土壤含水量对桔小实蝇蛹期存活的影响

浸水时间、土壤含水量对桔小实蝇Bactroceradorsalis(Hendel)蛹的存活及成虫羽化的影响的研究结果表明:(1)不同浸水时间对桔小实蝇蛹存活率的影响不同。浸水时间越长,蛹存活率越低;浸水对初期蛹的影响较大,蛹龄越大,浸水作用效果越低。浸水时间(TW)、蛹期(AP)和蛹存活率(SP)之间关系符合以下模型:SP=0.4165-0.00307TW+0.2290AP-0.00004496T2W-0.0002528A2P+0.00008258TWAP。(2)土壤含水量对桔小实蝇成虫羽化影响明显。当土壤含水量较低或较高时,羽化率都明显受到抑制。相对含水量在30%～80%之间,蛹的羽化率较高。相对含水量(Ws)和成虫羽化率(E)之间存在以下关系:E=0.396+0.01985W-0.000181W2。     

The red imported fire ant,Solenopsis invicta,modifies predation at the soil surface and in cotton foliage

Red imported fire ants, Solenopsis invicta, are generalist predators that can have major impacts on foliar arthropod communities in agricultural systems; however, their effects as predators at the soil surface have not been adequately characterized. We examined the contribution of fire ants to predation at the soil surface and in cotton foliage at two sites and over the course of two field seasons in Georgia, using egg masses of the beet armyworm, Spodoptera exigua. To assess interactions between fire ants and other arthropod species, we also measured the densities of edaphic predators and honeydew‐producing hemipterans at both sites. The sites occurred in different growing regions (Piedmont and Coastal Plain), and allowed us to characterize the importance of fire ants as predators under different climatic and soil conditions. Fire ant suppression decreased egg predation at both field sites, and predation by fire ants at the soil surface was equal to if not greater than that in cotton foliage. However, the impact of fire ants on predation varied between sites, likely due to differences in climate and the composition and activity of the extant arthropod communities. Our study also indicates that fire ant suppression is associated with decreases in the density of honeydew‐producing insects, and increasing abundance of whiteflies on the plants coincided with a decrease in egg predation at the soil surface. This finding suggests the mutualism between ants and whiteflies may lead to a shift in predation intensity from edaphic towards plant‐based food webs.     

Chromatic cues to trap the oriental fruit fly, Bactrocera dorsalis

Various colors have been used as visual cues to trap insect pests. For example, yellow traps for monitoring and control of the oriental fruit fly (Bactrocera dorsalis) have been in use for a very long time. However, the chromatic cue of using color traps has never been meticulously investigated. In this study, the spectral sensitivities of the photoreceptors in the compound eyes of B. dorsalis were measured intracellularly, and the theory of receptor quantum catch was applied to study the chromatic cue of fly attracting. Responses to five wavelength categories with peak wavelengths of 370, 380, 490, and 510 nm, and one with dual peaks at 350 and 490 nm were recorded. Based on spectral sensitivities, six colored papers were chosen to test the color preference of the fly, and an additional UV preference test was done to confirm the effect of the UV stimuli. It was concluded that UV and green stimuli (spectra: 300-380 nm and 500-570 nm) would enhance the attractiveness of a colored paper to the oriental fruit fly, and blue stimuli (380-500 nm) would diminish the attractiveness.     

Infection characteristics of Solenopsis invicta virus 2 in the red imported fire ant, Solenopsis invicta

Solenopsis invicta virus 2 (SINV-2) is the second virus identified from the fire ant, S. invicta Buren. SINV-2 is unique among positive-strand RNA viruses from insects by possessing four cistrons in a monopartite genome. Fire ant colonies testing positive for SINV-2 by RT-PCR did not exhibit any discernable symptoms. RT-PCR-based surveys for SINV-2 among 688 fire ant mounds in Alachua County, Florida, sampled during the period January, 2006 through December, 2007 showed that the prevalence of SINV-2 among nests ranged from 1.6% to 16.4%. Unlike S. invicta virus 1, no seasonal-associated prevalence was observed with regard to SINV-2 infection among fire ant colonies. No social form specificity was evident; SINV-2 was found in both monogyne and polygyne S. invicta ants. Real-time quantitative PCR experiments showed that SINV-2 genome equivalents per individual ant ranged from 1.9 × 10⁷ in. pupae to 4.3 × 10¹¹ in. inseminated queens. The SINV-2 infection was detected in all ant stages examined (eggs, larvae, pupae, workers, and queens). Tissue tropism studies indicated that the alimentary canal (specifically the midgut) is most likely the susceptible tissue. SINV-2 was successfully transmitted to uninfected S. invicta ants by feeding a partially purified homogenate of SINV-2-infected ants. The SINV-2 transmission rate ranged from 30% to 80%, and both positive (genomic) and negative (replicative) SINV-2 RNA strands accumulated in recipient ants over the course of the experiment. These results indicated that SINV-2 replicates within S. invicta.     

广东吴川红火蚁消长规律

采用系统调查的方法研究广东吴川红火蚁Solenopsis invicta Buren蚁巢数量、蚁丘体积和工蚁的年度变化规律,结果表明1年之中红火蚁活动蚁巢密度出现2个高峰期,分别在6~8月和10~12月;4~7月和10~11月新增活动蚁巢数量较大;蚁巢自然消亡出现在多个时间,其中以9月最多。4~11月红火蚁工蚁活动旺盛,用诱饵诱集法监测,5、6月和10、11月红火蚁工蚁出现2个明显盛期,而陷阱法中工蚁数量为单峰型,高峰出现在7月。2种监测方法获得的工蚁数量间相关系数为0.88,达到极显著相关。气温、地表温度、5cm土壤温度与2种方法获得的工蚁数量间相关系数分别为0.88,0.88,0.86和0.93,0.94,0.95,均达极显著水平。红火蚁蚁丘体积4~6月、9~12月增大幅度较大,其中6月份蚁巢增长最为明显。     

桔小实蝇雄成虫联系性嗅觉学习

【目的】为了探究桔小实蝇 Bactrocera dorsalis (Hendel)雄成虫的嗅觉学习能力。【方法】本研究采用经典性嗅觉条件反射训练法（classical olfactory conditioning）在室内对固定的羽化后14-17日龄的桔小实蝇雄成虫进行气味与食物的联合学习训练, 即薄荷精油和10%蔗糖溶液联合的奖赏性训练（appetitive conditioning）以及甲基丁香酚(methyl eugenol, ME)和饱和盐溶液联合的惩罚性训练（aversive conditioning）,并以伸喙反射行为（proboscis extension reflex, PER）作为学习与否的判定标准。【结果】经过奖赏性训练后,桔小实蝇雄成虫对薄荷精油的伸喙反射率可从0%增加至68%;而经过惩罚性训练后,桔小实蝇对甲基丁香酚的伸喙反射率可从100%降低至36.54%,且这种伸喙反射率的变化是通过气味条件刺激（conditioned stimulus）和食物非条件刺激（unconditioned stimulus）的对称性联合而产生的。【结论】结果表明,桔小实蝇雄性成虫具有较强的联系性嗅觉学习能力,并且两种刺激的联合是形成学习记忆的必要条件。     

几种饵料对红火蚁觅食的引诱作用

在荒地类型生境中测定花生酱、猫饲料、狗饲料、花生油、面包及蜂蜜等几种常见饵料对红火蚁的引诱作用。结果表明:面包、狗饲料、猫饲料和花生酱对红火蚁引诱力较强,花生油次之,蜂蜜最低;选择性试验结果表明红火蚁对供试的几种饵料无明显选择性。     

Revisiting the trail pheromone components of the red imported fire ant,Solenopsis invicta Buren

Ants use species-specific trail pheromones to coordinate their sophisticated foraging behavior. During the past decades, many trail pheromone components with various structures have been identified in ants, including the red imported fire ant, Solenopsis invicta, a notorious invasive species worldwide. Four compounds, Z,E- (ZEF) and E,E-α-farnesene (EEF), Z,E- (ZEHF) and E,E-α-homofarnesene (EEHF), have been reported as components of S. invicta trail pheromone. However, another study reported an analog of α-farnesene, Z,Z,Z-allofarnesene, as a key trail pheromone component. These contrasting results caused some uncertainty about the trail pheromone composition in S. invicta. In this study, we synthesized ZEF and EEF, ZEHF and EEHF, and reanalyzed the chemicals in the Dufour gland extract and in the trail pheromone fraction of S. invicta worker body extract. The reported isomers of farnesene and homofarnesene were detected and showed trail-following activity, with ZEF as the major compound, while no allofarnesene was found, neither in the Dufour gland extract nor in the whole-body extract. Our results confirm ZEF and EEF, ZEHF and EEHF as trail pheromone components of S. invicta.     

带土园艺植物传播红火蚁的风险调查

调查了广东广州、深圳40余个苗木花卉场74种带土园艺植物上红火蚁Solenopsis invicta Buren发生情况。调查结果表明,桉树苗、海枣、垂叶榕、黄金香柳、小叶榕、狗尾草、罗汉松等17种植物上红火蚁发生比率超过1%,是高风险带土植物。不同生产环境、不同栽培方式中盆/钵/袋栽红火蚁发生高于地面栽培方式,露天置于砂土、泥土、碎石上红火蚁发生风险较高,置于水泥地上的风险较低。提出了降低带土园艺植物传播红火蚁的管理措施。     

红火蚁雌蚁生殖发育的研究

通过解剖多后型红火蚁Solenopsis invicta Buren雌蛹、有翅雌蚁和脱翅雌蚁,观察了雌蚁内生殖系统的结构和发育进度。结果表明,多后型雌蚁内生殖系统形成于蛹期,其结构与单后型雌蚁存在一定差异。从发育进度来看,虽然雌蚁羽化后其卵巢大小和卵巢管数量仍有一定增长,但蛹期是卵巢大小、卵巢管数量快速增长的阶段;卵子发生始见于羽化后第4d,且卵量随个体发育而快速增加,直至脱翅后第10d达到高峰,随后开始下降;生殖系统的其它结构的变化较小。雌蛹、有翅雌蚁和脱翅雌蚁发育后期的卵巢平均大小分别为1149．23×712．42、1594．88×834．26和1975．60×1303．57μm;而卵巢管数量则分别为62．67、81．33和86．33条。至雌蚁脱翅后10d,卵巢中成熟卵和总卵量分别为20．00±4．62粒和34．00±2．31粒。     

红火蚁病原真菌分离鉴定及致病性研究

红火蚁Solenopsis invicta是世界上最具破坏力和威胁性的入侵检疫害虫之一,对农林业生产安全、公共设施以及人体健康都造成了巨大影响。为筛选对红火蚁有致病性的病原真菌,本研究通过组织分离法对自然罹病的红火蚁进行致病菌分离,结合病原形态学及分子生物学的方法对病原真菌进行鉴定并采用喷雾法测定了病原真菌对红火蚁的致病力。结果表明：从罹病红火蚁上分离出3株病原真菌HHYSFJ01、HHYSFJ02和HHYSFJ05,分别为红绶曲霉Aspergillus nomius、淡紫拟青霉Purpureocillium lilacinum和球孢白僵菌Beauveria bassiana。致病性测定,这3株病原菌对红火蚁均具有较强的致病性,且3株病原菌致病性间差异显著。经1.0×10^8孢子/mL孢子悬浮液喷雾处理红火蚁10 d后,球孢白僵菌菌株HHYSFJ05的致病性最强,红火蚁工蚁的校正死亡率为84.71%,LT50为4.67 d;红绶曲霉菌株HHYSFJ01和淡紫拟青霉菌株HHYSFJ02次之,红火蚁工蚁的校正死亡率分别为78.82%和73.29%,LT50分别为4.99 d和5.20 d。     

红火蚁巢穴土壤中生物碱成分分析

【目的】红火蚁Solenopsis invicta栖息在真菌和细菌较丰富的土壤环境中,容易受多种真菌和细菌性病原体的侵染,因红火蚁的毒液具有很好的防御和抗菌作用,致使红火蚁能生存于此类土壤环境中。为了探索这一奥秘,本研究旨在建立红火蚁巢穴土壤中的毒液生物碱的最佳提取方法,并对毒液生物碱成分进行定量分析。【方法】采集蚁巢周边3 m处的土壤,进行添加、回收红火蚁毒液实验。采用抽滤法提取土壤中的毒液生物碱,利用GC-FID对毒液生物碱成分进行定量分析,筛选最佳的提取溶剂,并且确定添加三乙胺的最佳体积比。然后用最优方法提取蚁巢土壤中的毒液生物碱,并进行定量分析。【结果】正己烷、二氯甲烷、乙酸乙酯、丙酮和甲醇5种提取溶剂中,正己烷处理的生物碱回收率略优。当添加的三乙胺的体积为1 mL及以上时,提取效果最佳。红火蚁巢穴土壤中的毒液生物碱成分中,trans-C15∶1的含量最高,trans-C13∶1的含量次之。巢穴土壤中总生物碱含量约为22μg/g。【结论】三乙胺有助于提取蚂蚁巢穴土壤中的毒液生物碱。红火蚁巢穴土壤中的生物碱浓度较高,有可能对巢穴土壤微生物群落产生重要影响。     

介绍红火蚁的野外采集和实验室饲养的方法

介绍了红火蚁Solenopsis invictaBuren的田间采集、蚁群分离和实验室饲养和操作方法及红火蚁人工饲料的制备,结合实验室饲养经验描述了日常红火蚁饲养所需设备和器具,简述红火蚁饲养的关键技术和注意事项。为开展红火蚁的生物学、生态学和药剂筛选提供切实可行的方法。     

桔小实蝇对几种寄主挥发物的触角电位反应

桔小实蝇寄主范围广,可危害芒果、柑橘、咖啡和红辣椒等250多种水果和蔬菜,现已成为中国、东南亚、印度次大陆和夏威夷群岛一带的危险性果蔬害虫。本文利用触角电位(electroantennogram,EAG)技术,测定了桔小实蝇雌雄成虫对8种寄主挥发物标准化合物(1,8桉叶素、α-蒎烯、β-石竹烯、柠檬醛、香草醛、乙醇、芳樟醇和月桂烯)的EAG反应。结果表明:上述标准化合物均能引起EAG反应,EAG反应值随着浓度增大(0.1μg/μL、1μg/μL、10μg/μL和100μg/μL)而显著不同。当柠檬醛和月桂烯浓度为100μg/μL时,桔小实蝇雌虫交配前、后的EAG反应值存在显著性差异。浓度为100μg/μL的1,8桉叶素对桔小实蝇交配后雌虫和雄虫的刺激反应存在显著性差异。桔小实蝇交配前雌虫和雄虫对浓度为100μg/μL乙醇的EAG反应值存在显著性差异。     

Characteristics of 11 polymorphic microsatellite markers in the red imported fire ant, Solenopsis invicta Buren

We have characterized 11 polymorphic microsatellite loci in the invasive ant Solenopsis invicta. Primer pairs were evaluated on fire ants collected from monogyne mounds in Lauderdale County, Mississippi. The observed and effective number of alleles ranged from two to six and from 1.31 to 2.64, respectively. The observed and expected heterozygosity values ranged from 0.1613 to 0.7826 and from 0.1491 to 0.6242, respectively. The polymorphism information content of the microsatellites ranged from 0.1482 to 0.6208. Probability tests indicated significant deviations from the Hardy-Weinberg equilibrium at three loci. Pairwise tests did not detect linkage disequilibrium between any pair of loci.     

蚁丘被破坏程度对红火蚁蚁群迁移的影响

本文调查研究了蚁丘被破坏的程度对红火蚁Solenopsis invicta Buren蚁群迁移的影响。结果表明,蚁巢地表部分被破坏可导致红火蚁蚁群发生分巢、搬巢等现象,蚁群的移巢比率随着蚁丘被破坏程度的增大而增大。当蚁丘体积被破坏75%时分巢比率最高,为14.44%;被破坏100%时搬巢比率、移巢比率均最高,分别为16.27%、27.00%。红火蚁蚁丘被破坏程度(D)与蚁群迁移比率(M)之间关系模型为M=4.3443+25.474D-3.4857D2。蚁丘受到破坏后,蚁群迁移距离平均为4.3m,迁移方向是随机的。     

研究红火蚁工蚁活动性的新方法-刻度图示法

应用一种新方法--刻度图示法研究红火蚁工蚁Solenopsis invicta Buren群体活动性规律,结果表明,标尺上红火蚁最高爬升高度、平均爬升高度、工蚁恢复平静时间、工蚁累计数量均随着蚁巢体积增大而增大,通过分析建立红火蚁工蚁活动性程度各指标值与蚁巢大小关系多个模型.     

中国红火蚁入侵扩散、防控及对策

红火蚁Solenopsis invicta Buren是全球百种最具危险性的外来入侵物种之一,被列为我国农业、林业和进境植物检疫性有害生物。红火蚁入侵我国初期,发生区域数量少、面积小,制定了相应的应急防控和根除策略。随着该蚁在我国呈现扩散加快、多区域多生境发生、多途径扩散等新态势新特点,其防控策略转向“老疫区常态治理、新疫区力争根除”。为了更好地防控红火蚁,未来工作应从部门协作、队伍建设、综合治理、检疫监管和宣传培训等多个方面加强。