Variations Of Cuticular Long-chained Hydrocarbons In The Different Stages Of Female Neotenic Reproductives In Reticulitermes Labralis And The Behavior Of Feeding Of Alates In R. Flaviceps

Reticulitermes are most widely distributed subterranean termites in China, which have a large number of nests and neotenic reproductives with strong reproductive competition. Colony numbers can recognize nestmates by cuticular long-chained hydrocarbons (CHCs), and the variations of CHCs correlate with reproductive status. Besides, whether winged alates, which will swarm for reproduction and found new nests, are fed by workers or feed by themselves during the period of eclosion to swarm in their natal colony remains controversial. Orphaned colonies of Reticulitermes labralis were established in laboratory. The differentiation process of neotenic reproductives from nymphs were observed, and the relevant CHCs pheromone variations in the neitenic reproductives were determined. Another experiment was to examine feeding and trophallaxis in R. flaviceps using rubidium (Rb) as a tracer. The results in the study can be applied to caste differentiation, behavior and control of the corresponding species.With the appearance of neotenic reproductives of R. labralis, each colony would gradually have its dominant reproductives (stable reproductives). Colonies with stable reproductives accounted for 43.3%, 83.3%, 93.3% and 100% of the orphaned groups on the 8th day,16th day, 25th day and 36th day, respectively. By analyzing the peak area ration (the peak area of each stage divided by the area of corresponding peak at the nymphal stage) in different stages of neotenic reproductives, we found that the peak area ratio of the compound with retention time 38.52 min, which was not detected in eggs, increased 14.14 times in reproductives laying 7-8 eggs as high as that in the nymph stage; while the compounds with the retention time of 35.50 and 39.21 min, which were detected in eggs, had significantly increased peak area ratios after the reproductives began to lay eggs. CHCs can not be used to discriminate fertile neotenics (neotenic reproductives that establish and maintain dominant reproductive status) from infertile neotenic reproductives (individuals with morph of neotenics, but unable to lay eggs in the colony), although they can be used to discriminate neotenic reproductives from nymphs easily. The compound with the retention time 38.52 min is a characteristic substance of reproductives. The compounds with the retention time of 35.50 and 39.21 min are characteristic substances of neotenic reproductives that have laid eggs.The experiments used over 5-instar workers,6-8 instar nymphs, alates and soldiers of R. flaviceps as samples to feed on dyestuff neutral red treated filter paper proved that alates could feed and the nymphs had the feeding capacity. Rb feeding study showed that workers and alates fed directly on different concentration Rb-treated filter paper. After 3 days workers and alates received the greatest amount of Rb, suggesting that worker was the main feeding castes and alates can normally feed themselves in the colony. Soldier did not feed on Rb-treated filter paper, though they obtained the Rb content over the marked level possibly through external contact with Rb-treated filter paper. In the trophallaxis study, both worker and alate were used as donors and recipients with other workers, alates and as donors for soldier. The results suggested that alates can transfer food to other alates, the transfer efficiency is 1.05%, and they rarely provided food for workers and soldiers. Workers can transfer food to workers and soldiers, with 1.02% and 0.5% transfer efficiency, respectively, but they rarely provided food for alates.