Study On The Effects Of Tempreture And Prey Species On Development And Reproduction Of Orius Minutus's Population Growth

Orius minutus(Linnaeus)(Heteroptera:Anthocoridae)is a valuable natural enemy.can prey on eggs and nymphs of spider mites,thrips,aphids,whiteflies and some other small insects[1-3],This paper studies the temperature and prey species on its growth and reproduction,and the cold storage conditions of the egg and the adult of O.minutus.Main conclusions are as follows:1.With Tyrophagus putrescentiae(Schrank)as the prey,at five constant temperature(15,20,25,30 and 35 ?)conditions,study the influence with temperature on development period,survival rate,adult fecundity and the population parameter of the O.minutus every insect state.Within the constant temperature ranging from 15 to 35 ?,The developmental duration of each stage of O.minutus larvae shortened as the temperature rose gradually,It needed 52.45 d to complete a life cycle at 15?,while it needed 14.85d at 35?.By the analysis of linear regression method,the developmental threshold temperature for O.minutus was 8.89 ?,and its effective cumulative temperature was 359.20 day-degree.The generation survival rate and the number of eggs laid per female reached the maximum at 25?,17.07%and 41 eggs laid per female adult,respectively.In addition,through a O.minutus population life table under different temperature,the population trend index was less than 1 at 15 and 35?,demonstrating that the mean population growth is negative;On the contrary.the population trend index was greater than 1 at 20?30? and reached the maximum(3.92)at 25?.The net reproductive rate,the intrinsic rate of increase and the finite rate of increase peaked at 25?.which were 3.32,0.04 and 1.04;respectively.The generation time of the population was the longest(57.76 d)at 15?,but was the shortest(17.50 d)at 35?.2.Under the condition of the temperature(25?).to study the influence on growth,reproduction and population parameter of O.minutu.s with feeded by T.putreseentiae,Brevicoryne brassicae,Tetranytrus cinnabarinus and apple pollen.Results show that feeding four kinds of food can complete development.Generation development period with B.brassicae to be shortest(15.50 d),with T.putrescentiae is longest(19.52 d).Adults get rate to highest with T.cinnabarinus,at 66.86%,the apple pollen breeding is lowest,at 14.17%.O.minutus when feeding pollen does not lay eggs,feed the single female average of the rest of the three kinds prey difference was not significant.Net proliferation rate and intrinsic growth rate highest raised with T.cinnabarinus,at 7.84 and 0.12,T.putrescentiae breeding get the lowest,which are 3.32 and 0.04.3.Set 4,7 and 10 ? of three different refrigeration temperature,in different refrigeration time for the study of the subject factor,study on the effect of O.minutus adult life survival,lay eggs,and refrigeration resistance of eggs and hatchability,preliminary has been clear about the refrigerated condition of O.minutus adult and eggs.Within 4?10?,short-term refrigeration(20d or less)does not affect the female adult reproductive capacity,the female life is prolonged,up to 29.90 d.At three temperature,egg hatching rate and decreased with the increase of the cold storage time.In the range of 4?10?,if the hatching rate to 80%for the standard,with 4 ? refrigerated 4 d,7 ? for 8 d and 10?for 14 d is most appropriate.