Ma, W.L., Shi, Y.Q., & Wan, J.J. 1985 [A preliminary study of Quadraspidiotus perniciosus on jujube.]. Plant Protection 11(1): 9-10.

Notes: The biology and ecology of the diaspidid Quadraspidiotus perniciosus was studied on jujube [Ziziphus sp.] in Akesu, Xinjiang, China, in 1981-83. There were 2-3 overlapping generations a year, and Q. perniciosus overwintered as 2nd-instar nymphs. Oviposition occurred in late May and early June. Adults emerged 20 days later with a female:male ratio of 1:2.74 on the leaves and 1:0.11 on the branches and fruits. In isolation, parthenogenesis was observed. The natural enemies included the coccinellid Chilocorus geminus and the aphelinid Aphytis sp. Predation by C. geminus reached 80%, but the predator population declined sharply in late July due to predation by Chrysopa sp. and a tit (Parus), as well as migration. Parasitism of Q. perniciosus by Aphytis sp. was 22-39.2% in June-September. Timely irrigation and micro-granules containing 3% carbofuran applied at 400-600 g/plant to the root area of 4-6 m high plants, greatly reduced fruit damage. In addition, sprays of detergent were also effective. It is suggested that in jujube orchards with low infestations of Q. perniciosus the natural enemies are protected and augmented, whereas in orchards seriously attacked by the pest carbofuran is used selectively.