The management type used in plum orchards alters the functional community structure of arthropod predators

Abstract

The management practices in agroecosystems can alter the community structure of pests’ natural enemies, which can consequently disturb their biocontrol function. Here, we investigated how organic or conventional farming influence the community structure of arthropod predators (spiders, coccinelids, anthocorids, ants) in orchards. The three conventional orchards studied were plum tree monocultures where mainly fungicides were applied. The three organic orchards studied were dominated by plum trees with admixture of apple trees and no agrochemical was applied. We found that management significantly affected only spiders that were less abundant in the conventional orchards than in the organic orchards. In addition, the conventional management resulted in reduced species density and altered the community composition of spiders. The conventional management reduced the functional dispersion of spider body size, which may narrow the size-spectrum of pests that could be reduced by spiders. The conventional management also reduced abundances of foliage hunters and space-web spiders. Since these spiders are effective against various insect pests, the conventional management of applying fungicides might result in increased crop damage via increased insect pests.     

中国尖尾蚁属：膜翅目：蚁科一新种

本文记述了3种分布于中国的尖尾蚁,其中一种为新种:Acropyga(Atopodon)jiangxiensis Sp.nov.文后附有中国尖尾蚁属种检索表。     

昆明西山森林公园东坡蚂蚁物种多样性研究

采用样地调查法研究了昆明西山森林公园东坡5个垂直带和5个水平带22块样地旱季的蚂蚁群落与物种多样性.物种数目在2～13种之间,个体密度在6.2～1 808.2头·m-2之间,优势度指数在0.183 8～0.982 8之间,物种多样性指数在0.049 9～1.554 9之间,均匀度指数在0.072 0～0.724 0之间.在垂直带上,物种数目、物种多样性指数和均匀度指数随着海拔升高基本呈现递减趋势,而优势度指数基本呈现递增趋势,这种规律性在中段太华寺垂直带表现最明显.水平带上,物种多样性指数和均匀度指数只在2 250 m水平带上呈现从南向北依次递减规律.从生物多样性保护角度来看,在西山森林公园东坡5个垂直带中以中段太华寺垂直带植被保护最好,在水平带上以海拔2 250 m山体中上部植被结构最好.蚂蚁群落之间的相似性系数显示,西山森林公园虽然范围不大,但无论垂直带或水平带上,蚂蚁群落之间的差异显著.     

太白山锐齿栎树干基部两种蚂蚁的筑巢生态学及其蚁巢、体表真菌组成研究(英文)

本文研究了太白山锐齿栎景观林带树干基部筑巢的两种蚂蚁的筑巢生态学及其巢内真菌的组成。研究结果表明:亮腹黑褐蚁Formica gagatoides Ruzsky是锐齿栎林中的优势蚁种,可在地表及树干上活动,主要取食栎树枝条上蚜虫所分泌的蜜露及其他昆虫和植物材料;盘腹蚁Aphaenogaster sp.仅在蚁巢周围活动,捕食其他小型昆虫;亮腹黑褐蚁F.gagatoides蚁巢材料含水量非常高,而盘腹蚁Aphaenogaster sp.的蚁巢较为干燥。锐齿栎林中树干的平均蚁栖率为20.3%,但蚁栖率随海拔差异而不同(海拔1800m的锐齿栎林带蚁栖率仅为6%,海拔1600m的锐齿栎林带蚁栖率高达38.5%)。两种蚂蚁的长期营巢活动造成树干基部腐朽、孔洞不断扩大,严重影响锐齿栎树干的水分、营养传输及生长,且极易倒伏和风折。两种蚂蚁巢内及其体表真菌的种类组成明显不同,从亮腹黑褐蚁F.gagatoides蚁巢材料中可分离出7种真菌,而从盘腹蚁Aphaenogaster sp.巢中仅分离出2种;从亮腹黑褐蚁F.gagatoides体表可分离出4种真菌,而从盘腹蚁Aphaenogaster sp.体表分离到3种真菌;其中Tri...     

The impact of harvester ants on decomposition, N mineralization, litter quality, and the availability of N to plants in the Mojave Desert

In arid areas of North America, nests of the seed-harvesting ant Pogonomyrmex rugosus tend to be elevated in mineral nitrogen and other soil nutrients relative to other microhabitats. We investigated the roles of decomposition, N mineralization, and plant nutrient uptake in maintaining high standing stocks of nutrients in P. rugosus ant nests. Decomposition rates of standard cellulose substrates placed on the surface of ant nests and other desert microhabitats suggest that conditions found in ant nests and bare areas are conducive to higher rates of decomposition than conditions under shrubs. In laboratory incubations of moist soil, net N mineralization rates were significantly higher in soil from ant nests than from bare areas and under two of three plant species. Net N mineralization rates measured in situ were much lower than those measured in laboratory incubations, but ant nest soil still exhibited higher rates at one of two sites. Litter collected from ant mounds, composed chiefly of seed chaff, was similar in N content to litter collected from underneath the dominant plant species, but had a significantly higher mean δ¹⁵N. Using this distinctive isotope signature as a tracer, we found no evidence that large perennial shrubs tap ant nests as a source of N. An invasive, annual grass species was significantly enriched in ¹⁵N, had higher leaf %N, and produced more seeds when growing on the mound than when growing several meters away; however P. rugosus nest surfaces are typically free of such annuals. We conclude that both high rates of nutrient cycling relative to other Mojave Desert microhabitats and low N utilization by the surrounding vegetation contribute to high standing stocks of mineral N in P. rugosus nests.     

Effects of fire retardant application on heathland surface-dwelling ant species (Order Hymenoptera; Family Formicidae) in Victoria,Australia

The effects of fire retardant application at varying rates on surface-dwelling ants in heathland communities were assessed over a 1-year period from March 2001 to March 2002. The study was conducted at two sites, one in East Gippsland at Marlo and the other in the Grampians region of south-west Victoria where a total across both sites of 6407 specimens representing 18 ant species contained in 5400 pitfall trap samples were collected. It was concluded that despite retardant application, no significant effect was observed within the major ant species Rhytidoponera metallica (Smith) and Pheidole sp. at both sites. These species appear to form a stable component of the heathland ant community. However, significant decreases in activity were observed for Camponotus terebrans (Lowne) at the Grampians site and Paratrechina sp. at the Marlo site. Evidence suggests that retardant application when combined with prevailing suitable climatic conditions, leads to foliage mortality, litter accumulation and weed invasion, leading to potential creation of habitat less suitable for activity of these species. When assessed in terms of taxon richness and community evenness, ant species were unaffected at the Grampians, while at Marlo, community evenness was affected due to the smaller number of individuals collected in the medium retardant treatment. When assessed by their functional groupings, the Subordinate Camponotini showed significantly reduced activity on the retardant treated sites at the Grampians directly as a result of C. terebrans activity. Further study is required to determine the combined effects of fire and retardant on ant species, as well as any longer-term effects past 1 year.     

云南大理苍山及邻近地区蚂蚁的物种多样性

采用样地调查法揭示了大理苍山及邻近地区蚂蚁物种的多样性规律。该地区蚂蚁丰富度在我国处于中等水平,其物种数、多样性和均匀度基本符合山地蚂蚁多样性分布规律,即随着海拔上升而降低,优势度的规律正好相反,但在山体中部的蚂蚁群落拥有更高的多样性和均匀度;该地区多数蚂蚁物种具有明显趋阳性生境特点,其个体密度在郁闭度较低的针叶林内较大;蚂蚁群落间差异显著,但是相邻的同一植被间表现出较大的群落相似性,生境的多样化和植被的差异性促成了蚂蚁群落的多样性．     

Five New Records of Ants (Hymenoptera: Formicidae) From Morocco

A recent catalogue of the rich ant fauna of Morocco included 214 species, with later studies adding an additional 12 species. Following recent fieldwork in the north of Morocco, we report five new records for the country (Plagiolepis pygmaea Latreille, 1798, Ponera testacea Emery, 1895, Strumigenys tenuipilis Emery, 1915, Temnothorax pardoi Tinaut, 1987, and Tetramorium parvioculum Guillem & Bensusan, 2009) and we present new data on the distribution and natural history of six additional species. This work brings the total number of ants known from Morocco to 233, taking into account two species which were omitted in the list of Cagniant.     

藏东南嘎隆拉和墨脱河谷蚂蚁群落研究

[目的]为了揭示藏东南地区蚂蚁群落的生态学规律,对藏东南嘎隆拉和墨脱河谷不同样地的蚂蚁群落进行了调查研究,揭示藏东南地区蚂蚁多样性。[方法]采用样地调查法和手拣法进行调查;利用Estmaete S 9.1.0程序对数据进行处理,分析抽样充分性;利用多样性分析法,分析了蚂蚁群落的组成、优势种、物种多样性、群落均匀度及群落相似性等群落特征。[结果]合计发现蚁科Formicidae昆虫8亚科,45属,96种。分析发现,不同植被类型优势种和稀有种组成不同,稀有种较多。低海拔区域的沟谷雨林和常绿阔叶林蚂蚁优势种具有明显的热带和亚热带特征。多样性分析发现,各样地中的蚂蚁群落物种丰富度0 42种,个体密度0.0 1 805.6头·m-2,多样性指数02.285 5,均匀度指数0.251 0 0.873 6,优势度指数0.147 0 1.000 0。其中海拔1 200 m沟谷雨林的蚂蚁物种丰富度最高(42种);海拔1 450 m季风常绿阔叶林的多样性指数最高(2.285 5),优势度最低(0.147 0);海拔2 960m高山松林均匀度指数最高(0.873 6);高海拔的针叶林蚂蚁物种丰富度和多样性均最低,优势度最高。北坡分布的物种稀少,南坡物种丰富;群落相似性系数表明不同海拔和植被的蚂蚁群落间差异显著。[结论]嘎隆拉和墨脱河谷生境存在明显差异,蚂蚁群落的物种数目、个体密度、多样性指数和均匀度指数总体呈现随海拔升高和植被的更替而降低的规律,但在南坡下部和中部出现2个峰值,分别为热带和温带物种的聚集群,表现出多域效应现象(Multi-Domain Effect)。植被、海拔和坡向对蚂蚁物种的分布和多样性影响深刻。     

甘肃蚂蚁初步名录

对甘肃省蚁科昆虫进行了调查。结果表明,甘肃省蚂蚁有39种,分属于6亚科17属,其中猛蚁亚科(Ponerinae)3种;伪切叶蚁亚科(Mymicinae)1种;切叶蚁亚科(Myrmicinae)11种;粗角猛蚁亚科(Cerapachyinae)1种;臭蚁亚科(Dolichoderinae)2种;蚁亚科(Formici-nae)25种。