Worker repellent pheromone

Young honey bee queens produce a repellent pheromone that effectively tranquilizes workers that may interact antagonistically with these virgin females (16). The active compoimd, o-aminoacetophenone, is a minor component in the anal exudate that is discharged by the molested queens ( ). This compound is also a defensive allomone of an ant species (34), raising the possibility that it may possess general deterrent activity for arthropods. 

The queen is usually reproductively dominant within the colony and uses chemical cues as both primer and releaser pheromones to suppress the production or fecundity of other sexuals, inhibit reproduction by worker castes, modulate reproductive behaviors (e.g., inhibit swarming and orient swarms), attract males, regulate worker tasks and worker ontogeny, and produce host repellents in slave-making species. Considering the importance of queen semiochemicals in social hymenoptera, few queen pheromones have been chemically identified. The queens of most social hymenopteran colonies are attractive to workers, allowing them to be properly tended as well as to facilitate the dissemination of other pheromone cues. However, the retinue pheromone has been chemically identified in very few species. In the 1980s, queen pheromone components were identified in the fire ant, Solenopsis invicta [91,92], and in the Pharaoh s ant, Monomoriumpharaonis [93]. 

Although many queen-produced pheromones are actively being studied in ants, particularly in the fire ant (Solenopsis invicta) [10,105-110], chemical identifications remain elusive. However, there have been a few recent advances in ants. The queen of the slave-making species Polyergus rufescens produces de-cyl butanoate 60 that repels host workers when upsurping a colony [111]. Males of Formica lugubris are attracted to alate queens by undecane 61, tridecane 62 and (4Z)-tridec-4-ene 63 [112]. 

Honey bee queens produce a rectal secretion which repels aggressive workers in the colony as an example of an intraspecific repellent (1 6). If such pheromonal repellents are commonly produced by social insects, a cornucopia of deterrent natural products awaits identification in the exocrine secretions of these arthropods. 

In the present report, we present results of very recent investigations on the chemistry and deterrent activities to ants of the diverse compotinds identified as exocrine compounds of thrips. In addition, we evaluate the repellency of some honey bee natural products to honey bee workers as an example of how pheromones themselves can be candidates as deterrents... 

The slave-maker workers conduct raids on colonies of another related species by means of a trail pheromone which guides the worker columns to the target area, where they kill or repel defending workers, after which they penetrate into the nest and carry pupae and large larvae to their own colony. When the captured pupae develop into adult workers, they accept the slave-makers as nest mates and assist them in the tasks of the colony (580, 581). 

Jaisson (1980) went on to show that early experience could also control environmental preferences in ants. Young Camponotus vagus and Formica polyctena workers were kept for three to five weeks in artificial nests containing thyme. They are normally repelled by the odour of thyme and there is some indication that it is toxic to the ants over a long period. In a choice chamber, the ants exposed to thyme then selected a part of the chamber containing thyme. The possibility remains that response to environmental odours and pheromones may depend in some measure on such learning processes. 

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