Formosan Subterranean Termite (Isoptera: Rhinotermitidae) Soldiers Regulate Juvenile Hormone Levels and Caste Differentiation in Workers

Lixin Mao, Gregg Henderson, Yuxiu Liu, Roger A. Laine
2005 Annals of the Entomological Society of America  
A caste structure is maintained in termite societies and juvenile hormone (JH) is generally regarded as the most important regulator in these termite colonies. Here, we demonstrate that the soldier caste regulates JH in workers of Coptotermes formosanus Shiraki. Worker termites (80 Ð100 individuals) were placed in petri dishes with 0, 5, 10, or 20% soldiers. JH III titers of groups of these workers were monitored at 14, 28, 42, and 56 d. Any changes in soldier caste proportions also were noted
more » ... t each sample date. On the Þrst sample date, the JH levels in workers were similar among treatments with different initial soldier proportions, and no new soldiers were formed. Over the next three sample dates, the worker JH levels were higher for low initial soldier proportion treatments and vice versa. Concurrently, soldier formation increased with lower initial soldier proportions. JH titers in workers showed a positive and statistically signiÞcant relationship to soldier numbers until a certain soldier proportion was reached. These results provide evidence that soldier caste proportions regulate JH levels and thereby caste differentiation in workers. The means by which this regulatory mechanism may proceed is discussed.
doi:10.1603/0013-8746(2005)098[0340:fstirs];2 fatcat:m2dj4u4tkvh6xg7gkylrsckfii