July 17, 2010

1 - Squash bugs are baaack.

Yard and Garden - July 17, 2010


My garden is doing very well except for the squash bugs, I have been going in the garden and killing them by hand daily and spraying with neem oil. However one of my squash plants fell victim to the squash bugs and died. If you can please give me any insight on how I can address these bugs please let me know.

- Anthony T.



Squash bugs are a common and much hated inhabitant of New Mexico gardens. An effective control method for squash bugs is to "squash" the squash bugs that is what you are doing. Some people develop tricks such as putting a cabbage wrapper leaf or small piece of plywood (propped up at one corner) on the ground next to the plants. The squash bugs congregate under the cabbage leaf or plywood at night and early in the morning you can flip the leaf or plywood over and with a small block of wood, you can smash the squash bugs. Squashing the squash bugs every day will help reduce their numbers. Squashing the small brown squash bug eggs is also a recommended method for reducing problems by preventing the juvenile insects from ever harming the plants.

There are some insecticides labeled for control of squash bugs, but most have very limited effectiveness. Some are effective when the very young, just hatched, squash bugs are treated. Most are ineffective when adult squash bugs are treated. Neem oil is supposed to work (on the very young insects just after hatching). Some of the "harder" chemicals are reported to be more effective, but these are often restricted-use chemicals that may only be applied by a licensed pesticide applicator. If you wish to hire a licensed applicator, that may be something to consider. Whether you use the organic chemicals or other products, they must be applied to the lower surface of the leaves to be most effective.

Treatment (whether manual or chemical) to reduce the squash bug population is important because the squash bugs inject a toxic fluid into the leaf when it feeds, this causes the wilting and other symptoms. They can also transmit a disease as they feed on plants, so if a plant shows severe symptoms, remove it as quickly as possible to prevent the insects from spreading the disease further.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.


For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.

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