Ehler, L.E. 1997 Obscure scale declines after parasitic wasp introduced.. California Agriculture 6: 29-32.

Notes: Control of Melanaspis obscura on Quercus species is reported in Capitol Park in Sacramento, California, by the release and establishment of Encarsia aurantii. Yellow card traps were positioned on release trees (Q. rubra, Q. palustris, Q. agrifolia and Q. wislizenii); the results of surveys of the pests and parasitoids are presented for 1992-96, showing that cumulative trap capture of parasitoids increased 5-fold by 1995, compared with a reduction in trapped immature M. obscura of about 16-fold by the end of 1996. Pest density on samples of twigs was reduced from 4.2 M. obscura per Q. wislizenii twig in 1994 to 0.18 M. obscura per twig in 1997. The numbers of twigs infested was reduced from 82% in 1994 to 10.6% in 1997. The amount of parasitism increased from 38.1% in 1994 to 83.3% in 1997.