avoiding the use of materials such as benomyl and the 

 pyrethroids that do greater damage to predator mites than 

 spider mites. Activity on point one is underway and 

 a^'ditional funding for this effort is being sought from the 

 Department of Food & Agriculture under the 

 Department's competitive biological control grants pro- 

 gram. A pesticide-resistant strain of Amblyseius fallacis 

 does exist and has been established in apple orchards in 

 Quebec where it has provided successful control of Euro- 

 pean red mite and two-spotted spider mite (Bostanian & 

 Coulombe, 1986). This resistant >1. /a//acw can be intro- 

 duced in Massachusetts orchards. The role of orchard 

 floor vegetation, the species of plants used and their 

 management, is not well understood. Such vegetation 

 influences winter survival of predators, the timing of their 

 spring movement back into trees, and their rate of repro- 

 duction, since plant pollens are used as food sources by the 

 predator. A project to research this topic in Massachusetts 

 has been funded by the Department of Food & Agriculture. 

 Work was initiated in 1987 and will continue this year. 



Aphids and San Jose Scale . Generally, existing 

 predators appear to keep the three aphid species in Mas- 

 sachusetts apples under satisfactory control unless dis- 

 rupted by pesticide use. The cecidomyiid, Aphidoletis 

 aphidimyza, is one of the more important aphid predators, 

 but various coccinellids, syrphids, and chamacmyiids also 

 exist in important numbers. The apple aphid is the best 

 studied of the three aphid species, and its control is 

 predominantly by predators. The woolly apple aphid has 

 a specific parasite, Apheliniis malt, that is important in 

 regulating that species. Least is known about biological 

 controls of the rosy apple aphid, one of the main aphid pests 

 of apples. San Jose scale is attacked by a specialized 

 parasite, Prospallella pemiciosi, of Asian origin, as well as 

 various generalist predators. Future plans for control of all 

 these pest species are based on the judgment that existing 

 parasites and predators do exist that will control these pests 

 in most cases unless disrupted by pesticide applications. As 

 such, the second-stage IPM strategy should improve the 

 degree and reliability of such control in the future. 



Leaftniners . The apple blotch leafminer is a classic 

 induced pest. In unsprayed areas its densities are kept low 

 by several efficient specialist parasites. In Massachusetts 

 the major species are Pholetesor (Apanteles) omigis, a 

 braconid, and the eulophid, Sympiesis marylandensis (Van 

 Driesche & Taub, 1983). Both species feed on older larvae 

 within mines. Under current orchard spray regimes these 

 parasites become common in orchards only late in the 

 season (August through October) after cover sprays are 

 ended. When limited to this short period, parasites cannot 

 suppress leafminers below economic levels. Terminating 

 non-fungicidal cover sprays after the end of May, as envi- 

 sioned by second-stage IPM, should create an opportunity 



for substantial increase in control of leafminer populations 

 by parasites. Two additional parasite species have poten- 

 tial for increasing the degree of leafminer control, the 

 braconid, Apanteles pedias, from New Zealand and the 

 encyrtid, Holcothorax testaceipes, from Japan. Both have 

 been imported successfully into Ontario by fruit entomolo- 

 gists at the University of Guelph and are established in that 

 area. A. pedias also has been released in New York state. 

 Dr. Chris Maier of the Connecticut Agricultural Experi- 

 ment Station recently received funding to import and 

 establish these parasites in New England. Studies in 

 Massachusetts will be needed following releases to deter- 

 mine the degree of control resulting from the introduction 

 of these new species. 



In conclusion, biological control, while not applicable 

 for plum curculio, apple maggot fly, or tarnished plant bug, 

 in the future will play the key role in suppressing mites, 

 leafminers, aphids, and San Jose scale. The principal way 

 in which this control will occur will be through better 

 conservation of existing predators and parasites by earlier 

 terminationofregular cover sprays. Certain newbiological 

 control agents, namely a pesticide-resistant strain of the 

 predator m\{c, Amblyseius fallacis, and two exotic species 

 of leafminer parasites, Apanteles pedias and Holcothorax 

 testaceipes, should be introduced. As controls become 

 increasingly based on predators and parasites, grower need 

 for information on the recognition and biology of the 

 specific beneficial species involved will increase. To meet 

 this need, new Extension literature discussing the details of 

 biological controls of specific apple pests will be required. 

 Plans to develop such materials exist and are being sup- 

 ported by funds from the Department of Food & Agricul- 

 ture. 



References Cited 



Bostanian, N. J. and L. J. Coulombe. 1986. An integrated 

 pest management program for apple orchards in south- 

 western Quebec. Can. Enlomol. 118:1131-1142. 



Hislop, R. G. and R. J. Prokopy. 1981. Integrated 

 management of phytophagous mites in Massachusetts 

 (USA) apple orchards. 2. Influence of pesticides on the 

 predator Amblyseius fallacis (Acarina: Phytoseiidae) 

 under laboratory and field conditions. Prot.Ecol. 3:157-72. 



Van Driesche, R. G. and G. Taub. 1983. Impact of 

 parasitoids on Phyllonorycter leafminers infesting apple in 

 Massachusetts, USA. Prot. Ecol. 5:303-17. 



Van Driesche, R. G. and E. Carey (eds.). 1987. Opportu- 

 nities for Increased Use of Biological Control in Massachu- 

 setts. Mass. Agric. Exp. Sta. Bull. 718. 



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