Posted on: 02 March, 2017
Author: Alexander P
It is well known that blowing smoke into a colony’s hive or nest helps to diminish aggression. This is partly because it induces many of the worker bees to ingest food from the storage cells whi... It is well known that blowing smoke into a colony’s hive or nest helps to diminish aggression. This is partly because it induces many of the worker bees to ingest food from the storage cells which reduces the likelihood that they will sting (Newton 1968, 1971; Free, 1968b). However, only about half the bees engorge when their colony is smoked and aggression begins to diminish immediately smoke is applied to a colony, so it seems likely that other effects of smoke on bees are also important to the beekeeper. Smoke may also inhibit aggression by deterring bees from leaving their comb, by distracting their attention from an intruder, or by masking an intruder’s alien scent. Moreover, particular components of smoke may mask the odour of alarm pheromones or prevent the antennal sensilla sensitive to alarm pheromones from functioning normally. If either of these two latter alterna- tives proves to be true it could lead to use of a more convenient material for pacifying colonies according to http://michaelspheros.blogspot.com/2016/11/the-power-of-unscented-pheromones.html Stingless bees Some species of Trigona (e.g. T. pectoralis and T. cupira) produce alarm pheromones that release mass attack. Different components of their alarm pheromone may have different functions. The alarm pheromone of T. pector- alis contains 2-heptanol, 2-nonanol, 2-heptanone and 2-nonanone. When exposed to 2-heptanone alone bees aggregate at the mouth of the entrance tunnel and remain motionless whereas exposure to 2-nonanone alone releases attack. The distance orientation behavior by males. It would be inefficient for males responding to low release rates to orient to fast pheromone-releasing females of another species, only to reach a critical concentration, which elicits searching behavior for a phantom female. Pheromone rhythms Differing circadian mating rhythms can also be important for the partitioning of fully sympatric Lepidoptera that use the same chemical communication system. In most Lepidoptera, the female secretes pheromone (calls) and is receptive to mating only during a relatively brief period during the day or night. As might be expected, the periodicity of male response is roughly coincident with the rhythm of female attractiveness. Long before the first sex attractant structure was elucidated, the potential importance of mating periodicity as a reproductive isolating mechanism was recognized. In a now classic series of experiments with saturniids, Rau and Rau (1929) demonstrated that silkworm moths could possess vastly different mating rhythms: for example, Callosamia promethea (Drury), was noted toattract and mate from 3 p.m. to 7 p.m. compared to 9 p.m. to 5 a.m. for Samia Cynthia (Drury). Indeed it now appears that such variation in mating periodicity isolates certain sympatric saturniids. C. promethea, C. angulifera (Walker) and C. securifera (Maas- sen) are all sympatric in South Carolina, where recent studies by Dominick and Edwards (Ferguson 1971-2) have shown that C. securifera commenced calling about 10 a.m. while males ceased ying between 3 and 4 p.m. At about this time, females of the second diurnal species, C. promethea, initiated calling and male response, which continued until sunset. Finally, C angulifera has an entirely noc- turnal cycle, reported to occur between dusk and midnight (Collins and Weast 1961; Ferguson 1971-2). At least two of the species, C. promethea and angulifera, are known to cross-attract (Collins and Weast 1961). Source: Free Articles from ArticlesFactory.com Alexander Pommett is a blogger that studies pheromones. He lives in Los Angeles, CA.