Posted on: 02 March, 2017
Author: Alexander P
Free and Williams (1983) provided evidence for the existence of both attractive and deterrent top pheromones. They used ‘articial owers’, each consisting of a small conical ask with a p... Free and Williams (1983) provided evidence for the existence of both attractive and deterrent top pheromones. They used ‘articial owers’, each consisting of a small conical ask with a plastic platform resting on top of it on which the bees could land. A glass capillary tube 50 mm long extended from a hole through the centre of the plate into the ask. A continuous supply of forage could be provided by allowing sucrose syrup from the ask to rise up the tube to replace any removed by foragers. The supply could be terminated by allowing air to enter the pheromone tube. Bees trained to forage at the articial owers were presented with a mixture of owers that had always provided sucrose syrup (rewarding owers), that had never provided sucrose syrup (unrewarding owers), that had their supply of sucrose syrup termin- ated ten minutes previously (terminated owers) and that had never been presented before (clean owers). More bees visited rewarding owers than unrewarding or terminated, and terminated owers were visited more than unrewarding owers. All of these ndings could reect the deposition of attractive pheromone on owers providing forage. However, clean owers received fewer visits than rewarding or terminated but more than unrewarding, indicating that the unrewarding were marked with a deterrent pheromo- ne. The results were similar whether the landing platform was plastic, geotrigona) do not make orientated pheromone communication dances, but deposit scent marks every few metres between the nest and food to form a trail that alerted nestmates follow (Lindauer, 1956; Lindauer and Kerr, 1958; Nedel, 1960). When a scout bee has discovered a food source it usually makes several trips between its nest and food before it lays down a pheromone trail. Scent marks are deposited on leaves, branches, pebbles and even clumps of earth. Distances between adjacent scent marks vary according to the species concerned from 2 m or less (T. bipunctata) to between 10 and 30 m (T. mnidadensis) (Kerr et al. , 1963). This is why they control pheromone production. Workers of T. subterranea place their scent marks in an irregular manner and the distance separating adjacent pheromone marks is very variable. The rst mark is placed at the food source and the second only 30—50 cm from it. Thereafter marks are placed 1-5 m apart in the direction of the nest. Individual bees have their own characteristic marking patterns (Blum et al., 1970). Different species also have their own preferred height at which to deposit scent trails (Kerr et al., 1981). Trail odours last only 8-19 minutes without reinforcement (Kerr et al., 1963). However, it is possible that the odour released by T. cupira is strong enough to form an aerial odour trail in the calm conditions of a tropical forest (Kerr, 1969). While foraging on owers workers of T. spinipes produce a strong pheromone odour from their mandibular glands that may attract recruits (Kerr, 1973). The scent trails of some species are more effective than honeybee dances in assembling recruits and in addition can provide pheromones information on the vertical component (Lindauer and Kerr, 1958). Article Tags: Control Pheromone Production, Control Pheromone, Pheromone Production, Sucrose Syrup, Scent Marks Source: Free Articles from ArticlesFactory.com Alexander P is a blogger from Los Angeles who studies pheromones.