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 : Pent atomidae) were studied in adults and 5th-instar nymphs. The structure was described by electron microscopy and the volatile fraction was ana lyzed by gas chromatography-mass spectrometry. There is a strong corre lation between the structural state and the secretory activity. In nym phs, the 1st pair is not very active, while the 2nd and the 3rd pairs are well-developed and possess abundant secretions. On the contrary, i n adults, only the lst pair remains active and possesses quantitativel y more compounds than the other residual pairs. The volatile fraction of the dorso-abdominal glands secretion shows an age-dependent composi tion. The common products in both the nymphs and adults are (E)-2-hexe nal, decane, tridecane and undecane (the major compound; between 36 an d 75% of the secretion). (E)-2-octenal and (E)-2-octenyl acetate are a dult-specific; 4-keto-(E)-2-octenal and (E)-2-hexenoic acid are nymph- specific. Functions of the dorso-abdominal glands are discussed.