Susceptibility of Apple Varieties to Oviposition by Apple Maggot, Rhagoletis

pomonella (Walsh)

Peter Jentsch Hudson Valley Research Lab

Cornell University

1. Life cycle of apple maggot (AM)

2. Emergence cycles.

3. Monitoring techniques & tools.

4. Susceptibility of old and new apple

varieties.

Presentation overview

Over-winter in soil

Oviposition

AM Pupa

Larval Damage

•  Adult females lay an average of 300 eggs.

•  Average adult lives 30 days.

•  Flies emerge over extended periods; June to September.

•  Climatic conditions do not significantly effect emergence.

•  Early maturing apple varieties are more susceptible than late maturing varieties after first emergence.

Biological Rules of Thumb

Ovipositional Tendencies of AM

•  Earliest recorded adult emergence on 10 June.

•  Peak adult emergence mean is 10 July.

•  Egg laying occurs 8 days after adult emergence.

•  AM oviposition follows the natural sequence of apple variety ripening.

AM emergence 1931 - 1969

Samples from McIntosh •  First Peak emergence ◊  Second peak emergence

Data taken from R.W Dean and P.J. Chapman �Bionomics of the Apple maggot in Eastern N.Y.�

Determination of Population Density

•  Using baited sticky spheres to monitor threshold.

•  In IPM programs, sticky traps are placed in commercial orchards to monitor AM flies.

•  Acceptable control in commercial orchards ia obtained using insecticides applied to kill females before they oviposit. Applications are made 7 to 10 days after the first fly has emerged.

• 10- to 14-day intervals while adults are active.

Determination of IPM AM Threshold

Data taken from R.W Dean and P.J. Chapman �Bionomics of the Apple maggot in Eastern N.Y.�

Ovipositional preference •  Delicious vs R.I. Greening •  Early vs late maturing

Ovipositional Preference of AM on Older Apple Varieties

AM damage on new �Enterprise� variety

�Trailworm� larval tunneling in fruit.

Arlet

Braeburn/M.9

Cameo

Creston

Enterprise

Fortune

Fuji (BC #2)

Gala Supreme

Ginger Gold

Golden Del./M.9

Golden Supreme

GoldRush

Honeycrisp

McIntosh (Pioneer)

NY 75414-1

Orin

Pristine

Sansa

Senshu

Shizuka

SunCrisp

Sunrise

Yataka/M.9

New Apple Varieties Evaluated for Susceptibility to AM Oviposition

Data taken from R.W Straub �Susceptibility of New Apple Cultivars to Various Arthropod Pests� N.Y. Fruit Quarterly Vol.11, No.2 Summer 2003.

Variety Preference of AM on New Apple Varieties