Grubs in the Lawn!

             I have had a number of calls from home owners who are finding large areas in their lawns where the grass is dead and brown.  The

             Right now the grubs are very large and ready to go into their pupa stage.  Insecticides are not very effective against them so we do not recommend any sprays at this time.  You will want to reseed the area to get new grass growing.  Don’t forget to irrigate regularly until your new grass is established.

White grub management is best timed when the white grubs are small and feeding in the turf root zone (late summer into early fall). In Maine, beneficial nematodes have been shown to be effective in managing white grubs whereas milky spore (a disease for the grubs) has had spotty results. Insecticides such as imidacloprid (Merit) or carbaryl (Sevin) are also an option to consider.  Targeting the grub stage in hope of relief from the adult beetle often leads to disappointment.

Be sure to read and follow label instructions on all management tools (traps, nematodes, and insecticides).

Source: Dill, J., Japanese Beetle, UMaine Extension Insect Factsheet, 2004, http://pmo.umext.maine.edu/factsht/japanese.htm

Tree and Shrub Pest Management

Birch Leafminer (Fenusa pusilla) - Tiny developing mines, resembling translucent spots along the margins of the new leaves, have begun to appear in the southern half of the State and will likely show up by the end of the month in the north.  Mines of another white birch leafminer (Messa nana) usually appear in June. Watch for black fly-like adults around the foliage from now through mid-June. Apply foliar treatment with carbaryl (Sevin) or acephate (Orthene) when small developing mines (seen as small translucent spots in the leaves) are evident.

  Viburnum Leaf Beetle – Both larva and adults feed voraciously on the foliage of viburnums.  Heavily attached plants will have every leaf skeletonized by this pest.  Prune off twigs with egg pockets on them before hatch (early- to mid-May). Treat infested shrubs early (before the end of May) with acephate (Orthene), carbaryl (Sevin) or chlorpyrifos.

Eastern Tent Caterpillar (Malacosoma americana) - There are a few more webs of the eastern tent caterpillars this year and they are becoming noticeable.  If you have a web in your crabapple or cherry tree you can simply remove the webs containing the caterpillars and place them in water with a squirt of dishwashing detergent or use a BT product.  Either approach will kill the caterpillars, but do not consider burning them out because this process will result in more injury to the tree than the caterpillars could ever cause.

These recommendations are not a substitute for pesticide labeling. Read the label before applying any pesticide. Pesticide recommendations are contingent on continued EPA and Maine Board of Pesticides Control registration and are subject to change. Other effective registered pesticides are available and marketed under other product names.  No endorsement or the exclusion of similar products not mentioned by the Maine Forest Service is intended or implied.  Ask your supplier for specifics, and always read the label of any product before applying on site. Caution: For your own protection and that of the environment, apply the pesticide only in strict accordance with label directions and precautions.

Source: Forest & shade tree-insect & disease conditions for Maine, May 15, 2008, Conditions Report No. 2, 2008, Maine Forest Service, Forest Health and Monitoring Division at: http://www.maine.gov/doc/mfs/Cond_2008_2.htm 

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