Analysis of X-ray irradiation effects on the mortality values and hemolymph immune cell composition of Apis mellifera and its parasite, Varroa destructor

• Published in: Journal of invertebrate pathology Vol. 204; p. 108109
• Main Authors: Sipos, Tamás, Glavák, Csaba, Turbók, Janka, Somfalvi-Tóth, Katalin, Donkó, Tamás, Keszthelyi, Sándor
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2024
• Subjects: Alternative control strategy; Animals; Bees - immunology; Bees - parasitology; Bees - radiation effects; Hemocytes; Hemocytes - immunology; Hemocytes - radiation effects; Hemolymph - parasitology; Hemolymph - radiation effects; Honey bee; Host-Parasite Interactions - radiation effects; Ionizing irradiation; Mortality; Varroidae - radiation effects; varroosis; X-Rays; Ionizing irradiation; Honey bee; Alternative control strategy; Mortality; varroosis; Hemocytes
• ISSN: 0022-2011; 1096-0805
• DOI: 10.1016/j.jip.2024.108109

[Display omitted] •50 Gy of X-ray radiation has health-deteriorating effects on Apis mellifera workers.•15 Gy irradiation against varroa is the most promising, which affects the bees least.•Apis mellifera immune cell composition changes because of X-ray irradiation.•The higher radiation doses increase plasmatocyte while decrease prohemocyte numbers. Varroa destructor is one of the most destructive enemies of the honey bee, Apis mellifera all around the world. Several control methods are known to control V. destructor, but the efficacy of several alternative control methods remains unexplored. Irradiation can be one of these unknown solutions but before practical application, the effectiveness, and the physiological effects of ionizing radiation on the host and the parasite are waiting to be tested. Therefore, the objective of our study was to investigate the effects of different doses (15, 50, 100, and 150 Gy) of high-energy X-ray irradiation through mortality rates and hemocyte composition changes in A. mellifera workers and record the mortality rates of the parasite. The mortality rate was recorded during short-term (12, 24, and 48 h) and long-term periods (3, 6, 12, 18, and 24d). The sensitivity of the host and the parasite in case of the higher doses of radiation tested (50, 100, and 150 Gy) been demonstrated by total mortality of the host and 90 % of its parasite has been observed on the 18th day after the irradiation. V. destructor showed higher sensitivity (1.52-times higher than the adult honey bee workers) at the lowest dose (15 Gy). A. mellifera hemocytes were influenced significantly by radiation dosage and the elapsed time after treatment. The higher radiation doses increased plasmatocyte numbers in parallel with the decrease in prohemocyte numbers. On the contrary, the numbers of granulocytes and oencoytes increased in the treated samples, but the putative effects of the different dosages on the recorded number of these hemocyte types could not be statistically proven. In summary, based on the outcome of our study X-ray irradiation can be deemed an effective tool for controlling phoretic V. destructor. However, further research is needed to understand the physiological response of the affected organisms.