The effects of two abundant ant species on soil nutrients and seedling recruitment in Brazilian Atlantic Forest

Ants can influence soil fertility and the spatial distribution of seeds, with possible effects on seedling recruitment. The ant species Pachycondyla striata Fr. Smith, 1858 and Odontomachus chelifer (Latreille, 1802) co-occur in many forest areas in the Neotropics. We assessed soil fertility and seed bank structure in soil samples close and distant (control) from ant nests in forest fragments. We also assessed the richness and abundance of seedlings on nests and control sites. In soil samples from ant nests, the concentration of phosphorus and potassium were respectively 55.6% and 36% higher than in control sites. Aluminium was 11–15% lower in soil samples from ant nests. In the greenhouse, soils from ant nests had higher plant abundance and species richness, but the same species composition in comparison with control sites. Although more plants emerged from soil samples of O. chelifer nests, in the field, the density and richness of seedlings were similar for the two ant species studied. Seedlings in the nest sites were, on average, 1.8 times more abundant and 1.6 times richer in species than in control sites. Our results showed that ant species can play a key role in seedling recruitment in forest fragments, where other animals with equivalent and positive effects, such as mammals, are missing.     

Discovery and optimization of covalent Bcl-xL antagonists

Over the last ten years, targeted covalent inhibition has become a key discipline within medicinal chemistry research, most notably in the development of oncology therapeutics. One area where this approach is underrepresented, however, is in targeting protein-protein interactions. This is primarily because these hydrophobic interfaces lack appropriately located cysteine residues to allow for standard conjugate addition chemistry. Herein, we report our development of the first covalent inhibitors of the antiapoptotic protein B-cell lymphoma extra-large (Bcl-xL), utilizing a sulfonyl fluoride (SF) warhead to selectively covalently modify tyrosine 101 of the BH3 domain-binding groove. These compounds display time-dependent inhibition in a biochemical assay and are cellularly active (U266B1). In addition, compound 7 was further elaborated to generate a chemical-biology probe molecule, which may find utility in understanding the intricacies of Bcl-xL biology.     

Occurrence of Amblycerus species in Cordia trichotoma seeds and their influence on germination

Forest species can have their seeds damaged by granivorous insects, especially by those in their larval stage. In this context, this study aims to report the occurrence of Amblycerus species in Cordia trichotoma seeds, to describe their main damage to seeds and effects on germination, as well as their associated hymenopteran parasitoids. Therefore, seven trees were selected in the municipality of Taquaruçu do Sul, RS, Brazil. Fruits were collected weekly from the medium third of the tree crown, from the beginning of their formation until total dehiscence. To examine the damage caused by granivorous insects within the fruits, 15 fruits from each tree were sectioned with a scalpel. Furthermore, 10 fruits from each tree were stored individually in clear plates to verify the occurrence and identification of granivorous insect species. Evidence of the damage caused to seeds was verified through the germination test by comparing preserved and damaged seeds, with four repetitions of 25 seeds each. The species Amblycerus longesuturalis and Amblycerus profaupar (Chrysomelidae: Bruchinae) were found associated with fruits of C. trichotoma. Female insects predominantly laid eggs on the superior part between the marcescent calyx and the fruit, and larvae perforated the fruit tegument to start consuming seed embryos and reserves. Bruquine larvae are parasitized by Hymenoptera of Bracon, Mirax, Omeganastatus and Triapsis genera. In conclusion, the germination of C. trichotoma seeds is significantly affected by emergence orifices caused by granivorous species.     

Co-occurrence patterns of wood-decaying fungi and ants in dead pines of South Korea

Interaction between fungi and insects such as ants, beetles, wasps and termites inhabiting dead pine trees has significant ecological implication in the forest as they can decompose wood debris and add nutrients to the soil; however, only scarce information is available regarding the interaction between wood-decaying fungi and ants. We investigated wood-decaying fungi co-occurring with ants in dead pine trees of South Korea. A total of 57 pairs of wood-decaying fungi and ants were collected from 11 localities. 30 species of wood-decaying fungi and 14 species of ants were identified based on morphology and molecular analysis. Fungal species belonging to Trichaptum, Xylodon, Hyphodontia, and Ceriporia were dominant and co-occurred with common ant species of Lasius, Camponotus, Pristomyrmex, and Crematogaster across most of the sampling sites. This study provides a new baseline in unravelling the complex interaction between wood-decaying fungi and ants in forest ecosystems.     

A new species of Youngomyia Felt from Brazil and new morphological data on Youngomyia pouteriae Maia (Insecta,Diptera, Cecidomyiidae)

Youngomyia matogrossensis Proença & Maia a new species of Cecidomyiidae (Insecta: Diptera) that induces cylindrical hairy galls on leaves of Pouteria torta (Mart.) Radlk. (Sapotaceae) is herein described and illustrated (larvae, pupal exuviae, male and female). The galler, gall and host plant were collected at Parque Nacional da Chapada dos Guimarães, in the state of Mato Grosso (Brazil). New morphological data and photographs of pupal exuviae, male and female of Youngomyia pouteriae Maia, 2001 are also provided.     

广东古兜山自然保护区蕨类植物群落的特征

通过对广东新会古兜山自然保护区中108个5m ×5m的蕨类植物样方调查,初步分析了样方中蕨类植物的种类组成和区系特点及种群的多度、频度、重要值、蕨类的生长型、叶的性质和群落的外貌、季相等群落学特征。结果表明:(1)古兜山自然保护区的蕨类植物种类具有典型的南亚热带植物区系特点,热带亚洲植物区系成分对古兜山蕨类植物区系有强烈影响;(2)由于蕨类植物种群的随机分布和环境因子的异质性,种群的多度和重要值分布表现出明显的正态分布规律;(3)样方中蕨类植物的形态外貌、叶的性质及其群落的外貌和季相均表现出典型的南亚热带蕨类植物群落特征;古兜山自然保护区的蕨类植物可划分为花篮状蕨类、树蕨类、匍匐类、攀援类、附生类5种生长型类型。     

Ecosystem engineering and manipulation of host plant tissues by the insect borer Oncideres albomarginata chamela

Ecosystem engineering by insect herbivores occurs as the result of structural modification of plants manipulated by insects. However, only few studies have evaluated the effect of these modifications on the plant responses induced by stem-borers that act as ecosystem engineers. In this study, we evaluated the responses induced by the herbivory of the twig-girdler beetle Oncideres albomarginata chamela (Cerambycidae: Lamiinae) on its host plant Spondias purpurea (Anacardiaceae), and its relationship with the ecosystem engineering process carried out by this stem-borer. Our results demonstrated that O. albomarginata chamela branch removal induced the development of lateral branches increasing the resources needed for the development of future insect generations, of its own offspring and of many other insect species. Detached branches represent habitats with high content of nitrogen and phosphorous, which eventually can be incorporated into the ecosystem, increasing nutrient cycling efficiency. Consequently, branch removal and the subsequent plant tissue regeneration induced by O. albomarginata chamela represent key mechanisms underlying the ecosystem engineering process carried out by this stem-borer, which enhances arthropod diversity in the ecosystem.     

Comparing performance of Aphis glycines Matsumura fed on two novel hosts relative to Glycine max (L.) Merrill

The soybean aphid, Aphis glycines Matsumura, is an important pest of soybean. During some years with occurrences of heavy aphid infestations in field, A. glycines can cause serious damage to soybeans. A. glycines has a heteroecious and holocyclic life cycle, with migration occurring between the primary and secondary hosts during each year. The primary hosts of A. glycines are Rhamnus spp., and the secondary hosts are soybean, Glycine max (L.) Merrill, and wild soybean species, Glycine soja Sieb & Zucc. In this study, A. glycines were fed on detached leaves and live plants of Trifolium repens L. and Metaplexis japonica (Thunb.) Makino, and their survival, development and reproduction were studied at five constant temperatures. These data were compared to those of controls fed on the known host plant G. max. When A. glycines were fed on detached leaves of T. repens and M. japonica, they showed vigorous development and reproduction. The novel and striking results were that: (1) A. glycines could not thrive on live plants of M. japonica, and only a few nymphs were deposited. (2) When A. glycines were fed on live plants of vegetative stage T. repens, adult longevity and fecundity were as long as 11.64 ± 1.17 days and as great as 12.92 ± 1.23 nymphs per adult, respectively. This work provides important evidence that M. japonica is not a host of A. glycines, but T. repens is probably an important host for this aphid.     

The population dynamics of three polyphagous owlet moths (Lepidoptera: Noctuidae) and the influence of meteorological factors and ENSO on them

The owlet moths (Lepidoptera: Noctuidae) Anicla infecta (Ochsenheimer 1816), Elaphria agrotina (Guenée 1852) and Spodoptera frugiperda (J.E. Smith 1797) occur in the entire American continent. These polyphagous moths have a preference for grasses, and have different biological habits. In this study, the populations of these three species were evaluated monthly with light traps in the Brazilian Savannah, ranging a span of four crop seasons (from July, 2013 to June, 2017). The population data were analyzed and correlated with the meteorological variables: maximum temperature, minimum temperature, relative humidity and precipitation. A total of 4719 individuals were collected in the following percentages: A. infecta (n = 459; 9.73%), E. agrotina (n = 1809; 38.33%) and S. frugiperda (n = 2451; (51.94%). The abundance of all species went down from the first crop season (2013/2014) to the third (2015/2016). In the fourth crop season (2016/2017), the populations of A. infecta and E. agrotina stabilized, but the abundance of S. frugiperda experienced further decrease. The numbers of individuals of three species declined when precipitation was much above (crop season 2014/2015) and below (crop season 2015/2016) than expected by the climatological normal. There were significant, but different degrees of correlation, between the meteorological factors and the ONI index (Oceanic Niño Index - indicator for monitoring El Niño-Southern Oscillation or “ENSO”) with respect to monthly population variations. The results are discussed in accordance with principles of the Integrated Pest Management (IPM) in mind, given the continental distribution and agricultural importance of the three owlet moth species studied.     

Two new species of Chrysis Linnaeus (Hymenoptera,Chrysididae) from Iran

The Iranian species in the Chrysis pulchella and C. varidens species groups are investigated. Six species are recognized, two of which are described for the first time: Chrysis gamberoonensis Farhad, Rosa and Talebi sp. nov. and Chrysis brunneamarginata Farhad, Rosa and Talebi sp. nov.. Chrysis gamberoonensis Farhad, Rosa and Talebi sp. nov. belongs to the C. pulchella group and is recognizable within this species group by its unique blue body coloration, scattered mesosoma punctures, polished pit row with elongated pits, and a small median tooth on the lateral edge of metasomal tergum 3. Chrysis brunneamarginata Farhad, Rosa and Talebi sp. nov. belongs to the C. varidens group and is recognizable by the usually colorless apical rim of metasomal tergum 3, and the unique shape of the anterior corners of the scutellum which are enlarged, thickened and directed backward covering the axillary trough. Dichotomous keys and distributional data for Iranian species included in these species groups are provided. Chrysis schwarzi Linsenmaier, 1968 is raised to species rank. The number of Iranian Chrysis species and subspecies is raised to 122.www.zoobank.org/urn:lsid:zoobank.org:pub:F419F860-3B90-4679-9A19-2CF5C255AE6B     

Insect pollinator diversity in four forested ecosystems of southern Punjab,Pakistan

This study investigated pollinator assemblage diversity and richness in four forested ecosystems of southern Punjab, Pakistan, with different landscape types. Pirowal is situated in the plains of irrigated Punjab, Lal Suhanra is part of a sandy desert ecosystem, Ghazi Ghat is part of the Indus River delta, and Fort Munro is located in dry hilly mountains. A yearlong survey of pollinator populations was carried out in these four forested ecosystems from January to December of 2010. Fortnightly hand netting was performed for collecting flower-visiting insects whereas, pan traps of three colors (white, blue, and yellow) were deployed for collecting the data. A total of 8,812 individuals from two orders (Lepidoptera and Diptera) were observed, including 22 families and 154 species. Bees were the most abundant, with 4,502 individuals, and the most species-rich taxa, with 70 species in five families, followed by flies having 2,509 individuals and 51species in 10 families. Wasps were the least abundant with 1,801 individuals and 33 species in seven families. The assemblage structure of pollinator communities as visualized through rank abundance curves showed that there were many species with low abundance and only a few species with a much higher abundance. The most abundant species among the bees, in order, were Nomia sp.3, Megachile bicolor, and Colletes sp.3; among flies, Syrphus sp.2, Calliphoridae sp.1, and Empididae sp.4; and among wasps, Tiphiidae sp.1, Myzininae sp.2, and Scelionidae sp.1.     

A new black fly species of the subgenus Gomphostilbia (Simulium: Simuliidae: Diptera) from India

Simulium (Gomphostilbia) agasthyamalaiense sp. nov. is described based on adults, pupae and mature larvae from a medium-flowing stream of Southern Western Ghats, India. This new species is placed in the Simulium batoense species-group of the subgenus Gomphostilbia Enderlein. This new species is characterized in the female by a scutum with three brownish-black longitudinal vittae and the hind basitarsus 5.7 times as long as wide; in the female by the large facets of upper eye with 20 vertical columns and 19 horizontal rows; in the pupa the respiratory gill with medium-long common basal stalk; and in the larva arrowhead-shaped postgenal cleft. Taxonomic notes are provided for this new species and it can be distinguished from closely related species of S. (G.) peteri. Keys are constructed to distinguish this species from ten species of the batoense species-group recorded in India.www.zoobank.org/urn:lsid:zoobank.org:pub:1D1CFEE5-A762-4F68-9EAE-9E31133146C0     

A polerovirus,Potato leafroll virus,alters plant–vector interactions using three viral proteins

Potato leafroll virus (PLRV), genus Polerovirus, family Luteoviridae, is a major pathogen of potato worldwide. PLRV is transmitted among host plants by aphids in a circulative–nonpropagative manner. Previous studies have demonstrated that PLRV infection increases aphid fecundity on, and attraction to, infected plants as compared to controls. However, the molecular mechanisms mediating this relationship are still poorly understood. In this study, we measured the impact of PLRV infection on plant–aphid interactions and plant chemistry in two hosts: Solanum tuberosum and Nicotiana benthamiana. Our study demonstrates that PLRV infection attenuates the induction of aphid-induced jasmonic acid and ethylene in S. tuberosum and N. benthamiana. Using transient expression experiments, insect bioassays and chemical analysis, we show that expression of three PLRV proteins (P0, P1, and P7) mediate changes in plant–aphid interactions and inhibition of aphid-induced jasmonic acid and ethylene in N. benthamiana. This study enhances our understanding of the plant-vector-pathogen interface by elucidating new mechanisms by which plant viruses transmitted in a circulative manner can manipulate plant hosts.     

Physiological characteristics of citrus plants infested with citrus blackfly

Aleurocanthus woglumi (Ashby, 1915) is an important agricultural pest that causes yield losses of 20–80% in citrus plants by removing plant nutrients while feeding and allowing the formation of sooty mold. The objective of this study was to evaluate physiological changes in citrus plants in response to A. woglumi infestation under field conditions. The experiment was conducted in a citrus orchard in Paço do Lumiar, Maranhão, Brazil. Thirty-two citrus plants were used, including eight of each of the following varieties: Tahiti lime, Tanjaroa tangerine, Nissey tangerine, and Ponkan tangerine. Four random plants with A. woglumi infestation and four plants free from this pest were selected from each variety. The physiological parameters evaluated were photochemical efficiency and gas exchange. Regarding photochemical efficiency, infested plants presented photoinhibition damage, with a performance index of 4.22. The gas exchange parameters of infested plants changed, with reductions in photosynthetic CO₂ assimilation of 69.7% (Tahiti), 64% (Tanjaroa), 68.8% (Nissey) and 63.3% (Ponkan). Plants infested with A. woglumi also presented physiological changes; their photosynthetic CO₂ assimilation, stomatal conductance, instantaneous transpiration, and performance indexes were affected. The infested citrus plants showed photoinhibition of photosystem II. The photosynthetic CO₂ assimilation decreased approximately 70% in Tahiti lime, Tanjaroa tangerine, Nissey tangerine, and Ponkan tangerine plants infested with A. woglumi.     

Coffee production in southern Saudi Arabian highlands: Current status and water conservation

Work aimed at assessing status and introducing water conservation regimes for coffee production in southern Saudi Arabian highlands. Data on farm locations, altitudes, areas, practices, irrigation, tree density, and annual coffee production were analyzed. Field experiment using chlorophyll fluorescence and different irrigation regimes was conducted to examine effects of reducing irrigation frequency on photosynthesis. Results indicated that Coffea arabica L. is commonly grown at altitudes of 1300–1400 m. Plants grown at 4–6 Trees m^?2 using 100 kg ha^?1 mineral fertilizer produce an average of 3 t ha^?1. High frequency 2-day-intervals irrigation regime practiced by farmers during the dry season presents ecological challenge to limited local artesian water resources. Changes in chlorophyll fluorescence under 14-day-intervals irrigation regime initiated water stress that markedly inhibited Photosystem II efficiency and quantum yield and increased non-photochemical energy dissipation. Applying a 7-day-intervals irrigation regime induced less inhibitory effects on Photosystem II. Results also indicated that shifting from 2-day-intervals irrigation regime to 7-day-intervals regime improves coffee agroecology and directs coffee production towards sustainability.     

Insecticidal effects of Vernonanthura nebularum against two economically important pest insects

Vernonanthura nebularum (Cabrera) H. Rob. (Asteraceae), an endemic species from the north of Argentina, is a rich source of elephantopus-type sesquiterpene lactones. These compounds have proved to be promising antiparasitic agents, but there is no report about their action against pest insects. In this work we studied for the first time the antifeedant and toxic effects of V. nebularum natural products against the fall army warm Spodoptera frugiperda Smith and the oviposition deterrent activity against the fruit fly Ceratitis capitata Wiedemann. As a result, we found that extracts, fractions composed of sesquiterpene lactones and pure sesquiterpene lactones altered larval feeding behavior in the food choice test. Nutritional parameters of S. frugiperda larvae were also affected. Fraction II (300 μg/g of diet.), containing compounds 1, 2 and 3, was the most toxic substance with 80% pupal mortality and wing malformations in adults. In oviposition deterrent experiments against Ceratitis capitata, we observed a moderate effect at 30 μg/cm² of the test compound. The most active substances were the methanolic extract, dichloromethane subextract and lactone 2. According to our results, V. nebularum natural products could be used for maximizing the effectiveness and specificity in future insecticide design with specific or multiple target sites, while ensuring the economic and ecological sustainability, in addition to combat the increasing resistance rates developed by synthetic pesticides.     

Targeting the R domain of coagulase by active vaccination protects mice against lethal Staphylococcus aureus infection

Coagulase (Coa) secreted by Staphylococcus aureus is associated with the establishment of staphylococcal disease, which activates host prothrombin and generates fibrin shields. The R domain of Coa, consisting of several conserved repeats, is important in immune evasion during S. aureus infection. However, previous research showed that the Coa R domain induced very weak specific antibody responses. In this study, we constructed a new R domain, CoaR6, consisting of 6 repeats that occur most frequently in clinical isolates. By fusing CoaR6 with Hc, the C-terminal fragment of the heavy chain of tetanus neurotoxin, we successfully increased anti-CoaR6 IgG levels in immunized mice which were hardly detected in mice immunized with CoaR6 plus alum. To further improve anti-CoaR6 responses, the combination adjuvants alum plus CpG were formulated with the antigen and exhibited a significantly higher specific antibody response. Moreover, active Th1/Th17 immune responses were observed in Hc-CoaR6 immunized group rather than CoaR6. Active immunization of Hc-CoaR6 with alum plus CpG showed protective effects in a peritonitis model induced by two S. aureus strains with different coagulase types. Our results provided strategies to improve the immunogenicity of R domain and supporting evidences for R domain to be an S. aureus vaccine candidate.