Scaffolds 01 index

(Art Agnello ama4@nysaes.cornell.edu, Entomology, Geneva)

We're pretty much rounding the clubhouse turn on the season's pest control needs, and as growers prepare to make what will probably be their last control decisions of the summer before settling in for the harvest activities, here's a quick rundown of some of the more important players to keep in mind for this checklist.

Apple Maggot

Adult catches continue to be recorded around the state, if somewhat erratically at times, even though the dry soil conditions would be expected to hamper their emergence. Mid-August is traditionally still fair game for a respectable number of flies to be out and laying eggs, although numbers have been tapering off a bit recently. This is another one of those seasons when localized trapping could pay off in the event that some blocks are under greater pressure than others, even on the same farm.

Oriental Fruit Moth

Trap counts for the 3rd flight of the year are increasing in the Niagara Co. peach sites where we've been working, and some varieties still have a couple of weeks to go before harvest. Pheromone disruption results have been encouraging so far, but the edges of blocks, especially those adjacent to apples, have seen some problematic fruit infestations.

OFM FRUIT DAMAGE

Assess the pressure in your specific situations, check the pre-harvest intervals, and determine whether a full or border spray might be in order. Asana would probably be the material of choice (14 days).

Western Flower Thrips

Although not normally a problem in our area, there have been some reports of suspected damage in nectarines from this pest in the Hudson Valley during past seasons. According to the (Penn State) Fruit Times, warm and dry weather conditions may allow a buildup of damaging population levels on both nectarines and peaches. The potential for damage can be reduced by an application of SpinTor (14-day PHI; use of an adjuvant is recommended). Pennsylvania scouting guidelines are to count the number of adults on 10 fruits at five locations in the orchard. Sample fruits from the ends of the branches and in the lower third of the canopy. Five adult thrips per 50 fruits or the presence of silvering may indicate a damaging population.

Dock Sawfly

The appearance of neat little (2 mm) holes bored into the side of apples in the late summer and early fall, similar in appearance to those caused by a stem puncture, may indicate an infestation of this relatively sporadic pest. Although this insect is a relative of the European apple sawfly, its appearance is quite different; the larva is a bright green worm with a light brown head, as contrasted with the EAS, which is whitish and feeds on young apples during the petal fall period.

DOCK SAWFLY

Dock sawfly confines its feeding almost entirely to plants belonging to the buckwheat family (Polygonaceae), including numerous docks and sorrels, the knotweeds and bindweeds, or else wild buckwheat or alfalfa.

The injury to apples consists externally of the small round holes bored by the larvae, which after a few days show a slightly sunken, brownish ring around them and occasionally may be surrounded by a larger discolored halo.

DOCK SAWFLY DAMAGE

These holes may occur anywhere on the surface, but are most numerous around the calyx and stem ends, or at a point where the apple touches a leaf or another apple, since it is easier for the larva to obtain a foothold here. Since the dock sawfly must live on the above-mentioned weeds, it becomes an apple pest only where these plants are growing in or around the orchard. There is little danger from this insect in orchards where the food plants don't exist. Now would be a good time to assess the weed situation in your orchard and make plans for such selective herbicide applications as may be appropriate regarding this insect.