Alkylpyrazines in the mandibular gland secretions of Ammophila wasps (Hymenoptera: sphecidae)

1.1. The chemistry of the mandibular glands of four Nearctic species of sphecid wasps in the genus Ammophila is reported.2.2. The alkylpyrazine identified in A. fernaldi and A. procera males and A. nigricans males and females is 2,5-dimethyl-3-isopentylpyrazine.3.3. There are sex differences in the alkylpyrazines of A. urnaria. Males have 2,6-dimethyl-3-propylpyrazine and females have 2,6-dimethyl-3-butylpyrazine.