Hachiro Shimanuki

Technique for rearing worker honeybees in the laboratory

SummaryA technique was developed for rearing worker honeybees (Apis mellifera) from larvae in the laboratory. Larvae were reared in beeswax cups in petri dishes at 34°C and 96% relative humidity (RH). Eighty-eight to 96% of larvae transferred at one day of age survived to the defecation stage on a mixed diet consisting of royal jelly (RJ), water, glucose, fructose, and yeast extract or on RJ for one or two days followed by the mixed diet. Fewer larvae survived (75%) when the mixed diet was prepared without yeast extract. Use of wax cells resulted in greater larval survival (90%) than use of plastic cells (57%). Success at metamorphosis was greater when larvae were transferred at the onset of defecation to a gauze rather than a wax substrate (75% vs 35%) at 70% RH. Adult weights were higher (average 112 mg) when larvae were reared on the mixed diet alone than when reared on RJ for one day followed by mixed diet (average 102 mg). The technique will facilitate studies of honeybee brood diseases.

An In Vitro Evaluation of Botanical Compounds for the Control of the Honeybee Pathogens Bacillus larvae and Ascosphaera apis, and the Secondary Invader B. alvei

ABSTRACT Bactericidal and fungicidal effects of eight plant extracts on the growth of two honeybee pathogens, Bacillus larvae (causative agent of American foulbrood) and Ascosphaera apis (causative agent of chalkbrood), and Bacillus alvei (a secondary invader in European foulbrood), were evaluated. Cinnamon oil completely inhibited the growth of B. larvae at 10 ppm for 72 h. Camphor and citronellal inhibited all growth at 100 ppm for 72 h. Bay oil, clove oil, origanum oil, and thymol inhibited all growth at 1,000 ppm for 72 h, and α-terpinene inhibited all growth at 10,000 ppm for 72 h. Cinnamon oil completely inhibited the growth of A. apis at 100 ppm for 168 h. Bay oil, citronellal, clove oil, origanum oil and thymol inhibited all growth at 1,000 ppm for 168 h. Camphor inhibited all growth at 10,000 ppm for 168 h, and α-terpinene inhibited all growth for 72 h at 10,000 ppm. Cinnamon oil and thymol completely inhibited the growth of B. alvei at 10 ppm for 72 h. Bay oil, camphor and origanum oil inhibited...

Mitochondrial Dna Relationships in an Emergent Pest of Honey Bees: Aethina tumida (Coleoptera: Nitidulidae) from the United States and Africa

Abstract The hive beetle Aethina tumida Murray is a new pest of honey bee colonies in North America. Specimens of A. tumida were collected throughout its current range in the southeastern United States, and from several sites in South Africa. A 1018-bp section of the mitochondrial cytochrome c oxidase I gene was amplified and sequenced in 26 beetles collected from Florida, Georgia, South Carolina, and North Carolina, and in 14 beetles collected from seven sites in South Africa. Mitochondrial DNA variation between all A. tumida samples was <0.8%, which was still considered within the range expected for a single species. The U.S. samples showed two distinct haplotypes, differing by 6 bp (0.6%). Both haplotypes were found across and within several geographic regions, a result consistent with a single introduction into the United States. However, a broad survey of 151 beetles from their new range revealed significant heterogeneity in haplotype frequencies, perhaps resulting from multiple introductions. Although the data do not allow a precise estimate of the point from which A. tumida were accidentally exported from Africa, the close genetic similarity between beetles from the United States and South Africa indicates that studies conducted on beetle physiology, parasites, and pathogens in South Africa will have a direct bearing on populations now found in the United States.

Brood-Rearing Capability of Caged Honeybees Fed Synthetic Diets

SummaryA chemically defined diet that contained 18 amino acids and 10 water-soluble vitamins supported brood rearing when it was fed to newly emerged honeybees. Another diet supplemented with cholesterol was poorly consumed and supported only low levels of brood rearing. Diet containing higher concentrations of amino acids did not support brood rearing. A diet supplemented with higher concentrations of vitamins and a salt mixture supported brood rearing, but less than a diet containing higher levels of vitamins without the salt mixture.

Evaluation of sampling methods for determining infestation rates of the tracheal mite (Acarapis woodi R.) in colonies of the honey bee (Apis mellifera): Spatial, temporal, and spatio-temporal effects

Current sampling methods for estimating infestation rates of tracheal mites in colonies of the honey bee,Apis mellifera, assume that infested bees are randomly distributed and that temporal fluctuations in infestation rates occur homogeneously throughout the colony. We examined these assumptions. Samples of bees were collected from up to five locations in each of eight colonies, and colonies were sampled several times throughout the year. Estimates of infestation rates varied, depending on the location in the colony from which a sample was obtained. Temporal fluctuations in infestation rates did not always occur homogeneously with respect to sampling location. These results demonstrate that assumptions of current sampling protocols for estimating tracheal-mite infestation rates are often violated. Consequently, estimates derived using these methods may not be accurate, and conclusions based on such estimates may not be valid.

Transmission of Chalk Brood Disease of Honeybees by Infected Queens, and Worker Brood and Adults

SummaryChalk brood infections were produced in disease-free nuclei by transferring honeybee queens, adult workers, and unsealed or sealed brood from diseased colonies. Bees fed Wheast patties remained disease free for 7 weeks, but all nuclei except the controls were infected 2 weeks after they were fed 2-year-old pollen. Bees that removed the diseased larvae most readily recovered from the disease and reared as much brood to the sealed stage as the controls. This suggests that selection for the best hygienic behaviour may be one way to control chalk brood. The disease disappeared in all nuclei during the study, but we were able to recover the fungus in either macerated queens or workers taken from the infected nuclei of bees by streaking suspensions onto plates of potato dextrose agar fortified with 4 g/litre yeast extract.