{"id":4465,"date":"2011-01-27T14:26:44","date_gmt":"2011-01-27T19:26:44","guid":{"rendered":"http:\/\/extension.umaine.edu\/ipm\/"},"modified":"2023-02-03T16:48:50","modified_gmt":"2023-02-03T21:48:50","slug":"5039e","status":"publish","type":"page","link":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5039e\/","title":{"rendered":"Sucking Insects That Affect Vegetable Plants"},"content":{"rendered":"
\n \n \"Print\n <\/a>\n <\/div>\n

Pest Management Fact Sheet #5039<\/h3>\n

James F. Dill, Pest Management Specialist
\nClay A. Kirby, Insect Diagnostician<\/em><\/p>\n

For information about UMaine Extension programs and resources, visit extension.umaine.edu<\/a>.
\nFind more of our publications and books at extension.umaine.edu\/publications\/<\/a>.<\/strong>
\n<\/span><\/strong><\/p>\n

Introduction
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The mouthparts of sucking insects are specialized for piercing and sucking.\u00a0 These pests damage plants by inserting their mouthparts into plant tissue and removing the juices.\u00a0 Heavily infested plants become yellow, wilted, deformed or stunted, and may eventually die.\u00a0 Some sucking insects inject toxic materials into the plant while feeding, and some transmit disease organisms.\u00a0 Some prime examples of piercing-sucking insect pests of vegetables are:<\/p>\n

Aphids: <\/strong>Aphids are small, soft-bodied insects.\u00a0 They range in color from black to green to yellow.\u00a0 Their numbers can greatly increase over a relatively short time period.\u00a0 They may cover the entire surface of a leaf or stem.\u00a0 They can be vectors of plant viruses.\u00a0 Encourage natural predators, such as ladybird beetles or lacewing larvae, to reduce their numbers.\u00a0 Lacewing eggs can be purchased from seed companies.\u00a0 The lacewing\u00a0 eggs soon hatch and provide good aphid control.\u00a0 Aphids can be washed off from plants with a garden hose.\u00a0 Chemical options for controlling aphids include insecticidal soap, horticultural oil, neem oil, or malathion.<\/p>\n

Leafhoppers: <\/strong>Leafhoppers are small, green, wedge-shaped insects that attack many garden, forage and fruit crops. They suck out plant juices causing yellowing, leaf-curling and stunting.\u00a0 They also transmit several disease organisms, especially those associated with bacterial yellows.\u00a0 Use pyrethrins or carbaryl (Sevin\u00ae) as a control.<\/p>\n

Stink bugs: <\/strong>Stink bugs comprise a family (Pentatomidae) of ‘true bugs’ in the order Hemiptera that feed on the fruit of a wide range of plants including beets, beans, pears, squash, tomatoes and corn, causing the fruit to become shriveled and deformed.\u00a0 The most common species attacking home gardens are the green stink bug and the brown stink bug. Hand-picking may lower numbers sufficiently for damage control.\u00a0 To control, use pyrethrins or carbaryl (Sevin\u00ae).<\/p>\n

Tarnished plant bugs:<\/strong> Tarnished plant bugs (family Miridae) feed on the leaves of many plants, causing them to curl, reducing growth, and transmitting diseases.\u00a0 These bugs also deform apples and cause corky, deformed strawberries.\u00a0 To control, use pyrethrins or malathion.<\/p>\n

Squash bugs:<\/strong> Mature squash bugs (family Coreidae) are about an inch long and are gray-black in color.\u00a0 While still immature, they are strikingly colored with white and black.\u00a0 Squash bugs suck juice from the leaves and stems of squash, pumpkins, melons and related plants, and thus spread disease.\u00a0 Hand-picking may be effective.\u00a0 Leaving boards or shingles out overnight between the rows of cucurbits is a way to “harvest” squash bugs.\u00a0 The bugs tend to use the boards and shingles for cover.\u00a0 They can easily be gathered from under such items and disposed of early in the morning.\u00a0 Eggs can be scraped off the foliage with one’s thumbnail.\u00a0 Insecticide options include insecticidal soap or carbaryl (Sevin\u00ae).<\/p>\n

Thrips:<\/strong> Thrips are minute insects that feed on pollen and tender plant tissues. They typically hide in the cracks and crevices of leaf buds,\u00a0 junctures, and flowers.\u00a0 They rasp the tissue and suck up the exuding sap.\u00a0 Leaves take on a silvery appearance after the thrips have fed on them, and plants become stunted and deformed.\u00a0 Thrips are usually a pest of seedling plants but may attack plants in any stage, especially gladioli, onions and blueberries.\u00a0 Neem oil, horticultural oil, spinosad and pyrethrins are options for thrips management.<\/p>\n

Spider mites:<\/strong> Spider mites are not insects, but are closely related to ticks.\u00a0 They suck out juices from leaves and stems, causing plants to become deformed or have a bronze or yellow appearance.\u00a0 Hot and dry weather favors their development and survival.\u00a0 Heavy infestations can cause leaf and flower bud-drop and death of the plant.\u00a0 Use insecticidal soap or neem oil to control spider mites.<\/p>\n

Management<\/h3>\n

A hand vac can be used for small-sized pests.\u00a0 Control of sucking insects with insecticides is often difficult because of their capacity to reproduce rapidly.\u00a0 Also, they may quickly develop resistance to the chemicals when only materials with the same mode of action are used repeatedly.\u00a0 Often a blast of water from a garden hose will knock the pests off the plants, and very rarely do they find their way back to them again before falling victim to the elements or to natural predators.<\/p>\n

Observe the waiting periods listed on the labels for insecticides (number of days from application to harvest).<\/p>\n

If possible, protect bees by spraying only in late afternoon or evening, and by not spraying plants when flowers are present.<\/p>\n\n\t\t