土壤干旱胁迫对韭菜迟眼蕈蚊种群动态的影响

Effect of drought stress on the population dynamics of Bradysia cellarum

【目的】为明确土壤干旱胁迫对韭菜迟眼蕈蚊Bradysia cellarum Frey生长发育、繁殖和种群动态的影响。【方法】基于年龄-龄期两性生命表的理论,研究韭菜迟眼蕈蚊分别在土壤干旱条件下和土壤湿润条件下的生命表参数和繁殖力参数;通过成虫期干旱处理试验进一步验证干旱胁迫对迟眼蕈蚊种群的影响。【结果】土壤干旱处理后卵、1龄幼虫、2龄幼虫和蛹的发育历期显著长于土壤湿润处理(P<0.05);干旱处理的迟眼蕈蚊在土壤湿润条件下,单雌产卵量较湿润处理降低37.8%,净增殖率(R_(0))、内禀增长率(r)和周限增长率(λ)与湿润处理相比均显著降低(P<0.05)。成虫试验表明,土壤干旱条件下,在韭菜断口处获得汁液的成虫产卵率和产卵量分别为5%和1.30粒,显著低于土壤湿润处理的100%和85.50粒(P<0.05),而当成虫无法从韭菜断口处获取汁液时所产的卵不能孵化。【结论】干旱胁迫抑制了韭菜迟眼蕈蚊的种群数量,且在10%土壤相对含水量的干旱条件下种群无法生存。本试验为控水防治韭菜迟眼蕈蚊提供依据。

[Objectives]To determine the effect of drought stress on the growth,development,reproduction and population dynamics of Bradysia cellarum Frey.[Methods]Based on an age-stage,two-sex life table,the life table and fecundity parameters of B.cellarum were calculated under dry and wet soil conditions.The effects of drought stress were further verified using a drought treatment experiment during the adult stage.[Results]Drought treatment significantly prolonged the developmental duration of the egg,1st instar,2nd instar and pupal,stages relative to the control group(P<0.05).Furthermore,female fecundity was 37.8%less than that of the control group.The net reproductive rate(R_(0)),intrinsic growth rate(r)and limited growth rate(λ)were also significantly less in the drought treatment group than in the control(P<0.05).The oviposition rate and number of eggs laid by the drought treatment group were 5%and 1.30,respectively,significantly less than the corresponding values of 100%and 85.50 for the control group(P<0.05).Eggs failed to hatch when adults were unable to obtain juice from chives.[Conclusion]The population dynamics of B.cellarum are adversely affected by drought conditions and populations are unable to survive if the relative soil moisture content is 10%or less.These results provide a scientific basis for controlling B.cellarum through managing soil moisture content.