Search

The biology of Apis cerana F., the Asian honey bee, is far less known than that of its sister species Apis mellifera L. The arrival of A. cerana in North Queensland has prompted the need to better understand the ecology and biology of this species in an invasive context. We evaluated the colour, shape and spontaneous landing preferences of free flying A. cerana using artificial shape of equal surface. A. cerana displayed a stable and marked preference toward yellow regardless of the season (wet or dry). However, for other colours, different preference patterns were observed depending on the season suggesting a learned preference. Bees had a strong preference for star shaped U.V. nectar guides regardless of the season. Conversely to A. mellifera, A. cerana appeared to minimise the perimeter surface ratio in its landing choice choosing circular over jagged surfaces. However, when tested using polygons and circle of same area and thus very similar perimeters the choice pattern showed no minimisation of perimeter/surface ratio. Surprisingly, bees had a clear preference towards odd number apex shapes and 3/4 of landings occurring on the heptagon, despite the rarity of such 7-lobed flowers in nature. [ABSTRACT FROM AUTHOR]

The author comments on the article "A common pesticide decreases foraging success and survival in honey bees" by M. Henry et al. It explores whether or not the consumption of thiamethoxam via nectar could be a causal factor of Colony Collapse Disorder (CCD) in honeybees. It measures the homing success after ecologically relevant thiamethoxam exposure and compares it to non-thiamethoxam exposed, control homing rates.

Unravelling the role of neuromessenger processes in learning and memory has long interested researchers. We investigated the effects of an acetylcholinesterase blocker, Methyl Parathion (MeP), on honeybee learning. We used visual and olfactory tasks to test whether MeP had a detrimental effect on the acquisition of new knowledge when this new knowledge contradicts previously acquired one. Our results indicate that treatment with MeP prior to conditioning was significantly detrimental to the acquisition of incongruous (but not irrelevant or congruous) new knowledge due to improved recall. The neurobiological and ecotoxicological consequences of these results are discussed. [ABSTRACT FROM AUTHOR]

Blaser, Couvillon, and Bitterman (2006) presented data obtained with honeybees that in principle challenged all traditional interpretations of blocking. They administered A + followed by either A + or + alone (where + indicates an unconditioned stimulus) and then tested on X. They observed less responding to X when they administered A + than when + alone was administered, a phenomenon they called “pseudoblocking”. Here we examined pseudoblocking in a rat fear-conditioning preparation. In Experiment 1, using a control procedure that was similar to our usual blocking control, we obtained conventional blocking but failed to observe pseudoblocking in our analogue to Blaser et al.'s procedure. In Experiment 2, we used Blaser et al.'s control procedure and again failed to observe the pseudoblocking effect with rats when we used the experimental context as an analogue to the honeybee feeder used by Blaser et al. After reviewing their protocol and previously published studies from their laboratory, we hypothesized that the feeder that they treated as a training context probably served as a punctate cue. We also tested this possibility in Experiment 2, using a punctate cue as a surrogate feeder, and were now able to reproduce their pseudoblocking phenomena. Our results are consistent with a simple overshadowing account of pseudoblocking, within the framework of existing theories of associative learning, which is not applicable to the conventional blocking paradigm. Thus, blocking remains a real phenomenon that must be addressed by models of associative learning. [ABSTRACT FROM AUTHOR]

During foraging flights, honeybees learn visual and chemical cues associated with a food source. We investigated whether learned olfactory cues can trigger visual and navigational memories in honeybees that assist them in navigating back to a known food source. In a series of experiments, marked bees were trained to forage at one or more sugar water feeders, placed at different outdoor locations and carrying different scents or colours. We then tested the ability of these bees to recall the locations (or colours) of these food sites and to fly to them, when the training scents were blown into the hive, and the scents and food at the feeders were removed. The results show that (1) bees, trained to a single-scented feeder at a given location, can be induced to fly to the same location by blowing the scent into the hive; (2) bees, trained to two feeders, each placed at a different location and carrying a different scent, can be induced to fly to either location by blowing the appropriate scent into the hive; and (3) bees, trained to two feeders, each decorated with a different colour and carrying a different scent, can be induced to find a feeder of either colour by blowing the appropriate scent into the hive. Thus, familiar scents can trigger navigational and visual memories in experienced bees. Our findings suggest that the odour and taste of the nectar samples that are distributed by successful foragers on returning to the hive, may trigger recall of navigational memories associated with the food site in experienced recruits and, thus, facilitate their navigation back to the site. [ABSTRACT FROM AUTHOR]

Imidacloprid (1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine) belongs to a new chemical family of chloronicotinyl compounds whose mode of action on the insect nervous system differs from that of traditional neurotoxic products. Imidacloprid, a strong systemic compound, is effective against several sucking and mining pests. The acute toxicity of contact and oral applications on two Apis mellifera subspecies, Apis mellifera mellifera and Apis mellifera caucasica, was investigated. In all toxicological studies, each dose included three cages of 20 individuals and each study was replicated three times. The dose--mortality relation revealed some unusual characteristics. At low imidacloprid concentrations, a biphasic mortality appeared, particularly with the contact exposure route. At moderate doses, mortality profiles at 24 and 48 h were different only after oral application. Response kinetics showed that mortality was delayed at the higher doses of imidacloprid. After oral intoxication, the LD50 values of imidacloprid at 24 and 48 h were about 5 ng/bee for both A. m. mellifera and A. m. caucasica. After contact application, the LD50 values at 24 and 48 h were approximately 24 ng/bee for A. m. mellifera and 14 ng/bee for A. m. caucasica. Imidacloprid ranks among the more potent contact insecticides in this important pollinator species. [ABSTRACT FROM AUTHOR]

The article discusses the systematic sublethal effects of insecticides to colony collapse disorder (CCD) in honeybees. A radio-frequency indentification (RFID) microchips was employed to evaluate the mortality resulting from homing failure of foraging bees (mhf). It notes that bees are likely to die if they are away from their hives based on the results of thiamethoxam-treated control groups. The authors argue that thiamethoxam seed treatment could constitute to the potential cause of CCD.