Age polyethism of queens and parental care of eggs in Coptotermes gestroi (Isoptera, Rhinotermitidae)
Vanelize Janei, Vanelize Janei , Ana Maria Costa-Leonardo
Laboratório de Cupins, Departamento de Biologia, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, Brazil; Laboratório de Cupins, Departamento de Biologia, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, Brazil ; Laboratório de Cupins, Departamento de Biologia, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, Brazil
In social insects, division of tasks infers individuals specialized with maturation of different organs, including exocrine glands. Behavioral repertories in a termite colony reflect differences in the activity of exocrine glands, such as the salivary glands. These glands are composed by multicellular acini and have many functions, some essential to the maintenance of the society. They perform role on digestion, communication, defense, construction and feeding of dependent castes, including immatures. Homeostasis in termite societies is kept by glandular secretions, and morphological methods, such as the histology, evidence the development of the glands. Age polyethism is defined when individuals of different ages display distinct tasks in the termite nests. The objective of this study was to evaluate age polyethism in queens using salivary glands and the parental care of eggs in incipient colonies of the Asian termite Coptotermes gestroi. We used queens and kings from incipient colonies (2mo-old) without workers (eggs and larvae present) and queens from 1-yr-old laboratory colonies with workers. For the histology of the salivary glands, the queen thoraxes were fixed in FAA (absolut alcohol, glacial acetic acid, 40% formaldehyde), included in historesin and sectioned with 3 µm thick. For observing the behavioral repertories of the royal couples, 8 incipient colonies were recorded with a Sony FullHD camera, totalizing 250 min of observation. The ethogram involved three behavioral activities on the eggs: mouth touch, grooming and transport, and frequency and duration of these activities were evaluated. The results showed no statistical differences (Mann-Whitney test) in the frequency and duration of the egg transport (P=0.4864/P=0.8108), grooming (P=0.8728/P=0.7592) and mouth touch (P= 0.6033/P=0.9540) performed by queens and kings. Old queens exhibited smaller acini than those more defined present in younger queens, which tasks included feeding the immatures.