10 



MONITORING 



Adults . STLM Adult seasonal activity may be monitored by employing 

 St icky traps baited with synthetic female sex pheromone caps (obtain- 

 able from Conrel Corporation, 110 A Street, Needham Heights, MA). 



Adults can also be captured on white sticky-coated visual 

 traps used for monitoring tarnished plant bug and European apple saw- 

 fly adults (obtainable from New England Insect Traps, Box 938, 

 Amherst, MA). In 1980, we plan to assess which color of visual trap 

 is most attractive to STLM adults. At present, there is no reliable 

 means of relating numbers of adults captured in pheromone or visual 

 traps to potential injury levels. Future research is aimed in this 

 direction. 



Larvae . In most orchard situations, the most useful monitoring method 

 to date has proven to be examination of the leaves for STLM larval 

 mines. For 1st generation larvae, leaf monitoring should begin at 

 late pink and continue at 4-7 day intervals until 1 week after petal 

 fall. For 2nd generation larvae, monitoring should begin in late 

 June and continue at 4-7 day intervals through late July. Monitor- 

 ing of 3rd generation larvae is unnecessary, as the New York research- 

 ers have found that while these larvae cause characteristic mines, 

 this injury occurs too late in the season to threaten the crop or 

 warrant additional insecticide applications. 



For monitoring , it is best to examine at least 10 leaves per 

 tree on at least 1 tree per acre. For 1st generation larvae, choose 

 fruit cluster leaves at head height in the lower half of the tree in- 

 terior. For 2nd generation larvae, choose leaves on new woody tissue 

 (but not water sprouts) from anywhere in the tree. 



It is extremely important to look carefully for evidence of 

 earliest sap-feeding mines on the lower leaf surface. This is best 

 done by holding the leaf toward the sky, and locating the thin wind- 

 ing brown trail and/or the light green or whitish appearing mine. 



CONTROL 



One or a combination of the following 3 pesticide- treatment 

 programs may be used for STLM control. Research conducted in New 

 York and Canada shows that high levels of adult immigration and/or 

 high overwintering mortality of STLM pupae render the previous year's 

 level of STLM abundance in a given block of little value in predict- 

 ing this year's STLM abundance. Thus, each grower should keep a 

 careful eye on each block during the current growing season. 



A. Endosulfan (Thiodan) Program . This program is aimed at control- 

 ling STLM adults and consists of 1 application of endosulfan 

 (half strength) at half inch green and a 2nd application (full 

 strength) at pink against 1st generation adults, and/or an 

 application of endosulfan (full strength) in late June or early 

 July timed to coincide with emergence of 2nd generation adults. 



