Bug Problem: Green Worm or Red Boxed Beetle?

Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
 

Client's Requests:  I have these pests on EVERYTHING from my tomato plants to my Rose bushes & flowers to my Lambs Ear plant! I'm certain the green worms are eating these because I've seen them on the leaf undersides. However, I'm not certain if the beetles are eating as well. I have an infestation of both pests every year along with White Flies & Aphids!! ?? We've sprayed with ALL the common treatments from Neem Oil to calling the pest control man. They continue to come back and destroy nearly every flower, or plant I have. Any thoughts??? Thank you, Very frustrated!

Help Desk Response:  Thank you for contacting the UC Master Gardener Program Help Desk. You asked about insects in your yard. There aren't insects named green horned worm or red boxed beetles, but you probably mean the tomato hornworm (a green worm with a pointy "horn" on its rear) and possibly the box elder bug or the red-shouldered bug. 

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Tomato Hornworm
Tomato Hornworm
omato hornworms are found on tomatoes and other plants related to tomatoes such as potato and eggplant. They are the caterpillar of a large moth. The hornworms can get very large--up to four inches long. Natural enemies (parasitic wasps, lacewings, spiders, and others) usually keep their population under control, but hand picking is also effective. Bacillus thuringiensis) or Spinosad is effective against smaller larvae.  Here is a UC link to more information about hornworms:  http://ipm.ucanr.edu/PMG/GARDEN/VEGES/PESTS/hornworm.html 

The insect you refer to as red boxed beetles could be either box elder bugs or red-shouldered bugs, also known as golden rain tree or soapberry bugs. Neither of these bugs does much damage to ornamental or fruit trees. You might be seeing the red-shouldered bugs right now. They are out in numbers in my yard. They eat the seeds of the golden rain tree or other related plants, but nothing else. Both of these bugs are more of a nuisance than a pest that needs to be controlled. Here is more information about box elder bugs: http://ipm.ucanr.edu/PMG/PESTNOTES/pn74114.html

Box Elder Bug
Box Elder Bug
Res Shouldered Bug
Red Shouldered Bug
 
You also mentioned problems with aphids and whiteflies which are very common pests throughout the County. The links below are to more information about both of these pests:   http://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html and http://ipm.ucanr.edu/PMG/PESTNOTES/pn7401.html

It is important to identify the pest before spraying. There are some pests that are controlled by natural predators that won't become more prevalent if the predators are indiscriminately killed by sprays. It is easier to deal with problems when they are caught early. As you notice something amiss, either damage from insects or disease, feel free to contact us. Photos of the problem/pest will help us diagnose it and enable us to send you information on what to do.  

Please don't hesitate to contact us again if you have more questions.

Don't miss our 2019 Great Tomato Plant Sale - 
Walnut Creek 3/30, Richmond 4/6, Antioch 4/13. 
Click here for more information:http://ccmg.ucanr.edu/tomato/

Help Desk of the UC Master Gardener Program of Contra Costa County (SEH)


Note:  UC Master Gardeners Program of Contra Costa's Help Desk is available almost year-round to answer your gardening questions.  Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone:  (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog.


By Steve I Morse
Author - Contra Costa County Master Gardener
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