What's Eating You? 7.12.12

Are you noticing that something has been taking a bite out of some of your plants?  Colorado Potato Beetles (CPB) are very active right now.  You may see them in all live stages, eggs, larvae and adults.  CPB's feed on leaves, flowers, terminal growth, stems, and even the fruits of a large variety of vegetable plants.  Their preferred hosts are tomato, potato and eggplant but they will also feed on many other plants and weeds including ground-cherry, jimsonweed, horse nettle, petunia, henbane, thorn apple, thistle, and mullein.  Chances are, if you're a home gardener,  you have few enough plants (and beetles) that you can manage these heavy foliar feeders with a gardeners best tool, your hands.  Inspect your plants (including the undersides of leaves) once weekly and pick off and crush all eggs, larvae and adults you happen to see, or drop them in a bucket of soapy water.  This will greatly reduce their populations as each generation will reach maturity within only 10 days.  Keeping your garden and surrounding area free of weeds will help to reduce populations.  It is also helpful to rotate solenaceous (the family to which tomato, potato and eggplant belong) plants as far as possible from the previous year’s planting to reduce beetle infestations.  Cheesecloth or non-woven nylon crop covers may help protect the foliage of young tomato and eggplant transplants from beetle damage.  For the larger scale growers or extreme infestations, a biological insecticide, Bacillus thuringiensis var. tenebrionis (BT) (commercially available as Novodor), may be used. BT is a biological pesticide which uses a bacterium to kill small potato beetle larvae.  It is harmless to most other insects and mammals.  As a last resort beetles may be treated with chemical pesticides labeled for control of CPB.  If a pesticide is used, target newly hatched eggs and small larvae making sure to thoroughly cover leaves and stems for best results. With any pesticide always read and follow all label directions before application and observe the required number of days wait before harvest for each particular crop. 

CPB eggs

CPB larvae (1st and 2nd instars)

CPB Adult