What is a sweep net?
A sweep net is a cost-effective way to monitor for the presence of a variety of insect pests. A sweep net is a funnel-shaped net attached to a long-handled frame that is swept back and forth through the foliage. Insects captured in the net are then counted.

Using a sweep net can help you determine whether or not you have enough insect pests to justify a spray. Sweep nets may be used with a variety of crops. Among them are alfalfa, blueberries, canola, carrots, cotton, cranberries, onions, peas, potatoes, rice, snap beans, soybeans and wheat. Among the numerous insect pests that may be captured in a sweep net are weevils, plant bugs, leafhoppers, stink bugs, aphids and bean leaf beetles.

There are many books and software programs that will help identify insect pests quickly and accurately. Other resources are local universities or Extension agents who specialize in your plants. An increasing amount of insect and crop information is available on the Internet and is accessible by a quick search of your crop and insect name.

What type of sweep net should I use?
Sweep net bags are made of cotton muslin (similar to a bedsheet) or sailcloth, a tougher cotton-canvas material. Muslin, which is lighter in weight and dries faster than sailcloth, is a good choice for sweeping soft, non-brushy plants such as small grains and many vegetable crops. Sailcloth bags will stand up better in brushy or spiny crops, such as alfalfa and cotton.

Standard nets have a diameter of 15 inches. It’s important to use a standard-sized net each time you sweep so you are able to compare your results to others in your field.

• Hold the net with the hoop end nearest to the ground in front of you. The plane of the hoop should be perpendicular to you.

• Swing the net from side to side in a full 180 degree arc. Sweep one stroke per step as you casually walk through the field or down the row.

• Tilt the net opening so the lower edge of the rim is slightly ahead of the upper rim.

• In Short vegetation, swing the net as deeply as possible In taller vegetation, sweep only deeply enough to keep the upper edge of the sweep net opening even with the top of the plants.  In general, don't let the net go more than 10 inches below the top of the plants.

Note: Each passage of the net is considered one sweep.  The number of sampling sites and sweeps needed will vary, depending on your crop and other factors such as crop height and the distribution of the pest.

What may affect the efficiency of a sweep net?

• Weather, particularly wind speed, air temperature, and intensity of solar radiation.   Different weather conditions may affect the number of insects in the area you are sweeping.
• Different habitats, especially the height of the plants
• Time of day, reflecting different cycles of behavior of the species.
• Different styles of sweeping
  

Benefits of using insect sweep nets

• Insect sweeping can often indicate if a spray is economically justified.
• Sweep net programs are a useful timing tool for spraying.
• Insect sweeping often targets adult stages of pests
• Insect sweeping can help detect certain problems before they cost you money
• Insect sweeping can indicate problem areas or hot spots requiring corrective action or spot treatments without having to treat all of your plants.
• Insect sweeping may help you reduce your use of pesticides