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Submitted to: Sociobiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/27/2005 Publication Date: 10/1/2005 Citation: Morales Ramos, J.A., Rojas, M.G. 2005. Testing methods for improving survival of incipient colonies of coptotermes formosanus (Isoptera: Rhinotermitidae) for laboratory comparisons. Sociobiology 46(2):375-384. Interpretive Summary: The Formosan subterranean termite, as one of the most important urban pests and invasive species in the United States, is subject to intensive research to improve the means to control this pest. Because the Formosan subterranean termite is a social insect, science needs to focus on the study of whole colonies rather than individual termites. Maintaining large numbers of termite colonies in the laboratory present serious technical difficulties, but, scientific research requires the study of large numbers of subjects. The objective of this study was to develop new diet formulations that reduce mortality of incipient colonies of the Formosan subterranean termites, thereby overcoming some of the technical difficulties of studying large numbers of termite colonies in the laboratory. Previous work has shown that incipient termite colonies reared in laboratory conditions suffer great mortality due to microbial infections. Four new diet formulations were tested and compared to a previously publish termite diet (basic formulation). Two of the diets included 50 and 20% of loblolly pine dust, respectively. The other 2 diets included 50 and 250 parts per million of solvent blue 58 colorant, respectively. Termite alates were collected using a black light trap and paired in the laboratory to form queen and king pairs. These pairs founded new colonies and were used for our study. Five groups of 90 incipient colonies were created. Each group was provided with one of the 5 diets formulations tested. Eggs were counted every 15 days to estimate queen fecundity. At the end of 6 months, the colonies were inspected to determine their size in number of individuals. The number of colonies surviving in each diet group was compared at the end of 6 months. There was no difference in queen fecundity and colony size among the 5 groups indicating that the nutritional value of the 5 formulations was similar. Survival; however, was much higher in the group feeding on a diet with 50 ppm of solvent blue 58 colorant. Loblolly pine dust reduced survival as compared to the basic diet formulation. The addition of the blue colorant to the diet improved survival of incipient termite colonies by 20%. This new diet formulation will provide the means for expanding termite research by providing an easy way to maintain large numbers of incipient colonies of the Formosan subterranean termite. Technical Abstract: Five variants of an alpha-cellulose-based diet for rearing incipient colonies of Coptotermes formosanus Shiraki were compared. The basic diet formulation consisted of 33.54% alpha cellulose, 66.14% water, 0.24% lecithin, and 0.08% ergosterol. The variant formulations included 1) basic formulation alone, 2) basic formulation with 50 ppm of solvent blue 58 colorant, 3) basic formulation with 250 ppm of solvent blue 58 colorant, 4) 80% basic formulation and 20% loblolly pine (Pinus taeda) dust, and 5) 1:1 mix of basic formulation and loblolly pine dust. Groups of 90 incipient colonies (one group for each diet variant) were provided with 1g of diet in small tight-seal dishes (50 X 9 mm). Eggs and progeny of colonies were counted each month without opening the containers. After six months dishes were opened to count progeny of colonies. Analysis of variance showed no significant difference in queen fecundity and colony size at the end of 6 months among the diet treatments. Colony survival was significantly higher in the diet formulation with 50 ppm of blue colorant compared to all other diets. Colonies feeding on diets with pine dust had a significantly lower survival than those feeding on diets without pine dust. This results show that solvent blue 58 in low concentrations increase the survival of incipient colonies in culture without affecting queen fecundity or colony growth. The usefulness of diet formulations with solvent blue colorant on increasing survival and improving sample sizes for biological comparisons is discussed. |
