Integrated Lygus management depends on the same fundamentals of management for any pest. There needs to be a system of monitoring (sampling), understanding of the density-yield relationship (thresholds) and other insecticide optimization practices (e.g., resistance management), and a plan for reducing the chance of infestation and need for remedial measures (avoidance). While all these guidelines are under current study, current recommendations represent a fundamental base on which to build an integrated Lygus management program that will also manage for susceptibility to our current insecticides. Key to this sustainable susceptibility system is limiting insecticide use to the lowest practical levels. This is best accomplished by careful sampling, careful assessment of thresholds and selection of the right compound for the job, but, most of all, avoidance of the problem from the start. Current recommendations are detailed below in light of the most recent research findings.

Green bolls (100/field) were sampled from the uppermost internodes within adjacent fields of Bt (Deltapine 33B) and non-Bt (Hyperformer HS 44) cotton experiencing severe pink bollworm pressure late in the growing season. Average top crop lint yield reductions ranging from 30 to 70% were observed in the uppermost bolls of the non-Bt cotton variety. Average top crop lint yield reductions ranging from 0 to 40% were observed in the uppermost bolls of the transgenic Bt cotton variety.

Growers, Pest Control Advisors (PCA), and University of Arizona Cooperative Extension personnel formulated and coordinated area-wide pest management strategies in the production area near Gila Bend, Az. from 1995-97. The primary pest target was whitefly with secondary control strategy implementation for pink bollworm in 1995. In 1995-1996, the coordinated effort encompassed approximately 10,000 and 6000 acres which included 10 and 8 cotton producers respectively and 6 pest control advisors. Due to producer interest and initiative in an adjoining production area, project acreage increased to over 18,000 acres and included 14 producers and 9 pest control advisors in 1997. The project cost of $3.00/acre was supported by participating producers with the monies used to hire University of Arizona trained students for field scouting of whiteflies. An economic development grant from the Electrical District #8 supported the project coordinator's salary who is a University of Arizona employee. Each field was sampled weekly for whitefly populations using recommended University of Arizona sampling procedure. The population data was then faxed to the responsible producer and pest control advisor on the date of sample. Treatment thresholds and chemistry class suggestions were made by Cooperative Extension with final control decisions and material choice at the producer and pest control advisor discretion. Weekly community wide meetings were conducted and used to discuss general area-wide and field specific population dynamics, treatment suggestions, crop condition, and agronomic and entomological area -wide production strategy recommendations.

Neither Tracer nor Proclaim appeared to be effective pink bollworm materials whether applied at day or night. However against cotton leafperforator, both Tracer and Proclaim provided sufficient control. Although all three formulations of Karate equally provided statistically significant pink bollworm control, it was not commercially acceptable. Shortening the spray interval from 7 to 4 days may have helped alleviate this problem. None of the Karate formulations evaluated appeared to offer outstanding cotton leafperforator control.

Cotton pesticide application histories in the Gila Basin were followed from 27 April through 20 September. The main interest was the effect of early season applications to control pink bollworm, Pectinophora gossypiella, and other pests on subsequent whitefly applications. Categories explored include, transgenic and non transgenic cotton, planting dates, and location within the valley. Regression analysis shows a significant effect due to the early season control for either P. gossypiella, or other pests (P > 0.009) but lower for them together (P > 0.026). Early applications for either PBW or other pest resulted in increased application for whitefly.

Steinernema riobravis Cabanillas, Poinar & Raulston infected pink bollworm Pectinophora gossypiella (Saunders), larvae over a temperature range of 15.6 - 38.0° C. Temperatures of 32.2° C and higher and exposure for 48 h or more often resulted in decreased numbers of nematode killed larvae with living nematodes and increased numbers of dead larvae with dead or no nematodes.

All of nine cotton cultivars tested were susceptible to silverleaf whitey, Bemisia argentifolii Bellows and Perring in Imperial valley, CA in 1995 and 1996. Using 4.1 adults per leaf turn as an insecticide- treatment action threshold, Deltapine (DPL) 5409 and 5415 required 5.5 applications of insecticide, DPL 50, 5461, and 5517 required 6 applications, DPL 5432 and 5690 required 65 applications, Louisiana (LA) 887 required 7 application, and Stoneville (ST) 474 required 7.5 applications. Results indicate the potential to reduce insecticide application by selecting appropriate cultivars that are commercially available.

Experimental insecticides were evaluated for control of sweet potato whiteflies relative to a commercial standard in cotton. Ni-25 provided excellent whitefly control and was equivalent to the commercial standard (Knack followed by Danitol + Orthene). Fenoxycarb + pymetrozine provided goodwhitefly control but seemed to require 2 sequential applications before control was equivalent to Ni-25. Diofenolan + pymetrozine appeared to be a slightly weaker treatment, but still provided acceptable whitefly control.

Ginning and lint cleaning effects on cotton stickiness were minimal but reduced amounts of trehalulose and reduced thermodetector counts occurred following each lint process Leaf trash from ginned seed cotton contained trehalulose and melezitose. Removal of leaf trash in ginning and lint cleaning probably accounts for some reduced lint stickiness.

We need efficient sampling methods, appropriate thresholds based on a well -defined Lygus density yield relationship, and knowledge of the most effective chemical controls available. Insecticides were evaluated for control of Lygus at 5 'at risk' grower locations, as well as at 4 other experimental sites. Application methods were different at each site according to grower practice or experimental protocol (5-20 GPA; by ground, air, or electrostatically-assisted ground sprayers). Evaluations were made based on the number of Lygus per 100 sweeps. Orthene®, Vydate® or to a lesser degree, Monitor® used alone and at high rates appeared to perform adequately at all sites. Both rates of Regent™, a new chemistry under development by Rhône- Poulenc, provided excellent levels of control comparable to Orthene in a high density test. In this same test, none of the experimental and registered pyrethmids provided adequate control when used alone. Thiodan®, when mixed with Mustang®, provided some level of control. Over all tests measured for yield, a positive net return was possible with no more than 2 sprays of solo materials which yielded between 0.3 and 0.5 bales/A more than untreated comparisons or between $51-130/A net return. Also, at one site where yields were in excess of 4.2 bales/A, optimum planting and fruit-set prior to heavy Lygus pressures and monsoon-associated heat stress was an important cultural tactic for avoiding losses to Lygus - the check yielded over 3.7 bales /A! As seen at grower sites and confirmed in experimental studies, solo compounds, at appropriate rates, performed as well or better than any combination tested. And, mixtures at this time do not appear to provide any additive, synergistic or economic benefits in the control of Lygus. Combinations, unless indicated by another pest problem (e.g., whiteflies), are not "worth it," and needlessly expose the grower to larger input costs, "empty" applications, and higher risks of resistance, pest resurgence, secondary pest outbreaks, and phytotoxic effects by insecticides.