Differential feeding of worker larvae affects caste characters in the Cape honeybee, Apis mellifera capensis

Factors affecting the dynamics of the honeybee (Apis mellifera) hybrid zone of South Africa

“…If capensis and scutellata larvae are cross-fostered into colonies of the opposite subspecies, capensis larvae are fed more by scutellata nurse workers than when reared by their own sisters (Allsopp et al, 2003). Conversely, scutellata brood receive less food when fed by capensis nurse workers (Allsopp et al, 2003). Colonies from the hybrid zone (which are presumably intercrossed colonies) feed capensis larvae significantly more and scutellata larvae significantly less than they do larvae of their own genotype (Allsopp et al, 2003).…”

“…Most important in this regard are the pheromonal cues that regulate the feeding of larvae. If capensis and scutellata larvae are cross-fostered into colonies of the opposite subspecies, capensis larvae are fed more by scutellata nurse workers than when reared by their own sisters (Allsopp et al, 2003). Conversely, scutellata brood receive less food when fed by capensis nurse workers (Allsopp et al, 2003).…”

“…Most likely F 1 colonies contain sufficient numbers of capensis-derived genotypes to prevent the expression of worker reproduction due to differences in the pheromonal thresholds that regulate reproductive division of labour. However, based on previous work (Allsopp et al, 2003), we strongly suspect that as soon as colonies contain a mixture of capensis-and scutellata-derived subfamilies, as in intercrossed colonies, differences in the pheromonal thresholds lead to misinterpretation of intersubspecies signals. Most important in this regard are the pheromonal cues that regulate the feeding of larvae.…”

“…Capensis workers tend to have: (1) a large number of ovarioles (10-20 compared with 3-5 in other subspecies (Ruttner, 1988)); (2) an organ, the spermatheca, normally used by queens for the storage of sperm which is absent in workers of all other subspecies (Onions, 1914) and (3) in laying workers, a pheromonal bouquet that resembles that of queens (Wossler, 2002). In addition to laying workers producing queen-like pheromonal bouquets, a capensis queen, and presumably her brood as well (Allsopp et al, 2003), produce a much greater quantity of pheromone than any other honeybee subspecies (Crewe, 1988). Hereafter we refer to the characteristics unique to capensis workers (thelytoky, high number of ovarioles, presence of spermatheca and queen-like pheromonal bouquets) as the capensis complex.…”

“…Queen-destined larvae receive larval food that is richer in certain sugars and receive it in greater amounts than do worker-destined larvae (de Wilde and Beetsma, 1982). Hence, worker larvae can potentially manipulate adult nurse workers by soliciting more larval food and becoming more queenlike as a result (Allsopp et al, 2003).…”