红火蚁专性药剂红蚁净对剑尾鱼的急性毒性试验

以剑尾鱼Xiphophorus helleri为试验对象,初步研究了不同浓度的红蚁净(pyragne)对剑尾鱼的急性毒性。结果显示:LC50,24 h=974.99 mg/L,LC50,48 h=606.74 mg/L,LC50,72 h=542.00 mg/L。按《化学农药安全评价试验准则》评价:红蚁净为低毒药剂。预测其安全浓度为70.50 mg/L。在实际应用中,进入水体中的药剂浓度远远低于安全浓度,所以在池塘或其他养殖等非饮用水体边缘使用红蚁净,只要按药剂使用浓度和方法进行,对鱼类是安全的。     

灭蚁威对不同生境下红火蚁的药效评价

在红火蚁发生区域选农田、山坡地、绿化带、草坪等4个不同生境地块,采用灭蚁威毒饵进行防治试验,并对其药效进行调查。结果显示,药后10 d,灭蚁威对红火蚁蚁巢的防效较差,且表现出不同生境而有所差异;但在药后35 d时,其对蚁巢和工蚁的校正防效均在95%以上,表现出良好的防治效果。本试验结果表明,灭蚁威的药效需一个月后才能充分发挥;在红火蚁发生区,对不同的生境均可采用灭蚁威饵剂进行防治。     

红火蚁对蚁运植物种子影响的研究概况

自然界中蚂蚁与蚁运植物的互惠关系是一种普遍的现象。蚁运植物种子的油质体是两者发生联系的纽带,它能为蚂蚁提供营养物质,且蚂蚁在消耗油质体的同时,搬运并散布了种子。红火蚁是近年来在华南地区严重发生的一种入侵性蚂蚁,能在短时间内迅速发展成为优势种,造成入侵地生物多样性降低和生态单一化,是世界范围内最具危险的社会性昆虫之一。由于该入侵蚂蚁极具侵略性、觅食能力强、种群庞大等特点,对蚁运植物具有深远的影响。为了深入、全面地了解红火蚁对蚁运植物种子的影响,本文综述了红火蚁对蚁运植物种子油质体的喜好及搬运行为,以及对蚁运植物种子的直接影响(搬运、取食、划痕或毁坏)及间接影响(排挤本地蚂蚁),最后展望了未来红火蚁对蚁运植物影响的研究方向。     

中国红蚁属分类研究(膜翅目:蚁科)

记述中国红蚁属Myrmica Latreille昆虫11种,其中1种为中国新纪录种,即盖列尼红蚁M.gallieni Bondroit;描述1新种,太白红蚁M.taibaiensis sp.nov。新种与M.inezae相近,其不同处为：1）新种上颚咀嚼缘具8齿,端部2齿尖长,从第3齿开始变为细齿,后者上颚咀嚼缘具9齿,端部4齿较粗大,2）新种并胸腹节刺指向斜后上方,后者并胸腹节刺较直立;3）新种体色成双色,胸部颜色明显淡于头部及腹部,后者体色一致。文中编制了11个种的工蚁分种检索表。     

红火蚁与热带火蚁间的干扰竞争

【目的】为了探讨入侵火蚁在我国成功定殖及其之间的竞争机制。【方法】运用行为学方法研究红火蚁Solenopsis invicta(Buren)和热带火蚁Solenopsis geminata(Fabricius)在个体水平和群体水平上的攻击性、攻击手段及合作能力。【结果】一对一攻击试验中,红火蚁和热带火蚁之间攻击级别多集中在3级,两种入侵蚂蚁间以相互威胁为主;红火蚁大型工蚁与热带火蚁兵、工蚁间最为好斗,其攻击级别达到4级的比例最高,分别为33.04%、37.92%。热带火蚁兵蚁与各型红火蚁间攻击强度差异不显著;热带火蚁工蚁与红火蚁小型工蚁之间的攻击性最强,其攻击性(3.49)显著高于热带火蚁工蚁与红火蚁大、中型工蚁的攻击性(3.32和2.97)。在攻击手段上,3级打斗时各型红火蚁更倾向以物理攻击主动威胁热带火蚁,而热带火蚁兵、工蚁会采取多种方式主动攻击红火蚁,双方皆以躲避应对为主;4级打斗时两种火蚁主要以混合攻击为主动或应对手段。群体攻击试验显示,红火蚁群体间攻击强度和合作性会随着群体数量的增加而显著增加,热带火蚁合作性较差,其群体对抗红火蚁的优势仅仅是由于个体数量的增加。【结论】红火蚁比热带火蚁具有更强的竞争优势。研究结果为入侵蚂蚁间不对称竞争机制和长期群落替代的内在原因提供理论基础。     

0.7％氟蚁腙饵剂对红火蚁的毒杀效果及行为影响

本文评价了0.7%氟蚁腙饵剂对红火蚁Solenopsis invicta Buren中型工蚁毒杀效果、聚集率、抓附能力和行走能力的影响。试验结果表明0.7%氟蚁腙饵剂对红火蚁具有较好的毒杀效果,并能有效降低红火蚁的聚集、抓附和行走能力。0.7%氟蚁腙饵剂处理0、1、2和3 d后,工蚁死亡率分别为7.50%、48.06%、86.04%和96.74%;聚集率分别为88.52%、83.89%、77.79%和0;抓附率分别为64.32%、33.88%、27.30%和0;正常行走率为86.30%、79.72%、61.27%和55.56%,行走速率分别为1.83 cm/s、1.50 cm/s、0.56 cm/s和0.27 cm/s。与饲喂氟蚁腙饵剂与空白饵料或糖水混合物相比,单独饲喂氟蚁腙饵剂,短时间内会产生更高的死亡率,但最终死亡率无显著性差异。本研究可为氟蚁腙饵剂控制红火蚁提供可行性参考,为氟蚁腙科学合理防治红火蚁技术提供数据支持。     

红火蚁与黑头酸臭蚁对不同食物资源的竞争

红火蚁Solenopsis invicta Buren与黑头酸臭蚁Tapinoma melanocephalum(F.)在不同食物资源上的竞争的实验结果表明:红火蚁与黑头酸臭蚁对鸡蛋诱饵的竞争最为激烈,当二者同时出现在鸡蛋诱饵时,红火蚁取胜并占有食物诱饵的比例为53%,略高于黑头酸臭蚁(47%),但二者的占有率没有显著的差异(P＞0.05).两种蚂蚁对蜂蜜和花生油诱饵表现出不同的喜好性.红火蚁喜好花生油食物诱饵,而黑头酸臭蚁喜好糖类食物诱饵.红火蚁在鸡蛋和花生油诱饵上的工蚁召集量平均分别为269头和219头,显著高于在蜂蜜诱饵上的平均工蚁数量,仅为16头;且对鸡蛋和花生油诱饵诱饵的占有率显著高于蜂蜜诱饵.黑头酸臭蚁在鸡蛋和蜂蜜诱饵上的工蚁召集量平均分别为240头和219头,显著高于在花生油诱饵的工蚁数量,为10头以下;且对鸡蛋和蜂蜜诱饵诱饵的占有率显著高于花生油诱饵.     

中国红蚁属一新种记述(膜翅目,蚁科)

描述陕西佛坪红蚁属1新种,即郑氏红蚁Myrmica zhengi sp.nov.。新种体色极浅;头部正面观方形;前中胸背板刻纹横形,但极不规则;并胸腹节刺粗壮,基部宽;后腹第1节背板基侧具明显细纵刻纹与近似种类相区别。模式标本保存于陕西师范大学动物研究所,副模标本分存于广西师范大学生命科学学院、西北农林科技大学昆虫博物馆、东北师范大学生命科学学院和西南林业大学标本馆昆虫标本室。     

红蚁属一中国新记录种记述

伊内兹氏红蚁ＭｙｒｍｉｃａｉｎｅｚａｅＦｏｒｅｌ,１９０２,中国新记录ＭｙｒｍｉｃａｉｎｅｚａｅＦｏｒｅｌ,１９０２,Ｒｅｖ．ＳｕｉｓｅｄｅＺｏｏｌ．１０：２２６．ＭｙｒｍｉｃａｉｎｅｚａｅＦｏｒｅｌ,Ｂｉｎｇｈａｍ,１９０３,Ｆａｕｎ,Ｂｒｉｔ．Ｉ...     

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.     

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。     

Population genetics and history of the introduced fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), in Australia

Abstract  The red imported fire ant, Solenopsis invicta , a damaging invasive pest, was discovered in February 2001 in Brisbane, Australia at two sites, Fisherman Islands and suburban Richlands-Wacol. Using four microsatellite loci and the protein marker Gp-9 , we compared the two infestations with each other, and with potential source populations in North and South America to better understand the history of their introduction to Brisbane. Based on an analysis of molecular variance, as well as a maximum likelihood tree of colonies from the two Australian sites, we found that the two sites were genetically distinct and were almost certainly introduced separately. All of the colonies at Fisherman Islands were monogynous, headed by a single queen, while the Richlands-Wacol site had a mixture of single-queen monogynous and multiple-queen polygynous colonies. However, the monogynous and polygynous colonies at the Richlands-Wacol site were not genetically distinct from each other, and probably constitute a single, mixed introduction. Based on allele frequencies at the microsatellite loci, and Gp-9 , both Australian infestations were more similar to North American populations than to South American, though the Fisherman Islands infestation was intermediate, making it difficult to assign. Thus, there has been one introduction from either a North or South American monogynous population at Fisherman Islands, and one introduction from a mixed monogynous/polygynous North American population at Richlands-Wacol. These findings have implications for the control of the current infestations, as well as for the quarantine regulations necessary to prevent additional introductions to Australia.     

严防危险性害虫红火蚁入侵

原产南美洲的红火蚁SolenopsisinvictaBuren,先后入侵美国和澳洲,最近又入侵中国台湾,对人类健康和环境安全构成重大威胁。该文介绍了红火蚁的形态特征、与近源种的形态区别、生物学特性、入侵特性、危害以及预防、控制等方面的知识,最后提出我国大陆需要高度警惕,严防红火蚁入侵。     

Multiple functions of fire ant Solenopsis invicta mandibular gland products

Alarm pheromones of social insects are best known for their role in the defence and maintenance of colony integrity. Previous studies with the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) demonstrate that the mandibular glands of workers (sterile females) and male and female sexuals produce an alarm pheromone, 2‐ethyl‐3,6‐dimethylpyrazine. The function of alarm pheromones in worker ants is well understood and divergent from the function of these compounds in the winged sexual forms. The present study quantifies the amount of pyrazine in the mandibular glands from male and female alate sexuals, as well as queens. Pyrazine production in female alates starts in the late pupal stage and increases until they reach mating flight‐ready maturity; however, after mating flight participation, the pyrazine level declines by >50%. Interestingly, mature male alates lose >85% of their mandibular gland pyrazine during mating flight activity. The results of the present study indicate that male and female sexuals use mandibular gland secretions for mating flight initiation and during mating flights. Furthermore, the ontogeny of mandibular gland products (pyrazine as the marker) from newly‐mated queens to mature colony queens shows a more than two‐fold increase in the amount of pyrazine by 6 months after mating. However, this is followed by a decline to trace amounts in mature colony queens (>2 years old), suggesting a function for mandibular gland products during colony development. Multifunctional use of social insect pheromones is well documented and data are reported in the present study suggesting new roles for mandibular gland products in fire ants.     

Culture-independent identification of gut bacteria in fourth-instar red imported fire ant, Solenopsis invicta Buren, larvae

Red imported fire ants (RIFA), Solenopsis invicta Buren, are medical, urban, and agricultural pests from South America. They are successful invaders due to their preference for disturbed habitats, high reproductive rates, and the ability to feed on a wide variety of food items (omnivorous). Fourth-instar larvae are used by the colony to digest solid food and then regurgitate it for consumption by workers and queens. Larvae are an ideal source of investigations of endosymbiotic bacteria possibly involved in nutrient distributions. Our study utilized 16S rDNA sequencing to describe the composition of the bacterial community in fourth-instar ant larvae in order to identify possible endosymbiotic bacteria present therein. The 16S rRNA gene was directly amplified from mixed-population DNA of whole fire ant larval guts and cloned into Escherichia coli. Bacterial communities from three geographically separated RIFA colonies were examined. Sequenced bacterial clones from guts were determined to be predominantly from the phylum Proteobacteria and the family Enterobacteriaceae. Our results did not detect the presence of endosymbiotic bacteria in the guts of RIFA larvae among the colonies. In addition, minimal species overlap was found when bacterial inventories were compared among colonies. Thus, bacteria coadapted with red imported fire ant larvae were not detected. Identified bacteria were not closely affiliated with endosymbiotic bacteria common in other insect species. Bacteria communities appeared to be unique to each geographical location and were determined by the foods consumed by the ants.     

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.     

Elucidating how the red imported fire ant (Solenopsis invicta) diffused spatiotemporally among different landscapes in north Taiwan, 2008–2015

Solenopsis invicta Buren, also known as the red imported fire ant (RIFA), has had a large negative impact on human and livestock health. However, few studies have further investigated the influence of human land use, which is an important factor affecting the habitats of insects, on the expansion of RIFAs. In addition, there is a lack of knowledge of the empirical associations between RIFA diffusion and land use within countries. Therefore, the objectives of this study were to provide an approach to delineate the areas of RIFA infestations and explore how land use influences the spatiotemporal diffusion of S. invicta. We used RIFA data from 2008 to 2015 from the RIFA surveillance system, which was conducted by the National RIFA Control Center in Taiwan. Two regions in Taiwan with different RIFA infestation levels were investigated. The ordinary kriging method was applied to show the spatial intensity of RIFAs, and the extreme distance estimator method was applied to determine the critical dispersal distances, which showed the distance of the highest probability of RIFAs in two consecutive years. In addition, network analyses were used to identify RIFA invasion routes between land‐use types. Finally, bivariate local indicators of spatial association were used to capture the invasion process in time and space. The results showed, paddy fields, main roads, and warehouses were identified as the top three land‐use types of diffusion sources. On average, the critical RIFA dispersal distances were 600 and 650 m in two consecutive years in high‐ and low‐infestation regions, respectively. Finally, RIFAs were likely to diffuse between main roads and warehouses in the low‐infestation region. Therefore, it is suggested that RIFA control activities be implemented at least 600 m from the observed spot. Additionally, control activities should be conducted on the identified three land‐use types of diffusion sources in the high‐infestation region, and the roadsides between main roads and warehouses in the low‐infestation region to prevent the accidental spread of RIFAs.     

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.     

Trophallaxis by temporal subcastes in the fire ant, Solenopsis invicta, in response to honey

ABSTRACT. Trophallactic behaviour of temporal subcastes in Solenopsis invicta Buren colonies was studied in two separate experiments. First, radiolabeled honey was presented to small colonies containing larvae, queens and marked workers; radioactivity in the head, thorax and abdomen of each ant was measured after 0.25, 1, 6, 12, 24, 48 and 72 h. The quantity of honey per subcaste was dependent on the total amount of honey collected. As more honey entered the colony, the quantity in foragers, queens and reserves increased more rapidly than that in nurses or larvae. The internal distribution of radioactivity in the head, thorax or abdomen indicated that differences between subcaste members in either the rate of food exchange or digestion existed. In a second experiment behavioural observations were made on marked workers in colonies before and after the presentation of honey. Reserves spent significantly more time engaged in trophallaxis than either foragers or nurses, both as active donors and active receivers. Based on number of encounters, nurses were more likely to receive honey while reserves and foragers were more likely to donate honey. The duration of encounters involving nurses tended to be shorter than those involving reserves or foragers.