## 1 Introduction  
_Tropilalelaps_ spp. mites are a serious ectoparasitic mite of honeybees, _Apis mellifera_, in Thailand and Asia. They reproduce rapidly and have a shorter phoretic stage than another honeybee mite, _Varroa_ spp. [1]. Many factors, including the hygienic behavior of honey bees, acaricide-use regime, the beekeeper's management, and climate are all considered to influence the prevalence of _Tropilalelaps_ spp. [2, 3, 4]. The intensity of _Tropilelelaps_ spp. parasitism is highest during honeybee brood rearing periods [4]. In Thailand, the prevalence of mites can vary among the regions. Mite populations are consistently present in the northern region of Thailand including Nan, Chiang Rai, and Phrae provinces [5]. The prevalence is usually high by the end of rainy and all winter seasons according to Thai beekeepers. Conversely, a high population of _Tropilelelaps_ spp. was observed in autumn (86%) and it was less in winter (15%) in China [6]. Currently, synthetic chemical acaricides are widely used to control _Tropilaelaps_ spp. such as amitraz, fluvalinate and flumenthrin [2; 7; 8; 9]. Formic acid is also applied in the colony to control the honeybee mites. However, these acaricides are not always effective against _Tropilaelaps_ spp. [9]. Moreover, the application of some acaricides in colonies can affect queen performance and colony growth and residual chemicals are also detected in beehives and bee products [10; 11; 12; 13]. Currently, alternative strategies including the use of essential plant oils have shown promise in controlling both honeybee mites, _Varroa_ spp. and _Tropilaelaps_ spp. [14; 15; 16]. Among the tested alternative products, some essential oils demonstrated high acaricidal activity against _Tropilaelaps_ spp. with less toxicity to the honey bees [16]. Although essential oils have shown efficacy against _Tropilaelaps_ spp. mites under laboratory conditions, the test of essential oils under colony conditions has demonstrated inconsistent efficacy [16]. The media materials and materials' surface functionalization could affect the release rate and distribution of essential oils within the colony. Different materials, such as a cardboard strip, grease and a sponge were used for testing as potential application methods to deliver the essential oil of cardamon (_Amomum krervanh_). The results showed that cardboard was a simple and suitable media to distribute the essential oil in honeybee colonies [16]. In order to improve the efficient distribution of essential oil, the surface of materials may need to be modified. Of the various methods for surface modification, non-thermal plasma (NTP) technology has gained attention as a new surface modification method.  
NTP is an electrically energized matter in a gaseous state at atmospheric pressure. Plasma is considered the fourth state of matter and is composed of ionized particles such as electrons, ions, neutrals, excited species, and reactive species [17; 18]. The surface properties of the materials can be modified through these ionized particles. NTP is widely used to modify the surface properties of polymers [19; 20; 21].  
In our previous work, three materials were investigated for the distribution of essential oils [16]. Nevertheless, the control of _Tropilaelaps_ spp. mites was still inefficient under the environmental conditions tested. In this study, the characteristics of various materials were investigated for essential oil distribution. The materials were surface modified with the non-thermal plasma to improve the essential oil adsorption and release rate of the treated cardboards for controlling parasitic mites.