Chemical analysis of Dufour’s gland of workers and gynes of Crematogaster rogenhoferi Mayr (Hymenoptera: Formicidae)

Abstract Background Dufour’s gland was the major source of defensive chemicals in Crematogaster species. To clarify the composition of the defensive chemicals in Crematogaster rogenhoferi , the chemicals in Dufour’s gland were analyzed in two different castes, workers and gynes, using gas chromatography-mass spectrometry (GC–MS). Results The results revealed that the average amount of chemicals was 83.421 μg in the Dufour’s gland of workers and 20.567 μg in the gynes’. Seven chemicals were found in Dufour’s gland of workers, 3-((4Z,7Z)-Heptadeca-4,7-dien-1-yl)phenol and (Z)-3-(Heptadec-10-en-1-yl)phenol are the main chemicals which accounted for more than 80% of relative percentage. The other chemicals were mainly long-chain phenol derivatives, including 2,2’-methylenebis[6-(1,1-dimethylethyl)-4-methyl-phenol], 3-pentadecyl-phenol, (Z)-3-(pentadec-8-en-1-yl)phenol, and 2 unidentified compounds. Fifteen chemicals were detected in the Dufour’s gland of gynes including hexadecane, 2-hexyl-1-decanol, 1-Octadecene, 9-octyl- heptadecane, Heptacos-1-ene, and 6-tetradecyl sulfonic acid butyl ester, as well as other long-chain alkane derivatives and long-chain ester compounds. Only 2,2’-methylenebis[6-(1,1-dimethyl-ethyl)-4-methyl-phenol was found in the Dufour’s gland of both workers and gynes. The average amount of 2,2’-methylenebis[6-(1,1-dimethyl-ethyl)-4-methyl-phenol is 0.233 μg per worker and only 0.128 μg per gyne. Conclusion This study revealed significant differences in the chemical composition and substance content of Dufour’s gland of workers and gynes with different roles in the colony.