Intercropping maize with the prostrate variety of mungbean, Vigna radiata （L.） Wilczek which grows flat along the ground can increase parasitism of the eggs of the Asian corn borer, Ostrinia furnacalis （Guenée...Intercropping maize with the prostrate variety of mungbean, Vigna radiata （L.） Wilczek which grows flat along the ground can increase parasitism of the eggs of the Asian corn borer, Ostrinia furnacalis （Guenée）, a crucial insect pest of maize in China, by Trichogramma ostriniae Pang Chen. This study investigated the behavioural responses of T. ostriniae to plant volatiles emitted from whole plants, leaves, and flowers of prostrate and erect varieties of mungbean in a 4-armed olfactometer. Female parasitiods were significantly attracted to the odours from some varieties of prostrate mungbean when the visit duration and the number of visits were considered, but were not attracted to the odours from any erect varieties. The attractive odours were shown to emanate from the leaves, rather than from the flowers of prostrate mungbean plants. These results have implications for the augmentation of Trichogramma parasitoids in bio-control of O. furnacalis and other crop pests.展开更多
Plagiodera versicolora Laicharting is a highly damaging leaf beetle foraging on willow leaves.In willow germplasm collections,observation has shown that Salix suchowensis Cheng was severely foraged by this leaf beetle...Plagiodera versicolora Laicharting is a highly damaging leaf beetle foraging on willow leaves.In willow germplasm collections,observation has shown that Salix suchowensis Cheng was severely foraged by this leaf beetle while Salix triandra L.was damage free or only slightly damaged.Results of olfactometer bioassays show that the headspace volatiles from leaves of S.triandra significantly repelled adult beetles,suggesting that this species produces volatile repellents against P.versicolora.S.suchowensis had no effect on the beetles.Gas chromatography-mass spec-trometry was carried out to profile the headspace volatile organic compounds and 23 compounds from leaves of the alternate species in significantly different concentrations were detected.The effects of 20 chemical analogs on host discrimination were examined.Olfactory response to these chemicals showed that o-cymene,a S.suchowensis specific constituent,significantly attracted adult P.versicolora.In contrast,cis-3-hexenyl acetate,a constituent concentrated more in S.triandra than in S.suchowensis,significantly repelled beetles.Mixing o-cymene and cis-3-hexenyl acetate in comparable concentrations as in the volatiles of S.suchowensis demonstrated that the latter could mask the attracting effect of the former,causing a neutral response by adult beetles to leaves of S.suchowensis against clean air.In addition,chemical analogs have the same effect as plants when resembling volatile organic compounds in real samples.Two volatile metabolites were detected triggering host discrimination by one of the most damaging insect pests to host and non-host willows.The two metabolites are of considerable potential for use as olfactory signs in manag-ing the beetles.展开更多
The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation. However, the effects of Alternaria toxins on insects have just begun to be investigated. Bioacti...The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation. However, the effects of Alternaria toxins on insects have just begun to be investigated. Bioactivities of toxins from four strains of Altemaria alternata on Rosa chinensis and rose aphid Macrosiphum rosivorum were tested in the present study. At a concentration of 50.0 pg/ml, the crude extract （toxin） of strain 7484 was found not to be harmful to rose plants with excised leaf-puncture method （P≥0.079）, and rose plants showed enhanced resistance to rose aphids when this Altemaria toxin was sprayed on the plants （P≤0.001）. However, this toxin caused no detrimental effects on aphids in insecticidal bioassay at a concentration of 10.0 to 160.0 μg/ml （P≥0.096）. Therefore, the Alternaria toxin had significantly induced the resistance of rose plants against rose aphids, demonstrating that the resistance mechanism triggered by the Altemaria toxin in the rose plant may also be used by the plant to defend itself against insects. Further bioassays aimed to discover the olfactory responses of aphids to the toxin-induced volatiles of host plants. The aphids were significantly more attracted to both volatiles emitted and collected from control rose plants than to both volatiles emitted and collected from the toxin-treated rose plants （P≤0.014）. This result showed that the toxin-induced resistance related to the volatile changes of host plants.展开更多
Anoplophora glabripennis(Motsch.)is a wood-boring beetle that is native to China.For a long time,it caused great losses in the economy and ecology of northwest China.Attractants are often used to control insects.The v...Anoplophora glabripennis(Motsch.)is a wood-boring beetle that is native to China.For a long time,it caused great losses in the economy and ecology of northwest China.Attractants are often used to control insects.The volatiles emitted from the host plant play an important role for insects in finding their target.To explore the mechanism of selec-tivity to different host plants,the response of Anoplophora glabripennis to four different host plants was investigated,which included Acer negundo L.,Acer mono Maxim.,Acer truncatum Bunge.and Acer platanoides L.,and the com-pounds in the profiles of volatiles were identified from these species.The olfactory responses of Anoplophora glabripennis to the odors of different plants showed preference for certain host plants:Acer negundo,Acer mono and Acer truncatum.The attraction of Acer negundo and Acer mono was signifi-cantly different(p<0.05).The attraction of Acer negundo to the insects was stronger than to Acer mono.Acer platanoides neither attracted nor repelled the insects.Compounds in the profiles of volatiles from the above four species were identified and quantified by gas chromatography-mass spec-trometry(GC-MS)equipped with a CP-4020 termodesorp-tion and cold trap(TCT)device.The constituents of volatiles and the relative concentrations were different in the four host species.The amount of ketones,alcohols and aldehydes in the four plants showed the same order:Acer negundo<Acer mono<Acer truncatum<Acer platanoides,while that of alkanes and esters was quiet different:Acer negundo L.>Acer mono Maxim.>Acer truncatum Bunge.>Acer platanoides L..1-penten-3-ol,ocimene and trans-Germanylacetone were repellent to Anoplophora glabripennis.1-penten-3-ol and trans-gerranylacetone were identified in Acer platanoides,and Ocimene was the most attractive to Anoplophora glabripennis among these species.The extent of feeding damage caused by Anoplophora glabripennis differed among four species.The sequences was Acer negundo>Acer mono>Acer truncatum>Acer platanoides.The epidermal hairs of the four host plants revealed that the extent of damage was related to the physical characteristics of the host plants.展开更多
基金supported by the National Natural Sci-ence Foundation of China (39770513)the Coop-erative Research Project between the National Crop Ex-periment Station, Rural Development Administration,Republic of Korea and the Institute of Plant Protection,Chinese Academy of Agricultural Sciences, China
文摘Intercropping maize with the prostrate variety of mungbean, Vigna radiata （L.） Wilczek which grows flat along the ground can increase parasitism of the eggs of the Asian corn borer, Ostrinia furnacalis （Guenée）, a crucial insect pest of maize in China, by Trichogramma ostriniae Pang Chen. This study investigated the behavioural responses of T. ostriniae to plant volatiles emitted from whole plants, leaves, and flowers of prostrate and erect varieties of mungbean in a 4-armed olfactometer. Female parasitiods were significantly attracted to the odours from some varieties of prostrate mungbean when the visit duration and the number of visits were considered, but were not attracted to the odours from any erect varieties. The attractive odours were shown to emanate from the leaves, rather than from the flowers of prostrate mungbean plants. These results have implications for the augmentation of Trichogramma parasitoids in bio-control of O. furnacalis and other crop pests.
基金The work was supported by the National Natural Science Foundation of China(grants 31570662 and 31500533)It was also enabled by the priority academic program development at Nanjing Forestry University.
文摘Plagiodera versicolora Laicharting is a highly damaging leaf beetle foraging on willow leaves.In willow germplasm collections,observation has shown that Salix suchowensis Cheng was severely foraged by this leaf beetle while Salix triandra L.was damage free or only slightly damaged.Results of olfactometer bioassays show that the headspace volatiles from leaves of S.triandra significantly repelled adult beetles,suggesting that this species produces volatile repellents against P.versicolora.S.suchowensis had no effect on the beetles.Gas chromatography-mass spec-trometry was carried out to profile the headspace volatile organic compounds and 23 compounds from leaves of the alternate species in significantly different concentrations were detected.The effects of 20 chemical analogs on host discrimination were examined.Olfactory response to these chemicals showed that o-cymene,a S.suchowensis specific constituent,significantly attracted adult P.versicolora.In contrast,cis-3-hexenyl acetate,a constituent concentrated more in S.triandra than in S.suchowensis,significantly repelled beetles.Mixing o-cymene and cis-3-hexenyl acetate in comparable concentrations as in the volatiles of S.suchowensis demonstrated that the latter could mask the attracting effect of the former,causing a neutral response by adult beetles to leaves of S.suchowensis against clean air.In addition,chemical analogs have the same effect as plants when resembling volatile organic compounds in real samples.Two volatile metabolites were detected triggering host discrimination by one of the most damaging insect pests to host and non-host willows.The two metabolites are of considerable potential for use as olfactory signs in manag-ing the beetles.
基金supported by the Scientific and Technological Department(No.2008CD140)the Education Department(No.08z0027)of Yunnan Province in China
文摘The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation. However, the effects of Alternaria toxins on insects have just begun to be investigated. Bioactivities of toxins from four strains of Altemaria alternata on Rosa chinensis and rose aphid Macrosiphum rosivorum were tested in the present study. At a concentration of 50.0 pg/ml, the crude extract （toxin） of strain 7484 was found not to be harmful to rose plants with excised leaf-puncture method （P≥0.079）, and rose plants showed enhanced resistance to rose aphids when this Altemaria toxin was sprayed on the plants （P≤0.001）. However, this toxin caused no detrimental effects on aphids in insecticidal bioassay at a concentration of 10.0 to 160.0 μg/ml （P≥0.096）. Therefore, the Alternaria toxin had significantly induced the resistance of rose plants against rose aphids, demonstrating that the resistance mechanism triggered by the Altemaria toxin in the rose plant may also be used by the plant to defend itself against insects. Further bioassays aimed to discover the olfactory responses of aphids to the toxin-induced volatiles of host plants. The aphids were significantly more attracted to both volatiles emitted and collected from control rose plants than to both volatiles emitted and collected from the toxin-treated rose plants （P≤0.014）. This result showed that the toxin-induced resistance related to the volatile changes of host plants.
文摘Anoplophora glabripennis(Motsch.)is a wood-boring beetle that is native to China.For a long time,it caused great losses in the economy and ecology of northwest China.Attractants are often used to control insects.The volatiles emitted from the host plant play an important role for insects in finding their target.To explore the mechanism of selec-tivity to different host plants,the response of Anoplophora glabripennis to four different host plants was investigated,which included Acer negundo L.,Acer mono Maxim.,Acer truncatum Bunge.and Acer platanoides L.,and the com-pounds in the profiles of volatiles were identified from these species.The olfactory responses of Anoplophora glabripennis to the odors of different plants showed preference for certain host plants:Acer negundo,Acer mono and Acer truncatum.The attraction of Acer negundo and Acer mono was signifi-cantly different(p<0.05).The attraction of Acer negundo to the insects was stronger than to Acer mono.Acer platanoides neither attracted nor repelled the insects.Compounds in the profiles of volatiles from the above four species were identified and quantified by gas chromatography-mass spec-trometry(GC-MS)equipped with a CP-4020 termodesorp-tion and cold trap(TCT)device.The constituents of volatiles and the relative concentrations were different in the four host species.The amount of ketones,alcohols and aldehydes in the four plants showed the same order:Acer negundo<Acer mono<Acer truncatum<Acer platanoides,while that of alkanes and esters was quiet different:Acer negundo L.>Acer mono Maxim.>Acer truncatum Bunge.>Acer platanoides L..1-penten-3-ol,ocimene and trans-Germanylacetone were repellent to Anoplophora glabripennis.1-penten-3-ol and trans-gerranylacetone were identified in Acer platanoides,and Ocimene was the most attractive to Anoplophora glabripennis among these species.The extent of feeding damage caused by Anoplophora glabripennis differed among four species.The sequences was Acer negundo>Acer mono>Acer truncatum>Acer platanoides.The epidermal hairs of the four host plants revealed that the extent of damage was related to the physical characteristics of the host plants.
