Eric H. Erickson

Extractable hydrocarbons and kin recognition in honeybee (Apis mellifera L.)

Hydrocarbons of worker honeybees of known pedigree were extracted and analyzed using gas chromatography and mass spectrometry. Variability in hydrocarbon extracts of individual workers is determined at least in part genetically. Correlations in hydrocarbon composition of extracts were highest among more closely related individuals. Individuals maintained in groups exchange hydrocarbons but still maintain enough self-produced compounds to retain genetically determined individual characteristics. These results demonstrate that extractable hydrocarbons of bees provide sufficiently reliable genetic information to function as labels for use during kin recognition.

Nectar Fluorescence under Ultraviolet Irradiation

Nectar, which fluoresces in the visible and absorbs in the ultraviolet spectrum when irradiated by ultraviolet light, occurs in many bee-pollinated plants. It is suggested that these characteristics function as direct visual cues by which bees can evaluate the quantities of nectar available. Thus, they assume an important role in pollination of the flowers and foraging efficiency of beers.

Soya-Bean Flowers: Nectary Ultrastructure, Nectar Guides, and Orientation on the Flower by Foraging Honeybees

SummarySoya-bean flowers possess most, if not all, of the anatomical adaptations characteristic of entomophilous plant species. A description of the flower is presented, based on photomicrographs and scanning electron micrographs. Specifically described and illustrated are: nectar guides, including those differentiated by ultraviolet light; the tongue channel and tongue guides; the ultrastructure of a highly developed nectary. The structure of the flower ensures that most foraging honeybees will contact an exposed sexual column with their ventral or facial hairs, thus effecting the transfer of pollen.

Honeybee (Apis mellifera L.) queen feces: Source of a pheromone that repels worker bees.

When placed in a small observation arena with workers, most young virgin honeybee queens released fecal (hindgut) material during agonistic interactions with workers and with each other. On release of this material, workers moved to the sides of the arena and groomed themselves. Bioassays of virgin queen fecal material demonstrated that it contains pheromone that repels workers and stimulates grooming behavior. Pheromone was present only in the feces of virgin queens that were more than 24 hr old and less than 2 weeks old. Feces of 2- to 4-day-old workers and virgin queens more than 2 weeks old did not elicit an avoidance response by workers. Moreover, the feces of young virgin queens had a strong fragrance, while that of older queens had a rancid odor and that of young workers had no detectable odor.

Ultrastructure of the Sunflower Nectary

SummaryHoneybees (Apis mellifera) exercise distinct foraging preferences among sunflower (Helianthus annuus) seed-parent lines and hybrid cultivars. Floral nectaries of over 100 sunflower cultivars/species were examined and compared to develop correlations between particular anatomical characteristics and honeybee predilection. The nectary, as revealed by light, scanning and transmission electron microscopy, may be circular or a 4- to 8-sided ring surrounding the base of the style directly above the ovary. Size of the nectary and number and placement of stomata differed among the genotypes and species studied. Florets of highly attractive genotypes had larger nectaries with more stomata than florets of less attractive ones. Results suggest that nectary characteristics may be heritable and that it may be possible through breeding to alter the relative attractiveness of plants to honeybees.

A comparison of two assays to test the defensive behaviour of honey bees ((Apis mellifera)

SUMMARYThe reliability of a traditional leather-patch assay to measure the stinging behaviour of honey bees was compared with that of a temper detection apparatus developed to electronically measure and record defensiveness. Colonies were tested with the two different assays during morning and afternoon hours. The traditional assay was more reliable than the automated electronic assay. Afternoon trials were more reliable than morning trials. Significant variation was observed among colonies with both methods, suggesting that these assays may separate highly defensive from gentle colonies. However, variation among trials within colonies may result in misclassifying colonies with intermediate degrees of defensiveness. The need for the development of more reliable assays is stressed.

Closed Population Honeybee Breeding 3. the Distribution of Sex Alleles with Gyne Supersedure

SummaryFormulae are derived for determining the effective size of closed (finite) breeding populations (Ne) of honeybees. It is shown that, for a given number of reproductive males and females, Ne is larger if each queen mother is replaced by her own daughter in each generation. Computer simulations show that the number of sex alleles and the proportion of viable brood produced within closed populations remain at an acceptably high level longer with gyne supersedure.

Pollination biology of Theobroma and Herrania (Sterculiaceae)—I. Floral Biology

Floral characteristics related to pollination were studied in four species of Theobroma and one species of Herrania (Sterculiaceae) in Costa Rica. Anthesis was complete in T. cacao, T. simiarum, T. speciosum, and T. mammosum at 0615 hr following an extended period of floral development throughout the night. Flowers of both T. cacao and Herrania cuatrecusana were fully open by dawn and pollen sacs dehisced throughout the morning hours. Stigma and style receptivity, assessed by hydrogen peroxide tests, were high throughout the morning and early afternoon in T. cacao. Bagged flowers resulted in no fruit-set. When petal ligules were experimentally removed there was no change in rates of flower abortion or total numbers of aborted flowers, tentatively suggesting that these structures play little or no role in attracting pollinators. Both Theobroma and Herrania flowers possess ultraviolet light reflectance/absorbance patterns which may play a role in pollinator attraction. Uptake of neutral red stain in T. cacao and T. simiarum showed scattered glandular activity on petals and sepals, perhaps indicating location of nectaries or other secretory organs. Conspicuous glandular trichomes on the ovary, on the lower third of the style, and in a conspicuous “basal ring” between petals and sepals (most pronounced and colorful in species other than T. cacao) may be sources of both floral attractant and reward.Differences in floral biology among Theobroma and Herrania species suggest divergence in pollination strategies. The data presented are discussed in terms of plant-pollinator specializations in the New World tropics.RésuméLes caractéristiques florales liées á la pollinisation ont été étudiées dans quatre espèces de Theobroma et une espèce de Herrania (Sterculiaceae) au Costa-Rica. L’anthèse était complète dans T. cacao, T. simiarum, T. speciosum et T. mammosum á 06.15 hr après une longue période de développement floral au cours de la nuit. Les fleurs de T. cacao et de Herrania étaient complètement déhiscentes á l’aube et les sacs de pollen se sont ouverts pendant toute la matinée. La réceptivité des stigmates et des styles mesurée par des tests d’hydrogène peroxyde était élevé pendant la matinée et en début de’après-midi pour T. cacao. Les fleurs ensachées n’ont pas produit de fruits. Quand les ligules des pétales ont été enlevées á titre d’expérience il ne s’est produit aucun changement dans le taux d’avortement ou le nombre total de fleurs avortées suggérant que ces structures n’influencent que peu ou pas l’attraction des polliniseurs. Les fleurs de Theobroma et de Herrania peuvent toutes deux réfléchir ou absorber la lumière ultraviolette, ce qui peut jouer un rôle dans l’attraction des polliniseurs. L’absorption de colorant rouge neutre a révélé une activité glandulaire diffuse des pétales et sépales, indiquant peut-etre la localisation de nectaires ou autres organes secréteurs. D’évidents trichomes glandularies sur l’ovaire á hauteur du tiers inférieur du style et un “anneau basel” bien visible entre les pétales et les sépales (très prononcés et colorés dans les espèces autres que T. cacao) sont peut-étre les sources de l’attraction florale et de récompense nourricière. Les différences de biologie florale entre les espèces Theobroma et Herrania suggèrent des différences dans les stratégies de pollinisation. Les données présentées sont discutées en termes de spécialisations des polliniseurs de plantes dans les tropiques du Nouveau Monde.

Temperature tolerance and water balance in feral and domestic honey bees, Apis mellifera L

Abstract Feral and domestic honey bees were compared to determine relative levels of adaptation to the Arizona desert. Feral honey bees were more tolerant to high temperatures than domestic honey bees. Monthly critical thermal maxima (CTMs) of feral bees were significantly different from those of domestic bees (P

Characterization of Floral Nectars by High-Performance Liquid Chromatography

SummaryTechniques were developed for fractional analysis of undiluted microquantities of floral nectar by HPLC. Quantitative and qualitative differences are shown between almond nectar secreted by freshly opened flowers and by those a few days old; they demonstrate the reproducibility of data obtained. HPLC characterizations may thus be utilized in plant breeding, to ensure that compatible genotypes with similar spectra of volatiles and taste components are brought together when cross-pollination is essential. They may also be useful in studies of foraging behaviour of bees among plant phenotypes and genotypes.