Wednesday | December 13, 2017
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What’s to do about all these kitchen flies?

I have a lot of fruit flies in my kitchen, hovering over my fruit bowl and around the sink. They are causing the fruit to rot. What can I do? I hate to spray in the kitchen.

In all probability, these are not fruit flies but rather what are commonly known as vinegar flies, or drosopila, in the insect family, Drosophilidae.

Unlike the fruitflies, which cause major damage to fruit and vegetables, the vinegar flies are found in association with overripe fruits and vegetables and do not cause the fruit to rot. They are actually attracted to rotting and fermenting food; their larvae feed principally on the yeast in the fermenting fluids.

Drosophila flies have been widely used by geneticists around the world in studying the laws of heredity.

This is because they are so prolific, have a short life cycle, and are easy to rear.

Vinegar flies do not bite humans and are strictly a nuisance pest.

For control, it is best to concentrate on eliminating the larval feeding sites and the breeding areas.

Sanitation is critical. By eliminating overripe fruit sitting on the counter and exposed kitchen garbage, these pests can be controlled; all exposed fruits and vegetables should be refrigerated.

Pyrethrin insecticides are commonly used and are effective in killing vinegar flies when contact is made. The poison, however, is ineffective in ridding an area of the pest.

From Ohio State University comes this simple trap. Take a Mason or similar jar and cover or paint the outside top third of the jar. Coat the inside of the jar with a sticky liquid such as diluted honey or vegetable oil. Invert the jar over bait such as crushed bananas. Rest the jar upside down on two blocks of wood to allow flies space enough to feed on the bait. After the flies leave the bait, they will fly upward to the light portion of the jar and get stuck on the sides when they rest.

Aloha, Nick. We have had problems with our green peppers. Those in raised beds in our greenhouse as well as plants started and growing in soil/compost mix in pots; they are showing crepe-y, dry, shriveled leaf formation at the crown of each plant. If peppers form at all, they are small, deformed and dry-looking.

We thought nematodes, but the potted starts are beginning to show it, too!

We have already pulled out all the spring transplants and now are thinking of pulling out the next generation! Any thoughts?

Your expertise is greatly appreciated. — C.C. Mountain View.

It sounds like the peppers have a case of cucumber mosaic virus, a common disease found on peppers. Leaves become crinkled and curled, with green and yellow mottling; plants are usually stunted. The fruit may be malformed and have conspicuous concentric rings or spots.

The virus is spread from plant to plant by aphids. Once an aphid acquires the virus, it can retain it for only a short time and thus the spread is local and very rapid within a planting. This virus has a wide host range including cucumbers, tomatoes, squash, watermelon, beets, eggplant and several landscape flowers.

Control: Unfortunately, no resistant varieties of peppers are currently available for this disease. Furthermore, pesticide strategies are not effective. Two ways to combat the virus are by eliminating weeds, as they may harbor the virus, and by using reflective mulch to cover the soil around the plants to repel the insect. In addition, the infected plants need to be removed since the aphids will spread the disease.

Hilo resident Nick Sakovich is a professor emeritus of the University of California. He has worked in the field of agriculture for 30 years. Email your questions to Sakovich at


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