Garden Detective

Garden Detective: What’s bugging readers? Grasshoppers and more

Reader Terry Pedersen found this odd brown cocoon on his potato vine. It’s a praying mantis egg case.
Reader Terry Pedersen found this odd brown cocoon on his potato vine. It’s a praying mantis egg case. Terry Pedersen

Q: How can I best eliminate grasshoppers from consuming (the soon-to-be) blossoms for next year’s citrus crop? I saw them last winter and didn’t react. I need to be proactive soon.

Doug Hinchey, Sacramento

A: According to UC master gardener June Bleile, grasshoppers are among the most difficult pest insect to manage in the garden.

If the population is low, they can be handpicked and squashed. Floating row covers provide some protection if the infestation is not high. If your citrus trees are not too large, you may consider this strategy.

Poultry, including chickens and guinea hens, are excellent grasshopper predators, but these birds can also cause damage to some garden plants.

One strategy that can be used in gardens where migration of grasshoppers frequently occur is to keep an attractive green border of tall grass or lush green plants around the perimeter of the garden to trap insects and divert them. Don’t mow this trap crop or let it dry out, or you will send the grasshoppers straight into the garden.

Insect sprays for grasshopper control are very toxic to bees, natural enemies of grasshoppers.

Find more tips on grasshopper control in the UC Pest Note 74103. Find it online at

Q: The leaves on my potato vines became brown and crumbling. I later found this cocoon. Any ideas? I sprayed and the vines seem better, but they cover a fence and I would hate to lose them.

Terry Pedersen, Sacramento

A: According to Bleile, the potato vine (Solanum jasminoides) is a fast-growing, evergreen or semi-evergreen vine that takes full sun and needs regular watering, weekly or more often in extreme heat. The photo of the insect egg case that you found on your vine had nothing to do with the leaves turning brown. This is a praying mantis egg case, an insect predator that consumes both pests and beneficial insects.

There are a variety of reasons for the brown foliage. The older, shaded foliage will naturally turn brown throughout the year. New foliage will show damage from either excess water or insufficient water. Too much fertilizer will also cause damage.

Since the potato vine is a fast-growing vine, twining rapidly to 30 feet in the first year, the damaged area will soon be filled in. Your vine should be back green and healthy in the spring.


Questions are answered by master gardeners at the UC Cooperative Extension services in Sacramento and Placer counties. Send questions to Garden Detective, P.O. Box 15779, Sacramento, CA 95852. Send email to h& Please put “Garden Detective” in the subject field and include your postal address. To contact UC Extension directly, call:

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