【作者】 陈浩涛；

【导师】 罗礼智；

【作者基本信息】 中国农业科学院 ， 农业昆虫与害虫防治， 2010， 博士

【摘要】 红火蚁Solenopsis invicta Buren(膜翅目:蚁科)是我国大陆于2004年发现、2005年确认的入侵害虫。目前红火蚁已在我国广东、广西、湖南、福建和江西等省区以及台湾、香港、澳门的局部地区发生。由于红火蚁威胁人体健康及生命安全,破坏生物多样性,损毁公共设施,危害农牧业生产,并给入侵地带来重大的经济损失。因此是被入侵国家或地区明文加以根除或限制扩散的对象,同时也是非发生(入侵)地区的头号检疫对象。但是我国对红火蚁的发生危害规律了解不多,监测、检疫及防治效果还不很理想。为了研究和阐明我国红火蚁的发生危害规律,为改善和提高红火蚁的监测、检疫和防治技术提供科学依据,并为控制红火蚁的蔓延和危害做出贡献,本文在认真分析了国内外已有研究结果的基础上,针对我国红火蚁监控实践中迫切需要解决的关键问题,对我国红火蚁的社会型、巢内蚁群结构、巢外活动的季节性规律、抗寒性和地理分布预测及风险评估等进行了较为系统的研究,取得了一些有意义的结果,主要的为:应用行为及生态学方法对红火蚁的社会型、蚁群内工蚁、幼虫和蛹的结构动态规律,以及蚁巢体积与巢内工蚁数量的关系进行了系统的研究,取得了一些新的结果:应用工蚁的攻击性结合蚁巢蚁后数量的测定方法对陆川、广州、珠海和深圳红火蚁的社会型进行研究的结果表明,我国的红火蚁以多蚁后型为主。在所测定的79个蚁巢中,多后型蚁巢占了73个,比例高达92.4%。其中陆川、珠海和深圳的蚁群全为多蚁后型,广州的30个巢群中有6个单后型蚁群。这些结果不仅再次肯定了我国的红火蚁主要是以多后型为主的结论,而且也为红火蚁社会型的判别提供了简易、可行的操作方法;从9月份到次年7月份每两月调查一次的结果表明,红火蚁蚁丘体积从开始调查时逐渐增大,到一月份增大到最大值后便开始逐渐变小,到五月份达到最小值后又逐渐增加。从而使得这一研究年中的蚁丘体积变化呈“V”型变化,并使不同季节之间的蚁巢大小差异显著;蚁巢内总蚁量及工蚁的百分比含量的变化也因季节的不同而异,并与蚁丘大小相对应。即蚁巢内的总蚁量在下半年持续增加,到1月达最大值后逐渐减少到7月份。不同季节间的蚁巢内个体数量差异显著;蚁丘内工蚁总量与蚁丘底部直径有显著的相关性(R=0.78,P<0.05),可以用y=1.335x2.894(r2=0.765,P<0.05)来描述两者之间的关系;幼虫、蛹、有翅蚁占蚁群个体总量的比在不同的季节中也存在着显著的差异,但他们的数量比与工蚁的数量比呈现出相反的趋势。这些结果不仅较为系统地阐明了我国红火蚁主要发生危害区的种群及结构动态规律,而且为改善和提高红火蚁的监控技术水平提供了重要的实验依据。应用行为生态学方法对红火蚁工蚁季节及白天巢外活动,以及有翅蚁的婚飞规律进行研究的结果表明:工蚁一年中的巢外活动强度随季节或月份的不同而存在着显著差异。就工蚁的季节性活动节律而言,以6月和10月份的活动强度最高,1月和2月份的活动最弱,工蚁在其余月份的活动强度居于这两个时间段之间。工蚁巢外活动的日节律随季节的不同而异:1～2月,工蚁活动较少,在气温较高的晴天才可能在中午前后活动;3～4月,工蚁中午活动最盛,呈单峰型;7～10月,中午活动减弱,呈双峰型;5～6月和11～12月,呈不明显的双峰型。这些结果表明,工蚁的巢外活动受气温的影响极大。另外,降雨后有利于工蚁的巢外活动,但在降雨时刻可抑制工蚁的巢外活动。在试验观察区内全年都可见到有翅蚁婚飞的现象,但婚飞主要集中在3～5月份,婚飞活动主要发生在雨前或雨后。这些首次获得的结果为开展红火蚁的监控活动以及制定正确、有效的监控技术提供了重要的科学依据。应用低、中和高三种干扰强度对大小不同的蚁群进行干扰后的工蚁行为反应进行观察的结果表明:蚁群受侵扰后出巢工蚁的最大数量随侵扰强度加大而增大。小型蚁巢对低侵扰强度反应时间(0.80±0.03s)明显长于对中(0.40±0.04s)、高侵扰强度时的反应时间(0.51±0.02s);但大、中型蚁巢对所有侵扰强度都能做出快速反应;侵扰强度越大、蚁巢越大,出巢的工蚁量越多,这个过程可以用不同的房室模型描述;1.5m和0.5m两种侵扰强度下任一计数时刻工蚁中大工蚁的百分比无显著差异;工蚁在蚁丘上同方位的等面积区域蚁量因距离加大而减少,在与中心等距离的等面积区域工蚁数量不因方位不同而异。这些结果为进一步了解红火蚁的攻击行为以及如何防护人体免于红火蚁的攻击提供了重要的实验依据。应用昆虫抗寒性原理及抗寒能力的研究方法测定了我国红火蚁蚁群中不同等级、虫态、地理种群、季节,以及不同饥饿程度的工蚁过冷却点。所得的结果表明:蚁群中不同等级和虫态的过冷却点差异显著。工蚁成虫的过冷却点(-11.8℃)显著低于有翅雌蚁(-8.1℃)及蚁后(-7.9℃)的,工蚁蛹和幼虫的过冷却点分别为-13.6℃和-12.1℃,蚁后蛹和幼虫的分别为-13.3℃和-12.2℃。工蚁蛹的过冷却点均显著低于成虫和幼虫的。蚁后蛹与幼虫的没有显著差异,但与成虫的差异显著。同一未成熟期不同等级之间的也没有显著差异;工蚁过冷却点有着明显的季节性差异,按春(-4.3±0.1℃)、夏(-6.6±0.2℃)、秋(-9.4±0.1℃)、冬(-12.0±0.2℃)依次降低;深圳、珠海、广州和陆川4个地理种群的工蚁过冷却点在春、秋和冬季的无显著差异,饥饿可使工蚁的过冷却点明显升高,但大工蚁较小工蚁的升高的幅度更大,饥饿15 d后的大工蚁比饥饿前的过冷却点升高了7.0℃,而小工蚁仅升高了4.9℃。这些结果的获得,为进一步明确红火蚁抗寒能力的发展,及其在我国分布北界的确定提供了进一步的实验依据。以高于发育起点温度的有效积温作为决定性因子,以年均降雨量和1月等温线-2℃作为限制性因子,应用GIS的Kriging空间插值功能对我国红火蚁的潜在分布区进行了预测的结果表明,红火蚁在我国的适生性分布情况可以分为高度适生区、适生区、轻度适生区和非适生区四个类型。其中海南、台湾最南部、南海诸岛、广东大部、香港、澳门、广西大部、云南玉溪市的局部、福建南角和西南角、江西和湖北大部是红火蚁的高度适生区。这些区域约占全国面积的7.4%;云南西南边陲窄长地带和玉溪极其周边局部地区以及楚雄与四川攀枝花交接处,广东西部及北部,广西北部小区域,河南与湖北和安徽交界处的局部极小区域,安徽西南角,浙江南部及濒临上海部分地区,上海市、江苏靠近上海的极小面积,重庆大部,四川靠近重庆小部分区域以及攀枝花与云南楚雄交接处小范围区域,湖南大部,贵州铜仁靠近湖南的部分区域,福建大部,台湾除南端外的大部,是红火蚁的适生区,这些区域主要是华中、华东和西南的部分地区,约占国土面积的8.4% ;轻度适生区主要分布在贵州东中部,云南大部,川、甘、陇交界附近地区,鲁、豫、皖、苏交界附近地区,福建戴云山周边高海拔地区,约占国土面积的6.0%。我国的西北、东北和华北以及西南的大部分地区,华中、华东部分地区,湖南雪峰山周边及衡山到湘西南的桂东、汝城山地,为红火蚁的非适生区,约占国土面积的78.2%。红火蚁的各类适生区涉及到中国大陆19个省、直辖市和自治区,以及港、澳、台等地,约占国土面积的21.8%。采用“多指标综合风险评估方法”对红火蚁生物学、地理分布、危害严重程度及经济影响,并结合上述研究结果的综合分析,对红火蚁在我国的检疫地位进行了系统的评价。结果显示红火蚁的综合风险值为2.23,属于高风险外来入侵生物,在我国具有很高的分布和危害风险,必须采取严格的检验措施防范该虫的传入与扩散。这些结果为政府扑灭红火蚁及制定检疫措施提供了科学依据。更多还原

【Abstract】 The red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) is an invasive pest that was found firstly in 2004 and affirmed to establish permanent colonies in China’s mainland in 2005. At present, it distributes sporadically in parts of the Guangdong, Guangxi, Hunan, Fujian and Jiangxi, Taiwan, Hong Kong and Macao, with the largest areas spreading in Guangdong province. The S. invicta, as one of the most detrimental pests that has tremendous capacity to injury and threaten to the safety of human being, living storks, wild animals, crop production and public utilities has been treated as a quarantine and eradicating species since it was found in China. However, the monitoring, quarantine and control efficacy of S. invicta in China is limited for it is a new pest to the country. The variations in social forms in different geographic locations, composition and supercooling points of various castes and developmental stages in the colonies, out-nest activity of worker ants and nuptial flight of alates, potential expansion range and the integrated risk assessment for S. invicta in China were studied to improve its monitoring, quarantine and management techniques, which are necessary to reduce the population and damages of fire ant in China’s mainland. The main results obtained were summarized as follows:Results on the social forms, variations in proportions of the worker ants, larvae and pupae in the colonies, relation between nest volume and the number of individuals were demonstrated through a year field investigation by applying ecological and behavioral principles and methods. Results obtained through combined investigations of aggressive behaviors of worker ants and nest dissection for queen numbers showed that 92.4% (73/79) of the colonies identified in four locations of Guangdong and Guangxi were belonged to polygene, while a small portion (6/30) investigated in Guangzhou was monogyne. These results were consistent to those identified by multiplex PCR of Gp-9 alleles and hence, provided a reliable and simplified method for the social forms identification methods that may used in the field. The results obtained from bimonthly field investigations from September to July showed that volume of the active mounds continued to increase from July and decrease after the mounds reached to their maximum volumes in January. The mounds kept to decrease afterwards until they reached to the minimum in March. Variations in mound volume made their annual growth curve look like a V shape and differed significantly. Total number of individuals and percentage of the worker ants in the mound corresponded to the size of mound and differed as the season varied. That is, total number of individuals in the mound increased and reached the maximum from September to November, then decreased until it reached the minimum in March, and increased again until July. Percentages of the larvae, pupae and alates in the mounds however, showed an opposite trend to that of the worker ants. There was a close relationship between the size of the mound and number of worker ants (r =0.78, P<0.05), which could be described by the formula Y = 1.335x2.894 (r2 = 0.765, P<0.05). All these results not only demonstrated the ecological and behavioral aspects of S. invicta in China’s mainland but also provided a substantiate basis to improve its monitoring and managing techniques. Daily and seasonal out-net activity of the workers and nuptial flights of the reproductive forms (alates) investigated in Guangzhou area (113°45E′, 22°43′N) of Guangdong province demonstrated that these activities of S. invicta differed significantly as season or month varied. Annually, the out-net activity of worker ants peaked in June and October, while that occurred in January and February was the lowest although they could be found in sunny and warm days during these period. The out-net activity of worker ants in a day also differed in different months. From January to February, worker ants hardly left their nest in general except the time when it was at noon on a warm and sunny day. From March to April, workers’activity peaked at noon, but from July to October, workers were more active in the morning and afternoon. From May to June, and November to December, the out-net activity of worker ants declined at noon in comparison with that in the morning and evening. All the out-nest activity of worker ants is dominated by temperatures. On the other hand, the out-nest activities of worker ants were enhanced before and after reining but was held back by depositions. Nuptial flights of alates took place all the year around, but occurred mainly in the afternoon from March to May. The nuptial flights of alates were also enhanced before or after raining.Results obtained showed that worker ants responded differently to various degrees of nest intrusion and size of the colonies. In general, the response of worker ants to the nest intrusion were speeded up as the intention of disturbance increased, which was exemplified by the evidences that the worker ants needed 0.80±0.03 s, 0.4±0.04 s and 0.51±0.02 s to rush out from the mounds that were hit by the ball fallen from the heights of 0.5 m, 1.0 m and 1.5 m, respectively. There were no significant difference between the percentages of large workers by the intrusions of balls fallen from the height of 1.5m and 0.5m. Besides, the response and number of worker ants from the larger mounds were much quicker and greater than those from the smaller mounds at the same degree of intrusion. As a consequence of that, the greater mounds would have more worker ants rush out when they subjected heavier intrusion. The processes of worker ants in different size of the mounds responded to different intrusion could be described by the Fang’s formulas. One thing worthy to be mentioned was that the number of worker ants was decreasing as the distance from center of the disturbing mound increasing but were insignificantly different at different orientation. These newly obtained data provided not only a basis to understand the aggressive behavior of S. invicta but also some helps to human beings to protect themselves from its attacks.To elucidate the cold hardness and provide basis for its risk assessment in China’s mainland, the supercooling points (SCPs) of various castes of adults, pupae and larvae, workers collected in different geographic locations and seasons and treated by durative starvations were examined and reported here. Our results indicated that the SCPs of fire ants differed significantly among castes and developmental stages. The worker ants had a significant lower SCP (-11.8℃) than those of the reproductive adults. Adults had a higher mean SCP than immature individuals. Queens had the highest SCPs (-7.9℃) while the pupae of workers had the lowest (-13.6℃). The SCPs was not significantly different in workers collected from different geographic locations of Luchuan, Guangzhou, Zhuhai and Shenzhen in spring, autumn and winter except those colleted in summer. SCPs of worker ants decreased as the season progressed, with the highest for spring (-4.3℃), the second for summer (-6.6℃), and third for autumn (-9.4℃) and lowest (-12.0℃) for winter colonies. The SCPs of worker ants increased greatly by a durative starvation of 15 days. The distribution of their SCPs shifted from a range of -14.7℃and -8.6℃before starvation to -10.4℃and -2.0℃at end of 15-days test. The SCP of major workers and minor workers increased 7.0℃and 4.9℃, respectively during the test period, indicating that the major workers are less resistant to starvations than the minor workers.The potential distribution range of S. invicta in China was predicted by using Kriging spatial interpolation function in the geographic information system (GIS) software, the number of degree-days as main determinant, and annual precipitation of 500 mm and the average temperature of -2℃in January as limiting factors. Results obtained demonstrated that the potential distribution range of S. invicta in China could be divided into four regions. They were named as the most suitable region (MSR), suitable region (STR), less suitable region (LSR) and unsuitable region (USR). The MSR included Hainan, Hong Kong, Macao, the great part of Guangdong, Jiangxi and Hubei, central and southern Guangxi, and part of southern Yunnan and Taiwan. The STR included northern and western Guangdong and Guangxi, the great part of Fujian, Hunan and Chongqing, northern Taiwan, southern Guizhou, the area of Sichuan near Chongqing, the southwestern area near the border line in Yunan, the southern and the northeastern of Zhejiang near to Shanghai, a small area of southern Jiangsu and the southwestern Anhui. The LSR included the central and eastern Guizhou, the area near the common boundary of Sichuan, Gansu and Shanxi, the area near the common boundary of Henan and Shandong. The other regions in the country that were not previously mentioned were the unsuitable area because of the limitations of drought and low temperature. The MSR, STR, LSR possesses 7.4%,8.4% and 6.0% of China’s territory, respectively. Briefly, the total ranges suitable for the expansion of S. invicta in China including large or small parts of 19 provinces, which equals to 21.8% of the territory in the country.The rank of quarantine importance of S. invicta was evaluated by an integrated risk assessment method combining analysis of the data on its biology, destructive capacity, potential geographic rage, economic impact and cost of eradication. The result showed that the integrated risk score for this pest is 2.23, suggesting that China is being at risk for S. invicta infestation and detrimental impacts. These results implied that quarantine officials should be vigilant for any accidental introductions of S. invicta in suitable regions of China and the quarantine regulations against this pest should be strictly followed in the country.更多还原