Plant and Insect Diagnostic Clinic Update - October 14, 2009

News Article

The following are highlights and updates about samples and questions received in the Clinic during the past two weeks:

Diseases

Insects

Yellowjacket wasps are still around, but the nature of the problem has shifted.  With cooler temperatures outdoors, wasps that are still alive in nests inside house walls are moving toward the heat and appearing inside the house rather than going to the yard to forage.  This creates the annoyance of a few to dozens of wasps in your house buzzing at the windows.  See the HHPN from October 31, 1995 for more explanation.  The bottom line is that sprays and dusts will not be of much use.  Keep the fly swatter and vacuum cleaner handy to remove invaders as they appear and wait for Nature to take its toll on the rest of the population.

Spiders are also sensing the cold and searching for sheltered places to spend the winter.  They often accidentally wander indoors this time of the year.  Homes are not the best place for them since they really need to be cold and inactive to survive the winter.  In homes it is too warm, the air is too dry, and there is not enough food.  The two most common accidental wanders indoors are grass spiders and wolf spiders.  They are not venomous and do not reproduce indoors, so no control is needed.  See the HHPN from Sept. 19, 2007 for more information.

Grass spider.   A common accidental invader in the fall.  Photo by Heather Oosterhuis. Grass spider. A common accidental invader in the fall. Photo by Heather Oosterhuis.

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