A scientific note about spectroscopic analysis of honey bee brood comb cappings in hygienic and non-hygienic honey bee colonies

Abstract

Hygienic behavior (HB) involves the detectionof diseased, dead, and infected larvae or pupae andtheir selective removal from brood cells by workerbees (Arathi et al., 2000;ArathiandSpivak,2001).The efficiency of HB is affected by the ability ofbees to recognize infected or infested brood (bychemical and physical cues). Among the variousfactors that have been studied that could influencethe detection of cells with dead or diseased brood(Arathi et al., 2000), visual cues had not been inves-tigated. We examined the light transmittance char-acteristics of the cappings of brood combs to deter-mine if it would be possible for bees to detect ab-normal brood within capped cells using visual cues.Cell cappings from old and new brood combs(50 each) from each of three colonies of hygienicand non-hygienic bee lines were removed andtested. These previously selected hygienic colonieshad a mean of 99.8% HB, while the non-hygieniccolonies had a mean of 2.3% HB.The cappings were fixed in a support device(mask) that permitted light passage only throughthe cappings. Initially, the intensity of the light thatpassed through the mask was measured without acapping. This corresponds to the incident light in-tensity (