Research on the Control Cover against Solenopsis invicta and Rapid Extinguishment of Its Epidemic

Based on the biological characteristics of Solenopsis invicta and the structural characteristics of its ant nest,a fast and efficient closed treatment device was developed.Compared with the simple chemical treatment commonly used at present,the developed treatment device(the ant nest control cover)is a fast and efficient method to exterminate S.invicta in 7 d,featured by short course,quick results and good effect.

New Evidence for the Hypothesis of Reducing Natural Enemy Pressure of Eupatorium adenophorum: Solenopsis invicta Competing with Doxrylus orientalis to Feed on E. adenophorum

Natural enemy insects are important factors in regulating plant invasion. The interactions between multiple insect species resulting from invasive plants remain poorly understood despite their potential. We observed notorious invasive plants Eupatorium adenophorum Sprengel were competedly fed by Solenopsis invicta Buren (Hymenoptera: Formicidae) and Dorylus orientalis Westwood (Hymenoptera: Formicidae) beside the scientific research base of Kunming University. It was first observed that D. orientalis was eating the epidermis, cortex, phloem and other root and stem tissues of E. adenophorum in soil. Two months later, it was observed that S. invicta ate the epidermis, cortex, phloem and other aboveground stem tissues of E. adenophorum. S. invicta attacked D. orientalis and displaced their living space by causing the later dead, injured, or even disabled. This phenomenon suggested that local herbivorous insects have adapted to E. adenophorum well, which will intensify the naturalization process of E. adenophorum in local habitats. In a homogeneous garden planting experiment of E. adenophorum conducted at the experimental base of Kunming University, the biomass of the introduced (China) populations of E. adenophorum was lower than that of the native (Mexico) populations, although there was no statistically significant difference. These results indicate a possible positive correlation between the increase in natural enemy pressure and the decrease in fitness of E. adenophorum.

6种饵料对红火蚁(Solenopsis invicta)引诱效果的测定

测定6种饵料对红火蚁(Solenopsis invicta)的引诱效果。结果表明,面包、火腿肠对红火蚁的引诱力最强,花生酱、豆豉鲮鱼次之,每瓶平均诱集工蚁分别达374.00、367.00、142.67和126.00头;在试验设置距离范围内,以离蚁丘外周10 cm处的引诱效果最强,之外则随与蚁丘距离的增大而降低。同时,诱饵对红火蚁的召集蚁量差异明显,面包、火腿肠召集的工蚁最多,到达最大召集蚁量的时间为60 min,持续召集时间可长达240 min。综合来看,面包、火腿肠对红火蚁的引诱效果最好,持续召集时间长,在对红火蚁的防控、监测与防效评价中可选作诱饵。

α-三联噻吩对红火蚁Solenopsis invicta觅食行为和触角功能的影响

通过研究光活化杀虫活性成分α-三联噻吩（α-T）对红火蚁Solenopsis invicta Buren工蚁觅食行为和触角识别功能的影响,探讨了光活化成分用于控制红火蚁的可行性。用Potter喷雾法将100μg/mL的α-T丙酮水溶液喷施于红火蚁中型工蚁体表,再经紫外（UVA）光照射30 min,在处理后5、10、15、20和30 min时,试蚁对火腿肠的识别率分别为20.00%、25.00%、38.33%、40.00%和41.67%,对杀虫剂饵料的识别率分别为3.33%、0、0、3.33%和0,聚集率分别为17.50%、38.33%、32.50%、45.00%和48.33%;经100μg/mL的α-T涂抹试蚁触角再经紫外光照处理30 min后,触角对丙酮反应的电位值为-0.177 mV,可正常行走的工蚁比率为75.00%;以100μg/mL的α-T涂抹试蚁触角并经紫外光照射30 min后10 h,红火蚁的死亡率为27.50%;上述结果均与α-T黑暗处理、对照（CK）光照处理和CK黑暗处理结果差异显著。α-T对红火蚁工蚁食物识别和探路行走能力均具有良好的光活化抑制作用,以其防治红火蚁具有良好可行性。

Insecticide induction of O-demethylase activity and expression of cytochrome P450 genes in the red imported fire ant (Solenopsis invicta Buren)

The red imported fire ant （Solenopsis invicta） is a global major invasive pest, and has caused significant economic, social and environmental impacts since its invasion to mainland of China in 2004. To date, chemical control has been the most effective measure. However, the long-term use of chemicals would lead to an unexpected rebound. To understand the risks and explore the mechanisms of detoxification or induction to insecticides in S. invicta, the O-demethylase activity and expression of cytochrome P450 genes of workers and queens, and the effects of chlorpyrifos and fipronil exposure in workers were investigated. Biochemical assays showed the O-demethylase activity of cytochrome P450 was significantly higher in workers than in queens （1.66-fold）, and was significantly induced in workers exposed to chlorpyrifos and fipronil, reaching a maximum （3.00- and 1.95-fold） at 48 h and then decreasing dramatically compared to controls （exposed to acetone counter- part）. The relative expression levels of 12 cytochrome P450 expressed sequence tags （ESTs） in workers were significantly higher than in queens （from 2.3- to 36.4-fold）. Multiple cytochrome P450 genes （except 9E4） were co-up-regulated （from 1.5- to 2.86-fold） in workers exposed to fipronil. These results indicated that the increased O-demethylase activity may result from the increased transcription levels of cytochrome P450 related to detoxification of insecticides in S. invicta. It appears that cytochrome P450 plays an important role in enhanced metabolic detoxification of insecticides. At the same time, it also provides the theoretical basis for resistance management and rational usage of insecticides to control S. invicta.

Control Effects of Three Poisonous Baits on Solenopsis invicta Buren

The field control effects of different concentrations of indoxacarb baits,fipronil baits and chlorfenapyr baits on Solenopsis invicta was evaluated. The results showed that at 21 post administration,the control effects of 0. 04% indoxacarb on nests and worker ants reached 100%; the control effect of 0. 02% and0. 06% indoxacarb on active nests and worker ants were 87. 50% and 100%,respectively; 0. 000 25% and 0. 000 5% fipronil and 0. 05% chlorfenapyr also had significant control effects on active nests and worker ants. At 30 d post administration,the decline rates of ant colony grade treated by 0. 04% and 0. 06% indoxacarb,0. 000 25% fipronil and 0. 05% chlorfenapyr were 100%,100%,91. 44% and 98. 11%,respectively,and the comprehensive control effect reached 97. 18%.

A global study of transcriptome dynamics in the venom gland of Solenopsis invicta Buren during laboratory rearing

Venom plays several important roles in the life of the fire ant,Solenopsis invicta Buren.Laboratory rearing significantly affected the toxin component of S.invicta.However,the molecular mechanism of the change of venomous components when kept in the laboratory is unclear.In this study,RNA sequencing technique(RNA-Seq)was performed to explore differentially expressed genes in the venom gland of S.invicta at 0,10,and 60 days after laboratory rearing.The RNA-Seq results showed that the expression of a large number of genes changed.The DEGs were involved in multiple pathways,including proteolysis,serine-type endopeptidase,and allergen.Furthermore,RNA-Seq and qRT-PCR data revealed that the expression of some genes related to proteolysis and allergen significantly decreased.Thus,our data generated new data relating to toxin-component and the transcriptome dynamics in the venom gland of S.invicta during laboratory rearing.

Toxicity of newly isolated piperideine alkaloids from the red imported fire ant, Solenopsis invicta Buren, against the green peach aphid, Myzus persicae (Sulzer)

The green peach aphid, Myzuspersicae (Sulzer), is a major insect pest of many agronomic and horticultural crops and is distributed worldwide. Aphid management is often based on application of insecticides. However, the aphid is now resistant to many of these and much interest has recently developed in identification of novel alternative insecticides. Venom isolated from the red imported fire ant, Solenopsisinvicta Buren, is composed of two groups of alkaloids, piperidines and piperideines, and has shown activity against many organisms including fungi, bacteria, mites and several insects. Prior to the study reported herein, no information on the venom’s activity to Myzuspersicae has been reported. Both of the alkaloids were active against M.persicae. The 24 h LC50 values were116.6 and 91.5 ppm for the piperideine and piperidine extracts, respectively. Based on overlap of the 95% fiducial limits the LC50 values for the two alkaloids did not significantly differ. At the high dosages, mortality occurred in as few as four hours and all treated aphids were dead by six hours. Little additional mortality was detected in the 48-hobservation. Both piperideine and piperidine extracts isolated from red imported fire ant venom possess sufficient activity to cause death of green peach aphids and at high dosages, death occurs rapidly. In the search for new replacements to synthetic insecticides, these extracts may offer a novel but potentially successful alternative.

The temporal-spatial expression and functional analysis of three gustatory receptor genes in Solenopsis invicta using sweet and bitter compounds

The insect gustatory system participates in identifying potential food sources and avoiding toxic compounds.During this process,gustatory receptors(GRs)recognize feeding stimulant and deterrent compounds.However,the GRs involved in recognizing stimulant and deterrent compounds in the red imported fire ant,Solenopsis invicta,remain unknown.Therefore,we conducted a study on the genes SinvGR1,SinvGR32b,and SinvGR28a to investigate the roles of GRs in detecting feeding stimulant and deterrent compounds.In this current study,we found that sucrose and fructose are feeding stimulants and the bitter compound quinine is a feeding deterrent.The fire ant workers showed significant behavior changes to avoid the bitter taste in feeding stimulant compounds.Reverse transcription quantitative real-time polymerase chain reaction results from developmental stages showed that the SinvGR1,SinvGR32b,and SinvGR28a genes were highly expressed in fire ant workers.Tissue-specific expression profiles indicated that SinvGR1,SinvGR32b,and SinvGR28a were specifically expressed in the antennae and foreleg tarsi of workers,whereas SinvGR32b gene transcripts were also highly accumulated in the male antennae.Furthermore,the silencing of SinvGRI or SinvGR32b alone and the co-silencing of both genes disrupted worker stimulation and feeding on sucrose and fructose.The results also showed that SinvGR28a is required for avoiding quinine,as workers with knockdown of the SinvGR28a gene failed to avoid and fed on quinine.This study first identified stimulant and deterrent compounds of fire ant workers and then the GRs involved in the taste recognition of these compounds.This study could provide potential target gustatory genes for the control of the fire ant.

施用茚虫威饵剂后红火蚁的蚁巢迁移及弃尸行为

红火蚁Solenopsis invicta是典型的社会性昆虫,在防控过程中容易引起红火蚁巢体迁移和弃尸等现象,影响防控效果。本研究对标记好的蚁巢施用茚虫威饵剂,然后定时观察新增加的蚁巢数量和工蚁弃尸量。结果表明,施用0.08%和0.1%茚虫威饵剂后,所有处理均有新蚁巢出现,施药后5~10 d,新蚁巢大量出现,随后蚁群趋向稳定,新增蚁巢减少,至处理后25~30 d,再次出现新蚁巢。0.1%茚虫威饵剂15 g/巢处理在施药后5 d出现8个新蚁巢,药后10 d和30 d分别又新增5个蚁巢,其他时间新增蚁巢数较少。按处理剂量,药后30 d,2种药剂15 g/巢处理出现的新巢数量均显著高于25 g/巢处理。0.1%茚虫威15 g/巢处理,校正蚁巢累计增加率高达124.98%,0.08%茚虫威饵剂15 g/巢处理为89.05%;0.08%和0.1%茚虫威饵剂25 g/巢处理,校正蚁巢累计增加率分别为12.00%和51.34%。施用15 g/巢饵剂后2 d开始有大量工蚁尸体被丢弃,至药后4 d弃尸量达最大值,0.08%和0.1%茚虫威饵剂处理弃尸量分别为330.5头/巢和300.2头/巢,随后呈逐步下降趋势,至14 d,弃尸量降至最低。施药后8 d内弃尸量达总弃尸量75.26%以上,至药后10 d,已达总弃尸量的90.08%以上。施用0.08%和0.1%茚虫威饵剂25 g/巢的处理新蚁巢出现较少,表明施用相对低剂量的饵剂,更容易引起蚁巢迁移。红火蚁的弃尸行为主要发生在饵剂施用后的前8 d。

红火蚁对亚洲玉米螟的捕食作用及其发生影响

蚂蚁在蛀茎害虫的综合治理方面发挥着重要的作用。全球分布性的入侵蚂蚁红火蚁取食多种无脊椎动物并在入侵区域成为优势物种。但是目前尚不清楚红火蚁对玉米重要害虫亚洲玉米螟的捕食作用。本文在实验室和野外条件下研究红火蚁对亚洲玉米螟的觅食和捕食行为。研究显示,对于隐藏度低的亚洲玉米螟,红火蚁发现该害虫的时间约为40s,召集时间少于1 h。对于隐藏度高的亚洲玉米螟,红火蚁发现该害虫的时间超过26 min,召集时间接近6 h。野外实验显示,红火蚁可以降低玉米中后期生长阶段中50%的亚洲玉米螟卵块、94.1%的亚洲玉米螟幼虫和92.9%亚洲玉米螟蛀食孔。研究提供更多的视角理解红火蚁对生物多样性影响。

饵剂投放站对田间红火蚁的饵剂搬运量及防控效果研究

饵剂诱杀是防控红火蚁Solenopsis invicta Buren最广泛和最有效的措施。本研究利用一种新型饵剂投放站(简称饵剂站)对比分析红火蚁工蚁对0.08%茚虫威杀蚁饵剂及其载体的搬运量,并使用5 g/巢、10 g/巢、20 g/巢3种剂量的饵剂对田间红火蚁蚁巢进行单蚁巢处理,评价饵剂站对田间红火蚁的饵剂搬运量及防控效果的影响。结果表明,红火蚁工蚁对饵剂站内0.08%茚虫威饵剂及其载体的搬运量少于直接撒施处理方式的搬运量。施药24 h后,红火蚁工蚁对饵剂站内和直接撒施的0.08%茚虫威饵剂搬运量分别为14.84±3.18 g和17.71±5.88 g,差异不显著。使用饵剂站施用10 g、20 g饵剂处理28 d后,工蚁减退率、蚁巢减退率、蚁群级别降低率和综合防治效果均可达到90%以上,与直接撒施处理方式均无显著差异。虽然饵剂站会一定程度上降低红火蚁工蚁对饵剂的搬运量,但却不影响对红火蚁的防控效果,基于其防雨、防潮的优点,饵剂站可显著延长红火蚁防控的窗口期。

大豆田生境红火蚁工蚁的活动性程度评价

应用刻度图示法观察记录了海口市大豆田生境红火蚁Solenopsis invicta Buren工蚁的活动性水平,并对蚁巢大小及活动时间与工蚁数量、爬升高度和恢复平静时间等指标值进行了通径分析。对41个蚁巢观察结果表明,除了1个蚁巢外,蚁巢惊扰后60 s时在观测尺平均爬升高度均大于15 s时平均爬升高度,且蚁巢被干扰后观测尺上工蚁数量和爬行高度随着时间的延长先快速增加,至45 s时达到最大,尔后逐渐减少至平静。相关分析表明,180 s内阳面平均爬行高度与测试时活动时间的相关性最高,恢复平静时间与蚁巢体积相关性最高,相关系数分别为0.4572和0.6233。通径分析表明,测试活动时间对15 s时阴面平均爬升高度、15 s时平均爬升高度及180 s内阳面平均爬行高度起正向作用,60 s时阴面平均爬升高度以及60 s时平均爬升高度与蚁巢体积起正向作用,蚁巢地表高度、蚁巢地表面积、蚁巢体积对恢复平静时间起正向作用。研究结果为了解热带地区大豆种植生境红火蚁行为活动特征,以及实施有效防控提供科学参考。

2种药剂在海南不同季节对红火蚁的防治效果

为弄清冬季施用药剂防治海南红火蚁能否取得良好的防控效果,对比了0.6%高效氯氰菊酯粉剂与0.08%茚虫威饵剂2种药剂在冬、夏季的防效差异。结果表明:药后时间、季节差异、药剂种类对红火蚁蚁巢的防治效果均影响明显,冬季于药后7~30 d范围,0.6%高效氯氰菊酯粉剂对红火蚁蚁巢的防治效果明显优于0.08%茚虫威饵剂,夏季于药后15~45 d范围,0.08%茚虫威饵剂对红火蚁蚁巢防治效果高于0.6%高效氯氰菊酯粉剂;0.08%茚虫威饵剂冬季对红火蚁蚁巢的防治效果随药后时间增加而上升,药后45 d最高(82.03%),夏季对红火蚁的防治效果15 d达92.49%,与30、45 d无显著差异;0.6%高效氯氰菊酯粉剂对红火蚁蚁巢的防治效果随药后时间的增加而下降,但冬季的下降速度慢于夏季。2种药剂对红火蚁工蚁的防治效果随药后时间的增加而下降;0.08%茚虫威饵剂对工蚁的防治效果除药后7 d外,冬季的防治效果均显著高于夏季;0.6%高效氯氰菊酯粉剂对工蚁的防治效果7~30 d内无明显差异,但在45 d时冬季(97.86%)明显高于夏季(80.57%)。综上,海南冬季天气晴好,且气温在13~21℃时,可选用0.08%茚虫威饵剂或0.6%高效氯氰菊酯粉剂对红火蚁实施防控,防控后防控效果的评价延后至药后30~45 d开展。

广西红火蚁发生扩散现状及防控策略

红火蚁Solenopsis invicta Buren是危险性极高、危害性极大的外来入侵生物,被我国列为进境植物检疫性有害生物和全国农业植物检疫性有害生物。自2005年在广西首次发现入侵以来,红火蚁已对当地的人畜健康、农林生产、生态环境、公共设施等方面构成了严重威胁,并呈现扩散速度加快、疫情发生加重的趋势。本文总结了近年来广西红火蚁的发生扩散现状、防控措施研究进展及工作举措,分析了红火蚁防控中存在的主要问题,并根据实际情况提出防控对策建议,以期为广西的红火蚁防控工作提供参考。

浙江省带土苗木传带红火蚁风险调查分析

带土苗木传带红火蚁Solenopsis invicta是导致红火蚁疫情进一步扩散蔓延的关键因素,摸清浙江省带土苗木传带红火蚁的风险,对其快速阻截与有效防控具有重要意义。2016年12月至2022年9月期间,本研究通过问询、目测踏查、诱饵诱集等监测方法,调查了浙江省11个地级市的39个区或县,包括251个苗圃地、26个花卉交易市场、576个档口的红火蚁发生情况。结果表明,龙血树Dracaena draco、玉兰Yulania denudata、山茶Camellia japonica、菜豆树Radermachera sinica、丝葵Washingtonia robusta、木犀Osmanthus fragrans、苏铁Cycas revoluta、樟Cinnamomum camphora、罗汉松Podocarpus macrophyllus、紫叶李Prunus cerasifera、加拿利海枣Phoenix canariensis、叶子花Bougainvillea spectabilis等是浙江省高风险传带红火蚁的带土植物种类。建议今后应该加大对该类带土苗木的检疫,快速发现并阻截红火蚁入侵。

互叶白千层精油对红火蚁的驱避作用及活性成分筛选

红火蚁Solenopsis invicta Buren是全球十大最具破坏性的入侵生物之一,对人畜安全、农林业生产以及生态环境造成巨大危害。从植物精油中筛选红火蚁天然驱避化合物是红火蚁综合防控的重要手段之一。本研究采用动物运动轨迹跟踪系统Ethovision XT测试6种植物精油对红火蚁的驱避行为活性,通过GC-MS技术分析驱避效果最佳精油的化合物成分,并利用GC-EAD技术筛选对红火蚁具有触角电生理活性的目标化合物,最后通过挖沙生测法和Y型尺法测试目标化合物对红火蚁的驱避活性。结果表明,在所测试的6种植物精油中,互叶白千层精油对红火蚁的驱避活性最强。互叶白千层精油中含量最高的4种化合物依次为4-松油醇、萜品烯、α-松油烯和4-异丙基甲苯,含量分别为41.43%、11.22%、5.24%和4.61%。这4种化合物均能引起红火蚁工蚁的触角电生理反应。通过挖沙生测和Y型尺法行为实验表明,4-松油醇对红火蚁的驱避活性最强,而α-松油烯与4-异丙基甲苯在高浓度下对红火蚁具有一定的驱避活性,萜品烯对红火蚁无驱避活性。上述研究结果表明,4-松油醇是一种具有开发成红火蚁驱避剂潜力的天然活性化合物。

腐生培养下爪哇虫草对寄主的转录组响应

爪哇虫草菌是广谱性虫生真菌,具有防治膜翅目社会性昆虫红火蚁Solenopsis invicta的生防潜能。为探究蚁巢弃尸堆中携菌虫体在侵染循环链的关键作用,探讨腐生条件下爪哇虫草Cordyceps javanica响应寄主的分子致病机制,本研究通过向培养基添加冷冻干燥的虫尸粉进行诱导,对诱导前后的菌丝孢子混合体进行转录组测序分析。结果表明,与纯培养条件相比,菌株经虫尸粉诱导后发掘新基因1912个,有379个得到功能注释。显著差异表达基因有242个,上调表达基因111个,下调表达基因131个;GO富集分析表明,生物学过程的代谢过程和细胞过程、细胞组分的细胞结构体及分子功能中参与催化活性和结合相关的基因可能在爪哇虫草响应寄主过程中发挥了重要作用;KEGG分类和富集分析表明,代谢过程分类的色氨酸代谢、缬氨酸、亮氨酸和异亮氨酸降解、糖酵解/糖原异生和乙醛酸和二羧酸酯代谢,遗传信息过程分类的碱基切除修复和内质网的蛋白质加工,环境信息过程分类的ABC转运蛋白和丝裂原活化蛋白激酶信号通路,细胞过程分类的自噬和过氧物酶体通路是爪哇虫草的主要代谢途径。随机筛选8个差异表达基因进行实时荧光定量PCR验证,这些基因的表达模式与转录组数据分析结果基本一致。本研究结果表明,爪哇虫草在适应腐生环境过程中与氨基酸代谢和能量代谢相关的基因活跃,这可能是其在垂直和水平扩散过程中需维持侵染力,为自身提供营养并转化为能量和中间产物等物质所致。

泉州地区红火蚁发生情况调查及防治药剂筛选

为明确泉州地区红火蚁的发生情况,筛选适合当地的红火蚁高效防控药剂。通过调查了当地红火蚁的栖息环境、生活习性和传播途径,测定1%噻虫胺颗粒剂、1.8%阿维菌素乳油、0.05%茚虫威杀蚁饵剂和5%鱼藤酮可溶液剂对红火蚁的田间防治效果,筛选最佳防控药剂。结果表明:泉州地区的红火蚁主要分布在草地(草坪)、苗圃、公园、农田、果园和绿化带等地带,其适宜的活动温度为19~32℃,食性杂、适应性强、传播扩散方式多样。田间药效试验显示,1%噻虫胺颗粒剂和0.05%茚虫威杀蚁饵剂对活动蚁巢和活动工蚁均具有好的速效性和持效性;5%鱼藤酮可溶液剂虽然速效性略慢,但持效性也较好;1.8%阿维菌素乳油的速效性和持效性均较差;因此,1%噻虫胺颗粒剂、0.05%茚虫威杀蚁饵剂和5%鱼藤酮可溶液剂适宜在田间推广应用。本研究结果可为制定针对性的防控措施提供技术支持和科学依据。

东革阿里提取物对红火蚁工蚁的生物活性研究

为明确东革阿里Eurycoma longifolia提取物对红火蚁Solenopsis invicta工蚁的防治效果,本研究采用水试管喂毒法测定了其主要成分苦木苦味素对红火蚁工蚁的毒杀活性和行为能力的影响。结果表明,喂毒后1~10 d,苦木苦味素化合物ep6对红火蚁工蚁的毒杀活性与处理时间和浓度呈正相关,20 mg/L浓度下处理10 d后的死亡率为77.78%。ep6对红火蚁工蚁的聚集率、抓附率、行走率、爬杆率和食物识别率有显著抑制活性,但对红火蚁食物消耗率基本没有显著影响。20 mg/L浓度下处理10 d的聚集率、抓附率、爬杆率、行走率、食物识别率和食物消耗率与对照相比分别降低了73.86、50.27、44.99、27.78、6.67和10.81百分点。苦木苦味素化合物对红火蚁工蚁具有良好的毒杀和抑制行为活性。