The specificity was reported even within species of same genus e.g., Vacin and Went (VW) for D. farmeri and D. primulium and Nitsch and Nitsch for D. moschatum and D. fimbriatum var. oculatum (Devi et al. 1990), Mitra et al.medium for Cymbidium macrorhizon (Vij and Pathak 1988), Nitsch and Nitsch for C. iridioides (Jamir et al. 2002), Knudson C for C. elegans (Sharma and Tandon 1990).