The blue gum chalcid, Leptocybe invasa Fisher ＆ La Salle, invaded China in 2007 and has subsequently caused substantial damage to eucalyptus trees. In the current paper, we investigated the susceptibility of 10 Eucal...The blue gum chalcid, Leptocybe invasa Fisher ＆ La Salle, invaded China in 2007 and has subsequently caused substantial damage to eucalyptus trees. In the current paper, we investigated the susceptibility of 10 Eucalyptus spp. and Eucahetus dunnii to L. invasa in the field, determined the density of galls as well as the gall volume on these tree species, and monitored the population dynamics of wasps in Hainan and Guangdong provinces of China. The order of susceptibility to L. invasa was Eucalyptus urophyllaxEucalyptus camaldulensis〉E, urophylla （coppices）〉Eucalyptus exserta〉 Eucalyptus grandisxE, urophylla in Hainan, and Eucalyptus propinqua〉Eucalyptus saligna〉E, exserta〉Eucalyptus microcorys〉Eucahetus dunnii〉E, camaldulensis〉Eucalyptus tereticornis〉Eucalyptus robust in Guangdong, China. Although L. invasa generally damages the midribs and petioles of young leaves and the tender bark of twigs of eucalyptus, galls were not observed on leaves of E. microcorys, E. camaldulensis, or E. dunnii. Gall volume significantly differed among the tree species, and gall volume and wasp number were positively correlated. In Dongfang, Hainan Province, the overwintering period of L. invasa emergencing through the year was from the end of December to March of the next year, and the number of population was the greatest on E. urophylla^E, camaldulensis, and the smallest on E. grandis E. urophylla. In Guangzhou, Guangdong Province, L. invasa hardly emerged in winter from December to June of the next year, and the population was the greatest on E. propinqua, and the smallest on E. microcorys.展开更多
Effects of entomopathogenic fungus Verticillium lecanii on biological characteristics and life table of Serangiumjaponicum, a predator of whiteflies against five different conidial concentrations （1 × 10^4, 1 &#...Effects of entomopathogenic fungus Verticillium lecanii on biological characteristics and life table of Serangiumjaponicum, a predator of whiteflies against five different conidial concentrations （1 × 10^4, 1 × 10^5, 1 × 10^6, 1 × 10^7, and 1 × 10^8 conidia/mL） were studied under laboratory conditions. The developmental periods for all immature stages （from eggs, 1 st, 2nd, 3rd, 4th instar nymph and pupae up to emergence） among the treatments were significantly different when compared to that of control, and the longest development period was observed as treated with 1 × 10^8 spore/mL. However, no significant difference on the percent survival of all immature stages was observed among the treatments and control. Also, there were no significantly different effects of V. lecanii on mean generation time, intrinsic rate, the finite rate of increase and longevity of S. japonicum among the treatments and control.展开更多
Entomopathogenic fungi have been used recently for the management ofwhite- fly （Bemisia tabaci） and diamondback moth （Plutella xylostella）. In previous studies, lsaria fumosoroseus has shown some potential to cont...Entomopathogenic fungi have been used recently for the management ofwhite- fly （Bemisia tabaci） and diamondback moth （Plutella xylostella）. In previous studies, lsaria fumosoroseus has shown some potential to control these insect pests. In this paper, the ef- fects of I. fitmosoroseus （strain PF0 l-N4） on the mortality, fecundity and other life table parameters were observed under laboratory conditions. As a first step, the susceptibility of second instars ofB. tabaci and P. xylostella was examined in dose-response experiments, which was followed by the studies on the effect of/. fumosoroseus on reproduction. Both B. tabaci and P. xylostella, were susceptible to I. fumosoroseus having median lethal con- centration values ofl.10 x 104 and 0.48 ~ 104 conidia/mL after 12 and 11 days treatment, respectively. The fungal infection significantly reduced the longevity and fecundity of B. tabaci. At 1 ~ 107 conidia/mL, a minimum average longevity of 9 days was observed as compared to 16.3 days for the control. Similar results were also observed in P. xylostella with an average longevity of 5.6 days as compared to 17.68 days in the control. In case of reproduction, the number of progeny produced by B. tabaci and P. xylostella decreased with an increase in conidial concentration, with the average values of 83.67 and 26.85, 10.92 and 225.51,112.08 and 31.02 eggs/female for control, 1 × 10^4 and 1 × 10^7 conidial/mL, respectively. There was a significant effect of L. fumosoroseus on intrinsic rate of natural increase.展开更多
基金supported by the Forest Special Fund of Guangdong Province for Technological Innovation Project, China(2010KJCX015-01)
文摘The blue gum chalcid, Leptocybe invasa Fisher ＆ La Salle, invaded China in 2007 and has subsequently caused substantial damage to eucalyptus trees. In the current paper, we investigated the susceptibility of 10 Eucalyptus spp. and Eucahetus dunnii to L. invasa in the field, determined the density of galls as well as the gall volume on these tree species, and monitored the population dynamics of wasps in Hainan and Guangdong provinces of China. The order of susceptibility to L. invasa was Eucalyptus urophyllaxEucalyptus camaldulensis〉E, urophylla （coppices）〉Eucalyptus exserta〉 Eucalyptus grandisxE, urophylla in Hainan, and Eucalyptus propinqua〉Eucalyptus saligna〉E, exserta〉Eucalyptus microcorys〉Eucahetus dunnii〉E, camaldulensis〉Eucalyptus tereticornis〉Eucalyptus robust in Guangdong, China. Although L. invasa generally damages the midribs and petioles of young leaves and the tender bark of twigs of eucalyptus, galls were not observed on leaves of E. microcorys, E. camaldulensis, or E. dunnii. Gall volume significantly differed among the tree species, and gall volume and wasp number were positively correlated. In Dongfang, Hainan Province, the overwintering period of L. invasa emergencing through the year was from the end of December to March of the next year, and the number of population was the greatest on E. urophylla^E, camaldulensis, and the smallest on E. grandis E. urophylla. In Guangzhou, Guangdong Province, L. invasa hardly emerged in winter from December to June of the next year, and the population was the greatest on E. propinqua, and the smallest on E. microcorys.
文摘Effects of entomopathogenic fungus Verticillium lecanii on biological characteristics and life table of Serangiumjaponicum, a predator of whiteflies against five different conidial concentrations （1 × 10^4, 1 × 10^5, 1 × 10^6, 1 × 10^7, and 1 × 10^8 conidia/mL） were studied under laboratory conditions. The developmental periods for all immature stages （from eggs, 1 st, 2nd, 3rd, 4th instar nymph and pupae up to emergence） among the treatments were significantly different when compared to that of control, and the longest development period was observed as treated with 1 × 10^8 spore/mL. However, no significant difference on the percent survival of all immature stages was observed among the treatments and control. Also, there were no significantly different effects of V. lecanii on mean generation time, intrinsic rate, the finite rate of increase and longevity of S. japonicum among the treatments and control.
文摘Entomopathogenic fungi have been used recently for the management ofwhite- fly （Bemisia tabaci） and diamondback moth （Plutella xylostella）. In previous studies, lsaria fumosoroseus has shown some potential to control these insect pests. In this paper, the ef- fects of I. fitmosoroseus （strain PF0 l-N4） on the mortality, fecundity and other life table parameters were observed under laboratory conditions. As a first step, the susceptibility of second instars ofB. tabaci and P. xylostella was examined in dose-response experiments, which was followed by the studies on the effect of/. fumosoroseus on reproduction. Both B. tabaci and P. xylostella, were susceptible to I. fumosoroseus having median lethal con- centration values ofl.10 x 104 and 0.48 ~ 104 conidia/mL after 12 and 11 days treatment, respectively. The fungal infection significantly reduced the longevity and fecundity of B. tabaci. At 1 ~ 107 conidia/mL, a minimum average longevity of 9 days was observed as compared to 16.3 days for the control. Similar results were also observed in P. xylostella with an average longevity of 5.6 days as compared to 17.68 days in the control. In case of reproduction, the number of progeny produced by B. tabaci and P. xylostella decreased with an increase in conidial concentration, with the average values of 83.67 and 26.85, 10.92 and 225.51,112.08 and 31.02 eggs/female for control, 1 × 10^4 and 1 × 10^7 conidial/mL, respectively. There was a significant effect of L. fumosoroseus on intrinsic rate of natural increase.
