Fat body modifications in virgin and functional queens of pest termites coptotermes gestroi and Cryptotermes brevis (Isoptera: Rhinotermitidae, Kalotermitidae): an ultrastructural approach

• Grant number: 10/05030-7
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2010
• End date: November 30, 2011
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Ana Maria Costa-Leonardo
• Grantee: Ana Maria Costa-Leonardo
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Associated researchers: Fabiana Elaine Casarin dos Santos

Abstract

A termite colony is composed of diverse castes with different behavior and morphology. Coptotermes gestroi and Cryptotermes brevis are the principal pest termites responsible for economical damage in urban areas of Brazil. Queens of C. gestroi present a physogastry or abdominal hypertrophy whereas queens of C. brevis do not develop it or the physogastry is incipient, once only occur an unwrapped of the tegumental cuticle. In termite queens, the physogastry is intimately associated with the fat body modifications, which is the organ responsible for the storage and synthesis of proteins, lipids and carbohydrates. Generally, in insects, the fat body is stimulated by the activity of juvenile hormone to produce the protein vitellogenin, which stimulates the vitellogenesis in the ovarian. However, recent studies showed that in termites the juvenile hormone not always stimulate the vitellogenesis in reproductives, and in Cryptotermes secundus the juvenile hormone titre do not differ significantly between virgin and functional queens. The aim of this project is to compare the fat body morphology among virgin queens, functional queens in the beginning of the colony foundation and functional queens of mature colonies in both termite species. Additionally, we intend to compare the fat bodies of C. gestroi physogastric queens with those of C. brevis queens. For the morphological study of the fat body, abdominal samples of the different queens will be fixed in glutaraldehyde postfixed in osmium tetroxide, included in Epon resin and, after routine proceedings, they will be observed with a transmission electron microscope (Phillips) that provides a better detail of this organ. The knowledgement of the termite pest biology is important, mainly those related to reproduction, because they may provide support for future strategies of management of these insects, since there is an increasing demand for using juvenile hormone analogs in the control of these insects. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COSTA-LEONARDO, ANA MARIA; LARANJO, LARA TEIXEIRA; JANEI, VANELIZE; HAIFIG, IVES. The fat body of termites: Functions and stored materials. JOURNAL OF INSECT PHYSIOLOGY, v. 59, n. 6, p. 577-587, JUN 2013. (10/05030-7)