Extension Report

Baldwin County Extension Office

302A Byrne Street

Bay Minette, AL  36507

Telephone (251) 937-7176 or

928-0860/943-5061 ext. 2222

FAX (251) 937-7285

Ayanava Majumdar

Extension Entomologist and Sustainable Agriculture Coordinator

November 30, 2010

INSECT PEST ACTIVITY IN ALABAMA AND MANAGEMENT USING SYSTEMIC INSECTICIDES

Alabama Cooperative Extension System (ACES) is committed to provide readers with unbiased research results. Integrated Pest Management or IPM is a science-based decision making system that incorporates the use of multiple pest control tactics with minimal environmental impact.  It is a pleasure for me to announce that ACES has recently received a US Department of Agriculture Extension IPM grant for $921,360 (3-years) that will support development and implementation of economically and environmentally sound IPM practices through research, demonstration, and outreach programs. Readers are strongly recommended to participate in hands-on crop production workshops organized by ACES in your area in order to take full advantage of the new initiatives. Following are reports on two critical IPM projects recently completed by the ACES Agronomic Crop, Commercial Horticulture and Home Grounds TEAMS.

Insect Pest Activity in Alabama, 2009-2010

Insect pheromones or attractants can be used to monitor insects in commercial as well as backyard settings. In order to promote the adoption of pheromone-based scouting system, ACES established a statewide insect pheromone trap network for monitoring six major pests of field crops and vegetables. A number of Regional Extension Agents and Specialists, farmers, and crop consultants participated in the two-year pest survey. In 2009, there were 14 observation sites in 12 counties and a total of 8,621 insects were collected in sticky traps. The lesser cornstalk borer (3,586 moths), fall armyworm (1,386 moths), beet armyworm (1,377 moths), corn earworm (589 moths), and the southern armyworm (393 moths) were the dominant species. In 2010, the pheromone trap network captured 16,588 insects from 32 sites including the lesser cornstalk borer (7,759 moths), beet armyworm (3,144 moths), fall armyworm (1,682 moths), tobacco budworm (791 moths), and corn earworm/tomato fruitworm (747 moths). Thus, we found consistent patterns in insect abundance and activity, and growers in Baldwin and Mobile Counties need to be on extra alert as the pest pressures are nearly 10 times more than the pest pressures in north Alabama. One alarming finding is the near doubling of the population of tobacco budworms in crop fields; caterpillars of this moth cannot be controlled by the use of pyrethroid insecticides and commercial farmers often misidentify this insect making expensive errors.  One of the major limitations for pheromone-based scouting system is that traps only capture actively flying insects like moths and some beetles; the traps do not capture caterpillars present inside crop canopy. Therefore, it is best to scout crops directly using appropriate methods and use pheromone traps to correctly time your efforts (to know what to look for). Despite the technological challenges, pheromone traps are affordable and reusable; they can assist producers and gardeners to develop ‘site-specific’ IPM action plan to manage pest outbreaks. Always purchase traps and lures from trusted sources. Growers are encouraged to visit the project website at www.aces.edu/go/85 for recent reports and pest advisories from 2009 and 2010. Readers also can subscribe to the weekly IPM newsletter (www.aces.edu/go/128) that provides up-to-date information on insect, disease and weed issues in Alabama by sending an email to bugdoctor@auburn.edu.

Pest Management using Systemic Insecticide for Backyard Vegetable Production, 2010

The availability of imidacloprid-containing systemic insecticide for home garden vegetable production was an exciting development in 2010. Imidacloprid is a systemic insecticide with good activity against many small sucking insect pests and flea beetles. Bayer Advanced has introduced the Fruit, Citrus and Vegetable Insect Control Concentrate (Bayer FCV) with a broad label; this new product has a 0.24% active ingredient. Until now, information regarding the efficacy of imidacloprid as a general use pesticide for backyard vegetable production was limited or none. Also, there was no information on how to integrate the use of imidacloprid with conventional (contact) insecticides. Therefore, ACES and the Baldwin County Master Gardener program conducted a preliminary evaluation of the systemic product, as an early season insecticide. On May 7 (2010), bell peppers (‘Sweet Hybrid’), okra (‘Clemson Spineless’), and tomatoes (‘C44’) were transplanted in a small vegetable garden (20 ft. x 10 ft.) at the Gulf Coast Research and Extension Center, Fairhope, AL. There were three replications of each insecticide rotation. The insecticide rotations evaluated in 2010 included imidacloprid at full rate combined with mid-season application of either the full or the half rate of carbaryl (Sevin Concentrate® with 0.26% active ingredient) and malathion (Malathion Concentrate® with 55% active ingredient). Imidacloprid was applied as a side-drench about 10 days after transplanting when the first aphids were first seen underside of leaves. Imidacloprid can take about 3-4 days to enter a plant through the roots and to get distributed in toxic amounts to be effective, so do not expect instant results from systemic insecticide. Due to moderate to low insect pressures (first year vegetable garden), one application each of carbaryl and malathion were done in late- June and July. Interestingly, okra was damaged heavily by flea beetles and imidacloprid side-drench provided significant benefit by reducing leaf loss. In untreated plots, loss of leaves in okra due to early pest attack delayed plant maturity and fruit harvest by two weeks. Similar harvest benefits were recorded in cases of tomatoes but not in bell peppers. Mid-season pests of tomatoes and bell peppers included the armyworms, hornworms, and few loopers (for detailed pest identification visit www.aces.edu/go/87). Imidacloprid had no effect on stink bugs that were prevalent in okra and tomatoes during flower and fruit development.

On the basis of plant yield, bell peppers showed linear effect of insecticidal concentrations; the plants that received imidacloprid followed by carbaryl full rate and malathion full rate produced twice the yield (3.6 lb/plant) compared to the untreated plants (1.8 lb/plant). Imidacloprid plus contact insecticide treated tomatoes produced 3.2 lb/plant while heavy flower and fruit drop was noticed in the untreated plots.  On the basis of yield, okra treated with contact insecticides did not have statistically different results (1.1 to 1.7 lb/plant).  The point of this discussion is that imidacloprid should be side-drenched within 7 to 10 days after transplanting to get an early season protection and promote good plant establishment. Imidacloprid, if used properly, will not affect pollinators in the garden. With contact insecticides, well-timed applications at the most vulnerable stage of insects is critical to raise good quality insect-free vegetable crops under moderate to high insect pressures as seen in south Alabama.

Email address: azm0024@auburn.edu

Phone: 937-7176 or 943-5061, ext. 2222

The Alabama Cooperative Extension System (Alabama A&M and Auburn Universities) in cooperation with the U.S. Department of Agriculture is an equal opportunity educator and employer.