Search

Histochemical staining of histological sections of Varroa destructor (Anderson and Trueman, 2000) mites reveal the internal body plan and are used to contrast the internal organs associated with feeding and reproduction of starved versus recently fed female mites. The gnathosoma is comprised of a powerful sucking pharynx, which employs 11 alternating dilator and constrictor muscles, the chelicerae, the salivary ducts, and the salivarium. Coronally, the esophagus is visible through the synganglion between its supraesophageal and subesophageal regions and connects posteriorly to the midgut. The midgut is devoid of food particles in starved mites, but in fed mites, the midgut epithelial cells are filled with innumerable globular spheroids replete with lipoproteins, including polyunsaturated lipids, whereas the lumen is filled with saturated lipids or other unidentified nutrients. In the opisthosomal body region of the fed female, the bilobed lyrate organ lies adjacent to the midgut on one side and the ovary on the opposite side, with very close cell to cell linkages that appear to form a syncytium. The fed female ovary contains an enormously enlarged ovum, and numerous elongated nurse cells extending from the lyrate organ. Dyes staining selectively for lipoproteins suggests rapid incorporation of neutral and polyunsaturated lipids and lipoproteins. Also evident near the ovary in fed females is the spermatheca filled with elongated, fully capacitated spermatozoa. The histological and histochemical findings reported in this study provide a fresh insight into the body structure, nutrition, and reproductive activity of the female of this harmful honey bee parasite and disease vector.

Honey bees face a broad range of threats globally. Many of these threats originate outside of North America because honey bees are an introduced species. Invasive pests are among the most widely distributed, damaging, and economically costly honey bee hive associates. As international trade and travel continue at a rapid pace, the list of invasive apicultural pests likely will grow. Details of these organisms' life history relevant to management and eradication efforts are addressed. Methods and proposed methods of detection and management encountered abroad are discussed.

Significance Varroa destructor causes considerable damage to honey bees and subsequently the field of apiculture through just one process: feeding. For five decades, we have believed that these mites consume hemolymph like a tick consumes blood, and that Varroa cause harm primarily by vectoring viruses. Our work shows that they cause damage more directly. Varroa externally digest and consume fat body tissue rather than blood. These findings explain the failure of some previous attempts at developing effectively targeted treatment strategies for Varroa control. Furthermore, it provides some explanation for the diverse array of debilitating pathologies associated with Varroa that were unexplained by hemolymph removal alone. Our work provides a path forward for the development of novel treatment strategies for Varroa., The parasitic mite Varroa destructor is the greatest single driver of the global honey bee health decline. Better understanding of the association of this parasite and its host is critical to developing sustainable management practices. Our work shows that this parasite is not consuming hemolymph, as has been the accepted view, but damages host bees by consuming fat body, a tissue roughly analogous to the mammalian liver. Both hemolymph and fat body in honey bees were marked with fluorescent biostains. The fluorescence profile in the guts of mites allowed to feed on these bees was very different from that of the hemolymph of the host bee but consistently matched the fluorescence profile unique to the fat body. Via transmission electron microscopy, we observed externally digested fat body tissue in the wounds of parasitized bees. Mites in their reproductive phase were then fed a diet composed of one or both tissues. Mites fed hemolymph showed fitness metrics no different from the starved control. Mites fed fat body survived longer and produced more eggs than those fed hemolymph, suggesting that fat body is integral to their diet when feeding on brood as well. Collectively, these findings strongly suggest that Varroa are exploiting the fat body as their primary source of sustenance: a tissue integral to proper immune function, pesticide detoxification, overwinter survival, and several other essential processes in healthy bees. These findings underscore a need to revisit our understanding of this parasite and its impacts, both direct and indirect, on honey bee health.

Traditional honey bee hunting and beekeeping are vital to the economic and spiritual lives of Asians. Bee products are known as not only food/food supplement but also traditional medicine for aiming to promote good health, especially in eastern regions. Honey bees also play crucial roles in pollination. Asia is regarded as the homeland of honey bees as it hosts at least nine honey bee species. The European honey bee was introduced from Europe, North America, and Oceania to Russia, Japan, India and other countries in Asia. The growth of global human population size, globalized trade economic wealth, and technological developments in transportation efficacy has promoted the transmission of bee diseases, parasites and pests. A great concern over honeybee population decline has accelerated research in bee diseases, parasites, and pests. This chapter provides an up-to-date information on bee diseases, parasites, and pests in Asia.

In this chapter, we briefly provide future directions for study that we believe will broadly benefit the bees and people of Asia and abroad. Asia maintains the highest biodiversity of native honey bee species on the planet, in addition to the introduced European honey bee. This intermingling of species has promoted a number of virus-host shifts that potentially threaten honey bees because of a lack of coevolution. This places Asia in a unique position—as a potential source of novel parasites and diseases to other parts of the globe, as well as a venue to study those parasites and diseases that have spread to the reaches of our planet in their native Asian honey bee hosts. Our knowledge of the coevolutionary arms race between Asian honey bees and their native parasites is sparse. Future efforts should be directed towards filling important gaps in our fundamental knowledge of honey bee defenses so that novel, sustainable management strategies can be developed.

Notwithstanding harsh climate conditions, the country of Mongolia is rich in insect fauna and is welcoming for managed honey bees. Since 1959, several different races or subspecies of managed honey bees have been introduced and subsequently maintained in Mongolia. These include Apis mellifera mellifera, Apis mellifera caucasia, Apis mellifera carpatica, (the Russian Far East bee), and the local Haliun bee line. These honey bees are well adapted to the climate condition of the country. A survey of honey bee species was conducted and revealed Varroa destructor, Nosema ceranae, and four viral infections distributed throughout Mongolia. Despite pathogens here the main stressors are climate variability. Cold conditions exist as the primary stress with the confluence of predators forming a secondary stressor for honey bees (bear attacks to hives, wasps, snakes, and ants). Aside from honey bees, nearly 30 species of bumble bees, in addition to other non-Apis bees, have been recorded in Mongolia. Little is known in the country about their biology or their importance for local pollination but it is assumed that they contribute essential pollination services as non-Apis bees do in other regions. Based on all given factors, it can be concluded that Mongolia is a great place for beekeeping and honey bee research.

The risk of transmission of honey bee parasites has increased substantially as a result of trade globalization and technical developments in transportation efficacy. Great concern over honey bee decline has accelerated research on newly emerging bee pests and parasites. These organisms are likely to emerge from Asia as it is the only region where all 10 honey bee species co-occur. Varroa destructor, an ectoparasitic mite, is a classic example of a pest that has shifted from A. cerana, a cavity nesting Asian honey bee to A. mellifera, the European honey bee. In this review, we will describe the potential risks to global apiculture of the global expansion of Tropilaelaps mercedesae, originally a parasite of the open-air nesting Asian giant honey bee, compared to the impact of V. destructor.

Coccinella novemnotata, the nine-spotted lady beetle, was historically one of the most common lady beetles across the US and southern Canada. In the 1980s it became extremely rare and has remained rare. In 2008 adult C. novemnotata were collected from field populations in Oregon and South Dakota and initial observations suggested that these individuals seemed smaller than the mean size of the species historically. These observations led to a series of experiments to determine if there had been significant decrease in size and if any decrease found was due to a genetic change or to environmental factors. In the first of these studies we quantified the size of C. novemnotata collected in the field and the size of Coccinella septempunctata, a congeneric introduced species that was collected in the same habitats and has been implicated as a cause for C. novemnotata decline. The size of these field-collected individuals of both species was compared with the size of historical specimens and individuals reared in the laboratory. Field-collected C. novemnotata adults were significantly (20%) smaller than specimens bred in captivity and specimens from collections. To determine if prey limitation alone could yield the range of sizes observed we reared larvae across a range of prey availability. There was a significant effect of prey availability and adult sizes across treatments bracketed the range we found in the field. Low fed larvae are significantly smaller than high fed larvae. While these results do not definitively point to any single explanation for the decline of this species they are consistent with expectations for competition between C. novemnotata and C. septempunctata.

The tendency of aphidophagous coccinellids to bite humans is a subject that has seen very little study in the scientific community. With the introduction of adventive species, anecdotal reports of biting lady beetles have greatly increased in frequency and seemed to warrant further investigation. Coccinellids of three native species [ Coccinella novemnotata Herbst, Coccinella trifasciata L., and Adalia bipunctata (L.)] and the two most common introduced species [ Harmonia axyridis (Pallas) and Coccinella septempunctata L.] were collected in the wild and reared separately in laboratory colonies. In caged biting trials, 40 individually marked coccinellids of a single species that were given either no source of food or water or aphids ad libitum were exposed to the experimenter's hand and forearm and the movement, bite frequency, and severity with which they bit into the skin were recorded. All species tested were shown to bite humans. Feeding treatment did not have a significant effect on biting propensity or bite duration in most species. Large adventive species such as Coccinella septempunctata were distinguished by a lower propensity to bite than the smaller native species. All species except H. axyridis and C. novemnotata exhibited a startling blood-feeding behavior that is not yet clearly understood and was heretofore undocumented in this family of beetles. In two trials affording A. bipunctata and C. novemnotata adults a choice between cotton wicks soaked in cow blood or wicks soaked in water, both species preferred blood, with Adalia bipunctata preferring blood to a much greater extent. Furthermore, survivorship of hematophagic coccinellids was tested as well by monitoring the survival and weight change across individuals afforded the following five treatments: 21 aphids per day, 3 aphids per day, 3 aphids per day in addition to blood, blood only, and water only. Coccinellids given 3 aphids per day exhibited very low mortality with only three dead individuals, while the treatment given the same number of aphids in addition to bovine blood exhibited a significant drop in survivorship very similar to that of the treatment given only blood. This remarkable trend is likely a result of oxidative stress and other hardships involved with feeding on vertebrate blood. Based on the level of mortality of coccinellids that overwinter within a building (the location of greatest exposure to humans) and their lack of adaption to human blood and tissue feeding, we predict that the currently rare behavior of biting humans should decline.