The hunter becomes the hunted: when cleptobiotic insects are captured by their target ants

Here we show that trying to rob prey (cleptobiosis) from a highly specialized predatory ant species is risky. To capture prey, Allomerus decemarticulatus workers build gallery-shaped traps on the stems of their associated myrmecophyte, Hirtella physophora. We wondered whether the frequent presence of immobilized prey on the trap attracted flying cleptoparasites. Nine social wasp species nest in the H. physophora foliage; of the six species studied, only Angiopolybia pallens rob prey from Allomerus colonies. For those H. physophora not sheltering wasps, we noted cleptobiosis by stingless bees (Trigona), social wasps (A. pallens and five Agelaia species), assassin bugs (Reduviidae), and flies. A relationship between the size of the robbers and their rate of capture by ambushing Allomerus workers was established for social wasps; small wasps were easily captured, while the largest never were. Reduviids, which are slow to extract their rostrum from prey, were always captured, while Trigona and flies often escaped. The balance sheet for the ants was positive vis-à-vis the reduviids and four out of the six social wasp species. For the latter, wasps began by cutting up parts of the prey’s abdomen and were captured (or abandoned the prey) before the entire abdomen was retrieved so that the total weight of the captured wasps exceeded that of the prey abdomens. For A. pallens, we show that the number of individuals captured during attempts at cleptobiosis increases with the size of the Allomerus’ prey.     

Vector navigation in desert ants, Cataglyphis fortis: celestial compass cues are essential for the proper use of distance information

Foraging desert ants navigate primarily by path integration. They continually update homing direction and distance by employing a celestial compass and an odometer. Here we address the question of whether information about travel distance is correctly used in the absence of directional information. By using linear channels that were partly covered to exclude celestial compass cues, we were able to test the distance component of the path-integration process while suppressing the directional information. Our results suggest that the path integrator cannot process the distance information accumulated by the odometer while ants are deprived of celestial compass information. Hence, during path integration directional cues are a prerequisite for the proper use of travel-distance information by ants.     

A comprehensive review of climate adaptation in the United States: more than before, but less than needed

We reviewed existing and planned adaptation activities of federal, tribal, state, and local governments and the private sector in the United States (U.S.) to understand what types of adaptation activities are underway across different sectors and scales throughout the country. Primary sources of review included material officially submitted for consideration in the upcoming 2013 U.S. National Climate Assessment and supplemental peer-reviewed and grey literature. Although substantial adaptation planning is occurring in various sectors, levels of government, and the private sector, few measures have been implemented and even fewer have been evaluated. Most adaptation actions to date appear to be incremental changes, not the transformational changes that may be needed in certain cases to adapt to significant changes in climate. While there appear to be no one-size-fits-all adaptations, there are similarities in approaches across scales and sectors, including mainstreaming climate considerations into existing policies and plans, and pursuing no- and low-regrets strategies. Despite the positive momentum in recent years, barriers to implementation still impede action in all sectors and across scales. The most significant barriers include lack of funding, policy and institutional constraints, and difficulty in anticipating climate change given the current state of information on change. However, the practice of adaptation can advance through learning by doing, stakeholder engagements (including “listening sessions”), and sharing of best practices. Efforts to advance adaptation across the U.S. and globally will necessitate the reduction or elimination of barriers, the enhancement of information and best practice sharing mechanisms, and the creation of comprehensive adaptation evaluation metrics.     

稳健变异函数在土壤污染物来源识别中的应用：以某重金属污染场地为例

空间特异值可以提供污染源的位置信息.以Genton稳健估计量为基础的变异函数为研究工具,对某重金属冶炼场地土壤中Cu、Zn、Pb、Cd、As、Se和Hg含量进行了空间特异值分析,并根据空间特异值的地理位置及土地利用方式等信息指示污染源.结果表明,7种元素变异函数曲线的理论模型符合球状模型,7种元素都具有较小的块金方差,Cu、Zn和Pb只为0.000.与Matheron估计量相比,该研究得到的变异函数具有更小的块金效应,说明Genton估计量能够消除或减弱特异值对变异函数的影响.7种元素的空间特异值多集中在个别小范围内,以簇状形式存在,与该区域冶炼高炉及尾渣堆放处的位置具有很好的相关性,说明冶炼行为及其相关过程是该区重金属的重要来源.     

Ambient volatile organic compounds at a receptor site in the Pearl River Delta region: Variations, source apportionment and effects on ozone formation

We present the continuously measurements of volatile organic compounds（VOCs） at a receptor site（Wan Qing Sha, WQS） in the Pearl River Delta（PRD） region from September to November of 2017. The average mixing ratios of total VOCs（TVOCs） was 36.3 ± 27.9 ppbv with the dominant contribution from alkanes（55.5%）, followed by aromatics（33.3%）. The diurnal variation of TVOCs showed a strong photochemical consumption during daytime,resulting in the formation of ozone（O₃）. Five VOC sources were ...