Research On The Biological Characteristrics And Artificial Rearing Technique Of Stethorus Punctillum Weise

Stethorus punctillum Weise was an important predator of mites.In this experriment were studied the biological characteristics and the artificial rearing technique of Stethorus punctillum.The main results were as follows:1.Five species host plants（Zea mays,Arachis hypogaea,Solanum melongena,Capsicum annuum and Vigna unguiculata）were chosen to rearing Tetranychus urticae.The results showed that the five species of host plans had different effects on the developmental durations and fecundity of Tetranychus urticae.The shortest developmental duration of Tetranychus urticae occured on the peanut（9.82 d）,the largest average fecundity of Tetranychus urticae occured on peanut（117.16 eggs）.2.The shortest developmental duration of Stethorus punctillum on the 5 species of plants were peanut and cowpea（no significant）;The fecundity of Stethorus punctillum on peanut,cowpea,corn,pappers and eggplant were 112.60 eggs,103.80 eggs,85.20 eggs,68.20 eggs and 53.40 eggs.The emergencing rates in peanut,cowpea,corn,pepper,eggplant were80.11%,70.26%,66.66%,9.70%and 29.81%,respectively.3.The pre-mating period of Stethorus punctillum was 2.64 d,the pre-oviposition period was 5.27 d.The fecundity of Stethorus punctillum were 55¹35 eggs.4 generations of Stethorus punctillum were reared,the fecundity of F₀,F₁,F₂ and F₃ generation were 112.80eggs,109.40 eggs,102.20 eggs and 81.60 eggs respectively,the fecundity of the F₃ generation was significantly lower than the F generation’s fecundity.4.Feeding spatial size and density had significant influence on the reproduction of Stethorus punctillum.In the feeding spatial size of 60cm³,two pairs per bottle were significantly higher than that of others.In the rearing spatial size of 250cm³,500cm³ and700cm³,the average fecundity of 2 pairs and 6 pairs of Stethorus punctillum were significantly higher than others.Under the rearing spatial size of 1000cm³ and 1400cm³,the average fecundity of 6,10 and 14 paris per bottle were significantly higher than others.The best rearing spatial size of Stethorus punctillum were 700cm³,1000cm³ and 1400cm³,the best rearing density of Stethorus punctillum were 2⁶ pairs per bottle.Considering the utilization rate of the Stethorus punctillum,6 pairs of Stethorus punctillum in 700cm³ rearing spatial size was the best choice.