Scanning Electron Microscopic and Chemical Study of the Metathoracic Scent Glands System of Rhaphigaster nebulosa (Poda, 1761) (Heteroptera: Pentatomidae)

Abstract

The metathoracic scent glands (MTGs) system of adult Rhaphigaster nebulosa (Heteroptera: Pentatomidae) was described by electron microscopy and secretion from them was analysed by a combination of gas chromatography and mass spectrometry (GC-MS). The MTGs is anatomically complex. It opens ventrally by paired openings located between the metathoracic furcae. It belongs to the paired MTG type and comprises on each side: median reservoir, lateral glands and evaporation surfaces. Median reservoir is sac-like and flanked by multitubular lateral glands. It is interconnected by a narrow bridge in the ventral mid-line. Metathoracic coxae are associated with crescent-like evaporation areas. Chemical analyses showed a typical pentatomid MTG composition. The glands of R. nebulosa males and females contain 9 same compounds: n-undecane, n-dodecane, n-tridecane, n-nonacosane, (E)-2-hexenal, (E)-2-octenal, (E)-2-decenal, (E)-2-hexenyl acetate, 2(5H)-furanone being the two major compounds n-tridecane and (E)-2-hexanal, which represent 90-95% of the secretion in the this species. The compounds n-tricosane, (Z)-cyclodecene, and (E)-2-decen-1-ol were detected only in females, while n-tetracosane, n-hexacosane, and 1-tridecene were detected only in males.