# Impacts of Diverse Natural Products on Honey Bee Viral Loads and Health  
[PERSON]  
1 Bee Research Laboratory, Beltsville Agricultural Research Center, US Department of Agriculture, Beltsville, MD 20705, USA; [EMAIL_ADDRESS] (D.L.B. ; [EMAIL_ADDRESS] (J.P.T. ); [EMAIL_ADDRESS] (E.C.P. ; j.l.f.f.j.f.j.f.j.f.j.f.j.f.j.f.j.f.j.f.j.f.j.f.j.j.f.j.j.f.j.j.f.j.j.f.j.j.j.j.j.j.j  
The honey bee parasitic mite _Varroa destructor_, an external parasite that feeds on adult and developing bees, is arguably the greatest challenge for honey bee colonies. Along with direct impacts on bee physiology [4; 5], this mite drives the spread of deadly bee viruses [6; 7; 8; 9; 10; 11]. Honey bees face dozens of RNA viruses that can cause developmental, longevity, and behavioral symptoms [12]. Arguably the most common and important of these is the mite-vectored deformed wing virus (DWV; [13]). DWV is worldwide [12], diverse [14], and hugely impactful on bee health. Other parasites affecting bee health include _Nosema ceranae_ and _Nosema apis_ (gut fungal microsporidian parasites) and the trypanosome _Lotmaria passim_ (unicellular parasitic flagellate protozoan) [12]. The result of these infections is lack of worker productivity at the colony level, which affects hive resources and reproduction as colony size decreases. These impacts drive searches for effective treatments for honey bee disease infection. Many similarities exist between the classes of viruses and fungi found in humans and honey bees, and one can infer that medicines that show promise against human infection might do the same for honey bees. Natural products (NPs), gleaned from nature for their pharmacological or biological activity, offer potential new solutions for hive diseases [15] while already playing a role in the lives of bees [16]. Phytochemicals are defined as bioactive nutrient plant chemicals in natural products such as fruits, vegetables, grains, and other plant foods that may provide health benefits [17]. In addition, traditional herbal medicines and purified natural products may guide the development of novel antiviral drugs [18]. Numerous studies have suggested that natural products can directly inhibit the growth and replication of viruses and bacteria [19; 20; 21; 22]; for example, cacao, which has broad-spectrum antimicrobial/antiviral activity when ingested in human studies [23]. Curiously, honey bees are frequently observed in nature collecting various natural products, such as resins, and applying them to the nest environment. [PERSON] and [PERSON] [24] showed that colonies challenged with the fungal parasite _Assosphaera apis_, the causative agent of Chalkbrood disease, responded with increased foraging for resin. Furthermore, bees showed lower pathogen levels if the colony was supplemented with resin [25; 26]. [PERSON] and [PERSON] reviewed the secondary metabolites of foraged hive products (alkaloids, phenolic acids and flavonoids) that may be ingested for self-medication by honey bees to decrease their parasite and pathogen load [27]. In a recent work, researchers found the antiviral activity of polypore mushrooms after feeding bees with these mushroom extracts and noticing that bees collect water from fungal sources, suggesting a possible case of self-medication [28]. Similarly, bees fed thymol (isolated from thymre) in sugar syrup tended to show lower levels of DWV [29] and below. Additional candidates include curcumin [30], a polyphenol isolated from turmeric; garlic oil, which is known prominently for its antimicrobial activity [31; 32]; and cacao bean shells [33], all of which have known pharmaceutically useful properties. NPs are also currently used as controls for _Varroa_ mites. Synthetic miticides, including amitraz, coumaphos, flumenthin, and fluvalinate, have proven effective but are vulnerable to increased levels of mite resistance [34].