摘要:

SummaryCytophotometric observation of corpora allata from workers and queens ofA. melliferashowed significant variations in DNA content from the 2nd to the 4th instar of both castes, but the differences between castes are present only in the 2nd instar.The corpora allata are characterized by the presence of diploid, as well as polyploid cells, distributed in classes that are well established since the earliest developmental stages. However the frequency of cell nuclei in the higher classes of ploidy increases with development. This occurrence is responsible for the increase of the average DNA content in older larvae.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101207

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryFour artificial honeybee swarms, as genetically similar to one another as possible, were established on the same day in the same apiary. Each contained a sister queen inseminated with 2 microlitres of mixed semen from seven drones. For each queen, the seven drones were taken respectively from each of seven drone-mother colonies. Each queen, accompanied by 0·91 kg of her own progeny, was placed in a 42–1 hive body provided with 1 frame containing approximately 40×30 cm of drawn comb, 9 undrawn frames of comb foundation, and 2·27 kg of sugar syrup. Foraging rates and hive contents were then periodically measured through the summer.The four colonies demonstrated synchronous fluctuations in foraging rates that were not generally associated with amounts of uncapped nectar, capped honey, pollen, or capped brood in the hives. Two colonies reduced their brood rearing early in the summer, and in these colonies there were no significant correlations between foraging rates and amounts of uncapped brood. The other two colonies reared brood at high levels throughout the summer, and the foraging rates were significantly positively correlated with their amounts of uncapped brood. The latter result is consistent with earlier reports of brood pheromone influences on foraging in larger established colonies.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101208

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryCapillary tubes were used to extract nectar accumulating in protected flowers of fireweed at various sites in coastal British Columbia. Mean sugar yields collected from individual flowers ranged from 0·66 mg/flower/day to 4·11 mg/flower day. Sixty four percent of the variation in daily yield was shared by different sites, suggesting that weather factors were of primary importance to nectar secretion patterns. Sunshine and mean temperature demonstrated the best correlations with nectar yield, explaining 62% and 63% of the variation, respectively. Flowers on plants defoliated 90% secreted an average of 68% of the sugar secreted by control flowers over a 3 day period, suggesting that stored phatosynthate was mobilized for secretion as nectar. Measurements of nectar secretion in a controlled environment under conditions of saturated photosynthesis revealed that variations in temperature alone could influence yield significantly. Mean yields of sugar collected under conditions of constant temperature ranged from 5–2 mg/flower at 14°to 8·7 mg/flower at 24°C. Further increases in temperature depressed yield. The thermal threshold for nectar secretion was found to be dependent on the intensity of illumination and ranged from<12°C at high intensity illumination toc.19°C at low light intensity. Flower longevity ranged from 2–3 days at 32°C to 5–6 days at 14°C.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101209

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryThe following pollen species were analysed for moisture, fat, carbohydrate, minerals and amino acids; white clover (Trifolium repensL,), willow (Salixsp. L,), hawkweed (Hieracium piloselaL.), broom (Cytisussp. L,), bush lawyer/blackberry (Rubussp. L.), matagouri (Discaria toumatouRaoul), pine (Pinussp. L.), thistle (Cirsiumsp. Miller) and kiwifruit (Actinidia deliciosaA. Chev.). The moisture content of the pollen ranged from 16·8% (matagouri) to 25·9% (willow). The fat content ranged from 0·17% (staminate kiwifruit pollen) to 13·40% (hawkweed). Total carbohydrate ranged from 12·6% (matagouri) to 29·6% (pistillate kiwifruit), while reducing sugars ranged from 11·1% (matagouri) to 25·7% (pistillate kiwifruit). The protein content, which is commonly regarded as an index of nutritional quality ranged from 2·9% (pistillate kiwifruit) to 23·5% (broom). Most of the species analysed contained sufficient nutrients for honeybee growth and development.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101210

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryA fast method for the determination of the carotene fraction from commercially purchased bee-collected pollen by isocratic HPLC is described, using ultraviolet detection at 453 nm and direct injection of the sample into a silica column. The mobile phase was n-hexane:2-propanol:acetic acid (100:0·5:0·1), using flow 1 ml/min. The mean value for carotene was 46·7 mgβ-carotene/100 g lipids.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101211

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryIn each of 6 experiments, about 300μl of honeybee (Apis melliferaL.) semen was diluted, mixed, and used to inseminate about 20 queens. The mixture for each experiment contained a portion of genetically marked sperm. Since the queens were also genetically marked, one could estimate the ratio of marked and unmarked sperm in each queen by counting her marked and unmarked progeny. The objective was to determine if each queen received equal proportions of marked sperm. In two experiments having semen mixtures with about 50% marked sperm, the 95% confidence interval for percent marked progeny was±9·7% among the 22 queens in group 1 (semen was diluted 1:1 and stirred for 3·5 min) and±9·0% among the 16 queens in group 6 (semen diluted 1:40 and centrifuged). The confidence intervals were similar and both were significantly greater than±4·5% (expected 95% confidence interval when sampling a perfect mix with 500 workers from each queen) (P<0·0l). In experiments having a very low frequency of marked spermatozoa in the mixture (1%, 2%, and 4%), at least one marked worker was found among the 500 progeny from each queen (n = 68 queens), even when insemination doses were<0·2% of the total semen mixture, Nonrandom changes in progeny frequencies were related to insemination volume, time, and sperm handling procedures. Since nonmixing would cause random changes in progeny frequencies, much of the variability may have been caused by sperm competition rather than nonmixing.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101212

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryUltrastructural changes in sporonts ofNosema apiswithin the midgut of honeybees exposed to 3 antiprotozoal drugs have been examined by transmission electron microscopy. After exposure to fumagillin for 12 h, cytoplasmic density decreased in the sporont; otherwise, the ultrastructure appeared normal. After 24 h, the number of ribosomes decreased and ribosomal clusters tended to form.Drastic ultrastructural changes occurred 12 h after the sporont had been exposed to emetine-HC1. The nucleoplasm became electron-lucent and the nuclear membrane lost definition. The endoplasmic reticulum either lost its membrane definition or became depleted of its ribosomes. Also, the cytoplasmic electron density decreased. Nuclear disintegration was observed in the sporont 24 h after treatment with emetine.Cytoplasmic condensation in the sporont 12 h after exposure to Formycin-B was observed. After 24 h of exposure, both the nucleoplasm and cytoplasm became electron-lucent, and the number of ribosomes appeared to decrease. These changes were confirmed by scanning electron microscope observations.These results suggest that all three drugs are potentially useful for controllingN. apis.The mechanism of action of each drug is discussed.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101213

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryInfected midguts of honeybees in the tissue culture medium received low dose gamma irradiation. After irradiation dramatic ultrastructural changes took place in various developmental stages ofNosema apis.In the irradiated sporoblasts and sporont stages, laminated endoplasmic reticulum was absent; instead there were numerous vacuoles in the cytoplasm. There were fewer nuclear pores in the nuclear envelope of irradiated organisms than in the untreated group. The diameter of the nuclear pore was larger in the irradiated group. The polar filament was not developed in the irradiated sporoblast. There were very few mature spores developed in the midgut 48 h after irradiation.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101214

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryA time-saving method for determining the duration of the capped stage (sealed brood) of large numbers of colonies is described. The results of 112 colonies covering 22 different origins and hybrids of European honeybee races are presented. Differences up to 9 h between strains and up to 19 h within individual colonies could be detected. Influenced by seasonal effects, the average capped period is about 7 h shorter in early than in late summer. For one group of test colonies (n= 21) theVarroainfestation after 18 months of undisturbed colony and mite population development has been determined. The correlation between the capped period and the susceptibility of the colonies to mites is calculated asr= 0·48. By linear regression, an 8·7% reduction of the final mite infestation is calculated for a 1-h reduction of the capped period. The heritability of the duration of the capped period is estimated withh2= 0·232. This may be a realistic value for test populations of European honeybee under field conditions.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101215

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryThe concentration of lead in 59 samples of New Zealand honey taken from several enterprises in three localities in the North Island, and from different stages in processing, was analysed. No samples had lead concentrations higher than the legal limit of 2μgg−1. No difference in lead concentration was found between honeys of the three districts (one of which was a zone of active mineralisation) but lead concentrations were found to be higher in all samples which had been stored in contact with lead solder.

ISSN:0021-8839    

DOI:10.1080/00218839.1990.11101216

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor