The Basic Reseach On Progation And Utilization For Stethorus (Allosstethorus) Parapauperculus Pang

To obtain the optimal food and plants for artificial propagation of Stethorus(Allosstethorus)parapauperculus Pang,and clarify its control effciency,in this study,the food and plants were selected for artificial propagation of S.(Allosstethorus)parapauperculus,and the foraging behaviors of S.(Allosstethorus)parapauperculus were systematically observed,and the perdation efficiencies of S.(Allosstethorus)parapauperculus on different stages of Tetranychus cinnabarinus were compared under different hunger levels.The results were shown as follows:1.Selection of S.(Allosstethoms)parapauperculus on different food and foraging behaviorsThere was randomness in the selection of S.(Allosstethorus)parapauperculus on T.cinnabarinus,Tetrancychus piercei,Paunonychus citri,Oligonychus mangiferus and Eotetranychus sexmaculatus.The mean feeding amounts of S.(Allosstethorus)parapauperculus on different mites were listed as follows:7.30,7.50,10.90,12.00 and 17.12 individuals.And there were no significant differences between each selection.There were significant differences in the mean feeding amounts of S.(Allosstethorus)parapauperculus on T.cinnabarinus eggs,larva,nymphs and adults,which were 23.2,15.8,10.5 and 8.0 individuals per day,respectively.The foraging behaviors of S.(Allosstethorus)parapauperculus included seven parts,which were searching,capturing,chewing,teasing,spreading wings,resting and excreting,respectively.2.Observation of the growth increment and storability of different plants and the selectivity of S.(Allosstethorus)parapauperculus to these plantsThere were differences in the duration for germination,stem height,leaf number and leaf area between four plants.Kidney beans germinated faster than the other three,and its stem height and grown leaf number are more than the other three at the 60th day after planting.But its mean single leaf area was the smallest,which was 31.73 cm2.The preservation time of in vitro leaves without mites were longer than those with mites in the same plants.The storability of different plant leaves without mites were as follows from high to low:cassava,kidney beans,eggplant and papaya.Under the condition of mites existing,the preservation time of in vitro leaves of cassava was the longest,followed by kidney beans,papaya and eggplant,which bad no significant differences.In addition,under the condition of on mites and mites existing,the highest selection ratios of S.(Allosstethorus)parapauperculus occurred on cassava,which were 45%and 58%,respectively.And the lowest ratios occurred on eggplant.3.Effects of different plants on the development and survival of S.(Allosstethorus)parapauperculusThere were differences on the developmental duration and survival of S.(Alosstethorus)parapauperculus between different plants.The shortest generation development duration of S.parapauperculus occurred on cassava,which was 20.51 d,and the longest occurred on eggplant,which is 25.54 d.S.(Allosstethorus)parapauperculus could not complete generation development on kidney beans.The generation survival rates of S.(Allosstethorus)parapauperculus on different plants were listed from high to low as follows:cassava,papaya,eggplant,which indicated that cassava was more advantageous to the growth and survival of S.(Allosstethorus)parapauperculus than others.4.Predation efficiency of S.(Allosstethorus)parapauperculus on T.cinnabarinusS.(Allosstethorus)parapauperculus was doing better in the predation on every instar of T.cinnabarinus under different hunger levels.With prey density increasing,the feeding amounts of S.(Allosstethorus)parapauperculus increased.The predation of S.(Allosstethorus)parapauperculus was significantly influenced by the degrees of hunger.The mean feeding amounts were listed from high to low as follows:48h after hunger,24h after hunger,no hunger.The Holling-II model could satisfactorily reflecting the feeding condition of S.(Allosstethorus)parapauperculus on every instars of T.cinnabarinus under different hunger levels.Taking the instantaneous attack rate(a')and the processing time(Th)as evaluation index,the predation effectiveness of S.(Allosstethorus)parapauperculus(a'/Th)reached the highest at 48h after hunger;in the same hunger condition,the predation efficiency of S.(Allosstethorus)parapauperculus on every instars of T.cinnabarinus were as follows from high to low:eggs,larva,nymphs,adults.There were competition and mutual interference between S.(Allosstethorus)parapauperculus individuals within certain space range.The Hassell-Varley model could satisfactorily reflect the different degrees of S.(Alosstethorus)parapauperculus interference by its density when feeding on every instar of T.cinnabarinus.In the same density,the hunger treatment can increase the exploring ability and predatory amount of S.(Allosstethorus)parapauperculus on T.cinnabarinus to certain extent,and the predation effectiveness of S.(Allosstethorus)parapauperculus reached the highest at 48h after hunger.In the same hunger level,predatory efficiency decreased and the interference effect increased with the density of S.(Allosstethorus)parapauperculus.