borers should be removed whenever they are noticed, but 

 while pruning is an excellent time to be on the watch for any that might have 

 been missed during the previous summer. Orange colored, frass pellets under the 

 infested cane indicates activity and be sure to remove the cane below where it is 

 tunnelled; and probe for any in the crown with a twig or wire if they have worked 

 that far down in the bush. Though not a reliable scale insect control, regular 

 removal of older, less productive canes low in the crown is helpful in retarding 

 the development of serious scale insect infestations. When scales become abun- 

 dant, a thorough spraying with superior oil in the dormant season is a reliable 

 control. 



On quiet, warm, sunny days in the spring after the fruit buds swell, but 

 before bloom has opened, is the time to be on the alert for cranberry weevil on 

 bushes around the edges of the field. An occasional one can be ignored, but if 

 they occur several to the bush, the field should be treated with dieldrln. One 

 application is usually sufficient to clean up the infestation for several seasons 

 if done before egg laying has occurred. This dieldrln application will also con- 

 trol currant fruit weevils and plum curcullo that may be present in the field. 



Later, when the field is in bloom and berries are beginning to set and grow, 

 they become attractive to egg laying cranberry frultworm and cherry frultworm 

 moths. In recent years cherry frultworm has been responsible for serious crop 

 losses in cultivated blueberry fields in Massachusetts and other states. An 

 application of malathlon or Sevln, applied soon after mid-bloom and repeated in 

 about 10 days, controls both of these species as well as leaf hoppers that are 

 present during that period. These applications will also reduce or control heath 

 splttlebug feeding at that time. 



