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Showing papers on "Varroa sensitive hygiene published in 1995"


Journal Article
TL;DR: Although honey bees may be important pollinators of some weeds, they probably do not contribute substantially to weed problems.
Abstract: Summary: Recent concern that honey bees may threaten natural areas by increasing weed abundances through increased pollination was investigated by reviewing the literature to determine which weed taxa surveyed from New Zealand Protected Natural Areas (PNAs) are visited by honey bees. The contribution made by honey bees to weed reproduction was assessed by checking reproductive strategies and pollination mechanisms of a subset of problem weeds. A substantial proportion of surveyed weeds in PNAs are probably visited by honey bees (43%) including half of the problem weeds. However, reproduction of the majority of problem weeds is characterised by plastic reproductive mechanisms and/or simple pollination mechanisms where honey bee influence is low or unimportant. Although honey bees may be important pollinators of some weeds, they probably do not contribute substantially to weed problems.

46 citations



Journal ArticleDOI
TL;DR: It has been suggested that genotypic variability derived from the subfamily structure of colonies, and recombination, may be important components in division of labor.
Abstract: Division of labor is fundamental to the complex organization of insect societies. It is generally assumed to be more efficient for colonies to accomplish tasks with groups of specialized individuals than with unspecialized workers [1, 2]. Worker honeybees (Apis mellifera) pass through distinct behavioral phases during their life. Young bees perform various tasks inside the nest, while older bees forage. This phenomenon has been called age polyethism [3, 4]. However, there is some plasticity in the age-based pattern enabling the colony to adapt the work force to the colony's need in response to environmental changes [4, 5]. Besides these ontogenetic and epigenetic determinants of division of labor, it has been shown that genetic determinants may also influence behavioral differences between workers [6]. Genetic heterogeneity among the individuals of a honeybee colony is a consequence of multiple mating and heterozygosity of the queen. Each colony consists of a number of genetically distinct subfamilies derived from the same queen but from different fathers. It has been suggested that genotypic variability derived from the subfamily structure of colonies, and recombination, may be important components in division of labor [7-91. Basically, two experimental approaches have been used to demonstrate the genetic variability among individuals for performing specific tasks. Either the behavior of unrelated coor cross-fostered workers derived from artificially selected strains of bees was compared [10, 11] or differences in behavior among members of different subfamilies within a colony were examined. When subfamily members

31 citations


Journal ArticleDOI
TL;DR: Inspecting of the frames 2 weeks later showed that ARS-Y-C-1 pupae were less frequently infested than Hastings and Louisiana pupae, while the infestation rate of the hybrids was intermediate, and the stocks did not differ in other parameters of Varroa infestation.
Abstract: SUMMARYA controlled experiment which utilized a larval transfer (grafting) technique was used to evaluate attractiveness of larvae from four different stocks of honey bees (Apis mellifera) to Varroa jacobsoni. The stocks of honey bees were: ARS-Y-C-1 (A. m. carnica, from Yugoslavia), Hastings (A. m. carnica, from Canada), an F1 hybrid between ARS-Y-C-1 and Hastings, and a Louisiana stock. Newly hatched larvae (target larvae) from each test stock were grafted into an area at the centre of a brood frame occupying 8 rows of 20 cells (160 cells). After larval transfer, each brood frame containing target larvae was introduced into a Varroa-infested colony. Inspection of the frames 2 weeks later showed that ARS-Y-C-1 pupae were less frequently infested than Hastings and Louisiana pupae (20% vs. 36% and 40%), while the infestation rate of the hybrids was intermediate (29%). The stocks did not differ in other parameters of Varroa infestation (mite load per infested pupa, number of females per infested pupa, numbe...

14 citations


01 Jan 1995
TL;DR: Invasion behaviour of Varroa jacobsoni into honeybee brood cells was studied using an observation hive to identify which factors and conditions may play a role during invasion of mites, and to help interpretation of observations in artificial settings.
Abstract: Invasion behaviour of Varroa jacobsoni into honeybee brood cells was studied using an observation hive. The mites were carried close to a suitable brood cell by the bees. Subsequently, the mites moved from the bees to the rim of the cell, walked quickly inside, crawled between the larva and the cell wall, and moved onto the bottom of the cell. Varroa mites were never seen walking across the comb, and entering and leaving brood cells as has been described for Tropilaelaps clareae. Differences in invasion strategies between V. jacobsoni and T. clareae are discussed. Introduction The parasitic mite Varroa jacobsoni is currently the most important pest of Apis mellifera, worldwide. Varroa mites parasitize both adult bees and bee brood. They feed on the haemolymph of adult bees and additionally use the bees as transport vehicles within the colony as well as for dispersal from colony to colony. Reproduction of the mites only takes place while residing on honeybee brood. Consequently, the mites have to leave the bees and invade the brood cells (Ritter, 1981; Ifantidis & Rosenkranz, 1988). Since invasion into brood cells is indispensable for reproduction, knowledge about invasion behaviour and the factors affecting this behaviour may provide a basis for development of new control methods. For example, the finding that Varroa mites invade drone cells in larger numbers than worker cells (e.g. Fuchs, 1990), prompted a biotechnical control method in which mites are trapped in drone cells and subsequently removed from the colony (Schulz et al., 1983; Rosenkranz & Engels, 1985). Invasion has been studied primarily at the population level. Studies have been done on the distribution of mites over different types of brood cells (e.g. Ruijter & Calis, 1988; Buchler, 1989; Fuchs, 1990), and on the distribution of mites over adult bees and brood cells (e.g. Woyke, 1987; chapters 2,3). In these studies the resulting distribution was studied, whereas the underlying behaviour was reconstructed indirectly by inference. Direct studies on behaviour of individual mites have been carried out in artificial settings (e.g. Otten & Fuchs, 1988; Le Conte et al., 1989; Rickli et al., 1992) because manipulations to see individual mite behaviour are difficult in a bee hive. Such studies are useful to provide answers to specific questions, e.g. whether mites react to certain odours (Le Conte et al., 1989; Rickli et al., 1992), but the relevance of these observations to the behaviour of mites under realistic conditions is not immediately obvious. In this study mite behaviour was observed in a more realistic setting to identify which factors and conditions may play a role during invasion of mites, and to help interpretation of observations in artificial settings.

8 citations