Gardening & Living in Grand Style
Garden and ornamental plant pests: Yucca weevil and squash bugs…
by Michael Johnson
Utah State University Extension Agent, Grand County
Jul 22, 2010 | 2143 views | 0 0 comments | 6 6 recommendations | email to a friend | print
A specimen of a yucca weevil was identified for the first time in Grand County this year. The yucca weevil, shown here, have brownish or black bodies and are about one-half inch in length.
A specimen of a yucca weevil was identified for the first time in Grand County this year. The yucca weevil, shown here, have brownish or black bodies and are about one-half inch in length.
slideshow
Squash bugs – dark, hard shelled insects that are less than an inch long and shaped like a shield are an annual annoyance in most area gardens. The squash bug attacks squash, pumpkins and sometimes other cucurbits, damaging and eventually destroying the plant.
Squash bugs – dark, hard shelled insects that are less than an inch long and shaped like a shield are an annual annoyance in most area gardens. The squash bug attacks squash, pumpkins and sometimes other cucurbits, damaging and eventually destroying the plant.
slideshow
Yucca weevil We had a unique insect brought to the office this spring in fact it was the first identified specimen of this insect in Grand County. The yucca weevil is from the genus Scyphophours, which includes insects that can damage yuccas and agaves. This yucca weevil was first found on a large yucca here in Grand County last year and when seen again this spring was brought into the office.

These weevils are about one-half inch in length with a dull brownish to black body. As with all weevils, the insect has an extended snout and chewing mouthparts.

In the spring, the female will burrow into the base of a plant and lay eggs, which then hatch into grubs that feed through the center of the plant.

As is the case with most beetles, controlling the yucca beetle is difficult. Once the beetle is discovered, the best solution is to destroy both the insects and the plant that is infested. However, should you want to try to save the specimen you could try either a broad-spectrum insecticide or a systemic insecticide.

Squash bug

Squash bugs – you’ve either got to dislike them or hate them, as there is usually no in-between. Squash bugs are dark-colored, hard-shelled insects that are about five-eighths of an inch long with a somewhat shield-like shape. They love to hang out on squash, pumpkins and sometimes other cucurbits.

They are quite destructive due to their feeding habit of sucking sap from plants and when insect numbers are high this feeding damage can result in the wilting and eventual death of the plants.

Even with our cold winter it appears that this year will be a heavy year for squash bugs, so if you haven’t seen them you might soon. The bugs hang out on the stems and under the leaves of the plants. Once you find them you will also see masses of eggs – small bronze-colored oblong eggs that are in a group and laid on the underside of the leaves and sometimes on the stems.

There rarely seems to be an end to squash bugs. In areas with small plantings, daily scouting of the plants by lifting up the leaves and removing and killing the insects can be very effective in controlling them. Also look for the eggs and either squash them or remove them from the plant by cutting out a section of the leaf or removing the whole leaf.

One way to help you in this scouting is to use a handheld dust buster to vacuum the insects up and then drop them in some soapy water. Mulching is not a good idea for squash plants since that gives the insects a great hiding place.

One organic control method gaining popularity is a combination of diatomaceous earth and pyrethrin applied around the base of the plant. There are some other non-organic insecticides that might help if applied early in the season.

I recently read about an experimental technique being tested at one university which involves companion planting of catnip, tansy, marigolds, beebalm, or nasturtiums amongst the squash. These other plants might help repel the squash bug although I wouldn’t expect 100 percent success.

Since adult squash bugs will over-winter in debris in the vicinity of plantings that have been infested, one of the best gardening chores you can do in the fall is to remove garden residues by either tilling the material into the soil, burning it or using high temperature – meaning correct – composting techniques. Just throwing all the plant debris in a pile doesn’t qualify as a correct composting technique.

For more information about these topics, call the Utah State University Extension Grand County office at 259-7558 or email Michael Johnson at mike.johnson@usu.edu.

Copyright 2013 The Times-Independent. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

report abuse...

Express yourself:

We're glad to give readers a forum to express their points of view on issues important to this community. That forum is the “Letters to the Editor.” Letters to the editor may be submitted directly to The Times-Independent through this link and will be published in the print edition of the newspaper. All letters must be the original work of the letter writer – form letters will not be accepted. All letters must include the actual first and last name of the letter writer, the writer’s address, city and state and telephone number. Anonymous letters will not be accepted.

Letters may not exceed 400 words in length, must be regarding issues of general interest to the community, and may not include personal attacks, offensive language, ethnic or racial slurs, or attacks on personal or religious beliefs. Letters should focus on a single issue. Letters that proselytize or focus on theological debates will not be published. During political campaigns, The Times-Independent will not publish letters supporting or opposing any local candidate. Thank you letters are generally not accepted for publication unless the letter has a public purpose. Thank you letters dealing with private matters that compliment or complain about a business or individual will not be published. Nor will letters listing the names of individuals and/or businesses that supported a cause or event. Thank you letters about good Samaritan acts will be considered at the discretion of the newspaper.