First record of the little fire ant,Wasmannia auropunctata(Hymenoptera:Formicidae),in Chinese mainland

In January 2022,we received ant specimens collected from three field colonies from Shantou City,Guangdong Province,China.They were identified as the little fire ant,Wasmannia auropunctata,through morphological and molecular analyses.Wasmannia auropunctata is listed as one of the 100 most dangerous invasive species by the International Union for Conservation of Nature(IUCN)and has spread from its native range in South America to every continent except Antarctica.DNA analysis of mitochondrial cytochrome c oxidase subunit I(COI)in nine specimens of W.auropunctata found that they had a close genetic relationship with specimens from Argentina.This study represents the first formal record of the establishment of W.auropunctata outdoor in Chinese mainland.However,the invasion stage and occurrence degree of W.auropunctata in China are not clear to date.The implementation of quarantine measures,investigation of the occurrence and distribution,and development of monitoring and control strategies are needed to actively respond to the threat posed by this highly invasive ant.

The Prokaryotic Expression and Bioactivity of the Recombinant Red Fire Ant Venom Allergen Sol i 4

The sting of red imported fire ant （RIFA） could cause serious allergic response in fraction of people. These allergic reactions are mainly caused by its venom, especially venom allergen Sol i 1-4. To produce large amount of RIFA venom allergen Sol i 4 for diagnosis of RIFA allergy and allergen-specific immunotherapy, the gene encoding this protein was amplified and cloned into the prokaryotic expression vector pET43, la. The recombinant plasmid was used to transform competent cells and the recombinant proteins were expressed in E. coll. SDS-PAGE and Western blotting analysis indicated that high-level expression of Sol i 4 protein was successfully achieved. Allergenic activity analysis of the recombinant allergen Sol i 4 was then performed on rabbit. The result showed that the recombinant protein obtained had significant allergenic activity. It indicated that the recombinant allergen Sol i 4 of RIFA venom was successfully expressed in E. coli, which provided foundation for further developing therapeutic and diagnosis reagents of RIFA allergy.

Toxicity and Efficacy of Two Emulsifiable Concentrates of 2-Tridecanone against Red Imported Fire Ants

2-tridecanone is a major constitute of defensive secretion in tawny crazy ants, Nylanderia fulva that is an ant species reported to be able to displace red imported fire ants, Solenopsis invicta in the field. 2-tridecanone was proven to be toxic to S. invicta. Although 2-tridecanone is commercially available, utilization of this naturally occurring compound in fire ant management has received little attention. In this study, toxicity and efficacy of two 2-tridecanone formulations were assessed against S. invicta. Two emulsifiable concentrates were prepared using 2-tridecanone as an active ingredient, vegetable oil as a solvent and polyoxyethylene tridecyl ether as a surfactant. Piperonyl butoxide (PBO) was used as a synergist in one formulation. Both formulations showed significant toxicity in laboratory bioassays. In a field trial, at application rate of 5.28 mL/L and 14 days after mound drench treatment, 100% control was achieved for formulation with PBO and 90% control for the formulation without PBO. In conclusion, both formulations had significant efficacy against S. invicta. Due to the low mammalian toxicity of 2-tridecanone, no involvement of hazardous synthetic organic solvents, no phytotoxicity at applied concentrations, and relatively low cost, both formulations are promising alternatives to commercial insecticide products for fire ant mound drench. The outstanding efficacy of both formulations observed in this study warrants further research on their efficacy against other pest insects.

The Impact of Fire Ants Solenopsis sp. on Upland Arthropods in Eastern India

Solenopsis sp. is an important invader on upland arthropod of Eastern India. This study was conducted to evaluate the role of this insect as potential biocontrol agent against some major pests of rice. The ant populations were sampled before and during appearance of hibernating larva and pupa of rice yellow stem borer （YSB） Scirpophaga incertulas （Walk.） inside the rice plant. Species richness and diversity of other ant species were also assessed from YSB protected field with insecticides and the crop grown under natural biological control. The maximum value of Barger-Parker index （d = 0.245） indicated that fire ant constituted 24.55% of the total population. Besides, in natural as in agricultural ecosystems, interference between fire ants and mealy bug as well as aphids was also recorded in different altitudes of the Eastern Himalayas and found that the incidence of fire ants Solenopsis sp. decreased the abundance of borer pests, but in contrast it increased the hopper pests in the same ecological niche.

Impact of the red imported fire ant Solenopsis invicta Buren on biodiversity in South China: A review

The red imported fire ant, Solenopsis invicta, is a problematic invasive species in China since at least 2003. Over the past 15 years, a numerous studies were published on the impacts of this species on flora, fauna, and ecosystem function in natural and agricultural systems. We reviewed the literature on S. invicta invasion biology and impacts on biodiversity in South China. Both monogyne and polygyne colonies of S. invicta were introduced to China and polygyne colony is the dominant type. The range expansion rate of S. invicta may reach 26.5–48.1 km yr–1 in China. S. invicta forage activities occur year-round, peaking in the summer and fall in South China and show a preference for insects and plant seeds. We describe the ecological impacts of S. invicta on various habitats in South China, including arthropod community structure disruption and decreases in diversity and abundance of native ant species. S. invicta can replace the role of native ants in mutualisms between ants and honeydew-producing Hemiptera, which results in loss of important food resources for native ants and natural enemies of hemipterans. Further research is required to assess the complex ecosystem-level impacts of S. invicta in introduced areas.

Juvenile hormone induces reproduction via miR-1175-3p in the red imported fire ant, Solenopsis invicta

Juvenile hormone(JH)acts in the regulation of caste differentiation between queens and workers(i.e.,with or without reproductive capacity)during vitellin synthesis and oogenesis in social insects.However,the regulatory mechanisms have not yet been elucidated.Here,we identified a highly expressed microRNA(miRNA),miR-1175-3p,in the red imported fire ant,Solenopsis invicta.We found that miR-1175-3p is prominently present in the fat bodies and ovaries of workers.Furthermore,miR-1175-3p interacts with its target gene,broad-complex core(Br-C),in the fat bodies.By utilizing miR-1175-3p agomir,we successfully suppressed the expression of the Br-C protein in queens,resulting in reduced vitellogenin expression,fewer eggs,and poorly developed ovaries.Conversely,decreasing miR-1175-3p levels led to the increased expression of Br-C and vitellogenin in workers,triggering the“re-development”of the ovaries.Moreover,when queens were fed with JH,the expression of miR-1175-3p decreased,whereas the expression of vitellogenin-2 and vitellogenin-3 increased.Notably,the suppression of fertility in queens caused by treatment with agomir miR-1175-3p was completely rescued by the increased vitellogenin expression induced by being fed with JH.These results suggest the critical role of miR-1175-3p in JH-regulated reproduction,shedding light on the molecular mechanism underlying miRNA-mediated fecundity in social insects and providing a novel strategy for managing S.invicta.

Impact of the invasion of the imported fire ant

The impact of the imported fire ant （IFA） is complex, in large part, because several very different species of＂Fire Ants＂ have invaded and one of these has two forms, all of which are hard to separate by the public, as well as, some investigators not focused on the ant. Each of these different ＂IFA＂ species and forms differ in their impact. Further, these ants impact a number of＂things＂ ranging from the environment and wildlife （plants and animals） as well as people, their environment and infrastructure. In addition, they can not only lead to death of living things （including people）, but they can destroy many aspects of our environment and infrastructure at the cost of millions of dollars. But there are some beneficial aspects and some people can make many thousands of dollars due to their presence. This is an attempt to look at these issues.

Integrated pest management concepts for red imported fire ants Solenopsis invicta （Hymenoptera： Formicidae）

Management of imported fire ant species has evolved since their accidental introduction into the United States and currently uses integrated pest management concepts to design, implement, and evaluate suppression programs. Although eradication is the management goal in certain isolated infestation sites, localized goals vary dramatically in larger infestations where reinvasion of treated areas is likely. These goals are influenced by regulatory policies, medical liabilities, ecological impact, and/or economic considerations. Tactics employed in fire ant management programs presented here include cultural and biological control options along with judicious use of site-specific insecticide products. In addition, program design considerations that include management goal（s）, action level（s）, ant form （monogyne or polygyne）, presence ofnontarget ant species, size of treatment area, seasonality, implementation cost, and environmental impact are also presented. Optimally, elegant IPM programs are target specific, threshold driven, environmentally friendly and cost-effective.

Potential range expansion of the red imported fire ant(Solenopsis invicta) in China under climate change

The red imported fire ant（RIFA, Solenopsis invicta）, a notorious invasive insect, has received considerable attention owing to its impacts on native biodiversity, agriculture, and human health. Under global warming, the inhabitable area of the RIFA may be enlarged. However, few studies have focused on the potential range expansion of the RIFA in East Asia. Using a process-based physiological model, we simulated the potential range of the RIFA in China based on gridded temperature datasets for the current（2004–2012） and future（2090–2100） climates under Representative Concentration Pathway（RCP） 4.5 and RCP 8.5. It was found that the southeastern part of China（below 32°N） is suitable for RIFA proliferation. The present distribution area of the RIFA corresponds well with the potential range simulated by the model. In the RCP 4.5 and RCP 8.5 warming scenarios, the inhabitable area of the RIFA along the northern boundary would on average extend 101.3±85.7（mean±SD） and 701.2±156.9 km, respectively, by the end of the 21 st century. Therefore, future climate change would significantly affect the inhabitable area of the RIFA. Our results provide the basis for local quarantine officials to curtail accidental introductions of this insect, especially in the certain and possible infestation zones.

Arthropod prey of imported fire ants （Hymenoptera： Formicidae） in Mississippi sweetpotato fields

The red imported fire ants, Solenopsis invicta （Buren）, are generally considered pests. They have also been viewed as beneficial predators feeding on other insect pests of various agroecosystems. This study documents the foraging habits of fire ants in a sweetpotato field in Mississippi. Fire ant foraging trails connecting outside colonies to a sweetpotato field were exposed and foraging ants moving out of the field toward the direction of the colony were collected along with the solid food particles they were carrying. The food material was classified as arthropod or plant in origin. The arthropod particles were identified to orders. Fire ant foragers carried more arthropods than plant material. Coleoptera and Homoptera were the most abundant groups preyed upon. These insect orders contain various economically important pests of sweetpotato. Other major hexapod groups included the orders Hemiptera, Diptera and Collembola. The quantity of foraged material varied over the season. No damage to sweetpotato roots could be attributed to fire ant feeding. Imported fire ant foraging may reduce the number of insect pests in sweetpotato fields.

Traits allowing some ant species to nest syntopically with the fire ant Solenopsis saevissima in its native range

Supercolonies of the red fire ant Solenopsis saevissima （Smith） develop in disturbed environments and likely alter the ant community in the native range of the species. For example, in French Guiana only 8 ant species were repeatedly noted as nesting in close vicinity to its mounds. Here, we verified if a shared set of biological, ecological, and behavioral traits might explain how these 8 species are able to nest in the presence of S. saevissima. We did not find this to be the case. We did find, however, that all of them are able to live in disturbed habitats. It is likely that over the course of evolution each of these species acquired the capacity to live syntopically with S. saevissima through its own set of traits, where colony size （4 species develop large colonies）, cuticular compounds which do not trigger aggressiveness （6 species） and submissive behaviors （4 species） complement each other.

The Guianese population of the fire ant Solenopsis saevissima is unicolonial

In this study, conducted in French Guiana, a part of the native range of the fire ant Solenopsis saevissima, we compared the cuticular hydrocarbon profiles of media workers with previous results based on intraspecific aggressiveness tests. We noted a strong congruence between the two studies permitting us to delimit 2 supercolonies extending over large distances （up to 54 kin）, a phenomenon known as unicoloniality. Solenopsis geminata workers, taken as an out-group for cluster analyses, have a very different cuticular hydrocarbon profile. Because S. saevissima has been reported outside its native range, our conclusion is that this species has the potential to become invasive because unicoloniality （i.e., the main attribute for ants to become invasive） was shown at least for the Guianese population.

面向客船火灾的人员逃生路径规划研究

文中针对火灾蔓延对人员逃生过程的影响,提出一种客船火灾蔓延条件下基于改进蚁群算法的逃生路径规划算法.根据客船三维模型进行火灾蔓延模拟以掌握火灾蔓延态势,定义逃生人员火灾产物耐受限值进行可逃生区域识别,确定安全逃生节点.引入目标方向改进启发函数,避免陷入局部最优,加入最差蚁群的影响和信息挥发系数自适应化,改进蚁群算法的信息素更新机制.通过安全路径二次优化,减少规划出的路径中多余拐点.结果表明:改进后的蚁群算法可以有效地用于客船发生火灾时人员的逃生路径规划.

基于改进蚁群-麻雀算法的建筑火灾疏散路径规划研究

结合改进蚁群算法(IACO)和改进麻雀搜索算法(ISSA),提出一种考虑火灾实时蔓延的动态疏散路径规划模型。采用火灾动力学软件(FDS)得到火灾环境参数,以表示火灾实时蔓延的危险程度。基于IACO强大的全局搜索能力得到初始疏散路径。采用收敛速度快的ISSA对初始路径进行优化,以提高路径的稳定性。以某综合建筑为例进行2组不同火灾环境下的仿真实验,结果表明:IACO-ISSA模型相比ACO能够根据火灾发展情况实时调整疏散路径,从而有效躲避火灾危险区域,避免了忽略火灾动态蔓延而引导疏散人员至危险区域的现象,进一步提高了疏散路径的安全性。

元谋干热河谷区红火蚁药剂防控研究

红火蚁是元谋干热河谷区一种具有重大危害的危险性入侵生物,为了筛选出适用于干热河谷区的红火蚁防治药剂,开展了7种杀虫剂对红火蚁的防效试验。结果表明:对蚁巢的防控效果,药后7 d以8%高效氯氰菊酯可湿性粉剂的最好,其次是0.73%氟蚁腙饵剂,平均防效分别为100.00%和93.75%,药后14和21 d时,8%高效氯氰菊酯可湿性粉剂和2.05%氟蚁腙吡虫啉杀虫饵剂的防效均达100.00%,其他药剂处理的防效均为93.75%;8%高效氯氰菊酯可湿性粉剂在施药后1 d时单个蚁巢工蚁的虫口减退率达100.00%,且显著高于除0.1%呋虫胺饵剂处理以外的其他处理,施药后7 d供试药剂的虫口减退率均在90%以上,但在施药后21 d时其虫口减退率均出现下降。因此,可交替使用7种供试药剂进行红火蚁的防控,建议先撒施0.2%高效氯氰菊酯粉剂、0.73%氟蚁腙饵剂、2.05%氟蚁腙吡虫啉杀虫饵剂等控制红火蚁,然后用8%高效氯氰菊酯可湿性粉剂灌巢彻底铲除红火蚁。

红火蚁觅食行为及其在防治中的应用

红火蚁Solenopsis invicta Buren是极具危害性的入侵生物,已在我国多个省份地区扩散成灾。近年来,国内外在红火蚁觅食行为领域取得了一系列研究进展,为红火蚁防控提供了新的思路与方法。本文回顾了红火蚁觅食行为的相关研究,综述了红火蚁觅食的过程、行为机制及影响因素,并分析了觅食行为与防治的联系。红火蚁可广泛地采集和利用不同类型、大小和成分的食物。其觅食过程分为食物搜寻、搬运与处理等阶段,在这一过程中也可能伴随着食物埋藏、铺路越障和工具利用等行为。目前已报道多种跟踪信息素和关键基因可以调控红火蚁的觅食行为。此外,多种生物和非生物因素也会影响红火蚁的觅食行为和策略。基于红火蚁特殊的觅食行为模式,有望开发出专一性更强、对非靶标生物安全的监测和防控技术。建议在今后的研究中进一步探索红火蚁觅食行为的模式及其分子和化学机制,更好地将理论研究与防治实践相结合,控制红火蚁疫情蔓延危害。

基于Pareto蚁群算法的双目标路径规划研究

针对复杂建筑环境人员应急疏散单一路径不能满足火灾环境变化需求的问题,基于改进蚁群算法,结合Pareto双目标解集思想,提出一种组合优化解集的双目标蚁群算法,通过排序优化的思想,实现人员多路径动态疏散规划。在构造Pareto解集的阶段协同考虑疏散路径长度以及火灾风险程度2个优化目标,计算各个解之间的支配关系。利用排序优化蚁群算法的正反馈机制将各组解的信息素按一定比例作为最优路径信息素的积累,加快解集的寻找。最后将其与传统双目标蚁群算法相比较,结果表明:优化后的双目标算法更加适合复杂建筑人员疏散路径规划问题,在寻找多组满足要求解的同时展示目标之间的利弊关系,供决策者选择合适的路径,提高疏散效率。

我国蚂蚁和白蚁防治农药登记现状与展望

有些蚂蚁和白蚁种类是重要的世界性害虫,对人类生活造成显著影响,有关防治工作特别是化学防治一直受到密切关注。本文整理了我国蚂蚁和白蚁防治登记用药,汇总分析了蚂蚁、红火蚁、白蚁等化学防治药剂的基础数据,提出了加强农药登记监管和市场抽检、鼓励有效成分和配方制剂研发、进行应用场景分类和抗性监测等结论和建议,以期能够在指导药剂合理使用、促进农药产品升级、推动新型农药发展等方面发挥积极作用。

入侵红火蚁对脊椎动物的影响研究进展

红火蚁(Solenopsis invicta)具有扩散迅速、攻击性强等特点,常对入侵地区造成巨大的生态危害。虽然很多文献报道了红火蚁对无脊椎动物的影响,但红火蚁对脊椎动物影响的研究较少,也缺乏系统的总结。综述了红火蚁对不同脊椎动物类群的影响和主要的研究方法(野外调查、案例分析、实验室评估、比较分析和人工移除红火蚁),以及脊椎动物对红火蚁的行为和生理防御机制。一般而言,红火蚁常以腹部末端的螯针攻击其他动物并释放毒液,可直接捕食、伤害各种脊椎动物的卵、幼体和成体,并影响动物的行为。此外,红火蚁可降低生境内无脊椎动物的丰度,间接影响捕食者的种群数量。尽管红火蚁是陆生生物,但鱼类可能取食掉落在水面的有翅繁殖蚁而中毒,且漂浮于水面的红火蚁蚁筏也可能对鱼类造成威胁。由于两栖类动物通常体型较小,运动能力较弱,且皮肤缺乏角质层与鳞片毛发等结构的保护,极易受到红火蚁的攻击和伤害。对于鸟类和爬行类,红火蚁主要捕食卵和幼体,并干扰成体的筑巢和育幼行为,降低其繁殖成功率。此外,红火蚁对小型哺乳动物的觅食行为和种群数量均可造成负面影响,并可蛰刺伤害牛羊等家畜,对畜牧业造成巨大的经济损失。一些动物对红火蚁具有行为防御,如用附肢蹬掉体表的红火蚁,或避免取食或接触红火蚁。此外,一些动物能对红火蚁的毒素产生抗体,或调整体内荷尔蒙水平以应对红火蚁的攻击。然而,仍不清楚这些行为和生理反应是否普遍存在于其他脊椎动物,以及能在多大程度上保护其免受红火蚁伤害。值得注意的是,几乎所有的相关研究都是由国外研究者完成的,建议我国学者更多的关注红火蚁对我国经济物种、珍稀动物和食蚁物种的影响。

改进蚁群算法的森林防火移动机器人路径规划

为解决森林防火移动机器人在森林地形条件的最优路径规划问题,提出一种基于拓展邻域的改进蚁群算法。首先引入定向邻域拓展策略,并将搜索邻域从8个拓展至10个拓展,以求扩大搜索效率与范围;然后综合考虑影响移动机器人的多种因素,利用路径长度和能耗改进启发函数;接着通过位置信息改进初始信息素;最后结合最大-最小蚂蚁系统(MMAS)和精英蚂蚁等算法模型的优点,改进信息素更新规则。结果表明,所提出的改进蚁群算法与传统蚁群算法、基于多启发因素的改进蚁群算法相比,路径长度分别缩短7.66%、6.53%,能耗指标分别下降62.2%、49.3%,综合指标分别下降32.6%、23.1%。研究显示所提出的改进蚁群算法具有更强的全局搜索能力和较好的应用价值。