their plantings were located on the Cape or along the southern 

 coastal region. The remainder of growers experienced problems 

 with GM in 1 or more years. 



None of the plantings was infested in 1979, and only 2 

 plantings were infested in 1980, a year in which 5.1 million 

 acres of forested land in the Northeast were defoliated by GM. 

 However, in 1981, 71% of the blueberry plantings infested during 

 a 4-year period experienced noticeable GM populations. The 

 problem continued in 1982, when 6 of 17 infested plantings had 

 sizable numbers of GM. 



A common concern of growers is whether or not a planting 

 infested with GM one season is likely to be infested the fol- 

 lowing season. Questionnaire responses do not provide a clear- 

 cut answer. On one hand, 2 plantings infested with GM in 1980 

 were reinfested in 1981. On the other, only 1 of 12 plantings 

 infested in 1981 was reinfested in 1982. These observations 

 indicate that an answer should only be attempted for particular 

 plantings after the following questions have been considered. 

 Were areas around the planting treated with insecticides? Were 

 surrounding woodlands defoliated by mid to late June or was a 

 considerable amount of foliage left after GM feeding? Were GM 

 moths observed in the woodlands and/or planting in August? 

 Were egg masses observed in the woodlands or planting in the 

 fall? 



Another matter often pondered is whether or not the pres- 

 ence and composition of woodlands around plantings influences 

 the likelihood of an infestation. Again, questionnaire res- 

 ponses do not enable a definite answer, but do provide a few 

 clues. Regarding borders, responses showed that 15 plantings 

 where GM was a problem had woodland on at least 1 side. Ten 

 plantings not infested by GM likewise were bordered on at least 

 1 side. Contrary tc popular belief, the directional relation- 

 ship of woodland to a planting had no apparent bearing on the 

 likelihood of infestation. Interestingly, 2 plantings not 

 bordered by woodland became infested with GM. It would seem, 

 then, that woodland borders do less to affect the probability of 

 an infestation than the presence or absence of GM in the general 

 locale of the blueberry planting. 



The composition of adjoining woodland does not seem to mat- 

 ter either, given that GM has accepted the tree species as food 

 plants. In 15 of 17 infested plantings, woodlands consisted of 

 deciduous species only or a mixture of deciduous and coniferous 

 species. In 2 other plantings, however, infestations originated 

 from solid stands of conifers, food plants that are known to be 

 less favored by GM. 



