Student Theses and Dissertations

Date of Award

1970

Document Type

Thesis

Degree Name

Doctor of Philosophy (PhD)

Abstract

The southern Florida termite Neotermes jouteli (Kalotermitidae) was found to provide exceptionally suitable material for the study of caste regulation, with special reference to the regeneration of reproductive forms. It was possible to collect entire natural colonies of this termite, including the reproductive pair, and to maintain them for long periods in the laboratory. In this way, the characteristics of individual colonies could be studied in a way not done in earlier work on caste regulation.

The present findings can be summarized as follows:

  1. All pseudergates in high Ir colonies are genetically capable of transformation to supplementaries. However, at any given time, only a certain proportion can immediately transform.
  2. Male and female reproductives play different roles in the inhibitory process with the female totally inhibiting female pseudergates and partially inhibiting males and the male equally but partially inhibiting both sexes. In contrast to previous findings, the sum of the separate effects accounts for the total inhibition observed. The separate effects of the two sexes imply the existence of at least two inhibitory substances if the pheromone theory is inhibitory as a normal bisexual pair.
  3. The extent to which a colony regenerates reproductives is proportional to the amount of time each day that reproductives are absent. The surplus inhibition experienced by female pseudergates can be seen under conditions of part-time orphaning.
  4. Reproductives with sealed anuses are probably just as inhibitory as normal reproductives and therefore proctodeal feeding is not the means by which the postulated inhibitory pheromones are transmitted. Likewise, restricting pseudergates to a diet of filter paper impregnated with rectal fluid has no significant inhibitory effect. These results conflict with what has previously been reported. The results of all these studies can be interpreted most easily in terms of the pheromone theory. However, the source and nature of the pheromones remain unknown.

The overall results fit into the general view that a termite colony is a "superorganism." The superorganism has differentiated parts; its members are integrated primarily through chemical interactions mediated by the behavioral systems of grooming and trophallaxis; it carries out coordinated behavioral patterns such as constructing and maintaining complex and finely regulated nests; and it has a life history of its own with physiologically different stages corresponding to the embryonic, juvenile and sexually mature stages of an individual organism.

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