2015 Pest Control Materials for Managing Insect and Mite Pests of Greenhouse-grown Crops

Dr. Raymond A. Cloyd

Department of Entomology

Kansas State University

Greenhouse pest management/plant protection involves using a multitude of strategies in order to minimize the prospect of dealing with arthropod pest (insect and mite) populations. The use of pest control materials (insecticides and miticides) is one component of a pest management/plant protection program that also includes pest identification and monitoring along with cultural, physical, and biological control.

Proper stewardship of pest control materials includes resistance management by rotating products with different modes of action. A system has been developed by the Insecticide Resistance Action Committee (IRAC) to facilitate the implementation of appropriate rotation programs. Pest control materials have been assigned a designated number (sometimes number and letter combinations) based on their mode of action. For more information consult the IRAC website (www.irac.online.org).

The information presented in Table 1 is not a substitute for the label. It is important to read and understand all information presented on the label before using any pest control material. Be sure to check county and state regulations to determine if there are any local restrictions associated with the use of specific pest control materials listed in this chart.

Biological control is a pest management strategy that is gaining favor by greenhouse producers. There are a number of natural enemies such as parasitoids and predators that may be used to regulate populations of the major insect and mite pests of greenhouse production systems. Table 2 provides information on the types of natural enemies that are commercially available. Products are shown in Table 2.

TABLE-1

TABLE-2

For more information contact Dr. Raymond A. Cloyd, Professor and Extension Specialist in Horticultural Entomology/Plant Protection at Kansas State University, Department of Entomology, 123 Waters Hall, Manhattan, KS 66506-4004

Phone: (785) 532-4750; Email: rcloyd@ksu.edu

Watch for broad mite symptoms

SYMPTOMS

Broad mite, Polyphagotarsonemus latus (Banks), has reared its ugly little head on a sample of English ivy which was examined by Nancy Taylor at the C. Wayne Ellett Plant and Pest Diagnostic Clinic at Ohio State University.  The grower explained that the plants were not growing and that the youngest leaves had been very stunted for a number of weeks. Nutritional testing had not revealed any problems; bromine being added to the irrigation water was suspected as a toxin but the grower did want the plants evaluated for evidence of a disease or insect problem.

Stunted and distorted new growth on English ivy caused by cyclamen mite

Stunted and distorted new growth on English ivy caused by broad mite
English ivy showing shortened internodes and stunted, curled foliage caused by cyclamen mite injury

English ivy showing shortened internodes and stunted, curled foliage caused by broad mite injury

The symptoms did, indeed, mimic a chemical injury but a very close look at the youngest leaves which were still emerging and expanding from the buds showed numerous eggs, nymphs and adult broad mites. These pests were responsible for the foliar distortion. Broad mites are tiny and very high magnification is required in order to see them, unlike other types of mites such as the more familiar two-spotted spider mite which shows up in greenhouses occasionally.

Broad mite eggs (L) and the mite itself (R) among leaf hairs.

Broad_mite_eggs_pepper

Broad mite eggs on pepper. Adults are below circle. The eggs are characteristic of the broad mite.

The grower reports that effective management practices for broad mite are contributing to the English ivy’s good recovery.

If you suspect a broad mite problem but do not have sufficient magnification to see them, samples can be submitted to the Clinic.  See the Clinic’s web site at http://ppdc.osu.edu.

BIOLOGY

Description: adults are very small,  light brown to light yellow in color, and they are difficult to see. Adult females can lay up to 76 eggs. Males live for 5-9 days, females 8-13 days.

Eggs are very characteristic, they are translucent with little white dots on top (wax-like domes).

Plants affected: English ivy, begonia, cyclamen, new guinea impatiens, African violet, ageratum, azalea, dahlia, gerbera, gloxinia, jasmine, lantana marigold, verbena, zinnia. Other plants include: citrus, tomato and pepper.

MANAGEMENT

One way to manage broad mites is through the use of miticides. The list below includes some products that have been labeled for use against broad mites on ornamentals.

Pylon (chlorfenapyr)

Avid (abamectin)

Sanmite (pyridaben)

Judo (spiromesifen)

Ultra-Fine Oil (horticultural oil)

M-Pede (potassium salts of fatty acids)

Note: Remember to read and follow the recommendations of all product labels before using any product. The listing of a product does not imply endorsement by the authors.

Biological control: the predatory mite Neoseiulus californicus has been reported as a good predator of this mite.

OTHER RESOURCES

http://www.ipm.ucdavis.edu/PMG/r280400211.html

http://www.ipm.ucdavis.edu/PMG/r107400311.html

http://www.entomology.umn.edu/cues/inter/inmine/Mitesb.html

http://www.ces.ncsu.edu/depts/ent/notes/O&T/flowers/note28/note28.html

http://www.sel.barc.usda.gov/acari/content/broad/a.html

http://entnemdept.ufl.edu/creatures/orn/broad_mite.htm

Nancy J. Taylor
Program Director
C. Wayne Ellett Plant & Pest Diagnostic Clinic
Ohio State University, 8995 E. Main St., Bldg. 23, Reynoldsburg, OH 43068-3399
614-292-5006 Office / 614-403-1640 Mobile / 614-466-9754 Fax
taylor.8@osu.edu http://ppdc.osu.edu

Luis Cañas, Ph. D.
Associate Professor, Insect Ecology in Controlled Environments
Dept. of Entomology
The Ohio State University
Ohio Agricultural Research and Development Center
1680 Madison Ave.
Wooster, Ohio  44691
Phone: 330-263-3818, Fax: 330-263-3686
Email: canas.4@osu.edu