# Effect of Near Ultraviolet Radiation on Varroa Destructor Using Digital Holographic Interferometry
## 1 Introduction  
In recent years, Varroa destructor has emerged as a major contributor to the decline in honeybee populations worldwide [1]. The mite not only feeds on the bodily fluids of adult and developing bees but also acts as a vector for various pathogens [1, 2]. Recent studies by [PERSON] et al. [3] suggest that the chemical attraction to the brood is the primary factor causing infestation. It is proposed that the fatty acid esters (such as methyl palmitate), naturally emitted by bee larvae to induce cell sealing by nurse bees, are the promoters of this attraction. While feeding, V. destructor can transmit various viruses: deformed wing virus, acute bee paralysis virus, Israeli acute paralysis virus, and Kashmir bee virus, among others. Without treatment of the honey bee colony, the number of parasites increases continuously with the growth in the bee population and its brood-rearing activity, leading to the colony's collapse within 1-4 years [3].  
Traditional control methods primarily include the application of chemical acaricides, with pyrethroids such as fluvalinate (Apistan(r)) and flumenthir (Bayarol(r)) being the most commonly used [2, 4, 5, 6, 7]. These acaricides have demonstrated high efficiency in combating Varroa mites, especially in their plastic strip formulations. However, underdosing and homemade preparations of these acaricides have led to the development of resistance in the mites [4]. Additionally, chemical acaricides can contaminate hive products, such ashoney and wax, with residues that could affect consumer health [3]. These limitations have driven the exploration of innovative approaches, such as the use of airborne ultrasound and ultraviolet radiation [2; 8; 9].  
Ultraviolet radiation is known to have detrimental effects on various organisms [10], and its potential as a control measure for arthropod pests has been investigated in different contexts [11]. However, the specific impact of UVA radiation on Varroa destructor remains relatively unexplored. Understanding the impact of UVA irradiation on this parasitic mite could open new avenues for integrated pest management in beekeeping practices, thereby promoting the well-being and resilience of honeybee colonies. This study seeks to address this gap by examining the consequences of UVA exposure on the external structure of Varroa destructor. Digital Holography (DH) represents a recent and innovative advancement in imaging technology. A digital hologram is an interference pattern created optically through the superposition of object and reference beams. This pattern is captured by a charge-coupled device (CCD) camera and digitized, transferring it to a computer as a numerical array [12]. To quantify surface damage, phase maps derived from various series of holograms were processed and analyzed. Changes in phase distribution provided a quantitative measure of alterations in the mite's surface topography caused by UVA exposure. The utilization of Digital Holographic Interferometry (DHI) allows for a precise assessment of surface damage, providing valuable insights into morphological changes. Through this investigation, we aim to contribute to the development of effective and sustainable strategies for Varroa destructor control. This research holds significance not only for apiculture but also for the broader ecological balance, as healthy honeybee populations play a crucial role in pollination and ecosystem stability.