Mulberry longicorn beetle, Apriona germari, has been reported to produce two endo-β-1,4-glucanases or AgEGases (accession Nos. Q6SS52 and Q5XQD1). AgEGase sequence contains catalytic motif (amino acid residues 37~48)...Mulberry longicorn beetle, Apriona germari, has been reported to produce two endo-β-1,4-glucanases or AgEGases (accession Nos. Q6SS52 and Q5XQD1). AgEGase sequence contains catalytic motif (amino acid residues 37~48), which is the characteristic of family Glycohydrolase 45 and is identified as the substrate binding site. The application of bioinformatics ap-proaches includes sequence analysis, structural modeling and inhibitor docking to relate the structure and function of AgEGases. We have dissected the sequence and structure of AgEGase catalytic motif and compared it with crystal structure of Humicola insolens endoglucanases V. The results show an involvement of sulfur containing amino acid residues in the active site of the enzyme. Cys residues and position of disulfide bonds are highly conserved between the two structures of endoglucanases of A. germari. Surface calculation of AgEGase structure in the absence of Cys residues reveals greater accessibility of the catalytic site to the substrate involving Asp42, a highly conserved residue. For the inhibition study, tannin-based structure was docked into the catalytic site of AgEGase using ArgusLab 4.0 and it resulted in a stable complex formation. It is suggested that the inhibition could occur through formation of a stable transition state analog-enzyme complex with the tannin-based inhibitor, as observed with other insect cellulases in our laboratory.展开更多
Larvae of Apriona germari （Hope）, found widely in China, cause serious damage to trees and are difficult to control. Since some biological control methods have not been applied effectively in the field, chemical con...Larvae of Apriona germari （Hope）, found widely in China, cause serious damage to trees and are difficult to control. Since some biological control methods have not been applied effectively in the field, chemical control methods are used widely. Because of low cost, no poisonous residues and relatively safe application, zinc phosphide sticks have been tested to control the larvae as a matter of urgency. However, there were no criteria about the dosage and use. Given the characteristics of larvae tunnels on triploid Populus tomentosa trees and the one-on-one way of using poison-fumigated sticks, the larvae were treated by three treatments with zinc phosphide sticks. The treatments are as follows： inserting one stick into the first hole of the tunnel from bottom to top （T1）, inserting a stick into each of the lowest two holes （T2） and inserting one stick into the first and third hole from bottom to top separately （T3）. We cleared the frass around the holes and on the ground before inserting the sticks and blocking every hole with mud for each treatment. After the fourth investigation was carried out, the larvae of CK were still active, and had caused serious damage and emanated fresh fi＇ass from old and new holes. Some larvae treated with T1 and T2 were in an intermediate state, but all of the larvae treated with T3 died completely and their old holes had healed. The results show that inserting zinc phosphide sticks （the extent of dispersion of the sticks was 20%） is a feasible method to control A. germari （Hope） larvae in triploid P. tomentosa of pulpwood trees. Because there were no statistically significant differences （p 〉 0.05） among the three treatments, we recommend that T1 should be used for economic efficacy.展开更多
Apriona germari larvae were obtained via sample collection in woodland and indoor rearing. In this study, larval instars were divided by Dyar＇s law, and the results showed that the larval stage of A. germari comprise...Apriona germari larvae were obtained via sample collection in woodland and indoor rearing. In this study, larval instars were divided by Dyar＇s law, and the results showed that the larval stage of A. germari comprised six instars, while the width of head capsule was the best instar-dividing structure. On the basis of instar division, tubercle numbers on the transverse furrow downside of first abdominal dorsal ambulatory ampullae, seta numbers of abdominal telson and lateral seta numbers of mandible were observed and statistically calculated. The accuracy of instar-dividing was verified by comparing with the Dyar＇s law. The coincidence rate of two instar-dividing results was 90. 47%. It is approved that the above morphological features could be used in instar division ofA. germari larvae.展开更多
The damage status of Apriona swainsoni （Hope） in Pingdingshan area is investigated combined with historical data, and the causes of heavy occurrence are analyzed. Moreover, according to production practice, it is pr...The damage status of Apriona swainsoni （Hope） in Pingdingshan area is investigated combined with historical data, and the causes of heavy occurrence are analyzed. Moreover, according to production practice, it is proposed that forecast of pests and annual control countermeasures are important for the control of A. swainsoni.展开更多
The reproduction characteristics of Aprostocetus prolixus, which is a new parasitioid on Apriona germarii, were studied. It demonstrated that the female adult can generate offspring by either sex reproduction or parth...The reproduction characteristics of Aprostocetus prolixus, which is a new parasitioid on Apriona germarii, were studied. It demonstrated that the female adult can generate offspring by either sex reproduction or parthenogenesis, but all the offspring were male if they were from the mode of parthenogenesis. The sex ratio, with investigating in nature, was 2.38∶1. The environmental conditions had notable influence on sex ratio, survival ratio and fecundity. Its sex ratio increased to 3.48∶1 by feeding complementary nutrition that adding with 20% honey. The temperature has great effect on Aprostocetus prolixus in terms of system research, of which adult longevity decreased with temperature from 17.5 ℃ to 35 ℃ and its ability of reproduction increased between 25 ℃ and 30 ℃ but the acme at 27.5 ℃. Without the feeding complementary nutrition, on the other hand, the female adult will both lose the ability of fecundity at the temperature below 17.5 ℃ and over 35 ℃. With humidity increasing from 40% to 80%, its fecundity increased significantly. It also showed that there was no significant influence of temperature on fecundity between the 4 ℃ to 8 ℃ when cold storage( i.e. the matured larvae for 90 d, the adults for 10 d and the host egg for 40 d).展开更多
Intestinal flora of 47 Apriona germari(Hope) larvae,collected from fields,had been isolated and identified.The results showed that the predominant bacteria were Staphylococcus.Its viable count was 7.63±0.21,and t...Intestinal flora of 47 Apriona germari(Hope) larvae,collected from fields,had been isolated and identified.The results showed that the predominant bacteria were Staphylococcus.Its viable count was 7.63±0.21,and the detection rate was 100%.Meanwhile,a strain of cellulose-utilizing bacterium was isolated from the fore-midgut fluid of A.germari larvae with the cellulose-congo red agar medium.The bacterium was tentatively identified as Cellulomonas.The detection rate of the cellulolytic bacterium was 23.40%,and the count was 3.84±0.54 approximately.Its contribution to the borer′s cellulose digestion needs further investigations.展开更多
本文对桑天牛卵长尾啮小蜂Aprostocetus prolixus LaSalle et Huang的寄主选择定位行为进行了系统研究。已有研究表明,寄主植物-寄主昆虫复合体释放的挥发物对寄生蜂有显著的引诱作用。为了查明寄主植物-寄主昆虫复合体中挥发性引诱物...本文对桑天牛卵长尾啮小蜂Aprostocetus prolixus LaSalle et Huang的寄主选择定位行为进行了系统研究。已有研究表明,寄主植物-寄主昆虫复合体释放的挥发物对寄生蜂有显著的引诱作用。为了查明寄主植物-寄主昆虫复合体中挥发性引诱物质的来源,对不同处理桑枝(正常桑枝、机械损伤桑枝、系统枝、桑天牛Apriona germari(Hope)咬食和产卵桑枝)、桑天牛虫粪及雌雄两性桑天牛所释放的挥发物分别进行了测定。结果显示:不同处理桑枝对寄生蜂都具有显著的引诱作用,而且产卵桑枝的引诱活性最大;桑天牛虫粪的气味对寄生蜂有引诱活性,而雌、雄桑天牛体表挥发物对寄生蜂的引诱效果不明显。桑天牛爬行痕迹对寄生蜂的微栖境接受行为没有影响,而桑天牛虫粪中的信息物质在寄生蜂的微栖境接受过程中起着重要作用。寄生蜂对产卵桑枝段的选择几率明显高于正常桑枝段和咬食桑枝段,而对不同植物上产卵刻槽的选择没有差异;刻槽表面存在着与此卵寄生蜂寄主识别相关的信息物质。展开更多
文摘Mulberry longicorn beetle, Apriona germari, has been reported to produce two endo-β-1,4-glucanases or AgEGases (accession Nos. Q6SS52 and Q5XQD1). AgEGase sequence contains catalytic motif (amino acid residues 37~48), which is the characteristic of family Glycohydrolase 45 and is identified as the substrate binding site. The application of bioinformatics ap-proaches includes sequence analysis, structural modeling and inhibitor docking to relate the structure and function of AgEGases. We have dissected the sequence and structure of AgEGase catalytic motif and compared it with crystal structure of Humicola insolens endoglucanases V. The results show an involvement of sulfur containing amino acid residues in the active site of the enzyme. Cys residues and position of disulfide bonds are highly conserved between the two structures of endoglucanases of A. germari. Surface calculation of AgEGase structure in the absence of Cys residues reveals greater accessibility of the catalytic site to the substrate involving Asp42, a highly conserved residue. For the inhibition study, tannin-based structure was docked into the catalytic site of AgEGase using ArgusLab 4.0 and it resulted in a stable complex formation. It is suggested that the inhibition could occur through formation of a stable transition state analog-enzyme complex with the tannin-based inhibitor, as observed with other insect cellulases in our laboratory.
基金supported by the National Project of ScienceTechnology for the 11th Five-Year Plan in China (Grant No. 2006BAD32B)the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT0607)
文摘Larvae of Apriona germari （Hope）, found widely in China, cause serious damage to trees and are difficult to control. Since some biological control methods have not been applied effectively in the field, chemical control methods are used widely. Because of low cost, no poisonous residues and relatively safe application, zinc phosphide sticks have been tested to control the larvae as a matter of urgency. However, there were no criteria about the dosage and use. Given the characteristics of larvae tunnels on triploid Populus tomentosa trees and the one-on-one way of using poison-fumigated sticks, the larvae were treated by three treatments with zinc phosphide sticks. The treatments are as follows： inserting one stick into the first hole of the tunnel from bottom to top （T1）, inserting a stick into each of the lowest two holes （T2） and inserting one stick into the first and third hole from bottom to top separately （T3）. We cleared the frass around the holes and on the ground before inserting the sticks and blocking every hole with mud for each treatment. After the fourth investigation was carried out, the larvae of CK were still active, and had caused serious damage and emanated fresh fi＇ass from old and new holes. Some larvae treated with T1 and T2 were in an intermediate state, but all of the larvae treated with T3 died completely and their old holes had healed. The results show that inserting zinc phosphide sticks （the extent of dispersion of the sticks was 20%） is a feasible method to control A. germari （Hope） larvae in triploid P. tomentosa of pulpwood trees. Because there were no statistically significant differences （p 〉 0.05） among the three treatments, we recommend that T1 should be used for economic efficacy.
基金Supported by Innovation Project of Graduate Education of Jiangsu Province(CXZZ11_0538)Project of Nanjing Construction Committee and the Administration Bureau of Dr.Sun Yat-sen's Mausoleum(200409)
文摘Apriona germari larvae were obtained via sample collection in woodland and indoor rearing. In this study, larval instars were divided by Dyar＇s law, and the results showed that the larval stage of A. germari comprised six instars, while the width of head capsule was the best instar-dividing structure. On the basis of instar division, tubercle numbers on the transverse furrow downside of first abdominal dorsal ambulatory ampullae, seta numbers of abdominal telson and lateral seta numbers of mandible were observed and statistically calculated. The accuracy of instar-dividing was verified by comparing with the Dyar＇s law. The coincidence rate of two instar-dividing results was 90. 47%. It is approved that the above morphological features could be used in instar division ofA. germari larvae.
文摘The damage status of Apriona swainsoni （Hope） in Pingdingshan area is investigated combined with historical data, and the causes of heavy occurrence are analyzed. Moreover, according to production practice, it is proposed that forecast of pests and annual control countermeasures are important for the control of A. swainsoni.
文摘The reproduction characteristics of Aprostocetus prolixus, which is a new parasitioid on Apriona germarii, were studied. It demonstrated that the female adult can generate offspring by either sex reproduction or parthenogenesis, but all the offspring were male if they were from the mode of parthenogenesis. The sex ratio, with investigating in nature, was 2.38∶1. The environmental conditions had notable influence on sex ratio, survival ratio and fecundity. Its sex ratio increased to 3.48∶1 by feeding complementary nutrition that adding with 20% honey. The temperature has great effect on Aprostocetus prolixus in terms of system research, of which adult longevity decreased with temperature from 17.5 ℃ to 35 ℃ and its ability of reproduction increased between 25 ℃ and 30 ℃ but the acme at 27.5 ℃. Without the feeding complementary nutrition, on the other hand, the female adult will both lose the ability of fecundity at the temperature below 17.5 ℃ and over 35 ℃. With humidity increasing from 40% to 80%, its fecundity increased significantly. It also showed that there was no significant influence of temperature on fecundity between the 4 ℃ to 8 ℃ when cold storage( i.e. the matured larvae for 90 d, the adults for 10 d and the host egg for 40 d).
文摘Intestinal flora of 47 Apriona germari(Hope) larvae,collected from fields,had been isolated and identified.The results showed that the predominant bacteria were Staphylococcus.Its viable count was 7.63±0.21,and the detection rate was 100%.Meanwhile,a strain of cellulose-utilizing bacterium was isolated from the fore-midgut fluid of A.germari larvae with the cellulose-congo red agar medium.The bacterium was tentatively identified as Cellulomonas.The detection rate of the cellulolytic bacterium was 23.40%,and the count was 3.84±0.54 approximately.Its contribution to the borer′s cellulose digestion needs further investigations.
