Gut Content and Laboratory Survival of the Termite Cornitermes cumulans (Isoptera: Termitidae: Syntermitinae) with Different Diets Including Nest Stored Food.

Cornitermes cumulans (Kollar, 1832) is a mound-building termite that stores food nodules in the nest, which seems to be pre-chewed and regurgitated by workers. Information on the food resources used by this species is still scarce, and this study aimed to understand the feeding habits of C. cumulans using a qualitative analysis of the worker gut contents, and to select the best food to keep termites under laboratorial conditions. Thus, four food resources and five artificial diets were tested to evaluate the laboratory survival of C. cumulans. Food nodules from nests were used as a positive control, and no food was available in cages for negative control. Ten replicates using 30 workers plus three soldiers were performed for each type of food and for each control. The experiments were daily examined for termite survival during a 40-day period. Data were analyzed using the log-rank (Mantel-cox) test (P < 0.05). The qualitative analysis of the gut contents showed different materials, such as plant parts, fungi, and minerals. Data analysis showed that all of the survival curves of termites fed with artificial diets and food items were significantly different from that obtained with termites fed on food nodules, which showed the highest survival, followed by the diets of α-cellulose, corn stalk, and sugarcane bagasse. Then, our findings showed that the most adequate artificial foods to maintain populations of C. cumulans in the laboratory were the diets of α-cellulose, corn stalk, and sugarcane bagasse.

Rehydration After Water Stress in Forager Workers of Coptotermes gestroi (Wasmann) (Blattaria: Rhinotermitidae).

Water maintenance is vital for termite survival under dry conditions, hence environment humidity is one of the most important factors that controls the distribution of Isoptera. To understand the dynamics of termite rehydration after water loss, two bioassays were performed with forager workers of Coptotermes gestroi (Wasmann) submitted to water stress. Insects were weighed and placed into Petri dishes without water and food for periods of 3, 15, and 30 h. For each period of water stress, 10 replicates were performed in the treatment and control groups, totalling 120 experimental units. Forager workers lost body mass across all periods of water stress and tested with the highest reduction for the 30 h exposure period. Subsequent access to water resulted in termite rehydration, and final weight values were near to initial body mass values. These results demonstrate that workers of C. gestroi experienced large reductions of body mass under water stress, but these reductions were not severe enough to cause mortality. Additionally, termites were able to rehydrate after water stress conditions. This is a potential risk factor to be considered in cases of new infestations because C. gestroi workers will be able to cause economic damage in their new locations even when deprived of water during their transportation by humans.