Abstract. Lygus bugs are a severe pest of bean production in many parts of the Central Valley. Insecticides should be combined with other management approaches to provide cost-effective management of this pest. Registered and experimental insecticides were evaluated to determine their efficacy against lygus bugs (adults and nymphs) and impacts on bean yield and quality in blackeye cowpeas…
Abstract. The late-season sucking in sect complex (cotton aphids and sweetpotato whiteflies) has hindered cotton production in the San Joaquin Valley (SJV) during the 2000’s. The effects on cotton quality have been most problematic. Insecticides are a primary management tool for late-season insect infestations and Lorsban® 4E is a commonly used treatment. Recent concerns over volatile organic compounds in the SJV have pinpointed emulsifiable concentrate pesticide formulation s, particularly Lorsban 4E, as contributing factors. The activity and mode of action of this formulation make it ideal for controlling aphids on the leaf undersides within the large canopy. This research examined the efficacy of alternative chlorpyrifos formulations and other aphid-active materials against mid-season and late-season infestations of cotton aphids and as a second objective pinpointed and refined the threshold level for treatment of populations. Members of the neonicotinoid class of chemistry, organophosphates, and carbamates and single representatives from the pyridinecarboxamide and pyridine azomethines classes were compared. Aphid populations in 2007 were fairly low and well below threshold values. For mid-season populations, 12 of the 19 treatments provided at least 80% control. Assail® 70WP and Carbine® exhibited the best combination of speed-of-kill, efficacy, and residual control. Aphid control during the late-season…
Preventing sticky cotton is crucial in producing quality cotton. Late-season populations of cotton aphid and Silverleaf whitefly can produce significant amounts of honeydew when populations build. These pests are of most concern from mid-boll filling through harvest, when insect populations build and threaten exposed lint. Pest management guidelines for cotton aphid and silverleaf whitefly focus on strategies to use once threshold pest populations are reached, with the approach varying with the composition of the developing population (nymphs, adults), crop growth stage, and with the presence of exposed lint. Current pest management guidelines for whitefly and aphid can be interpreted as meaning defoliation is the final event of the season. This is based on the assumption…
INTRODUCTION
Bemisia whitefly populations are a significant annual threat to cotton production, particularly pima cotton, in the San Joaquin Valley. This pest has the potential to reduce cotton yields; however, the prospect of cotton lint contamination, creating a condition called sticky cotton, is the primary concern associated with whitefly infestations. Important research on sampling, damage potential, and management of Bemisia whiteflies has been conducted in Arizona. This research has formed the backbone of our present management scheme in California. In summary, this research supported three stages of whitefly management during the season with different insecticide chemistries during each stage. The need to management resistance and the characteristics…
INTRODUCTION
Integrated pest management of California cotton insect and mite pests is based on a long record of successful research and implementation. Maintaining cost-effective and efficacious insecticides and miticides is a constant, evolving process. As the pest biology, cropping patterns, cotton varieties, production techniques, and other factors change in the cotton agroecosystem, pest management needs change. The development of resistance in pests and regulatory actions are two of the key actions that influence the availability of crop protection tools. Fortunately, new materials are developed to facilitate control and to compensate for these losses. Regulatory actions with pesticides are ongoing and appear inevitable in California. Most recently, volatile organic compound (VOCs) issues have surfaced and regulations to restrict many…
Introduction
Arthropod management practices in California cotton production involve the use of various insecticides and acaricides for protection of yield and quality. Cotton aphid control relies mainly on the neonicotinoid insecticides but organophosphate and carbamate insecticides are also used. Spider mite control relies on acaricides and the chemical types used for both cotton aphids and mites are important for resistance management considerations due to their mode of…
INTRODUCTION
The silverleaf whitefly (SL WF) and cotton aphid are not new insects to the SJV, but only in recent years have late-season populations of both of these pests become widespread. The silverleaf whitefly was first found in the SJV in 1992. The SL WF has continued to adapt to SJV conditions and cropping patterns and starting in 2001 SL WF populations expanded greatly both in severity and particularly in range. Populations in significant numbers occurred farther northward and westward into the SJV. This has pushed the whitefly into the primary cotton production area. The cotton aphid occurred sporadically in cotton throughout…
Introduction:
Integrated pest management is an accepted tool in dealing with cotton pests. Insecticidal control of the key cotton arthropod pests in California is a major component ofour cotton IPM programs. Are insecticides the only answer and a long-term solution? No, for several reasons. First, insecticides must be compatible with biological control; this natural control is very important in California cotton. Studies should be conducted…
Introduction:
During the last 10 years, the cotton aphid (Aphis gossypii) has developed from a non-pest to one of the most significant insect pests of California cotton. For instance,in1997, cotton aphid outbreaks were severe and an estimated 3.5% yield loss occurred despite -$40/acre control costs which were incurred. Cotton aphid infestations during the mid-season (July to mid-August) reduce cotton lint yields since the aphids act as a significant sink, competing with the bolls, for energy. The late-season infestations (mid-Aug.to Sept.) are problematic because the aphids deposit honeydew on the exposed cotton lint, which reduces the lint value. Reasons for this change in pest status of cotton aphid are unclear; however, one of the most noticeable changes in cotton production over the last 10 years is the use of a plant growth regulator instead of irrigation and nitrogen deficits to limit early-season cotton vegetative growth. This has allowed cotton production practices in the SJV to evolve to higher nitrogen fertilization and irrigation inputs.
The goals of our research are to examine the role that naturally-occurring predators play in controlling spider mites and determine if predatory mite releases can improve spider mite control. During 1996 & 1997, we performed large-scale releases of the western predatory mite using low release rates and found that releases did not increase predatory mite numbers and did not improve spider mite control. Thus,we have attempted to identify factors that could be limiting predatory mites in hope that we can improve spider mite biological control. During 1998 & 1999, we completed four experiments…