Potato/Maize intercropping reduces infestation of potato tuber moth, Phthorimaea operculella(Zeller) by the enhancement of natural enemies

The potato tuber moth(PTM),Phthorimaea operculella(Zeller),is one of the most economically significant insect pests for potato in both field and storage worldwide.To evaluate the infestation,reduction of potato yield and the control efficacy for PTM,field tests were conducted in two seasons by intercropping of potato as the host plant with maize as a non-host plant of PTM.Three intercropping patterns were tested,which were 2 rows of potatoes with either 2,3,or 4 rows of maize(abbreviated 2 P:2 M,2 P:3 M,and 2 P:4 M),and the monocropped potato as the control,2 rows of potatoes,without maize,(abbreviated 2 P:0 M).Results showed that the population and infestation of PTM in the 2 P:3 M intercropping pattern was significantly lower than those in 2 P:2 M,2 P:4 M and the monocropping pattern of 2 P:0 M,due to the enhancement of natural enemies.Cumulative mines and tunneling in potato leaves in 2 P:3 M intercropping were significantly lower than those in 2 P:2 M and 2 P:4 M patterns.The population of parasitoids and the parasitism rate of PTM in intercropping pattern of 2 P:3 M were significantly higher than that in intercropping pattern of 2 P:2 M,2 P:4 M and monocropping pattern of 2 P:0 M.We conclude that the potato intercropped with maize reduced the adult and larva populations,and reduced the damage from PTM by enhancing the number of parasitoids and the level of parasitism.The greatest population density of parasitoids and parasitism rate were in the intercropping pattern of 2 rows of potatoes with 3 rows of maize.These data indicate that the host/non-host intercropping patterns can be used as a biological control tactic against PTM by enhancing the density of natural enemies in the agro-ecosystems.

Optimization of the sex pheromone-based method for trapping field populations of Phthorimaea operculella(Zeller)in South China

Despite the identification of the potato tuber moth Phthorimaea operculella(Zeller)sex pheromone,no effective application based on this pheromone has yet been developed and evaluated.This study investigated the effect of pheromone lures,trap densities,heights of trap deployment,and pheromone doses in Yunnan,China,for the purpose of increasing the control efficiency of P.operculella and improving the application of pheromone technology in the field.The results showed that lures made of corn oil and red PVC pipes attracted the highest number of moths(11.73±1.90 per trap per day).Sex pheromone loading of 100μg was optimal for trapping moths,but higher doses of pheromone inhibited attraction.The density of traps did not affect capture rates;therefore,the optimum trap density was 30–40 traps ha^(–1).The optimum height of trap deployment was not above the height of the plant canopy.This study provides technical details necessary for the monitoring and control of potato tuber moth using sex pheromones.

Spatial distribution and sampling of larvae of Phthorimaea operculella(Zeller) and its harmfulness

Studies in tobacco fields were conducted in 1993. The results showed that the distribution pattern of the larva was aggregative,and the aggregation did not change with the densities of population of the larva. The characteristics of the vertical distribution of the larva on tobacco plants was more in the lower leaves than in the upper. The difference of population density among the tobacco fields with an elevation of 490 meters and 900 meters was not significant. The number of sampling was given under different precisions by using two-stage sampling technique. The average of leaf area loss caused by the larva in tobacco fields was 12.654 cm2.

马铃薯块茎蛾取食胁迫下马铃薯根际土壤微生物代谢功能多样性变化

为研究昆虫取食胁迫对植物根际土壤微生物群落功能多样性的影响,采用Biolog ECO技术研究了马铃薯块茎蛾取食胁迫对云南省2个马铃薯主栽品种(合作88、丽薯6号)根际土壤微生物群落多样性以及土壤碳源利用的影响,以未受虫害胁迫为空白对照。结果显示,马铃薯块茎蛾取食胁迫提高了衡量根系微生物代谢活性的平均颜色变化率(AWCD,96 h),即取食胁迫处理下2个马铃薯品种根际土壤微生物对31种碳源利用的AWCD值均提高,且在取食胁迫第7天达到最大;同时,取食胁迫处理下2个马铃薯品种根际微生物的多样性Shannon和Simpson指数均高于对照,且在取食胁迫第7天达到最高;对其碳源利用的分析表明,在取食胁迫下,2个马铃薯品种的根际微生物对6类碳源的利用率不同,但2个品种胁迫处理均提高了根际微生物对各类碳源的利用;另外,主成分分析表明,取食胁迫处理改变了2个马铃薯品种根系微生物的群落结构。综合以上结果表明,马铃薯块茎蛾取食胁迫能提高马铃薯根际土壤微生物群落的功能多样性。

马铃薯块茎蛾取食胁迫对马铃薯根际细菌群落结构与多样性的影响

【目的】探究马铃薯块茎蛾取食胁迫对马铃薯根际细菌群落结构与多样性的影响,系统解析植物—害虫—根际微生物互作效应,为筛选和利用马铃薯根际有益微生物提供参考依据。【方法】在室内以盆栽马铃薯品种合作88为试验材料,对马铃薯苗期、块茎形成期、淀粉积累期和成熟期4个生育期根际细菌组成结构及多样性进行分析,同时于马铃薯苗期第5枝侧枝伸长时接种马铃薯块茎蛾3龄幼虫取食胁迫处理,以不接虫为对照处理与对照分别于12、24、36和48 h时采集根际土壤,通过Mothur对4个生育期及苗期不同取食胁迫时间和对照的马铃薯根际细菌群落进行α多样性分析和主成分分析;使用MEGA7.0基于细菌16S r RNA序列相似性对丰度排名前20的菌株进行序列比对并构建系统发育进化树,利用PICRUSt1对根际细菌16S rRNA进行功能预测。【结果】马铃薯成熟期根际细菌物种ACE和Chao1指数显著高于其他3个时期(P<0.05,下同)。马铃薯块茎蛾取食胁迫后,马铃薯根际细菌群落主要优势菌门排序为放线菌门>变形菌门>绿弯菌门>酸杆菌门>厚壁菌门,其中放线菌门相对丰度在胁迫12、24、36和48 h时分别增加7.91%、26.54%、21.56%和2.97%,取食胁迫增加了变形菌门和拟杆菌门的相对丰度,降低了酸杆菌门的相对丰度;在属水平上,取食胁迫后,马铃薯根际细菌节杆菌属相对丰度在胁迫后12、24、36和48 h时较CK分别增加137.39%、113.58%、93.12%和61.87%,取食胁迫增加了鞘氨醇单胞菌属的相对丰度,降低了norank_f_norank_0_Vicinamibacterales和norank_f_Vicinamibacteraceae的相对丰度。主成分分析结果表明马铃薯根际细菌微生物对照组和处理组明显分离;系统发育进化树结果显示相对丰度前20的菌株隶属于放线菌门、绿弯菌门、厚壁菌门、酸杆菌门和芽单胞菌门;COG注释的功能分类有24个,其中氨基酸转运和代谢功能最为富集。【结论】马铃薯块茎蛾取食胁迫引起马铃薯根际细菌群落结构及相对丰度发生变化,其中放线菌门及节杆菌属细菌相对丰度变化最显著。

马铃薯块茎蛾肠道细菌分离鉴定及其对植物源大分子化合物的降解作用

为弄清马铃薯块茎蛾肠道可培养细菌的群落结构及其功能。本研究采用牛肉膏蛋白胨培养基,对马铃薯块茎蛾4龄幼虫肠道细菌进行了分离培养,采用16S r DNA序列对各菌株进行种属鉴定,并采用酶鉴定培养基法测定了肠道各细菌对淀粉、纤维素、木聚糖和果胶等植物源大分子物质的降解作用。从马铃薯块茎蛾肠道内共分离到细菌8属10种,分别为不动杆菌属Acinetobacte、葡萄球菌属Staphylococcus、肠杆菌属Enterobacter、节细菌属Arthrobacter、鞘氨醇杆菌属Sphingobacterium、寡养单胞菌属Stenotrophomonas、束村氏菌属Tsukamurella和克雷白氏杆菌属Klebsiella。其中仅鞘氨醇杆菌属菌株LZD10、阿氏节杆菌属菌株LZN13、烟草节杆菌属菌株HZN9对淀粉具有明显的降解作用,但对纤维素、木聚糖和果胶无降解作用,而其余菌株对4种化合物均无降解作用。该研究结果将为深入研究马铃薯块茎蛾对马铃薯块茎的食物适应机制及防治提供理论依据。

白僵菌对马铃薯块茎蛾致病力的测定

在国内首次进行白僵菌对马铃薯块茎蛾致病力的测定。用7个分离自本地的球孢白僵菌菌株和一株从CIP引进的布氏白僵菌对马铃薯块茎蛾幼虫的致病力作了室内测定。实验表明,菌株XW0108001对马铃薯块茎蛾幼虫有较强的致死率;在108个/mL孢子浓度下,其校正死亡率达89 4%,毒力回归方程为:y=0 366x+3 409((R=0 956),剂量效应的LC50=2 24×104孢子/mL 每毫升含107个孢子的时间效应的LT50为4 3d。

球孢白僵菌对马铃薯块茎蛾的毒力及其与常用农药的生物相容性测定

室内测定了从云南分离的7株球孢白僵菌对马铃薯块茎蛾幼虫的毒力,结果表明,在接菌孢子浓度为105个/mi和107个/mL下,接种后7d马铃薯块茎蛾幼虫累积死亡率分别为23.3%～70.0%和33.3%～86.7%,添加吐温80的清水对照死亡率仅为3.3%.筛选出毒力较高的Eb7001、Bb7004、Bb8001 3个菌株,其中菌株1b8001对马铃薯块茎蛾幼虫的毒力最高,在孢子浓度1×105、1×107个/mi下,第7天的累计死亡率分别为70.0%和86.7%,其毒力回归方程Y=0.366X+3.409(R=0.956),剂量效应LC50=2.24×104个/mL,孢子浓度107个/mL下的LT50为4.3do测定了毒力较高的菌株与12种农药的生物相容性,结果表明在供试农药推荐用量及其10、100倍稀释液下,球孢白僵菌Eb7001、Bb7004、Bb8001的3个菌株孢子在含所选农药的营养液中生物相容性良好的农药有:苏云金芽孢杆菌可湿性粉剂(Bt)、10%吡虫啉可湿性粉剂、2.5%菜喜悬浮剂及松毛虫病毒可湿粉剂,可配伍使用;而阿维菌素、农安、卡死克、抑太保对球孢白僵菌有很强的抑制作用,应避免配伍使用.

马铃薯块茎蛾综合防治技术

随着气候变暖,以及马铃薯、烟草、蔬菜的扩大种植,马铃薯块茎蛾危害加重,成为阻碍马铃薯产业发展的主要虫害之一,本文从马铃薯栽培防治、贮存防治两个方面,通过种薯选择、化学防治、生物防治、田间管理等措施,总结了马铃薯块茎蛾的综合防治技术,希望对马铃薯块茎蛾的防治有所帮助。

滇杨叶片提取物对马铃薯块茎蛾产卵选择性的影响

[目的]探讨滇杨叶片提取物对马铃薯块茎蛾产卵行为的影响。[方法]在室内利用选择性产卵试验方法分别测定了新鲜及萎蔫滇杨叶片的5种质量浓度(375～6000 g/L)的二氯甲烷提取物对马铃薯块茎蛾产卵选择性的影响。[结果]试验结果表明:不同质量浓度的新鲜滇杨叶片和萎蔫的滇杨叶片的二氯甲烷提取物均对马铃薯块茎蛾的产卵具有显著的抑制作用。对马铃薯块茎蛾产卵的抑制效果随浓度的升高而增强。