home Susbcribe About Us Contacts Past Issues Print this issue


Looking Ahead

Forages & Grains

Corn

Soybeans

Fruits

Vegetables

Nursery & Forest

Degree Days

Fruits
Volume 60 Number 15 Date 07/30/2015


APPLE MAGGOT - Counts have been variable since emergence began four weeks ago, with some of the highest numbers occurring in orchards with fruits damaged during earlier hailstorms. According to John Aue of Threshold IPM Services, the volatiles produced by ripening, hail-damaged apples are highly attractive to AM and other fruit flies, and the number of AM flies captured on traps represents only a fraction of the fruit flies potentially entering the orchard. He notes that other flies in the genera Rhagoletis and Drosophila can inflict similar damage to hail-injured fruit.

Continued maintenance of traps will be important as harvest approaches in August. Baited traps should be concentrated in late summer varieties (i.e., cultivars ripening before Paula Red) for monitoring of apple maggot pressure.

WHITE APPLE LEAFHOPPER - Second generation eggs are beginning to hatch. Apple growers who observed damage caused by the first generation several weeks ago should scout for stippling and whitish spots on leaves in the interior of tree canopies. The summer generation of nymphs feeds well into September and can cause significant chlorophyll loss. Ordinarily, control should target first generation nymphs, but if justified, treatments for the second generation are also effective.

JAPANESE BEETLE - A few growers have noted light to moderate damage to apples, but beetle activity has been sporadic this season. If levels increase next month and treatment is required, growers can minimize insecticide use by spot treating only the most heavily infested varieties. Conventional growers may use pyrethroids or Imidan for immediate knock-down control, while organic producers could target first with PyGanic and follow up the next day with Neem oil as a repellent. For maximum effectiveness, controls should be applied on a warm, sunny afternoon, when the beetles are most active.

CODLING MOTH - John Aue advises orchardists to continue monitoring pheromone traps to determine options for second generation control. If counts exceed five moths per trap per week and treatment is warranted, materials such as Altacor and Delegate can be applied within five to seven days of harvest. The three formulations of codling moth granulosis virus may be used until harvest and will provide five to seven days of protection.

STINK BUG - Apple growers who experienced stink bug damage last season should begin inspecting fruits for dimples or dark, irregular circular depressions typical of stink bug feeding, and flag sites with multiple depressions on the same fruit or tree. This pest commonly migrates into orchards from field crops and wild hosts at this time of year. Damage is usually limited to specific areas in the orchard and depending on the distribution of the population, spot treatment may be adequate.

-- Krista Hamilton, DATCP Entomologist