Macrotermes Carbonarius Research Articles

Respiratory rate and energy utilization by Macrotermes carbonarius (Hagen) (Isoptera, Termitidae, Macrotermitinae) in Penang, Malaysia

There were significant variations in oxygen consumption and carbon dioxide evolution of Macrotermes carbonarius (Hagen) among the soldiers and workers over a 10-hr experimental period. This suggested that the insects exhibited rhythmic respiratory behaviour in spite of being separated from their nest system and in the stressful situation of confinement of a respiratory flask at 29°C. The correlation between body fresh weight (mg) and respiratory rate ml O2/mg fresh wt/hr was significant. A respiratory quotient of 1.0–1.1 suggested that glucose was the respiratory metabolic substrate utilized and that both aerobic and anaerobic processes could have been taking place. Most of the leaf litter imported into the mound was utilized by the fungus on the fungus comb for metabolism with the release of carbon dioxide, heat and water. The heat released was sufficient to maintain the brood chamber temperature at 29.1 ± 03°C despite fluctuations of the ambient temperature and the temperature of the surrounding soil.

The role of termites in an equatorial rain forest ecosystem of West Malaysia : II. Leaf litter consumption on the forest floor.

To estimate the rate of consumption of leaf litter by termites on the forest floor of Pasoh Forest Reserve, Negeri Sembilan, West Malaysia, newly fallen leaves were marked and distributed on the ground. The loss of leaf area due to termites was determined either photometrically or visually. An average of 1.70% of the total surface area of the leaf litter disappeared per week in experiment 1 and 1.25% in experiment 2 in Plot 1, and 2.9% per day in other plots located near the mounds of Macrotermes carbonarius. The amount of leaf litter accumulation in the Ao layer was estimated at about 2.3 t/ha at Plot 1, so it was likely that an amount equivalent to about 32% of the daily leaf-litter fall was transported by M. carbonarius to their mounds in experiment 1 and 22% in experiment 2. It was considered that the termites had an important role in the detritus food chain of the ecosystem.

The role of termites in an equatorial rain forest ecosystem of West Malaysia : I. Population density, biomass, carbon, nitrogen and calorific content and respiration rate.

1. Density of nests, population number, biomass, nitrogen and carbon content, calorific content and respiration rate of termites were studied at Pasoh Forest, West Malaysia mainly with four dominant species of epigeous nest builders, Macrotermes carbonarius, Dicuspiditermes nemorosus type-a, type-b and Homallotermes foraminifer, to reveal their role in the ecosystem. 2. The density of nests or mounds was 15-41/ha in M. carbonarius, 60-110/ha in the two types of D. nemorosus and 85-165/ha in H. foraminifer. 3. The population number per nest or mound was about 88,000 in M. carbonarius, 45,000 in D. nemorosus type-a, 47,000 in D. nemorosus type-b and 13,000 in H. foraminifer. The population number per hectare was about 1.8x106 for M. carbonarius, 4.3x106 for D. nemorosus type-a, 5.2x106 for D. nemorosus type-b and 2.1x106 for H. foraminifer. 4. The ratio in number of workers to soldiers was 6.4 for M. carbonarius, 19.0 for D. nemorosus type-a, 23.1 for D. nemorosus type-b and 8.9 for H. foraminifer. The ratio in number of adults (workers plus soldiers) to larvae was 1.4 for M. carbonarius, 0.59 for D. nemorosus type-a, 1.76 for D. nemorosus type-b and 3.84 for H. foraminifer. 5. The number of adults per nest of D. nemorosus type-a, type-b and H. foraminifer was linearly correlated with the weight of nest on the log-log coordinates. 6. The ratio of dry body weight to live weight was 0.24-0.30 for workers, 0.19-0.29 for soldiers and 0.15-0.22 for larvae. 7. The ash content of termite body was 26-66% for workers, 2-24% for soldiers and 1-4% for larvae. 8. The carbon content ranged from 45% to 66% of ash-free dry weight and the nitrogen content from 5.6% to 12.6%. 9. The mean calorific value of termite body was 5.3 gcal/mg in workers and soldiers on an ash-free weight basis, but was greater in nymphs and winged reproductives in the nest (6.7-6.9 gcal/mg) owing probably to their large fat storage. 10. The relation of CO2 evolution rate to temperature in these termites was similar to what has been found in other insects. 11. The total biomass of the four termite species was estimated at 6.01 kg ash-free dry weight/ha, equivalent to 0.55 kg nitrogen/ha and 3.09 kg carbon/ha. 12. The role of the fungi cultivated by M. carbonarius on their fungus combs was discussed in relation to the nutrition of termites and the decomposition of leaf-litter with special reference to their nitrogen metabolism. The high nitrogen content of fungus spherules growing on fungus combs seemed to have an important bearing on the nutrition of termites. 13. It was concluded that the termites played a very important role in the organic matter decomposition cycle of Pasoh Forest.

Wehrsubstanzen und wehrverhalten der termite Macrotermes carbonarius

Soldiers of the termite Macrotermes carbonarius which forage on the surface have a special defensive behaviour: they stab their sickle-shaped mandibles into the skin of the enemy and by crossing them they are irreversibly fixed. After this a brownish watery secretion from the huge labial glands is discharged by rhythmic contractions of the abdomen. The secretion was analysed by thin-layer chromatography and u.v.-spectroscopy. The main compound is toluquinone. A minor component is benzoquinone,