The entomopathogenic fungus Beauveria bassiana （Balsamo） Vuillemin and predatory mite Neoseiulus barked Hughes are effective biological control agents of Frankliniella occidentalis Pergande （Thysanoptera： Thripida...The entomopathogenic fungus Beauveria bassiana （Balsamo） Vuillemin and predatory mite Neoseiulus barked Hughes are effective biological control agents of Frankliniella occidentalis Pergande （Thysanoptera： Thripidae）, one of the most important pests of ornamentals and vegetables world-wide. Combined application of both may enhance control efficiency. The functional response for N. barked on the first instar larvae of western flower thrips which were infected by B. bassiana for 12 and 24 h in the laboratory （（25＋1）℃, （70＋5）% RH, L：D=16 h：8 h） was determined. The virulence of B. bassiana against the second instar and pupae of the thrips attacked by N. barked were also tested. The results showed that N. barked exhibited a Holling type II functional response on treated thrips. After having been treated with the fungus for 12 h and then offered to the predator, thrips were more vulnerable to be killed by N. barked. The second instar larvae and pupae of the thrips which had been attacked by predatory mites were markedly more susceptible to B. bassiana infection than normal thrips; the cumulative corrected mortality of B. bassiana of the second instar and pupae which were attacked by N. barked were 57 and 94%, respectively, compared to 35 and 80% in controls on the day 8. These findings highlight the potential use of B. bassiana in combination with N. barkeri to control F. occidentalis.展开更多
The effect of seven constant temperatures of 15, 20, 25, 27, 30, 35 and 37℃ on developmental time ofNeoseiulus barkeri Hughes were determined in laboratory conditions under 65% - 5% RH and a photoperiod of 12 ： 12 ...The effect of seven constant temperatures of 15, 20, 25, 27, 30, 35 and 37℃ on developmental time ofNeoseiulus barkeri Hughes were determined in laboratory conditions under 65% - 5% RH and a photoperiod of 12 ： 12 （L ： D） h on nymphal stages of Tetranychus urticae Koch. Total developmental time of females （from egg to adult emergence） at the above-mentioned temperatures was 26.59, 14.43, 6.32, 5.64, 4.59, 3.98 and 4.67 days, respectively. Developmental rate of the N. barkeri increased as temperature increased from 15 to 35℃, but declined at 37℃. A linear and two nonlinear models were fitted to developmental rate of immature stages ofN. barkeri to predict the developmental rate as a function of temperature, as well as to estimate the thermal constant （K） and critical temperatures （i.e., Tmin, Topt and Tmax）. The estimated values of the Tmin and K for total developmental time using the linear model were 12.07℃ and 86.20 degree-days （DD）, respectively. The Trnin and Tmax estimated by the Sharpe-Schoolfield-Ikemoto （SSI） model were 11.90℃ and 37.41℃, respectively. The estimated Topt for overall immature stage development ofN. barkeri by the Lactin and SSI models were 33.89℃ and 24.51℃, respectively. Based on the biological criteria of model evaluation, the linear and SSI models were found to be the best models for describing the developmental rate of overall immature stages of N. barkeri and estimating the temperature thresholds.展开更多
基金supported by the Special Fund for AgroScientific Research in the Public Interest, China (200903032)National Modern Agricultural Science and Technology City Industry of Beijing, China (Z121100001212006)
文摘The entomopathogenic fungus Beauveria bassiana （Balsamo） Vuillemin and predatory mite Neoseiulus barked Hughes are effective biological control agents of Frankliniella occidentalis Pergande （Thysanoptera： Thripidae）, one of the most important pests of ornamentals and vegetables world-wide. Combined application of both may enhance control efficiency. The functional response for N. barked on the first instar larvae of western flower thrips which were infected by B. bassiana for 12 and 24 h in the laboratory （（25＋1）℃, （70＋5）% RH, L：D=16 h：8 h） was determined. The virulence of B. bassiana against the second instar and pupae of the thrips attacked by N. barked were also tested. The results showed that N. barked exhibited a Holling type II functional response on treated thrips. After having been treated with the fungus for 12 h and then offered to the predator, thrips were more vulnerable to be killed by N. barked. The second instar larvae and pupae of the thrips which had been attacked by predatory mites were markedly more susceptible to B. bassiana infection than normal thrips; the cumulative corrected mortality of B. bassiana of the second instar and pupae which were attacked by N. barked were 57 and 94%, respectively, compared to 35 and 80% in controls on the day 8. These findings highlight the potential use of B. bassiana in combination with N. barkeri to control F. occidentalis.
文摘The effect of seven constant temperatures of 15, 20, 25, 27, 30, 35 and 37℃ on developmental time ofNeoseiulus barkeri Hughes were determined in laboratory conditions under 65% - 5% RH and a photoperiod of 12 ： 12 （L ： D） h on nymphal stages of Tetranychus urticae Koch. Total developmental time of females （from egg to adult emergence） at the above-mentioned temperatures was 26.59, 14.43, 6.32, 5.64, 4.59, 3.98 and 4.67 days, respectively. Developmental rate of the N. barkeri increased as temperature increased from 15 to 35℃, but declined at 37℃. A linear and two nonlinear models were fitted to developmental rate of immature stages ofN. barkeri to predict the developmental rate as a function of temperature, as well as to estimate the thermal constant （K） and critical temperatures （i.e., Tmin, Topt and Tmax）. The estimated values of the Tmin and K for total developmental time using the linear model were 12.07℃ and 86.20 degree-days （DD）, respectively. The Trnin and Tmax estimated by the Sharpe-Schoolfield-Ikemoto （SSI） model were 11.90℃ and 37.41℃, respectively. The estimated Topt for overall immature stage development ofN. barkeri by the Lactin and SSI models were 33.89℃ and 24.51℃, respectively. Based on the biological criteria of model evaluation, the linear and SSI models were found to be the best models for describing the developmental rate of overall immature stages of N. barkeri and estimating the temperature thresholds.
