Bugs - Ask Extension
Can you identify this bug. Good/bad. Its on my corn, and something is eating my pole beans.
Knowledgebase
Bugs #421623
Asked August 16, 2017, 1:38 PM EDT
Can you identify this bug. Good/bad. Its on my corn, and something is eating my pole beans.
Linn County Oregon
Expert Response
Hello. The photo is of a cucumber beetle. It is a general feeder and may also be what is bothering your beans. Bad bug. Look for little round holes on the surface of your beans and holes in the leaves.
Thanks. How I organically treat it?
- Hello again. Unfortunately cucumber beetles are not easily controlled with any type of chemical, synthetic or organic. The first question to ask yourself is; “Is my problem so bad that I feel the need to use a chemical?” Plants usually survive their attack, they just look ugly. Cucumber beetles produce two generations every year, we are just now getting the summer generation as it emerges from the soil. Control is difficult as fertilized females overwinter in weeds. The ones flying around now are the ones that will provide you with the same problem next year. One way to control next year is to cover your crops with row cover as you plant them. Plants usually are most vulnerable to these pests when young. After they have put on about 7 leaves they are usually large enough to withstand the beetles and you can remove the barrier. By excluding them at the beginning of the season you reduce the second generation somewhat. Another method may be the presentation of sacrificial rows of plants. Plant these ‘trap’ crops to attract them and causing less damage to your preferred plants. In my mind this could also increase the population of the beetles in you garden as you are giving them free food and a place to breed, trap cropping such as this has not been proven to work in Oregon. Yellow sticky tape is sometimes used in an agricultural setting. It comes in 6 inch wide tape and must be hung at specified distances from the ground and strung parallel to the ground. The Pacific Northwest Insect Handbook does list several chemicals that are listed for Home use against these pests. These are the ones that have organic formulas that are approved for use by OMRI. They are azadirachtin (neem oil)-, Beauvaria bassiana, insecticidal soap, pyrethrins and kalolin clay. You must read the label and take precautions to protect yourself as well as properly applying the chemical you choose. These are the chemical names and you must check the labels to determine if the product you choose contains them. Also know that some these chemicals come in multiple formulas check to see that the product is OMRI approved which will be noted on the label. Be aware if you choose to treat, organic chemicals will also impact good bugs as well as the bad ones. If you kill a benefical bug YOU inherit its job and another problem may surface in your garden. Some of those good bugs could be targeting the beetles already. The down side of the chemicals is that the life cycle of these critters makes delivery of a fatal dose difficult as the larval stage is underground feeding on plant roots and chemicals will not reach there. Organic chemicals break down quicker than synthetics and must be applied more often. The kalolin clay must cover the plant and as the plant grows must be reapplied so leaf surfaces are covered. I did read one source that stated that even if the Neem product did not kill these beetles that they saw that the beetles seemed to lose their appetite and damage on plants was lessened. I did not find a second source that mentioned this but it might make the neem oil worth a try and see how it works for you. I practice the squish method. Any beetle I can get my hands on gets squashed, one less to breed next year’s generations.
Thanks. Very informative. I prefer to squish also.
