This technical article was written by Dr. Emily Symmes, PhD in Entomology and Technical Field Manager at Suterra.
Leading University experts recently published the results of a multi-year study demonstrating the efficacy and value of incorporating CheckMate® CRS mating disruption into an integrated pest management program for California Red Scale in Citrus1. Suterra’s mating disruption products interfere with the natural ability of a species to locate mates and reproduce, thereby reducing the overall population and crop damage. CheckMate® CRS dispensers are specifically designed to permeate the orchard environment with the insect’s sex pheromone, precisely within the tree canopy where the pests are located.
The Journal of Economic Entomology publication details the research of “Mating Disruption of the California Red Scale, Aonidiella aurantii (Hemiptera: Diaspididae) in Central California Citrus.” All studies used the commercially available CheckMate® CRS dispenser product, applied according to manufacturer label specification for proper rate and placement in the tree canopy. The team, led by renowned University of California citrus specialist, Dr. Elizabeth Grafton-Cardwell, concluded with several key findings as a result of their 2016-2019 studies in 12 commercial citrus orchards.
Significant reductions in pheromone trap capture, twig and leaf infestations, and infested fruit were consistently demonstrated where CheckMate® CRS mating disruption was applied compared to non-mating disruption reference plots. Suppression of male capture in pheromone traps, an indicator of effective mating disruption, averaged 90%. Twig and leaf infestations were reduced by an average of 75%, and the percentage of highly infested fruit at harvest was less than 0.5% in 9 of the 10 mating disruption blocks in 2018 and 2019.
Summary conclusions within the publication state, “mating disruption using CheckMate® CRS can be an effective method to reduce California red scale populations throughout the 4+ generations that occur in central California,” adding that “mating disruption has the potential to reduce or eliminate pesticide applications.” It is important to note that the decision to reduce or eliminate any inputs in the overall IPM program should be determined on an individual basis in consultation with your crop adviser.
California Red Scale can prove costly to citrus growers due to downgrades at the packinghouse, and infestations can cause overall negative impacts to plant health. As noted by the University researchers, CRS management has become more challenging in recent years due to a variety of factors. An increase in the number of generations per year due to warmer, earlier springs and hotter summers means the potential for larger build-up of populations year over year. California red scale populations have also developed resistance to all of the broad-spectrum insecticides historically relied upon for control and are exhibiting increased resistance to “softer” chemicals, such as insect growth regulators, after several years of use. In addition, populations of natural enemies, including several species of parasitoids and predators, are taking a bigger hit due to the necessary insecticide applications for invasive pests such as Asian Citrus Psyllid.
Mating disruption as a technology has been used for decades to minimize the impacts of many severe pests of agricultural crops. Over the last several years, citrus growers have widely adopted this technology as a baseline component of their IPM programs for California Red Scale due to the noted traditional management challenges and proven efficacy of CheckMate® mating disruption, with great results.
To learn more about IPM and mating disruption for California red scale in citrus, please visit our webinar library, or contact our team of experts. A short video on best practices for deploying CheckMate® CRS dispensers is also available.
The Suterra team of experts is happy to help set you on the path to success. Contact your local Suterra field representative or send us a message online using our contact form here.
1Grafton-Cardwell, E. E., J. T Leonard, M. P Daugherty, and D. H. Headrick. 2021. Mating Disruption of the California Red Scale, Aonidiella aurantii (Hemiptera: Diaspididae) in Central California Citrus. Journal of Economic Entomology 114(6): 2421-2429. https://doi.org/10.1093/jee/toab188.