Behavioral responses of potato tuber moth (Phthorimaea operculella) to tobacco plant volatiles

Potato tuber moth(PTM)Phthorimaea operculella,also known as tobacco splitworm,is an important pest of tobacco plants.The knowledge on the interaction of tobacco plant volatiles and PTM behavior is limited.To clarify the effect of tobacco plant volatiles on the orientation and oviposition behaviors of PTM and to identify potential compounds for PTM control,tobacco plant volatiles were collected by headspace collection method,and volatile compounds were identified by gas chromatography-mass spectrometry.Thirteen electrophysiological active compounds were screened by employing coupled gas chromatography-electroantennogram detection and from which nine available compounds were further verified by electroantennogram recording.cis-3-Hexen-1-ol showed significant attractant effect on the orientation behaviors of both male and female moths.Nonanal and decanal could only attract females,while octanal exhibited repellent effect on males.Oviposition selection experiment indicated that nonanal,decanal,decane and methyl hexadecanoate could stimulate the gravid females to lay more eggs,while octanal and 2,6-bis(1,1-dimethylenthyl)-4-methyl phenol inhibited their oviposition.Our study added more compounds to the list that could serve as potential PTM deterrents or attractants.

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.

Potential of Steinernema carpocapsae(Weiser) as a biological control agent against potato tuber moth, Phthorimaea operculella(Zeller)(Lepidoptera: Gelechiidae)

The entomopathogenic nematode,Steinernema carpocapsae,was evaluated for control of the potato tuber moth,Phthorimaea operculella,under laboratory conditions.We evaluated different concentrations of S.carpocapsae for control of 2 nd,3 rd,and 4 th instar P.operculella.The median lethal concentration(LC50)of S.carpocapsae infective juveniles(IJs)to 2 nd,3 rd and 4 th instar larvae of P.operculella was 200,363,181 IJs mL–1,respectively.With the extension of treatment time,the cumulative mortality increased for 2 nd,3 rd,and 4 th instar larvae and pupae of P.operculella.Fourth instars were the most susceptible for all observation periods.Therefore,our results suggest that S.carpocapsae could be an effective biological control agent for P.operculella.

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.

Establishment of Beauveria bassiana as a fungal endophyte in potato plants and its virulence against potato tuber moth, Phthorimaea operculella (Lepidoptera: Gelechiidae)

The potato tuber moth,Phthorimaea operculella,is the most damaging potato pest in the world and is difficult to control as the larvae are internal feeders in the foliage and tubers.Entomopathogenic fungi that colonize plants as endophytes have lethal and sublethal pathological effects on insect pests.We show that Beauveria bassiana colonizes the aerial parts of potato plants endophytically after inoculation through soil drenching.Endophytic B.bassiana persisted in potato foliage for more than 50 days postinoculation.Bioassays indicated that foliage of B.bassiana-inoculated potato plants were pathogenic against larvae of P operculella.Sublethal experiments indicated that B.bassiana negatively affected the growth,development,and reproduction of P operculella.Development experiments showed that the weight of P.operculella pupae reared on B.bassianacolonized potato plants(4.25 mg)was significantly less than that of those reared on uninoculated control plants(8.89mg).Compared with newly eclosed larvaefed on control plants,those fed on B.bassiana-inoculated plants had significantly lower survivorship,with only 17.8%developing to the adult stage.Oviposition of P operculella females reared on B.bassiana endophytically colonized plants was significantly lower(35 eggs/female)than of those reared on uninoculated plants(115 eggs/female).This study demonstrates that endophytic B.bassiana can be a potential biological control agent for the control and management of P operculella.Comparing pupal weights of P operculella reared on potato plants inoculated with the B.bassiana strain GZGY-1-3 and on untreated control plants,pupae from the control plants were significantly heavier than those from treated plants.

马铃薯块茎蛾取食胁迫对马铃薯根际可培养细菌物种多样性和群体多度的影响

【目的】通过根际可培养细菌多样性研究马铃薯对马铃薯块茎蛾(Phthorimaea operculella)取食胁迫的生理响应,为植物—蛀食性害虫—根际微生物互作效应及马铃薯块茎蛾的防治提供科学依据。【方法】室内盆栽青薯9号马铃薯,接种马铃薯块茎蛾3龄幼虫,分别于取食胁迫3、7和14 d时对马铃薯根际土壤进行取样,采用LB培养基分离培养根际土壤细菌,结合细菌形态特征及16S rRNA测序法鉴定细菌种类,分析可培养细菌的组成结构及多样性。【结果】马铃薯块茎蛾取食胁迫改变了马铃薯根际土壤细菌群落的组成结构及多样性,其中,胁迫3 d时马铃薯根际土壤细菌较对照多3种[海水罗塞略莫拉氏菌(Rossellomorea aquimaris)、长孢黄色链霉菌(Streptomyces longisporoflavus)和阿尔及利亚微杆菌(Microbacterium algeriense)];胁迫7 d时,较对照多2种[稻壳罗塞略莫拉氏菌(R.oryzaecorticis)和马氏副球菌(Paracoccus marcusii)];胁迫14 d时,较对照多2种[产吲哚金黄杆菌(Chryseobacterium indologenes)和布鲁氏菌根瘤菌(Brucella rhizospha)]。马铃薯块茎蛾取食胁迫后马铃薯根际可培养细菌的相对多度发生变化,其中在胁迫第3天变化程度达到最大。在取食胁迫3、7和14 d时,放线菌门(Actinobacteria)细菌相对多度分别增加23.49%、12.56%和28.06%,节杆菌属(Arthrobacter)相对多度分别增加103.50%、65.37%和28.57%。【结论】马铃薯块茎蛾取食胁迫可影响马铃薯根际细菌群落的物种组成结构及多样性,其中节杆菌属细菌的相对多度明显增加。研究结果为马铃薯根际对害虫取食胁迫的响应及马铃薯根际功能细菌的筛选提供基础。

马铃薯块茎蛾取食诱导的马铃薯防御反应

为探究马铃薯在应答马铃薯块茎蛾Phthorimaea operculella取食时相关抗虫指标的动态变化,本研究以‘青薯9号’‘合作88’‘米拉’3个马铃薯品种为材料进行室内盆栽试验,在马铃薯块茎蛾取食0、3、6、12、24、48、72、96 h时取样测定各品种生理指标。结果表明,被马铃薯块茎蛾取食的叶片中过氧化氢酶、多酚氧化酶、萜烯合成酶活性,单宁和类黄酮含量与对照相比都有不同程度的显著升高,总氨基酸含量显著下降,且各指标在马铃薯品种之间存在差异。从各指标平均增降率来看,‘合作88’对马铃薯块茎蛾取食的响应程度要强于‘青薯9号’和‘米拉’‘米拉’的响应程度最小。本研究为进一步明确马铃薯抗虫生理防御机制和害虫综合防治提供理论依据。

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。

马铃薯应对马铃薯Y病毒与非介体昆虫胁迫的植物激素水平和基因表达变化

马铃薯Y病毒(potato virus Y,PVY)及其非介体昆虫马铃薯块茎蛾(Phthorimaea operculella)是世界马铃薯产业的重要病虫害,为探究PVY是否影响马铃薯对马铃薯块茎蛾的生理响应,本研究分析了马铃薯块茎蛾在PVY侵染和健康对照植株上的生长表现,并对无病虫害、PVY侵染、模拟虫害处理(用马铃薯块茎蛾口腔分泌物涂抹),以及PVY侵染和模拟虫害协同处理的植株叶片进行了植物激素测定和比较转录组分析。结果显示:马铃薯感染PVY后对马铃薯块茎蛾的抗性显著提高;PVY侵染可抑制模拟虫害造成的脱落酸含量上升;与健康对照组相比,模拟虫害和PVY侵染处理分别诱导产生3998个和104个差异表达基因,而两者协同处理可诱导产生9178个差异表达基因,说明这2种胁迫共存对马铃薯产生了极大的生理影响。与模拟虫害处理相比,PVY侵染和模拟虫害协同处理诱导产生743个差异表达基因,而这些基因主要富集在转移酶活性、内质网中蛋白质加工、苯丙素生物合成等通路中,而脱落酸合成通路中众多基因表达下调,与该植物激素变化情况一致。综上所述,本研究系统分析了马铃薯应对PVY侵染、马铃薯块茎蛾模拟虫害以及两者协同处理的生理反应,为探究“植物-病毒-非介体昆虫”三者互作提供了科学依据。

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。

庚醛与桉叶油醇组合对马铃薯块茎蛾产卵选择的影响

马铃薯块茎蛾（Phthorimaea operculella）是世界上为害马铃薯最严重的害虫之一,本研究利用桉叶油醇与庚醛驱避-引诱组合对其产卵行为进行调控,以探究最佳驱避-引诱组合规律及影响因素。在室内条件（27±1℃,L∥D=14h∥10h,RH：50%~70%）测定了桉叶油醇与庚醛单组分及两种组分驱避-引诱组合对马铃薯块茎蛾产卵选择的影响。桉叶油醇在6~12mg/L浓度范围内对马铃薯块茎蛾表现为产卵引诱作用,在18~30mg/L浓度范围内则表现为产卵驱避作用;庚醛在6~30mg/L浓度范围内对马铃薯块茎蛾表现为产卵驱避效果。将对马铃薯块茎蛾产卵行为引诱效果较好的桉叶油醇（3,6,12 mg/L）与驱避效果较好的庚醛（12,18,24mg/L）进行引诱-驱避组合,12mg/L庚醛与3mg/L桉叶油醇push-pull组合效果最好,push-pull效应达36.6%。对马铃薯块茎蛾产卵行为调控最佳的驱避-引诱组合为最低驱避浓度（12mg/L庚醛）与最低引诱（3mg/L桉叶油醇）浓度组合。产卵选择指数和push-pull效应与交配率、单雌产卵量不具有相关性,但是浓度变化可以导致交配率和单雌产卵量的变化。

马铃薯块茎蛾对几种茄科植物的嗜食性研究

在单寄主和多寄主不同选择压力下,进行了马铃薯块茎蛾对马铃薯、烟草、番茄、茄子、辣椒、蔓陀萝、龙葵7种茄科寄主植物的嗜食性研究。结果表明,在单寄主或多寄主选择压力下受害最严重的是烟草和马铃薯,其次是茄子、曼陀罗、番茄和辣椒,但对龙葵不危害;马铃薯块茎蛾对寄主有较明显的选择性,在供试的7种茄科植物中,烟草、马铃薯、茄子为最敏感寄主植物（PI〉0.2）,为马铃薯块茎蛾嗜食作物,曼陀罗、番茄为次敏感寄主植物（0.2〉PI〉0.1）,辣椒、龙葵为不敏感寄主植物（PI〈0.1）。在相同条件下用上述几种寄主作物饲养马铃薯块茎蛾完成1个世代的历期差异较大,马铃薯为32～40 d、烟草为28～37 d、茄子为30～40 d、曼陀罗为35～45 d、番茄为35～45 d,辣椒苗、龙葵饲养未能完成世代。

3种植物提取物对马铃薯块茎蛾产卵的抑制作用

通过室内试验测定了1种寄主植物烟草和2种非寄主植物滇杨、桉树叶的不同溶剂（石油醚、氯仿和乙醇）提取物，在0—72h对马铃薯块茎蛾的产卵抑制效果。结果表明，3种植物中均含有抑制马铃薯块茎蛾产卵的化学物质。烟草的石油醚提取物对雌虫无产卵抑制活性，乙醇提取物在0～24h表现出显著的产卵抑制活性，而氯仿提取物的产卵抑制活性可持续48h。滇杨叶的3种溶剂提取物均对马铃薯块茎蛾雌蛾表现出显著的抑制效果，但石油醚提取物的作用时间仅为24h，而氯仿与乙醇提取物的作用时间可达48h。桉树叶的3种溶剂提取物均在24h内对雌蛾表现出显著的产卵抑制效果，但氯仿提取物在24～48h内对雌蛾有显著的产卵促进作用。

植物次生代谢物烟碱对马铃薯块茎蛾生长发育的影响

以一种重要的检疫性害虫马铃薯块茎蛾Phthorimaea operculella(Zeller)为研究对象,连续5代用含有植物次生代谢物烟碱(Nicotine)的人工饲料分别饲养二龄和三龄幼虫,饲养至羽化时分别测定烟碱对马铃薯块茎蛾幼虫体重、发育历期和蛹重的影响。结果表明,烟碱处理后,幼虫发育延缓,显著抑制幼虫体重的增长。连续饲养5代,与对照相比,烟碱处理对二龄和三龄幼虫体重的抑制率分别从45%降至20%、32%降至17%;烟碱显著抑制马铃薯块茎蛾的蛹重,连续饲养5代后,与对照相比,烟碱处理二龄和三龄幼虫的蛹重抑制率分别从25%降至4%、28%降至5%;烟碱处理会延迟幼虫的生长发育,使得世代历期延长;而且烟碱对低龄幼虫的抑制作用更加明显。随着继代代数的增加,烟碱对幼虫体重和蛹重的抑制作用减小,幼虫发育期缩短,马铃薯块茎蛾世代历期缩短。本研究说明植物次生代谢物烟碱能够影响马铃薯块茎蛾的生长发育,经过一定世代后,马铃薯块茎蛾可以通过自身调节,逐渐提高对烟碱有毒物质的适应能力,逐步缓解有毒物质的抑制作用。

五种杀虫剂对烟草潜叶蛾的毒力测定

为筛选出有效的烟草潜叶蛾防治药剂,试验了5种药剂对烟草潜叶蛾卵及幼虫的毒力。研究结果表明,五种药剂对烟草潜叶蛾卵的毒力排序为三氟氯氰菊酯>溴氰菊酯>甲氨基阿维菌素苯甲酸盐>高效氯氰菊酯>氰戊菊酯;五种药剂对烟草潜叶蛾幼虫的毒力排序为三氟氯氰菊酯>溴氰菊酯>高效氯氰菊酯>氰戊菊酯>甲氨基阿维菌素苯甲酸盐。因此在防治中可选用三氟氯氰菊酯和溴氰菊酯对烟草潜叶蛾进行药剂防治。

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。

烟草潜叶蛾的过冷却点测定

为了明确烟草潜叶蛾的抗寒能力,对烟草潜叶蛾三龄幼虫、四龄幼虫和蛹的过冷却点分别进行了测定,初步明确了不同龄期、不同寄主植物和冷驯化等因素对其过冷却点的影响。结果表明:不同龄期下过冷却点由低到高排列顺序为蛹、三龄幼虫、四龄幼虫,其中蛹的过冷却点显著低于三龄、四龄幼虫。以烟草和马铃薯为寄主的蛹和四龄幼虫的过冷却点没有显著差异。经过冷驯化处理的四龄幼虫过冷却点低于未经冷驯化的对照组,但差异不显著;经过冷驯化的蛹的过冷却点高于对照组。本研究有助于了解烟草潜叶蛾的抗寒性及其越冬分布区域。

核桃叶粗提物对马铃薯块茎蛾产卵选择以及幼虫钻蛀性的影响

采用乙醇和二氯甲烷分别浸提核桃叶片,获得粗提物,并在室内测定了不同浓度粗提物溶液对马铃薯块茎蛾(Phthorimaea operculella)成虫的产卵选择性及幼虫钻蛀性的影响。结果表明:两种核桃叶粗提物均对马铃薯块茎蛾的产卵以及幼虫钻蛀表现出强烈的抑制效果,而且这种抑制效果随着粗提物浓度的上升而增强;2~162 g E/L的两种粗提物溶液均不影响马铃薯块茎蛾雌蛾的交配行为;两种粗提物对块茎蛾幼虫钻蛀行为的药效能够持续36 h。