Biology subjects

Tonge, G.

Publications and source records attributed to Tonge, G..

3 recordsLinked to original sources

bioRxiv2024

Assessment of the levels of resistance of Tropilaelaps mercedesae to a variety of synthetic miticide.

The introduction of the western honey bee Apis mellifera to Asia has seen the parasitic mites Varroa destructor and Tropilaelaps spp. transfer from their native Asian honey bee hosts (Apis cerana and Apis dorsata respectively) to infest the brood of A. mellifera causing significant damage to colonies and colony losses. T. mercedesae was recently detected in Europe for the first time in A. mellifera colonies and is considered a more damaging parasite of A. mellifera than Varroa. Beekeepers rely heavily on the use of synthetic miticides and organic chemicals to control Varroa and Tropilaelaps which has resulted in Varroa developing resistance to many synthetic miticides and these treatments becoming less effective. Less is known about chemical resistance in Tropilaelaps as no study has been undertaken that specifically looks at this issue, but there is evidence to suggest that Tropilaelaps do have resistance to chemicals such as Amitraz, Coumaphos, Flumethrin and Fluvalinate. The use of synthetic miticides is widely recommended for surveillance and detection of Tropilaelaps and this recommendation forms a part of the contingency response of several government agencies. The study developed a novel chemical resistance test for Tropilaelaps and sought to test the efficacy of commercially available synthetic miticides and found that mites were resistant to all the synthetic chemical treatments tested apart from Amitraz which was shown to be 64% effective. Understanding and managing miticide resistance in this species is critical to prevent its further spread and colony losses.

zoology↗

bioRxiv2024

An in vitro investigation into the survival of Tropilaelaps mercedesae on a range of matrices.

Tropilaelaps spp. are a parasitic mite that feed and reproduce within honey bee brood (Apis spp.) and cause significant damage and mortality to Apis mellifera colonies. T. mercedesae is found outside the range of its natural host A. dorsata and was recently detected in Europe for the first time in 2024. It is widely believed that Tropilaelaps spp. are unable to survive without brood. However, studies have demonstrated that T. mercedesae can survive during broodless periods while parasitising A. dorsata and without brood in overwintering colonies of A. mellifera in temperate climates. This study sought to examine the survival of T. mercedesae on a range of matrices and found that mites could survive for more than 96 hours on live adult A. mellifera and more than 144 hours and 168 hours on decomposing A. mellifera pupae and adults respectively. These findings could indicate one possible mechanism which allows T. mercedesae to survive without brood. These findings also have implications towards better understanding possible transmission routes for Tropilaelaps. Previously bee sales in the form of queens and packages and used beekeeping equipment were considered a relatively low risk for transmitting Tropilaelaps spp. due to the absence of live brood. This study demonstrates Tropilaelaps ability to survive in these scenarios and the increased potential for it to spread globally.

zoology↗

bioRxiv2024

Assessment of the efficacy of field and laboratory methods for the detection of Tropilaelaps spp.

Tropilaelaps spp. are invasive mites that cause severe disease in Apis mellifera colonies. The UK has deployed an elaborate surveillance system that seeks to detect these mites early in any invasion to allow the best opportunity to eradicate any incursion. Effective field and laboratory protocols, capable of reliably detecting low numbers of mites, are key to the success of any intervention. Here we compared the efficacy of established field monitoring using brood removal with an uncapping fork, and brood bump methods with novel methods for Tropilaelaps detection modified from Varroa monitoring schemes. In addition, we monitored the efficacy of the laboratory method for screening for mites in hive debris by floating mites in ethanol. Our results clearly indicated that novel methods such as uncapping infested brood with tweezers, catching mite drop using sticky traps and rolling adult bees in icing sugar were all significantly more likely to detect Tropilaelaps than existing methods such using an uncapping fork on infested brood, or the brood bump method. Existing laboratory protocols that sieved hive debris and then floated the mite containing layer failed to detect Tropilaelaps mites and new efficacious protocols were developed. Our results demonstrated that the national surveillance protocols for Tropilaelaps mite detection required modification to improve the early detection of this damaging invasive mite.

ecology↗