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This publication is designed to provide information on managing spider mites on hops grown in Florida to hops growers, UF/IFAS Extension agents, and other crop protection professionals. Hops (Humulus lupulus L.) (Cannabinaceae), a new crop for Florida, has been studied at the UF/IFAS Gulf Coast Research and Education Center (GCREC) since 2016. A fall and spring crop have been cultivated each year, providing opportunity to observe pests and evaluate pest management strategies over several seasons. Spider mites (Trombidiformes: Tetranychidae) have been a consistent pest of hops at GCREC each season. Information on chemical and biological control is provided.

The two-spotted spider mite, Tetranychus urticae, is an important pest of horticultural crops worldwide and has developed resistance against multiple kinds of pesticides. To date, information on the resistance to pesticides is inadequate for T. urticae populations in Hainan, south China. In the current study, we determined the resistance to seven pesticides in five field populations of T. urticae that were collected on cucurbit crops in Hainan in 2021. The results showed that T. urticae populations developed high to extremely high resistance to abamectin and bifenthrin and medium to high resistance to pyridaben, profenofos, and cyflumetofen. However, four of the five populations were either susceptible to or had only low resistance to bifenazate and B-azolemiteacrylic. We also determined the frequencies of mutations previously associated with T. urticae resistance to abamectin, pyrethroids, organophosphates, bifenazate, or pyridaben; mutation frequencies as high as 100% were detected for some of the mutations in some of the populations. The results should facilitate the development of rational strategies for the chemical control of T. urticae populations in Hainan, China.

Celem pracy było porównanie skuteczności zwalczania roztoczy Varroa destructor za pomocą tymolu, amitrazy oraz kwasu szczawiowego w rodzinach pszczelich z czerwiem. Badania wykonano w pasiekach zlokalizowanych w miejscowości Senično i Bohinj (położonych w strefie klimatu kontynentalnego) oraz w miejscowości Vipava (położonej w strefie klimatu śródziemnomorskiego) na Słowenii. Do zwalczania pasożyta zastosowano Thymovar (Andermatt BioVet AG); Apiguard (Vita Europe Ltd., UK); 12,5% roztwór amitrazy w formie odymiania oraz wodny roztwór kwasu szczawiowego, zawierający 2,9% kwasu szczawiowego i 31,9% cukru. Po wykonaniu zabiegów leczniczych, we wszystkich rodzinach stwierdzono istotny wzrost śmiertelności roztoczy (p

The present study compared the efficacy of Apivar (a.i. amitraz) and Apiguard (a.i. thymol) in controlling the mite Varroa destructor during spring 2010 and autumn 2011, in the Balearic Islands (Spain). Number of fallen mites (NFM) was counted weekly and the efficacy of treatments was evaluated by using the percentage of reduction of the average daily fallen mites (%R). During spring assay, the average NFM was highly reduced in Apiguard (89.8%) compared to Apivar (64.3%) group, with significant differences between Apiguard and control group (untreated group) in post-treatment week. In autumn assay, Apivar and Apiguard colonies had an average reduction of the NFM of 17.9% and 30.8% respectively, showing a tendency in reduction between control and Apiguard group in post-treatment week. In both assays, %R was higher in Apiguard than in Apivar, but no significant differences were found between treatments in any of the seasons. Apiguard was less efficacious during November-December, probably due to the low external temperatures that hampered an optimal volatilization of the product. The lower efficacy of Apivar is probably related to the resistance of V. destructor to this chemical miticide, which has been used during the last 30 years. Results of this study showed that in Mediterranean conditions, spring is an appropriate period for applying Apiguard to the colonies, whereas application in late autumn would decrease the efficacy of the product. Apiguard may represent an alternative product for integrated control due to the low risk of mite resistance and residues in bee products.