Colony Population Growth Research Articles

Natural Products can Efficiently Control the Greater Wax Moth (Lepidoptera: Pyralidae), but are Harmless to Honey Bees

Honey bees (Apis mellifera L.) have great global socioeconomic and environmental importance. However, the greater wax moth (Galleria mellonella L.) is a pest that causes serious worldwide damage to honey bee colonies. Good beekeeping practices and physical, chemical, or natural methods can be used to control wax moths. The use of natural products is a more sustainable option because of their lower toxicity to the environment and the colony. Therefore, we evaluated the efficiency of four natural products for greater wax moth control: neem oil (Azadirachta indica), eucalyptus oil (Eucalyptus spp.), tobacco extract (Nicotiana tabacum), and malagueta pepper extract (Capsicum frutescens). We also evaluated their effects on adult bees and on the population growth of colonies. The 4th instar wax moths and adult bees were subjected to in vitro bioassays of different concentrations of the products. The results allowed usto establish a concentration for each product that was safe for the bees and effectively controlled the moth. Then, we sprayed them on bee colonies to evaluate their effects on population growth. The neem and eucalyptus oils caused wax moth mortality at low concentrations, but did not affect colony population growth. However, they did have a toxic effect on adult bees. The tobacco and pepper extracts efficiently controlled the moth, but did not cause adult bee mortality or interfered with the population growth of the colonies. Therefore, the tobacco and pepper extracts could efficiently control the greater wax moth, without damaging honey bees.

Mapping floral resources for honey bees in New Zealand at the catchment scale.

Honey bees require nectar and pollen from flowers: nectar for energy and pollen for growth. The demand for nectar and pollen varies during the year, with more pollen needed in spring for colony population growth and more nectar needed in summer to sustain the maximum colony size and collect surplus nectar stores for winter. Sufficient bee forage is therefore necessary to ensure a healthy bee colony. Land-use changes can reduce the availability of floral resources suitable for bees, thereby increasing the susceptibility of bees to other stressors such as disease and pesticides. In contrast, land-based management decisions to protect or plant bee forage can enhance pollen and nectar supply to bees while meeting other goals such as riparian planting for water-quality improvement. Commercial demand for honey can also put pressure on floral resources through over-crowding of hives. To help understand and manage floral resources for bees, we developed a spatial model for mapping monthly nectar and pollen production from maps of land cover. Based on monthly estimated production data we mapped potential monthly supply of nectar and pollen to a given apiary location in the landscape. This is done by summing the total production within the foraging range of the apiary while subtracting the estimated nectar converted to energy for collection. Ratios of estimated supply over theoretical hive demand may then be used to infer a potential landscape carrying capacity to sustain hives. This model framework is quantitative and spatial, utilizing estimated flight energy costs for nectar foraging. It can contribute to management decisions such as where apiaries could be placed in the landscape depending on floral resources and where nectar limited areas may be located. It can contribute to planning areas for bee protection or planting such as in riparian vegetation. This would aid managed bee health, wild pollinator protection, and honey production. We demonstrate the methods in a case study in New Zealand where there is a growing demand for mānuka (Leptospermum scoparium) honey production.

Population growth of Varroa destructor (Acari: Varroidae) in commercial honey bee colonies treated with beta plant acids.

Varroa (Varroa destuctor Anderson and Trueman) populations in honey bee (Apis mellifera L.) colonies might be kept at low levels by well-timed miticide applications. HopGuard® (HG) that contains beta plant acids as the active ingredient was used to reduce mite populations. Schedules for applications of the miticide that could maintain low mite levels were tested in hives started from either package bees or splits of larger colonies. The schedules were developed based on defined parameters for efficacy of the miticide and predictions of varroa population growth generated from a mathematical model of honey bee colony–varroa population dynamics. Colonies started from package bees and treated with HG in the package only or with subsequent HG treatments in the summer had 1.2–2.1 mites per 100 bees in August. Untreated controls averaged significantly more mites than treated colonies (3.3 mites per 100 bees). By October, mite populations ranged from 6.3 to 15.0 mites per 100 bees with the lowest mite numbers in colonies treated with HG in August. HG applications in colonies started from splits in April reduced mite populations to 0.12 mites per 100 bees. In September, the treated colonies had significantly fewer mites than the untreated controls. Subsequent HG applications in September that lasted for 3 weeks reduced mite populations to levels in November that were significantly lower than in colonies that were untreated or had an HG treatment that lasted for 1 week. The model accurately predicted colony population growth and varroa levels until the fall when varroa populations measured in colonies established from package bees or splits were much greater than predicted. Possible explanations for the differences between actual and predicted mite populations are discussed.

Fine-scale linkage mapping reveals a small set of candidate genes influencing honey bee grooming behavior in response to Varroa mites.

Populations of honey bees in North America have been experiencing high annual colony mortality for 15–20 years. Many apicultural researchers believe that introduced parasites called Varroa mites (V. destructor) are the most important factor in colony deaths. One important resistance mechanism that limits mite population growth in colonies is the ability of some lines of honey bees to groom mites from their bodies. To search for genes influencing this trait, we used an Illumina Bead Station genotyping array to determine the genotypes of several hundred worker bees at over a thousand single-nucleotide polymorphisms in a family that was apparently segregating for alleles influencing this behavior. Linkage analyses provided a genetic map with 1,313 markers anchored to genome sequence. Genotypes were analyzed for association with grooming behavior, measured as the time that individual bees took to initiate grooming after mites were placed on their thoraces. Quantitative-trait-locus interval mapping identified a single chromosomal region that was significant at the chromosome-wide level (p<0.05) on chromosome 5 with a LOD score of 2.72. The 95% confidence interval for quantitative trait locus location contained only 27 genes (honey bee official gene annotation set 2) including Atlastin, Ataxin and Neurexin-1 (AmNrx1), which have potential neurodevelopmental and behavioral effects. Atlastin and Ataxin homologs are associated with neurological diseases in humans. AmNrx1 codes for a presynaptic protein with many alternatively spliced isoforms. Neurexin-1 influences the growth, maintenance and maturation of synapses in the brain, as well as the type of receptors most prominent within synapses. Neurexin-1 has also been associated with autism spectrum disorder and schizophrenia in humans, and self-grooming behavior in mice.

Ege Bölgesi’nde Muğla Ekotipi ve İtalyan Melezi Bal Arılarının Kimi Performans Özellikleri Bakımından Karşılaştırılması

Summary In this research, colony population growth, brood production, attractiveness, flight activity and honey production of Mugla ecotype and Italian cross honey bees have determined and evaluated with comparison in Aegean Region. Genotype effect did not found statistically important on colony population growth and brood production (P>0.05). Flight activity and honey yields of Italian cross honey bees determined more higher than Mugla ecotype whereas Mugla ecotype showed better performance than Italian cross for adaptation of environmental condition. At the end of the research, determining of performance characteristics and protecting of Mugla ecotype that of Aegean Region is suggested with making breeding programs.

CHEMICAL ACARICIDES IN APIS MELLIFERA (HYMENOPTERA: APIDAE) COLONIES; DO THEY CAUSE NONLETHAL EFFECTS?

AbstractColonies of the honey bee, Apis mellifera Linnaeus, infested with the parasitic mites Acarapis woodi (Rennie) (Acari: Tarsonemidae) or Varroa jacobsoni Oudemans (Acari: Varroidae) require acaricidal treatment to control infestations that could affect colony growth and honey production. We investigated the effects of three acaricides, fluvalinate (formulated as Apistan®), formic acid, and menthol, on honey bee colony population growth, foraging activity, adult worker longevity, and honey production. Effects of in-hive treatments of Apistan® and formic acid were measured by examining colony weight gain, brood survival, sealed-brood area, emerged-bee weight, number of returning foragers, pollen-load weight, and worker longevity. These characteristics were not different between fluvalinate-treated colonies, formic-acid-treated colonies, and control colonies. Adult bee population, brood survival, number of returning foragers, and honey production did not vary among menthol-treated colonies, formic-acid-treated colonies, and control colonies. Sealed-brood area was lower in formic-acid-treated colonies than control colonies, but not different from menthol-treated colonies. Although not statistically significant, formic-acid-treated colonies experienced lower honey production than both menthol-treated and control colonies. Numbers of workers attending the queen in the retinue and queen behaviour patterns were not different after colonies were treated with formic acid.

Comparative Development of Queen Nests of Four Species of Yellowjackets (Hymenoptera: Vespidae) Reared under Identical Conditions

Queen nest growth rates and immature stage durations were compared for nests initiated in a controlled environment chamber by four yellowjacket species: Vespula maculifrons (Buysson), V. germanica (F.), V. vulgaris (L.), and V. vidua (Saussure). Nests of the first two species averaged a daily increase of 1.90 and 2.76 cells, respectively. The single nests of V. vulgaris and V. vidua grew more slowly. Average size of the queen nest at first worker emergence was 62.2 cells for V. maculifrons and 71.3 cells for V. germanica. Immatures of V. germanica averaged the fastest total development (27.4 days), but all four species showed considerable variation in duration of all life stages. Percentages of brood composition at the time of first worker emergence were in reasonably close agreement with percentages estimated by M. E. Archer for nests of V. vulgaris at the same stage. However, relative percentages of brood composition in queen nests changed over time. Ways are discussed in which the data from this study can be applied to models simulating colony population growth. Possible reasons for the apparent larger size of laboratory-grown queen nests in comparison with field-collected nests, and for the lack of extensive envelope construction by V. maculifrons queens, are also considered.

Population studies of two colonial orb-weaving spiders

Colonial spiders have individual capture webs (territories) within a communally shared web structure. I describe here the life histories and colony population dynamics of two communal species, Ctrtophora moluccensis (Doleschall) (Araneidae) in Papua New Guinea and Philoponella republicana (Simon) (Uloboridae) in the Panama Canal Zone. In both species, dispersal and foundation of new colonies are primarily by groups of immatures. Population growth of new-colonies was rapid during the first generation, but then colony population size decreased markedly. Colonies of P. republicana rarely lasted more than one generation, whereas those of C. moluccensis attained an equilibrium population size and often persisted for many generations at the same site. Reproduction occurred during the wet season in P. republicana colonies and year-round in colonies of C. moluccensis. Reproduction was synchronized in widely separated colonies of P. republicana. Factors controlling population growth and survival of colonies are discussed. Cyrtophora moluccensis colonies were probably regulated by density dependant factors, especially predation and parasitism, and perhaps a shortage of flying insects due to colony visibility. Philoponella republicana colonies were most likely limited by climatic conditions and instability of the habitat (i.e. density independent factors). Colonial social organization influences both dispersal and colony population growth. Coloniality is, however, compatible with various life history strategies.

A Mathematical Model for Tribolium Confusum Populations N. W. Taylor

A deterministic mathematical model is constructed to describe the population growth in colonies of the grain beetle, Tribolium confusum, under laboratory conditions. It is shown how (1) changes in the egg laying rate and the adult mortality, (2) the destruction of some eggs by larvae as well as by adults, and (3) the destruction of some small larvae by larvae and adults, lead to a theoretical population growth which agrees closely with the laboratory experiments.

A Theoretical Study of Population Regulation in Tribolium Confusum

A deterministic mathematical model is constructed to describe the population growth in colonies of the grain beetle, Tribolium confusum, under laboratory conditions. It is shown how the eating of eggs by adults can account for the main features of the observed population growth, in particular the occurrence of a maximum in the adult numbers and the tendency then to reach a steady state.