E-7 7-09 Managing Cotton Insects in the Lower Rio Grande Valley 2009 Contents Page IPM Principles ................................................................................................. 3 Insecticide Resistance Management ............................................................. 3 Biological Control ............................................................................................. 3 Bt Transgenic Cotton ....................................................................................... 4 Crop Management ............................................................................................ 4 Short-season Production .................................................................................... 4 Full-season Production ...................................................................................... 5 Monitoring Cotton Growth and Fruiting Rate .................................................... 5 Early Stalk Destruction and Field Clean-up ....................................................... 6 Stalk Destruction Laws ..................................................................................... 6 Management Decisions ................................................................................... 7 Scouting Decisions ........................................................................................... 7 Early-season Pests ........................................................................................... 8 Silverleaf Whitefly ............................................................................................ 8 Cotton Fleahopper ............................................................................................ 8 Overwintered Boll Weevil ................................................................................. 8 Mid-season and Late-season Pests ................................................................ 9 Silverleaf Whitefly .................................................................................................. 9 Boll Weevil ............................................................................................................10 Bollworm and Tobacco Budworm ....................................................................10 Plant Bugs (Creontiades spp.) ............................................................................11 Occasional Pests ..............................................................................................11 Aphids .............................................................................................................11 Beet Armyworms .............................................................................................12 Cabbage Looper ...............................................................................................12 Cutworms ........................................................................................................12 Saltmarsh Caterpillar .......................................................................................12 Thrips..............................................................................................................13 Spider Mites ....................................................................................................13 Fall Armyworms ..............................................................................................13 Ovicides .............................................................................................................14 Microbial Insecticides ....................................................................................14 Protecting Bees from Insecticides ................................................................15 Policy Statement for Making Pest Management Suggestions .................15 Endangered Species Regulations ..................................................................15 Worker Protection Standard ..........................................................................15 Additional References ....................................................................................16 For recommended insecticides refer to E-7A, Suggested Insecticides for Managing Cotton Insects in the Lower Rio Grande Valley—2009: http://insects.tamu.edu/extension/publications/index.cfm or http://AgriLifebookstore.org Managing Cotton Insects in the Lower Rio Grande Valley D. L Kerns and M. G. Cattaneo* A committee of state and federal research person- Insecticide Resistance Management nel and Extension specialists meets annually to review cotton integrated pest management (IPM) research and Experience has shown that reliance on a single class management guidelines. These guidelines are directed of insecticides that act in the same way may cause pests toward maximizing profits for the Texas cotton produc- to develop resistance to the entire group of insecticides. er by optimizing inputs and production. To delay resistance, it is strongly recommended that growers use IPM principles and integrate other control methods into insect or mite control programs. One strat- IPM Principles egy to help avoid pest resistance is to rotate the use of insecticide groups, taking advantage of different modes The term “integrated pest management” (IPM) ap- of action. In addition, do not tank-mix products from plies to a philosophy used in the design of insect, mite, the same insecticide class. Such insecticide management disease and weed pest control programs. It encourages practices should delay the development of resistance the use of the most compatible and ecologically sound and also provide better overall insect control. combination of available pest suppression techniques. These management techniques include cultural control, Insecticides with similar chemical structures af- such as manipulation of planting dates and stalk de- fect insects in similar ways. For example, pyrethroids struction; crop management practices, such as variety (including esfenvalerate, bifenthrin, cyfluthrin, cyhalot- selection and timing of irrigation; biological control, hrin, deltamethrin, zeta-cypermethrin and tralomethrin) involving conservation of existing natural enemies; host all act on an insect’s nervous system in the same way. plant resistance; and the wise use of selective insecti- Other types of insecticides — organophosphates (methyl cides and rates to keep pest populations below econom- parathion, dicrotophos) or carbamates (thiodicarb) — ically damaging levels. also affect the insect’s nervous system, but in a differ- ent way than do the pyrethroids. Major factors to be considered when using insec- ticides include protecting natural enemies of cotton The Insecticide Resistance Action Committee (IRAC) pests, possible resurgence of primary pests, increased has developed a mode of action classification system numbers of secondary pests following applications and that is based on a numbering system (see http://www. pest resistance to insecticides. Therefore, insecticides irac-online.org/). This system makes it simpler for pro- should be applied at the proper rates and used only ducers and consultants to determine different modes when necessary, as determined by frequent field in- of action among the insecticides. Insecticides with spections, to prevent economic losses from pests. the same number (e.g., 1) are considered to have the same mode of action. Producers should rotate among The IPM concept rests on the assumption that pests different numbers where appropriate to delay resis- will be present to some degree in a production system, tance. The objective of successful insecticide resistance and that at some levels they may not cause significant management is to delay the selection of resistance to losses in production. The first line of defense against insecticides. The IRAC numbering system is used in the pests is prevention through the use of good agronomic "Suggested Insecticides for Cotton Management" publi- practices or cultural methods which are unfavorable for cations to assist producers with their choices. the development of pest problems (discussed below). Properly selected control measures should be taken only when pest populations reach levels at which crop Biological Control damage suffered could result in losses greater than the cost of the treatment. This potentially injurious pest Insect and mite infestations are often held below population or plant damage level, determined through damaging levels by weather, inadequate food sources and natural enemies such as disease, predators and par- regular field scouting activities, is called aneconomic asites. It is important to recognize the impact of these threshold or action threshold. Precise timing and execution of each production operation is essential. In natural control factors and, where possible, encourage short, pest management strives to optimize rather than their action. (See E-357, Field Guide to Predators, Para- maximize pest control efforts. sites and Pathogens Attacking Insect and Mite Pests of Cot- ton, Texas AgriLife Extension Service.) Biological control is the use of predators, parasites and disease to control *Extension Entomologist, Extension Agent—IPM , respectively, Texas AgriLife Extension Service, The Texas A&M System pests. Important natural enemies in cotton include min- 3 ute pirate bugs, damsel bugs, big-eyed bugs, assassin Bt Transgenic Cotton bugs, lady beetles, lacewing larvae, syrphid fly larvae, spiders, ground beetles and a variety of tiny wasps that Bt cottons are insect-resistant cultivars