ABSTRACT
Deleurance (1955) demonstrated that failure of larval development in Polistes did not depend on any of the more obvious factors such as temperature or lack of food supplies. In one experiment he produced similar premature death in the larvae by severing the salivary ducts of the workers, and proposed that the saliva of the nurses contained some substance essential to larval growth which falls in supply at the end of the season. In the field, West (1969) did not observe the same phases in P fuscatus as Deleurance described ini? dominulus (= P. gallicus) kept in captivity. Similar events only occurred in colonies transferred to the laboratory. West also objected that the reproductive condition of the queen was not taken into account and was of the opinion that the numerous attempts to explain the phenomenon were all inconclusive. West (1969), reported that in the nests she had observed the phenomenon only occurred after the foundress queen had stopped laying eggs. In the tropical wasp P erithrocephalus (= P canadensis), West also found that there was a correlation between phenomena associated with cessation of nest growth and the end of egg laying or disappearance of the queen (West 1969). In one nest under observation, 101 eggs and 47 out of 106 larvae disappeared three weeks after the last cell had been built. This suggests that the presence of a reproductively active queen is essential for normal nest expansion and brood care. In another colony, eggs disappeared after the queen was temporarily removed, suggesting that eggs are neglected in the queen's absence, or else that egg care is a function of the queen herself or is at least stimulated by her presence. Miyano (1986) also reported heavy egg destruction in orphan nests of P chinensis antennalis.
