Laboratory and In situ Selenium Bioaccumulation Assessment in the Benthic Macroinvertebrates Hyalella azteca and Chironomus dilutus.

Selenium (Se) bioaccumulation and toxicity in aquatic vertebrates have been thoroughly investigated. Limited information is available on Se bioaccumulation at the base of aquatic food webs. In this study, we evaluated Se bioaccumulation in two benthic macroinvertebrates (BMI), Hyalella azteca and Chironomus dilutus raised in the laboratory and caged in-situ to a Canadian boreal lake e (i.e., McClean Lake) that receives continuous low-level inputs of Se (< 1 µg/L) from a uranium mill. Additional Se bioaccumulation assays were conducted in the laboratory with these BMI to (i) confirm field results, (ii) compare Se bioaccumulation in lab-read and native H. azteca populations and (iii) identify the major Se exposure pathway (surface water, top 1 cm and top 2-3 cm sediment layers) leading to Se bioaccumulation in H. azteca. Field and laboratory studies indicated overall comparable Se bioaccumulation and trophic transfer factors (TTFs) in co-exposed H. azteca (whole-body Se 0.9-3.1 µg/g d.w; TTFs 0.6-6.3) and C. dilutus (whole-body Se at 0.7-3.2 µg Se/g d.w.; TTFs 0.7-3.4). Native and lab-reared H. azteca populations exposed to sediment and periphyton from McClean Lake exhibited similar Se uptake and bioaccumulation (NLR, p = 0.003; 4.1 ± 0.8 µg Se/g d.w), demonstrating that lab-reared organisms are good surrogates to assess on-site Se bioaccumulation potential. The greater Se concentrations in H. azteca exposed to the top 1-3 cm sediment layer relative to waterborne exposure, corroborates the importance of the sediment-detrital pathway leading to greater Se bioaccumulation potential to higher trophic levels via BMI.

Seed morphology and germination of Willd. ex Schult. emulating environmental conditions within ant nest.

Damiana (Turnera diffusa Willd. ex Schult.) is a species of plant used in traditional Mexican medicine for its aphrodisiac properties. Although it has a high commercial demand, both nationally and internationally, its sexual propagation is not usual due to the low percentage of seed germination. It has been proposed that ants play an important role in germination, due to the presence of elaiosomes. Therefore, the objectives of this study were to characterize the seed morphology of T. diffusa for agronomic purposes, analyze their viability, and evaluate their germination by simulating environmental conditions of an ant nest. For the morphological characterization, 30 seeds were selected and evaluated for the variables of color, size, and weight. Viability was evaluated with a tetrazolium test using two lots of seeds collected in 2016 and 2017, with different concentrations and three exposure times at 40°C. The germination of T. diffusa was evaluated under three pre-germination treatments and nine germination treatments. The results of the study showed that the seeds of T. diffusa have an average size of 0.725 mm long and 0.182 mm wide; the color of the seeds varies from brown to black when ripe and yellowish white when immature. There are no significant differences in the viability percentage (60%) for seeds collected in 2016 and 2017 (p = 0.20). On the other hand, there are significant differences between all the pre-germination and germination tests analyzed. Seeds of T. diffusa have the highest percentage of germination (36%) with the presence of elaiosome and 500 ppm of GA3. The germination interval of the seeds occurs over a period of six to 39 days. The application of GA3 in the germination of the seeds indicates that they present a physiological latency which was inhibited at concentrations of 500 and 300 ppm.

Coupled Oscillators in an Agroecosystem: Integrating Direct and Indirect Effects.

AbstractAgricultural pests are increasingly appreciated as subjects of ecology. One particular case, a pest in coffee production, is analyzed here using the conceptual framework of complex systems, increasingly acknowledged as having an obvious home in the field of ecology, notorious for its complex structures. The particular case analyzed here arguably falls under the control of the complexity of the ecological system rather than of a simple magic bullet of population regulation. The system, which has been under study in southern Mexico for the past quarter century, is analyzed through the lens of neutral oscillations of the classical nondissipative Lotka-Volterra system. Based on three consumer/resource pairs (populations of [1] an ant, [2] a scale insect, [3] a beetle predator of the scale insect, [4] a fungal pathogen of the scale insect, and [5] a fly parasitoid of the ant), this five-dimensional system is well known qualitatively. Coupling all agents through both direct effects and trait-mediated indirect effects, the behavior of the neutral oscillation form of the system reveals a complex set of behaviors, including harmonized invariant sets, chaos, and/or quasiperiodicity. Such behaviors are well-known subjects in the science of complex systems and, it is argued, are ultimately sufficient to effect a degree of regulation on the pest, independent of explicit density-dependent feedback. Control of the system is thus seen as arguably actuated through its complexity, independent of any classic dissipative force.

Fumigant toxicity and behavioral alterations of six plant essential oils against the red fire ant (Solenopsis invicta Buren).

The red imported fire ant (RIFA), Solenopsis invicta Buren (Hymenoptera: Formicidae), is an invasive species that is considered to be among the 100 most dangerous species to human health and the environment. RIFA is currently controlled primarily by chemical insecticides. However, human health concerns and environmental problems require environment friendly, green insect pest control technology. In this study, the HS-SPME-GC/MS method was used to determine the volatile components of six essential oils, namely Illicium verum Burm, Blumea balsamifera (L.) DC., Citrus limon Burm, Acorus tatarinowii Schott, Mosla chinensis Maxim, and Cinnamomum cassia Presl, as well as their fumigation activity against RIFA. D-Limonene was identified as a core volatile in all six essential oils. The effects of volatile substances from essential oils on the fumigation activity and behavior of RIFA workers were studied by closed fumigation method. Except for C. limon essential oil, all other five plant essential oils exhibit excellent fumigation activity under the treatment of a concentration at 10 µL/ cm3 within 24 h. All plant essential oils are capable of causing the death of all red fire ants, while C. limon essential oil exhibited the lowest fumigation activity at 63.25%. Significant reductions in RIFA aggregation, aggressiveness, and gripping abilities were observed with all plant essential oils, and antenna sensilla appeared to bend or break. Moreover, after treating red ant fire ants with essential oil for 24 h, three protective enzyme activities were assessed. All six plant essential oils were shown to have enhanced enzyme activities for superoxide dismutase (SOD), glutathione S-transferase (GST), and catalase (CAT). It has been shown that plant essential oils have the capability of reducing the viability of red fire ants via receptor and behavioral factors, ultimately causing them to die off. As a conclusion, plant oils were demonstrated to be negatively affecting RIFA and providing a green and environmentally sustainable control method in this study.

Silver nanoparticles induced with aqueous black carpenter ant extract selectively inhibit the growth of Pseudomonas aeruginosa.

Aqueous black carpenter ant extract (ABCAE) was used to synthesize silver nanoparticles (AgNPs). The ABCAE was rich in water-soluble compounds such as hydrophilic polypeptides that behaved as both reducing and stabilizing agents for generating AgNPs from Ag+ ion precursors. The diameter of the observed AgNPs was mostly in the range of 20-60 nm. The AgNPs were tested as an antibacterial agent for the growth inhibition of two pathogenic bacteria (Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 27661) and one common bacteria (Escherichia coli K12 ATCC 10798). Disk diffusion test showed that the AgNPs selectively inhibited the growth of P. aeruginosa but not for the other two species, suggesting the potential application of the green-chemically synthesized AgNPs as a selective antibacterial agent without harming other beneficial bacteria.

Predacious Natural Enemies Associated With Suppression of Onion Thrips, Thrips tabaci (Thysanoptera: Thripidae), in Intercropped Onion-Barley Agroecosystems.

The effects of two possible factors, prevention of pest immigration and enhancement of natural enemies, in suppressing onion thrips, Thrips tabaci L., were estimated in a small-scale experimental system of spring-planted onions intercropped with barley. The population dynamics of the thrips and their potential predatory natural enemies were investigated in four treatments: control (bare ground), insect net barrier, and onion-barley intercropping with or without trimming. We found that intercropping significantly suppressed onion thrips. It is unlikely that this effect was due to the prevention of thrip immigration because they seemed to move over the camouflage and/or physical barriers of the barley and the net barrier surrounding the onions easily. Intercropping with barley significantly increased hoverfly (Syrphidae) larvae numbers on onion leaves, and that of some groups of ground-dwelling predators such as large carnivorous ground beetles (Carabidae), ants (Formicidae), and wolf spiders (Lycosidae). We conclude that the suppression of thrips in this system was associated with the enhancement of hoverfly larvae abundance, mainly Sphaerophoria macrogaster (Thomson) (Syrphidae: Diptera) because they were observed together with thrips on onions and have been reported to predate thrips as well as aphids. Some hoverfly larvae on barley might move to nearby onions to search for new food sources and attack thrips.

Fumigant toxicity and behavioral inhibition of garlic against red imported fire ants (Solenopsis invicta).

In order to control the Solenopsis invicta (S. invicta) in a safe and ecofriendly manner, this study evaluated the fumigating activity of garlic and its effect on the behavior of S. invicta. The volatile compounds and chemical constituents from garlic were collected by solid phase micro-extraction and identified by gas chromatography-mass spectrometry (GC-MS). The results showed that garlic contains 21 compounds, and that diallyl disulfide (46.51%) and (E)-1-Allyl-2-(prop-1-en-1-yl) disulfane (34.68%) were the main constituents in garlic. In addition, garlic showed strong fumigant activity and behavioral inhibition against workers. The LC50 values of diallyl disulfide and methyl allyl disulfide against S. invicta at 12 h were 0.05 and 0.07 µg/L, respectively. The grasping and walking abilities of ants were significantly suppressed. Moreover, minor workers were more susceptible than major workers. Thus, S. invicta can be controlled with garlic and some of its compounds as an eco-friendly approach. Results from the study could provide valuable advances for future fumigant development and possible utility in fumigant use.

Nest refuse of Acromyrmex balzani (Hymenoptera: Formicidae) increases the plant vigor in Turnera subulata (Turneraceae) / O substrato de descarte de Acromyrmex balzani (Hymenoptera: Formicidae) aumenta o vigor da planta Turnera subulata (Turneraceae)

Abstract Some studies report the positive effect of organic residues from ant nests on soil properties and on the structure of the adjacent plant community in field experiments, but there is a gap about the effect on individual species. The purpose of the present study was to compare the soil nutrient content and the development of Turnera subulata Smith, an ornamental species, in the presence of the nest refuse (basically composed of fragments of grass leaves and the symbiotic fungus) produced by the leaf-cutting ant Acromyrmex balzani (Emery, 1890) or in control soil through a greenhouse pot experiment. The experiment was carried out with two treatments: control soil and soil with 25% of nest refuse. The plants were kept in 1L pots for 90 days. We evaluated the parameters: plant height, stem diameter, root length, number of leaves, dry weight of the root, dry and fresh aboveground biomass. Additionally, the relative chlorophyll content and leaf nutrients were used as nutritional parameters. As a result, plants that grew in the soil with nest refuse showed significant higher values of all parameters evaluated when compared to the control treatment (p < 0.001). We conclude that this biofertilizer contributed to the production of more vigorous plants, being able to act on the local dynamics of nutrients in the ecosystems where A. balzani occurs. As it is relatively abundant and easy to collect, the refuse of A. balzani has the potential to be used as an alternative substrate in the production of shortlife cycle plants.

Resumo Alguns estudos relatam o efeito positivo de resíduos orgânicos de formigueiros nas propriedades do solo e na estrutura da comunidade de plantas adjacentes em experimentos de campo, mas há uma lacuna sobre o efeito em espécies individuais. O objetivo do presente estudo foi comparar o desenvolvimento de Turnera subulata Smith, uma espécie ornamental, na presença do substrato de descarte (SD) de formigueiros produzido pela formiga cortadeira Acromyrmex balzani (Emery, 1890) por meio de experimento em casa de vegetação. O experimento foi conduzido com dois tratamentos: solo controle e solo com 25% de SD. As plantas foram mantidas em vasos de 1L por 90 dias. Foram avaliados os parâmetros: altura da planta, diâmetro do caule, comprimento da raiz, número de folhas, massa seca da raiz, biomassa seca e fresca da parte aérea. Além disso, o conteúdo relativo de clorofila e os nutrientes foliares foram usados como parâmetros fisiológicos. Como resultado, as plantas que cresceram no solo com SD apresentaram valores significativamente maiores de todos os parâmetros avaliados quando comparadas ao tratamento controle (p < 0.001). Concluímos que esse biofertilizante contribuiu para a produção de plantas mais vigorosas, podendo atuar na dinâmica local de nutrientes nos ecossistemas onde A. balzani ocorre. Além disso, por ser relativamente abundante e fácil de coletar, o SD de A. balzani tem potencial para ser utilizado como biofertilizante na produção de plantas de ciclo de vida curta.

Nest refuse of Acromyrmex balzani (Hymenoptera: Formicidae) increases the plant vigor in Turnera subulata (Turneraceae) / O substrato de descarte de Acromyrmex balzani (Hymenoptera: Formicidae) aumenta o vigor da planta Turnera subulata (Turneraceae)

Some studies report the positive effect of organic residues from ant nests on soil properties and on the structure of the adjacent plant community in field experiments, but there is a gap about the effect on individual species. The purpose of the present study was to compare the soil nutrient content and the development of Turnera subulata Smith, an ornamental species, in the presence of the nest refuse (basically composed of fragments of grass leaves and the symbiotic fungus) produced by the leaf-cutting ant Acromyrmex balzani (Emery, 1890) or in control soil through a greenhouse pot experiment. The experiment was carried out with two treatments: control soil and soil with 25% of nest refuse. The plants were kept in 1L pots for 90 days. We evaluated the parameters: plant height, stem diameter, root length, number of leaves, dry weight of the root, dry and fresh aboveground biomass. Additionally, the relative chlorophyll content and leaf nutrients were used as nutritional parameters. As a result, plants that grew in the soil with nest refuse showed significant higher values of all parameters evaluated when compared to the control treatment (p < 0.001). We conclude that this biofertilizer contributed to the production of more vigorous plants, being able to act on the local dynamics of nutrients in the ecosystems where A. balzani occurs. As it is relatively abundant and easy to collect, the refuse of A. balzani has the potential to be used as an alternative substrate in the production of shortlife cycle plants.

Alguns estudos relatam o efeito positivo de resíduos orgânicos de formigueiros nas propriedades do solo e na estrutura da comunidade de plantas adjacentes em experimentos de campo, mas há uma lacuna sobre o efeito em espécies individuais. O objetivo do presente estudo foi comparar o desenvolvimento de Turnera subulata Smith, uma espécie ornamental, na presença do substrato de descarte (SD) de formigueiros produzido pela formiga cortadeira Acromyrmex balzani (Emery, 1890) por meio de experimento em casa de vegetação. O experimento foi conduzido com dois tratamentos: solo controle e solo com 25% de SD. As plantas foram mantidas em vasos de 1L por 90 dias. Foram avaliados os parâmetros: altura da planta, diâmetro do caule, comprimento da raiz, número de folhas, massa seca da raiz, biomassa seca e fresca da parte aérea. Além disso, o conteúdo relativo de clorofila e os nutrientes foliares foram usados como parâmetros fisiológicos. Como resultado, as plantas que cresceram no solo com SD apresentaram valores significativamente maiores de todos os parâmetros avaliados quando comparadas ao tratamento controle (p < 0.001). Concluímos que esse biofertilizante contribuiu para a produção de plantas mais vigorosas, podendo atuar na dinâmica local de nutrientes nos ecossistemas onde A. balzani ocorre. Além disso, por ser relativamente abundante e fácil de coletar, o SD de A. balzani tem potencial para ser utilizado como biofertilizante na produção de plantas de ciclo de vida curta.

Studying the Rationale of Fire Ant Sting Therapy Usage by the Tribal Natives of Bastar Revealed Ant Venom-Derived Peptides with Promising Anti-Malarial Activity.

Prevailing drug resistance in malaria imposes the major roadblock for the existing interventions necessitating the timely need to search for alternative therapies. Ants in Solenopsis spp, termed 'Fire ants', are well known for their aggressive behavior, which leads to the release of toxic venom. Notably, the tribal natives of the malaria-laden densely forested Bastar region, Chhattisgarh, India, use fire ant sting-based therapy to cure malaria-like high fever. Inspired by this, we have collected the fire ants from the forest of Bastar and extracted peptide and alkaloid fractions from ant venom using HPLC and analyzed them by LC/MS-based applications. Evaluation of the anti-malarial efficacy of these peptide fractions demonstrated a significant reduction in the growth of Plasmodium falciparum (Pf 3D7) in vitro, whereas the alkaloid fraction showed a negligible effect. in vitro hemolytic activity confirmed the venom peptide fraction to be non-hemolytic. Additionally, the venom peptide fraction is purely non-toxic to HepG2 cells. Anti-malarial efficiency of the same in Plasmodium berghei ANKA infected mice models showed a drastic reduction in parasitemia representing promising anti-malarial activity. Overall, our study has unraveled the scientific rationale underlying fire ant sting therapy used as a tribal naturotherapy for curing malaria-like fever, thus, introducing a way forward to develop nature-inspired anti-malarial chemotherapeutics.

1-Octanol emitted by Oecophylla smaragdina weaver ants repels and deters oviposition in Queensland fruit fly.

Humans have used weaver ants, Oecophylla smaragdina, as biological control agents to control insect pests in orchards for many centuries. Over recent decades, the effectiveness of weaver ants as biological control agents has been attributed in part to deterrent and oviposition inhibiting effects of kairomones produced by the ants, but the chemical identity of these kairomones has remained unknown. We have identified the kairomone responsible for deterrence and oviposition inhibition by O. smaragdina, providing a significant advance in understanding the chemical basis of their predator/prey interactions. Olfactometer assays with extracts from weaver ants demonstrated headspace volatiles to be highly repellent to Queensland fruit fly, Bactrocera tryoni. Using electrophysiology and bioassays, we demonstrate that this repellence is induced by a single compound, 1-octanol. Of 16 compounds identified in O. smaragdina headspace, only 1-octanol evoked an electrophysiological response from B. tryoni antennae. Flies had greatly reduced oviposition and spent significantly less time in an olfactometer arm in the presence of 1-octanol or a synthetic blend of headspace volatiles containing 1-octanol than in the presence of a synthetic blend of headspace volatiles without 1-octanol, or clean air. Taken together, our results demonstrate that 1-octanol is the functional kairomone component of O. smaragdina headspace that explains repellence and oviposition deterrence, and is hence an important contributor to the effectiveness of these ants as biological control agents.

New antibacterial depsidones from an ant-derived fungus Spiromastix sp. MY-1.

Six new (1-6) and seven known depsidones (7-13) were isolated from the culture of an ant (Monomorium chinensis)-derived fungus Spiromastix sp. MY-1. Their structures were elucidated by extensive spectroscopic analysis including high resolution MS, 1D and 2D NMR data. The new bromide depsidones were obtained through supplementing potassium bromide in the fermentation medium of Spiromastix sp. MY-1. All isolated compounds showed various bioactivities against the tested phytopathogenic bacteria. Particularly, new bromide compound 4, named spiromastixone S, exhibited the strongest activity against Xanthomonas oryzae pv. oryzae with a MIC value of 5.2 µmol·-1.

Spatiotemporal Foraging Dynamics of Solenopsis invicta (Hymenoptera: Formicidae) and its Potential Effects on the Spatial Structure of Interspecific Competition.

The ant communities on coffee farms in the West/Central Mountains of Puerto Rico are composed of mainly invasive species, although many have a long history of occupation and are effectively naturalized. The ecological forces that maintain such communities are thus of interest, and are evidently related to the spatial patterns in which they inevitably occur. Furthermore, the spatial patterns in which members of the native ant community forage almost certainly include limitations related to the structure of the networks of subterranean foraging tunnels that extend from the nest mounds of Solenopsis invicta. Here we explore some details of that structure. We ask, what is the pattern of foraging exit holes and the gaps between them, and how does that pattern change from farm to farm and from time to time? We encounter typical underground foraging trails punctuated by foraging exits, which, we propose, create a structure above ground of relatively small foraging exits in a matrix of effective foraging gaps. This pattern varies from nest to nest and farm to farm. Other ant species clearly occupy those gaps and seem to gain some of their resilience in the system from this peculiarity of S. invicta's foraging area structure.

Positive Eusocial Impacts on Ants by Taurine Derivatives.

The present study is to investigate potential eusocial effects on ants from treatment of taurine or its derivatives: galactose-taurine (GT) or xylose-taurine (XT). Japanese carpenter ants (Camponotus japonicus) were maintained on taurine-supplemented diets, and their performance was evaluated according to arbitrary eusocial indexes. Four classes of criteria were employed: establishment of residence chambers, survival at severe conditions, cooperative defense index (CDI), and population size. Taurine or its derivatives were administered orally in 0.1 mM sucrose solution. When fed with taurine or taurine derivatives, ants built more chambers than the non-fed control. Among the taurine groups, the XT-fed group showed the highest number of chambers. Differences in survivorship were obvious between the control and taurine-fed groups at the extreme conditions of light exposure and high temperature. More ants survived when fed with taurine or its derivatives. The taurine-supplemented groups took less time to organize a defense form than the control. The XT-fed group showed a high level of CDI which refer to the willingness to participate in defense against a foreign queen. The taurine-fed group sustained higher total numbers of ants. The XT-fed groups showed a 15% increase in the number of workers and an 11% increase in the number of eggs. The taurine-fed ants positively responded according to the eusocial vitality indexes, especially when fed with XT. In summary, these results show that ants respond more like superorganisms when treated with XT among taurine or its two derivatives.

Phylogenomic analysis and metabolic role reconstruction of mutualistic Rhizobiales hindgut symbionts of Acromyrmex leaf-cutting ants.

Rhizobiales are well-known plant-root nitrogen-fixing symbionts, but the functions of insect-associated Rhizobiales are poorly understood. We obtained genomes of three strains associated with Acromyrmex leaf-cutting ants and show that, in spite of being extracellular gut symbionts, they lost all pathways for essential amino acid biosynthesis, making them fully dependent on their hosts. Comparison with 54 Rhizobiales genomes showed that all insect-associated Rhizobiales lost the ability to fix nitrogen and that the Acromyrmex symbionts had exceptionally also lost the urease genes. However, the Acromyrmex strains share biosynthesis pathways for riboflavin vitamin, queuosine and a wide range of antioxidant enzymes likely to be beneficial for the ant fungus-farming symbiosis. We infer that the Rhizobiales symbionts catabolize excess of fungus-garden-derived arginine to urea, supplementing complementary Mollicutes symbionts that turn arginine into ammonia and infer that these combined symbiont activities stabilize the fungus-farming mutualism. Similar to the Mollicutes symbionts, the Rhizobiales species have fully functional CRISPR/Cas and R-M phage defenses, suggesting that these symbionts are important enough for the ant hosts to have precluded the evolution of metabolically cheaper defenseless strains.

Taxonomic revision of the Pheidole megacephala species-group (Hymenoptera, Formicidae) from the Malagasy Region.

Background: The Malagasy Region, one of the top megadiversity regions, hosts one of the highest numbers of endemic and threatened organisms on earth. One of the most spectacular examples of ant radiation on the island has occurred in the hyperdiverse genus Pheidole. To this date, there are 135 described Madagascan Pheidole divided into 16 species-groups, and 97% of Malagasy species are endemic to the island. This study is a taxonomic revision of the Pheidole megacephala group, one of only two species-groups comprising a combination of native, endemic taxa and widely distributed introduced species. Methods: The diversity of the Malagasy members of the megacephala group was assessed via application of qualitative morphological and DNA sequence data. Qualitative, external morphological characteristics (e.g., head shape, gaster sculpture, body colouration) were evaluated in order to create a priori grouping hypotheses, and confirm and improve species delimitation. Mitochondrial DNA sequences from cytochrome oxidase I (COI) gene fragments were analyzed to test the putative species previously delimited by morphological analyses. Results: We recognize three species belonging to the megacephala group: P. megacephala (Fabricius, 1793), P. megatron Fischer & Fisher, 2013 and P. spinosa Forel, 1891 stat. nov. Pheidole spinosa is redescribed and elevated to the species level. The following names are recognized as junior synonyms of P. spinosa: P. megacephala scabrior Forel, 1891 syn. nov., P. picata Forel, 1891 syn. nov., P. picata gietleni Forel, 1905 syn. nov., P. picata bernhardae Emery, 1915 syn. nov., and P. decepticon Fischer & Fisher, 2013 syn. nov. The results are supplemented with an identification key to species for major workers of the megacephala group, high-resolution images for major and minor workers, and comments on the distribution and biology of all Malagasy members of the group. Our study revealed that Pheidole megacephala, a species listed among the 100 worst invasive species worldwide, occurs in both natural and disturbed sites in the Malagasy region. The two remaining members of the megacephala group, most likely endemic to this region, are also present in anthropogenic habitats and often co-occur with P. megacephala. It appears that the Malagasy members of the group are generalists and dominant in anthropogenic habitats. Additionally, we documented the presence of supermajors in colonies of P. spinosa-a phenomenon previously not known for this group.

Transfer of elements into boreal forest ants at a former uranium mining site.

Ants can influence ecological processes, such as the transfer of elements or radionuclides, in several ways. For example, they redistribute materials while foraging and maintaining their nests and have an important role in terrestrial food webs. Quantitative data of the transfer of elements into ants is needed, e.g., for developing improved radioecological models. In this study, samples of red wood ants (genus Formica), nest material, litter and soil were collected from a former uranium mining site in Eastern Finland. Concentrations of 33 elements were analyzed by Inductively Coupled Plasma-Mass Spectroscopy/Optical Emission Spectroscopy. Estimated element concentrations in spruce needles were used as a proxy for studying the transfer of elements into ants via aphids because spruces host the most important aphid farms in boreal forests. Empirically determined organism/medium concentration ratios (CRs) are commonly used in radioecological models. Ant/soil CRs were calculated and the validity of the fundamental assumption behind the of use of CRs (linear transfer) was evaluated. Elements that accumulated in ants in comparison to other compartments were cadmium, potassium, phosphorus, sulfur, and zinc. Ant uranium concentrations were low in comparison to soil, litter, or nest material but slightly elevated in comparison to spruce needles. Ant element concentrations were quite constant regardless of the soil concentrations. Non-linear transfer models could therefore describe the soil-to-ant transfer better than conventional CRs.

A global review of socioeconomic and environmental impacts of ants reveals new insights for risk assessment.

Risk assessments are fundamental to invasive species management and are underpinned by comprehensive characterization of invasive species impacts. Our understanding of the impacts of invasive species is growing constantly, and several recently developed frameworks offer the opportunity to systematically categorize environmental and socioeconomic impacts of invasive species. Invasive ants are among the most widespread and damaging invaders. Although a handful of species receives most of the policy attention, nearly 200 species have established outside their native range. Here, we provide a global, comprehensive assessment of the impacts of ants and propose a priority list of risk species. We used the Socioeconomic Impact Classification for Alien Taxa (SEICAT), Environmental Impact Classification for Alien Taxa (EICAT) and Generic Impact Scoring System (GISS) to analyze 642 unique sources for 100 named species. Different methodologies provided generally consistent results. The most frequently identified socioeconomic impacts were to human health. Environmental impacts were primarily on animal and plant populations, with the most common mechanisms being predation and competition. Species recognized as harmful nearly 20 years ago featured prominently, including Wasmannia auropunctata (little fire ant, electric ant), Solenopsis invicta (red imported fire ant), Anoplolepis gracilipes (yellow crazy ant), and Pheidole megacephala (African big-headed ant). All these species except W. auropunctata have been implicated in local extinctions of native species. Although our assessments affirmed that the most serious impacts have been driven by a small number of species, our results also highlighted a substantial number of less well publicized species that have had major environmental impacts and may currently be overlooked when prioritizing prevention efforts. Several of these species were ranked as high or higher than some of the previously recognized "usual suspects," most notably Nylanderia fulva (tawny crazy ant). We compared and combined our assessments with trait-based profiles and other lists to propose a consensus set of 31 priority species. Ever-increasing global trade contributes to growing rates of species introductions. The integrated approaches we used can contribute to robust, holistic risk assessments for many taxa entrained in these pathways.

[Ant i-inflammatory mechanism of active components in Olibanum and Myrrha based on network pharmacology and cell experiments].

Two terpenes, 3-keto-tirucalla-8,24-dien-21-oic acid(KTDA) and 2-methoxy-5-acetoxy-furanogermacr-1(10)-en-6-one(FSA), are isolated from Olibanum and Myrrha respectively, which are characterized by high yield and easy crystallization during the preparation. The present study explored the regulatory targets and anti-inflammatory mechanism of KTDA and FSA based on network pharmacology and cell viability assay. First, the drug-likeness of KTDA and FSA was predicted by Swiss ADME. The target prediction of active components was carried out by Swiss Target Prediction and Pharmmapper. TTD, Drug Bank, and Gene Cards were searched for inflammation-related target genes of KTDA and FSA. Protein-protein interaction(PPI) analysis was performed on the inflammatory targets of KTDA and FSA by STRING, and Cytoscape was used to conduct topological analysis of the interaction results and construct the PPI network. GO function and KEGG pathway enrichment analyses of inflammatory targets of KTDA and FSA were carried out by DAVID, and a " component-target-pathway" network was constructed. Finally, lipopolysaccharide(LPS)-induced RAW264. 7 cells were treated with KTDA and FSA at different concentrations, and nitric oxide(NO) concentration and protein and m RNA expression levels were detected. The results showed that both KTDA and FSA showed good drug-likeness. A total of 157 and 142 inflammation-related targets of KTDA and FSA were screened out. PPI network analysis showed that MAPK1, AKT1, MAPK8, PIK3 CA,PIK3 R1, EGFR, etc. might be the key proteins for the anti-inflammatory effect. PI3 K/AKT and MAPK signaling pathways were obtained by KEGG and GO-BP enrichment. Cell experiment results showed that KTDA and FSA could exert anti-inflammatory effects by inhibiting NO production, reducing the phosphorylation levels of JNK, p38, and AKT proteins, and down-regulating the m RNA expression of interleukin(IL)-1ß and IL-6. Meanwhile, FSA could also inhibit ERK phosphorylation. The results indicated that KTDA and FSA had significant anti-inflammatory activity, which provided a scientific basis and important support for the further research,development, and utilization of Olibanum and Myrrha.

Using essential oils from Citrus paradisi as a fumigant for Solenopsis invicta workers and evaluating the oils' effect on worker behavior.

The red imported fire ant is one of the world's most devastating invasive species, adversely affecting humans, wildlife, crops, and livestock. To control infestations, chemical pesticides are deployed extensively around the world. However, their extensive use has led to negative effects on the environment and human health. Essential oils, which are safe and ecofriendly, can potentially be used as alternatives to chemical pesticides. In this study, grapefruit essential oils were used as fumigant agents to control red imported fire ants. The crude grapefruit oil (GO1) contained 28 compounds, and the concentrated grapefruit oil (GO2), which was refined from GO1 by vacuum distillation, contained 20 compounds. D-Limonene was the dominant constituent in both GO1 (70.1%) and GO2 (73.96%), and other important constituents included ß-pinene, α-pinene, ß-phellandrene, octanal, d-carvone, α-terpineol, and linalool. Both the essential oils and their individual constituents (α-pinene, α-terpineol, ß-phellandrene, octanal, and d-carvone) showed strong lethal fumigant effects against workers. Workers were more susceptible to GO2 than GO1, and octanal was more toxic to workers as compared with the other four constituents. When antennas of workers were treated with the two oils or the five constituents, their walking and gripping abilities were significantly suppressed, and there was an obvious bending or breaking phenomenon on the sensilla of the antennas. Fumigant activity by grapefruit essential oils and their main compounds were associated with their effects on the walking and gripping behavior of workers, and this confirmed that grapefruit essential oil is a promising, ecofriendly, and safe fumigant for the control of red imported fire ants.