The soldier caste in termite colonies has traditionally been considered responsible for colony defense. The soldier’s enlarged head, mandibles, and defensive secretions help it protect the colony from invaders. Soldiers have also been speculated to play a role in caste differentiation by influencing juvenile hormone (JH) titers of nest mates. In our research, soldier head extract (SHE) was isolated, separated using thin layer chromatography, and then used in model presoldier induction assays. SDS-PAGE showed no indication that SHE contained any protein. Preliminary GC/MS analysis indicated that a major component of soldier head extract was a sesquiterpene. To date, our research indicates that extracts from soldier heads applied in combination with JH III, synergistically increase worker-to-presoldier morphogenesis. These findings suggest two alternate hypotheses regarding how soldiers utilize semiochemicals for caste regulation; 1) soldiers induce soldier formation; or 2) soldiers sequester caste-regulatory semiochemicals from the colony, thus inhibiting soldier formation. Our results using JH III contradict previous research in which SHE applied in combination with juvenile hormone analogs inhibited presoldier formation (Okot-Kotber B.M. et al 1991. Sociobiology. 19,1: 77-89. Korb J.E. et al. 2003. Insect. Soc. 50:299-303). These results provide a significant step toward elucidating the role of the soldier in termite caste differentiation and optimization. Studies are currently ongoing to identify the role of SHE in caste differentiation.
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