Plant & Insect Diagnostic Clinic Update - June 3, 2009

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


Insects


Bagworms may be present now. Japanese tree lilacs and catalpa trees, phenological indicator plants, have started to bloom in central Iowa. As explained in the last issue, this is an indication that tiny, first instar bagworm caterpillars could be present. Now is the time to begin inspecting trees for caterpillars and treat if they are present and numerous. Keep checking for the next several weeks if you find nothing this early.


The lonely, solitary cockroach seen wandering on the floor in the middle of the day at this time of year is often a wood roach. These "outdoor" roaches wander indoors by mistake especially in May and June. See our Insect Note and the photo below. The usual "control" is to sweep or vacuum up and discard.


Wood roach. Male, above, has clear stripes along edge of wings and thorax. Female has short, functionless wing pads.Wood roach. Male, above, has clear stripes along edge of wings and thorax. Female has short, functionless wing pads.



We received a great picture this week of a disfigured asparagus plant exhibiting a disorder called fasciation. This bizarre appearance (elongated, flattened stem) is believed to be caused by a hormonal imbalance. While fasciation affects the plant’s appearance, it has little affect on the health of the plant.



The following diseases were also submitted:


Botryosphaeria canker on junipers.


Peach leaf curl


Iris leaf spot

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