Pheromone, juvenile hormone, and social status in the male lobster cockroach Nauphoeta cinerea.

In this study, the major pheromone component, 3-hydroxy-2-butanone (3H-2B), released by dominants was measured during early scotophase. Both the JH III titer in the hemolymph and the 3H-2B content of the sternal glands of the dominants and subordinates were then measured during late scotophase and late photophase. These investigations were performed on encounter days 1, 2, 3, 5, 7, 9, 12, and 20. The results showed that, for non-aggressive posture (AP)-adopting socially naïve males (SNMs), both the 3H-2B release and the hemolymph JH III titer were maintained at a low level. Once a fight occurred, 3H-2B release was raised significantly in the AP-adopting dominants, but not in non-AP-adopting subordinates, and remained raised throughout the entire experimental period. At 30 min after the first encounter, the hemolymph JH III titer was significantly increased in dominants, but not in subordinates. A significantly higher hemolymph JH III titer was observed in dominants during late scotophase on days 3, 5, 12, and 20 and during late photophase on days 3, 5, and 20. After fighting, the sternal gland 3H-2B content of the dominants or subordinates was significantly lower than in SNMs. In dominants, the sternal gland 3H-2B content during late scotophase was significantly lower than that during late photophase in the first 9 domination days, while, in the subordinates, the 3H-2B content during late scotophase was either similar to, or significantly higher than, that in late photophase. In the dominants, 3H-2B release and JH III titer were positively correlated. In rank switchers, the switched social status was positively correlated with both 3H-2B release and JH III titer. Comparison of 3H-2B release and JH III titer in 1-time, 3-time, or 5-time dominants showed that, although winning significantly increased both 3H-2B release and JH III titer, there is no significant difference in 3H-2B release between 3- and 5-time winners, while the JH III titer was most significantly increased in the 3-time winners. The possible relationship between pheromone release, JH III titer, and social status is discussed.