Torrubiella tenuis Petch, Ann. R. Bot. Gard. Peradeniya 7: 323 (1922)

Anamorph state: unknown

Specimens were found on the underside of mostly dicotyledonous leaves of forest plants. Hosts are whitefly nymphs (Aleyrodidae). The fungus produces a white mycelium over the insect, completely covering the host, ca. 900-1200 µm in diam. Perithecia developing either on the stroma or on the edges of the stroma, elongated flask-shaped to conical, white turning cream with age, up to 750 µm long. Asci cylindrical, up to 700 µm long x 3.5 µm wide, ascospores filiform 350- 600 x 1 µm, whole. In culture the colonies on PDA are moderately fast growing, attaining a diam. of 3-4 cm in 14 d at 25°C. Colonies white, floccose with cream reverse. Conoideocrella tenuis is a common species infecting scale insects in Thailand. The anamorph was not seen and did not develop in culture. Immature specimens with only the sterile stroma covering the host can be collected all year round. The sexual state usually develops later in the rainy season until the cold season in November to January in central and northern Thailand but throughout the year in places that are constantly high in humidity. Like Conoideocrella luteorostrata, the other member of the genus, the ascospores in the perithecia, when mature, seem to be discharged all at once. As a result, these cannot be seen easily in herbarium specimens.

Hywel-Jones, N.L. (1993). Torrubiella luteorostrata a pathogen of scale insects and its association with Paecilomyces cinnamomeus with a note on Torrubiella tenuis. Mycological Research 97: 1126-1130. Johnson, D., Sung, G.-H., Hywel-Jones, N.L., Luangsa-ard, J.J., Bischoff, J.F., Kepler, R.M. & Spatafora, J.W. (2009). Systematics and evolution of the genus Torrubiella (Hypocreales, Ascomycota). Mycological Research 113: 279-289. Petch, T. (1922). Interim notes on entomogenous fungi. Annals of the Royal Botanic Gardens Peradeniya 7: 323-327. Petch, T. (1923). Studies in entomogenous fungi. Transactions of the British Mycological Society 9: 108-128. Sung, G.-H., Hywel-Jones, N.L., Sung, J.-M., Luangsa-ard, J.J., Shrestha, B. & Spatafora, J.W. (2007). Phylogenetic classification of Cordyceps and the clavicipitaceous fungi. Studies in Mycology 57: 5-59.