Silba arcana
Diagnostic description:
Male terminalia ; phallus two segmented, basal section rectangular, apical section a uniformly narrow rod, apical three quarters characteristicly angled inwardly at 35 degrees with respect to basal quarter. Inner surface of surstyli with a near vertical row of 6-8 prensisetae 3 largest posteriorly. anterior 3 or 4 smaller, occasioanlly with one out of line. - small posterior projection of surstylus covered internally with small black setulae. In hypandrium pregonites with covering of rather coarse black setulae on rod-like medial part.