Genetic structure and division of labor in honeybee societies

Summary Recent studies have demonstrated a genotypic component to the division of labor among worker honeybees. However, these studies used artificially-selected strains of bees or colonies derived from queens that were instrumentally inseminated with the semen from very few males. We present evidence for genotypic variability among groups of workers performing tasks in colonies with naturally-mated queens. These results demonstrate that genetic structure is a level of social organization in honeybees.     

Auslösende Faktoren beim Duftmarkieren von Sammelbienen

Summary Scent marking behaviour (exposure of the Nasonov gland) of foraging honeybees (Apis mellifica) depends on the flux of sugar per unit-time in the food source.     

Comparison of inhibitory effects of royal jelly acid and myrmicacin on germination ofCamellia sinensis pollens

Summary Royal jelly acid (10-hydroxy-2-decenoic acid) secreted by honeybees and ant-origin myrmicacin (3-hydroxy-decanoic acid) inhibited germination ofCamellia sinensis pollens, and the latter was stronger in the inhibition. Their inhibiting activities were stronger at lower pH, and their inhibitions were reversible.     

Queen success is correlated with worker-brood genetic relatedness in a primitively eusocial wasp (Ropalidia marginata)

Ropalidia marginata is a primitively eusocial polistine wasp in which, although there is only one queen at any given time, frequent queen replacements lead to a system of serial polygyny. One of the most striking features of this system, is the enormous variation in the success of different queens. Measuring queen success as queen tenure, total number of offspring produced, number of offspring produced per day of tenure, and proportion of eggs laid that develop into adults, we show here that each measure of queen success is correlated with worker-brood genetic relatedness and not correlated with worker: brood ratio or the age of the queen at takeover. We interpret these results as meaning that queens are better able to obtain the cooperation of workers when worker-brood genetic relatedness is high.     

Determination of the kinetic parameters of enzyme inhibition of the K-type mechanism: application to the control of alpha-glucosidase activity of honeybee hemolymph by glucose]

The alpha-glucosidasic activity of emerging honeybees haemolymph is submitted to a feed-back inhibition by glucose, according to a mechanism of the "K" type (competitive). The "resulting affinity-constant" (measured in the presence of the enzyme both with substrate and inhibitor) is linear function of the inhibitor concentration. The affinity constants between enzyme and pure substrate on one hand, and between enzyme and pure inhibitor on the other hand, were determined by means of this relation, which led to respectively equivalent values after determinations under in vitro or in vivo inhibitions.     

Memory

The molecular mechanisms underlying the induction and maintenance of memory are highly dynamic and comprise distinct phases covering a time window from seconds to even a lifetime. Neuronal networks, which contribute to these processes, have been extensively characterized on various levels of analysis, and imaging techniques allow monitoring of both gross brain activity as well as functional changes in defined brain areas during the time course of memory formation. New techniques developed in honeybees and fruit flies even allow for manipulation of neuronal networks and molecular cascades in a short temporal domain while a living animal under observation acquires new associative memories. These advantages make honeybees and flies ideal organisms to study transient molecular events underlying dynamic memory processing in vivo. In this review we will focus on the temporal features of molecular processes in learning and memory formation, summarize recent knowledge and present an outlook on future developments.     

An improved test for Africanized honeybee mitochondrial DNA

Mitochondrial DNA derived from Apis mellifera scutellata, the ancestor of the Africanized bees of the New World, lacks a BglII restriction site found in other types of honeybee. We present primers allowing amplification of a 485-bp section of the cytochrome b gene containing this site, using the polymerase chain reaction. Digestion of the amplified product with BglII yields contrasting patterns between Africanized and other honeybees.     

Serum cholesterol level in a typical suburban commercial community in Nigeria

Forty-one apparently healthy businessmen and-women and an equal number of government workers matched for age and sex underwent serum cholesterol determinations. The mean serum cholesterol levels of businessmen and-women were significantly higher than those of their government worker counterparts (p<0.001). The marked increase in the serum cholesterol of the business subjects was attributed to their overindulgence and/or eating habits and lack of physical activity. The cardiovascular risk implications of the high cholesterol value and other risk co-factors such as obesity and alcoholism observed among the business subjects are highlighted. We advise that for communities similar to the one described here, public enlightenment programmes about the health benefits of periodic medical assessment and recreational physical activities are necessary. A further comprehensive study of lipid, lipoprotein and other risk factors in these subjects should be encouraged.     

A fossil entomogenous fungus from Dominican amber

Summary A worker ant (Formicidae: Hymenoptera) embedded in amber (25 million years old) from the Dominican Republic was covered with an entomogenous fungus containing characters very similar to present day strains ofBeauveria bassiana. This represents the first report of a fossil insect-pathogenic fungus belonging to the class Deuteromycetes.     

An improved test for Africanized honeybee mitochondrial DNA

Mitochondrial DNA derived fromApis mellifera scutellata, the ancestor of the Africanized bees of the New World, lacks aBglII restriction site found in other types of honeybee^1,2. We present primers allowing amplification of a 485-bp section of the cytochrome b gene containing this site, using the polymerase chain reaction. Digestion of the amplifiel product withBglII yields contrasting patterns between Africanized and other honeybees.     

Levels of lead on the livers of dogs from the Paris region]

Lead level has been determined in the liver of 51 Dogs of different ages, sex and breed from districts of Paris. This level is from 0,16 ppm (fresh weight) up to 5,4 ppm. 23 p. cent of Dogs examined have more than 3 ppm in their livers. The level is not correlated with sex, breed and size. It increases with age of animals.     

Why do parent birds swallow the feces of their nestlings?

Summary Goldfinches (Carduelis carduelis) consume the feces of their nestlings until the digestive efficiency of nestlings and adults is nearly equal. With increasing nestling age from the first day onwards, the energy content of the nestlings' feces decreases. The percentage of fecal pellets swallowed by the adults during the course of the nestling period is negatively correlated with their energy content. It may be concluded that adults use the feces of their young as an energy source.     

The role of zinc in the activation of the enzyme cellulase in termites

Summary Chemical analysis had revealed an exceptionally high amout of zinc in the worker bodies of termites. Further investigation of the digestion of cellulose in vitro demonstrated that zinc functions as activator of the enzyme cellulase.     

The isolation,identification and synthesis of the alarm pheromone ofVespula squamosa (Drury) (Hymenoptera: Vespidae) and associated behavior

Summary A material that elicits alarm and attack behavior byVespula squamosa (Drury) workers was isolated from venom extracts and identified by spectroscopic methods as N-3-methylbutylacetamide. This compound elicited attack responses from worker wasps identical to those responses observed when venom was applied at the same dosage. This is the first behavioral role reported for this compound.The authors thank E. Adamak, R. Murphy and F. Takken for technical assistance. This article reports the results of research only. Mention of a proprietary product does not constitute an endorsement or the recommendation for its use by USDA.     

Medium‐term forecasts of potential GDP and inflation using age structure information

Economic behaviour as well as economic resources of individuals vary with age. Swedish time series show that the age structure contains information correlated to medium‐term trends in growth and inflation. GDP gaps estimated by age structure regressions are closely related to conventional measures. Monetary policy is believed to affect inflation with a lag of 1 or 2 years. Projections of the population's age structure are comparatively reliable several years ahead and provide additional information to improve on 3–5 years‐ahead forecasts of potential GDP and inflation. Thus there is a potential scope for using age structure based forecasts as an aid to monetary policy formation. Copyright © 2004 John Wiley & Sons, Ltd.     

Memory

Our understanding of the cellular and molecular mechanisms underlying learning and memory formation derives from studies of species as diverse as worms, mollusks, insects, birds and mammals. Despite the quite different brain structures and neuronal networks, the studies support the current notion that neuronal activity leads to changes in synaptic connections as the neural substrate of behavioral plasticity. The analysis of the mechanisms underlying learning and memory formation reveals a surprisingly high conservation between invertebrates and mammals, both at the behavioral as well as the molecular level. This special issue provides an overview of the current knowledge on cellular and molecular processes underlying memory formation. The contributing reviews summarize the findings in different organisms, such as Aplysia, Drosophila, honeybees and mammals, and discuss new approaches, developments and hypotheses all aimed at understanding how the nervous system acquires, stores and retrieves information.     

Chemical crypsis in predatory ants

Summary The repellent responses of worker termites to ants are determined by the exocrine gland secretions of the latter. Specialized termite predators produce non-repellent aliphatic alcohols as the major components of their mandibular glands, whereas unspecialized con-generics usually produce repellent ketones and aldehydes.Acknowledgment. A C.A.S.E. Award (C.L.) from S.R.C. and the Centre for Overseas Pest Research is gratefully acknowledged as are facilities provided by the Ahmadu Bello University, Nigeria at Mokwa.     

A mitochondrial DNA polymorphism in honeybees (Apis mellifera L.)

Summary Mitochondrial DNA (mtDNA), isolated from worker honeybee larvae, was digested by each of seven 6-base restriction enzymes. Only one enzyme (BglII) showed a mtDNA difference between the three tested races (Apis mellifera carcia, A. m. ligustica, A.m. caucasica). BothA.m. carnica andA.m. ligustica showed the same pattern, differing fromA.m. caucasica. The degree of fragment pattern similarity revealed that there is only a small level of mtDNA variation between the three races tested. This is in line with previous investigations of enzyme polymorphisms.     

Untersuchungen zur Verdauungsphysiologie vonFormica polyctena Foerst. (Hymenoptera,Formicidae)

Summary In this investigation the spectrum of digestive-acting carbohydrates present inFormica polyctena Foerst. was analysed. The digestive tract of worker ants was dissected and the enzymatic activity tested by incubation with different carbohydrates. The results for crop, midgut, malpighian tubes and hindgut are given in the Table.     

Heat stress induced enhancement of heat shock protein gene activity in the honey bee (Apis mellifera)

We employed in vitro translation of mRNA and product separation using SDS-PAGE to examine the heat-shock response of the worker honey bee. Increases in the levels of 6 translatable RNA populations were observed following heat stress. The greatest response was observed among bees aged 9 days. Slight levels of induction of 70 and 82 kDa heat shock proteins were evident among bees taken directly from the colony.