FINE-STRUCTURE AND PHYSICOCHEMICAL ANALYSIS OF THE NYMPHAL AND IMAGINAL SCENT GLAND SYSTEMS OF LINCUS-SPURCUS (ROLSTON) (HETEROPTERA, PENTATOMIDAE)

The dorso-abdominal scent glands of Lincus spurcus (Heteroptera : Pentatomidae) were studied in adults and 5th-instar nymphs. The structure was described by electron microscopy and the volatile fraction was analyzed by gas chromatography-mass spectrometry. There is a strong correlation between the structural state and the secretory activity. In nymphs, the 1st pair is not very active, while the 2nd and the 3rd pairs are well-developed and possess abundant secretions. On the contrary, in adults, only the lst pair remains active and possesses quantitatively more compounds than the other residual pairs. The volatile fraction of the dorso-abdominal glands secretion shows an age-dependent composition. The common products in both the nymphs and adults are (E)-2-hexenal, decane, tridecane and undecane (the major compound; between 36 and 75% of the secretion). (E)-2-octenal and (E)-2-octenyl acetate are adult-specific; 4-keto-(E)-2-octenal and (E)-2-hexenoic acid are nymph-specific. Functions of the dorso-abdominal glands are discussed.