Mani, E., & Baroffio, C. 1997 Biologische Bekämpfung der San-Jose-Schildlaus im Kanton Zug mit der Schlupfwespe Encarsia perniciosi. [Biological control of the San Jose scale in Zug Canton with the parasitic wasp Encarsia perniciosi].. Obst- und Weinbau 133: 392-394.

Notes: Control of San Jose scale (Quadraspidiotus perniciosus) in old fruit trees with rough bark in Switzerland using mineral oil was ineffective, so biological control on apple and plum using the parasitoid Encarsia perniciosi was investigated during 1994-96. The percentage parasitism of Q. perniciosus increased from approx equal to 20% in 1995 to approx equal to 75% in 1997, and the number of males of Q. perniciosus (caught in pheromone traps in the centre of the release site) fell from approx equal to 2500 in 1994 to almost zero in 1996.