In this Issue:
GUEST ARTICLE
Customer Awareness Series--Part 3
VEGETABLE NEWS
STRAWBERRY NEWS
Seasonal Reminders for Strawberry Growers
APPLE NEWS
Apple Pest Focus: Spotted Tentiform Leafminer (Phyllonorycter blancardella)
Have a Great July 4th Holiday!
There will be no IPM News published on July 5th.
We will return the following week.
| Vol 1 No.8 | June 28, 2004 |
Apple Pest Focus:
Spotted Tentiform Leafminer
(Phyllonorycter blancardella)
Spotted tentiform leafminer (STLM or TLM) is an introduced pest of apple in North America. It also occurs on crabapples, and has 3 generations per year in Minnesota (early May - September). STLM overwinter as pupae in mines in leaves on the orchard floor. In Minnesota, emergence of spring (first generation) adults usually coincides with the tight cluster stage of apple.
The adult moth (shown left) is slender, brown, with distinct gold, black, and white wing patterns. Body length is about 3.5 mm with a wingspan of 7 mm. Spring moths tend to be larger and darker than summer moths.
Eggs are small, elliptical, creamy to transparent, and are laid on the undersides of leaves. Eggs laid by spring adults begin to hatch when the apple trees bloom.
Larvae go through five instars. The first three instars feed on the sap from the spongy mesophyll of the leaves, separating the outer layer of the leaf undersurface from the tissue above. They produce mines that are only visible from the underside of the leaf.
Pupae are long and yellow early turning to dark brown later, about 4 mm long. Prior to adult emergence, the pupa can be partially seen on the lower leaf surface of the mine. After the moth has emerged, the pupal skin will still be attached to the leaf.
Young STLM larvae are legless, white to pale green, deeply segmented, wedge-shaped, and range from 1 to 3 mm in length. They are sap feeders. Mature larvae are cylindrical, caterpillar-like, white to pale green and turning yellow immediately before pupation. Body length is about 4.5 mm. They are tissue feeders, and produce tent-like mines.
STLM feeding injury within the mines can reduce leaf photosynthesis. Reduction in photosynthesis can affect fruit set, size, and quality. Furthermore, STLM infestation may cause leaf drop and premature fruit drop.
For information on management options see Integrated Pest Management Manual for Minnesota Apple Orchards, 2003 at: www.mda.state.mn.us/ipm/applemanual
ACKNOWLEDGEMENTS
Co-Editors: Bill Hutchison, Department of Entomology,
University of Minnesota, hutch002@umn.edu
Jeanne Ciborowski, Minnesota Department of Agriculture, Ag. Resources Division,jeanne.ciborowski@state.mn.us
Suzanne Wold-Burkness, Department of Entomology, University of
Minnesota, woldx018@umn.edu
The Newsletter is published weekly from May through August, cooperatively, by the Minnesota Department of Agriculture (MDA) and the University of Minnesota (U of MN). Reports are posted on the U of MN and MDA web sites on Fridays. If you have suggestions and/or comments, please send your contributions by 4 p.m., Tuesday to Jeanne Ciborowski, 651-297-3217, jeanne.ciborowski@state.mn.us , MDA, 90 W. Plato Blvd., St. Paul, MN 55107-2094. You can access the Newsletter at the U of MN web site in htm. format at: www.vegedge.umn.edu/MNFruit&VegNews/mnindex.htm and at the MDA web site in pdf. format at: www.mda.state.mn.us/biocon/fruitreports/default.htm
Partial funding for this publication is provided through partnership agreements with the Minnesota Fruit and Vegetable Growers Association and the United States Department of Agriculture – Risk Management Agency (RMA) and the RMA Community Outreach and Assistance Partnership Program. These institutions are equal opportunity providers.
DISCLAIMER
References to products in this publication is not intended to be an endorsement to the exclusion of others which may have similar uses. Any person using products listed in this publication assumes full responsibility for their use in accordance with current manufacturer directions.
Last Revised June 25, 2004.
The University, including the Minnesota Extension Service, is an equal
opportunity educator and employer. ©1999-2004 Minnesota Extension Service,
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