Insect Control

Insect Control

Greenhouse growers offer their tomatoes, lettuce, and cucumber plants a favorable environment to produce fruit. At the same time, they create a favorable habitat for insect pests. Unlike crops that grow in the field, greenhouse vegetable pests are not plagued by the weather, natural predators, or parasites in the greenhouse. As a result, these pests can reproduce rapidly and cause quite a bit of damage if left unchecked.

The pests that are the most common to these three crops include aphids, whiteflies, leafminers, tomato pinworms, cucumber beetles, and spider mites. In this article, we will discuss these insects, the damage they can cause, and some helpful tips on control measures.

Aphid

The pear-shaped and soft-bodied aphid may be winged or wingless. In either case, this pest feeds in colonies, causing discoloration or mottling of foliage. It often transmits virus disease and excretes honeydew, on which sooty mold grows.

Cabbage Loopers

This green caterpillar with white stripes is about 30 millimeters in length. It has three pairs of legs near the head. Young larva typically can be found on the underside of leaves, consuming the tender leaf tissue and leaving most of the veins intact.

Cucumber Beetle

The cucumber beetle is oval-oblong and is 5 to 6 millimeters in length with a bright yellowish-green body with 12 black spots on wing covers or a pale yellow body with three black stripes on wing covers. This pest not only leaves holes in foliage and stems, it feeds on blossoms and scars fruit.

Leafminer

This pest is colorless to bright yellow with a pointed head. When it enters fruit, the leafminer makes a serpentine mine that is slightly enlarged at one end. As an adult, it is 1.0 to 1.8 millimeters long.

Tomato Pinworm

These young, yellowish-gray larva are only a few millimeters long, but they are able to leave blotch-like mines in leaves. Older yellow, green, or gray purple-spotted larva are up to 8 millimeters in length. They bore into stems, buds, and fruit.

Two-Spotted Spider Mite

The spider mite is very tiny, almost microscopic. It is pale to dark green in color with two or four darkly colored spots. Adults and nymphs have eight legs; larvae have six legs. This mite feeds on undersides of leaves. Infested foliage will have silvery or pale yellow stipples.

Whitefly

There are two types of whiteflies: greenhouse and silverleaf. The greenhouse whitefly is a white, moth-like insect about 1.5 millimeters long that is usually found with tiny yellow crawlers and/or green oval, flattened, immobile nymphs and pupae. These pests cause leaves to yellow and drop from plants. Some plants are stunted and non-reproductive. A black, sooty mold often is present on leaves.

The silverleaf whitefly is slightly smaller and a darker yellow color than the greenhouse whitefly (0.96 millimeters for the female and 0.82 millimeters for the male). It causes similar damage to plants as the greenhouse whitefly.

 

Management And Control

A well-planned, properly administered management program can frequently prevent damaging populations of insects and keep levels under control. Prevention is key.

Sanitation, screened openings, insect-free transplants, daily inspection of plants, and isolation are important considerations in a greenhouse pest control program.

The use of biological controls also is encouraged. Yellow sticky traps help keep adult whiteflies and aphids in check and monitor their movement and development in concert with the use of the parsitic wasp Encarsia formosa against the whitefly; the predatory mite Phytoseilus persimilis against the spider mite; and the parasitic wasp Diglyphus isaea against leafminers. The introduction of lady beetles, lacewings, or midges for aphids, and the use of the natural insecticide Bacillus thuringiensis for worms offers additional tactics in the battle against bugs in the greenhouse. Regular and frequent inspections of plants for pests and beneficials and good record keeping are essential to pest management.

Environmental management can also influence pest development in the greenhouse. Temperatures above 85°F and below 60°F slow the development of pests and give parasites an advantage. High and low relative humidity also slows the development of certain pests. Likewise, the misting of foliage during the day will dislodge aphids, leafminer adults, and adult whiteflies.

The use of ventilation fans or the constant use of circulating fans and the use of airblast sprays also discourage the settlement of adult whiteflies and leafminer adults in the tops of plants. Obviously, extreme high or low temperatures between crops will kill certain pest stages.            

Leave a Reply

Featured Stories
These wildflowers, planted near a California almond orchard, can be extremely effective in aiding pollinators. (Photo credit: Katharina Ullmann, Xerces Society)
Production
July 27, 2016
Survey: Fruit And Vegetable Growers Support Pollinators
Most of the berry, almond, melon, pumpkin, and tree fruit growers surveyed are being careful about how they manage their farms to minimize pesticide impacts and improve bees’ habitats. Read More
potato late blight leaves
Potatoes
July 27, 2016
Hail Hammers Potato Crops In North Dakota
Storms have wreaked havoc on crops in the Peace Garden State. Read More
cash money in hand
Citrus
July 27, 2016
Stockholders OK Dow, DuPont Merger
Companies intend to separate into three, independent companies. Read More
Tall Spindle Axe featured
Stone Fruit
July 26, 2016
Take A Closer Look At The Tall Spindle Axe Training System
One of the more traditional three-dimensional canopies, Tall Spindle Axe data shows consistent early and sustained yields. Read More
Workers picking in a Florida strawberry field
Berries
July 26, 2016
Wish Farms Commits $100K To Food Safety Cause
Central Florida berry operation will donate $20,000 annually over the next five years to fund various research projects backed by the Center for Produce Safety. Read More
Spanish speaking employees
Fruits
July 26, 2016
Popular Spanish-Speaking Fruit Summer Tour Returns
Second-annual tour designed to educate Spanish-speaking employees or farmworkers on fruit growing practices. Read More
Feature Im-Perfect-Wal-Mart-Fruit-Apples (Photo credit: Walmart)
Apples & Pears
July 26, 2016
Walmart Begins Selling So-Called ‘Ugly Fruit’
Cosmetically challenged apples are the company’s first foray into a global movement to cut food waste. Read More
Bee Sperm - Washington State University Cryo Lab (Photo credit: WSU)
Production
July 26, 2016
Importing Frozen Honeybee Sperm Is Key To Conservation
The Washington State University (WSU) bee program has worked with researchers from around the world to create more honeybee genetic repositories like the one at WSU. Read More
apple tree trellising washington state
GenNext Growers
July 26, 2016
Tour Dedicated To Next Generation Tree Fruit Growers In Washington
Newly formed Next Generation Tree Fruit Alliance to tour orchards, network. Read More
Photo courtesy of American Sweet Potato Marketing Institute
Farm Management
July 26, 2016
Mexico Has Potential For U.S. Sweet Potato Exports  
Assessment concluded that opportunities abound if Mexican buyers better understand grades, sizes, and quality of U.S. product. Read More
The Latest
Production
July 27, 2016
Survey: Fruit And Vegetable Growers Supp…
Most of the berry, almond, melon, pumpkin, and tree fruit growers surveyed are being careful about how they manage their farms to minimize pesticide impacts and improve bees’ habitats. Read More
Potatoes
July 27, 2016
Hail Hammers Potato Crops In North Dakot…
Storms have wreaked havoc on crops in the Peace Garden State. Read More
Citrus
July 27, 2016
Stockholders OK Dow, DuPont Merger
Companies intend to separate into three, independent companies. Read More
Stone Fruit
July 26, 2016
Take A Closer Look At The Tall Spindle A…
One of the more traditional three-dimensional canopies, Tall Spindle Axe data shows consistent early and sustained yields. Read More
Berries
July 26, 2016
Wish Farms Commits $100K To Food Safety …
Central Florida berry operation will donate $20,000 annually over the next five years to fund various research projects backed by the Center for Produce Safety. Read More
Fruits
July 26, 2016
Popular Spanish-Speaking Fruit Summer To…
Second-annual tour designed to educate Spanish-speaking employees or farmworkers on fruit growing practices. Read More
Apples & Pears
July 26, 2016
Walmart Begins Selling So-Called ‘…
Cosmetically challenged apples are the company’s first foray into a global movement to cut food waste. Read More
Production
July 26, 2016
Importing Frozen Honeybee Sperm Is Key T…
The Washington State University (WSU) bee program has worked with researchers from around the world to create more honeybee genetic repositories like the one at WSU. Read More
GenNext Growers
July 26, 2016
Tour Dedicated To Next Generation Tree F…
Newly formed Next Generation Tree Fruit Alliance to tour orchards, network. Read More
Farm Management
July 26, 2016
Mexico Has Potential For U.S. Sweet Pota…
Assessment concluded that opportunities abound if Mexican buyers better understand grades, sizes, and quality of U.S. product. Read More
Crop Protection
July 25, 2016
Study: GMO Ban Would Hurt Economy And En…
Food prices and greenhouse gas emissions would rise, according to paper by Purdue University agricultural economist. Read More
Farm Management
July 25, 2016
Seven Reasons You Need To Attend The Uni…
Education sessions and Capitol Hill visits will focus on key issues, such as labor, facing the fresh produce industry. Read More
Tomatoes
July 25, 2016
New Research Uncovers Gene That May Be K…
Scientists identify a gene that encodes an enzyme which plays a pivotal role in controlling tomato softening. Read More
Crop Protection
July 25, 2016
Organic Insect Control Product Available…
The mycoinsecticide is EPA registered and controls a variety of insect pests. Read More
Citrus Achievement Award
July 25, 2016
Citrus Achievement Award Winner: Adaptin…
Marty McKenna says hurdles like HLB forces growers to step up their game, which is a good thing. Read More
Insect & Disease Update
July 22, 2016
Marco Rubio Backs Bill To Save Florida C…
Senator co-sponsors measure that would provide growers with incentives to plant more trees. Read More
GenNext Growers
July 22, 2016
Farming’s Next Generation Seeking …
Several innovative resources are available to help first-time growers acquire the property they need. Read More
Farm Marketing
July 22, 2016
How To Book A Great Band For Your Festiv…
Want to add live music to your fall festivals? Here's a step-by-step guide on how to find the right band for the right price. Read More
[gravityform id="62" title="false" description="false"]