The ecology of killer yeasts: Interference competition in natural habitats

Competitive interactions among widely sympatric species of terrestrial plethodontid salamanders have received little attention. I investigated whether interspecific interference competition for space occurs between one such pair of species, Plethodon kentucki and P. glutinosus. Encounters between heterospecific adults in the laboratory resulted in aggressive interactions as often as did encounters between conspecific adults. However, intense aggression (bite-holds) occurred more often during pairings between conspecifics, indicating that interference competition is greater among individuals of the same species. Plethodon glutinosus was dominant more often than P. kentucki during encounters with heterospecifics in the laboratory. During a second laboratory experiment, both species preferentially used large cover sites in single-species control groups, whereas P. kentucki used small cover sites significantly more often in mixed-species experimental groups, indicating competitive exclusion of P. kentucki by the larger P. glutinosus. In natural habitats, individuals of both species were usually found alone under cover objects, and the extent of home-range overlap did not differ between conspecifics and heterospecifics. My results indicate that these species compete for space and defend territories against heterospecifics as well as conspecifics. Greater intraspecific than interspecific interference competition may permit coexistence if the former is more important in limiting the population growth of each species.

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Parasite commonality at Swamp Deer (Mammalia: Artiodactyla: Cervidae: Rucervus duvaucelii duvaucelii) and livestock interface

Journal of Threatened Taxa ◽

10.11609/jott.4812.12.3.15364-15369 ◽

2020 ◽

Vol 12 (3) ◽

pp. 15364-15369

Author(s):

Animesh Talukdar ◽

Bivash Pandav ◽

Parag Nigam

Keyword(s):

Intestinal Parasites ◽

Uttar Pradesh ◽

Anthropogenic Pressure ◽

Wildlife Sanctuary ◽

Natural Habitats ◽

Coprological Examination ◽

Parasitic Load ◽

Abundance And Diversity ◽

Swamp Deer ◽

Different Levels

Interactions between wildlife and livestock have increased over time with increased anthropogenic pressure on limited available natural habitats. These interactions have resulted in sharing of pathogens between the species resulting in impacting the wild animals’ fitness and reproduction and further influencing their abundance and diversity. The spatial overlap between Swamp Deer and livestock was studied at Jhilmil Jheel Conservation Reserve (JJCR), Uttarakhand and Kishanpur Wildlife Sanctuary (KWLS), Uttar Pradesh in India, having different levels of interaction with livestock. The prevalence, load and commonality of gastro-intestinal parasites in the species was studied through coprological examination. Parasitic ova of Strongyle sp., Trichostrongylus sp., Fasciola sp., and Moniezia sp. Amphistomes were encountered in swamp deer and livestock from both the sites. The parasitic species richness and prevalence however, varied between JJCR and KWLS. The study recorded significant differences between the parasitic load in Swamp Deer with the eggs per gram of 487.5±46.30 at JJCR and 363.64±49.97 at KWLS at varying levels of livestock interactions.

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Larval Feeding: Mechanisms, Rates, and Performance in Nature

10.1093/oso/9780198786962.003.0007 ◽

2018 ◽

Keyword(s):

Marine Invertebrates ◽

Spatial Scales ◽

Size Spectrum ◽

Larval Feeding ◽

Natural Habitats ◽

Feeding Mechanism ◽

Temporal And Spatial ◽

And Performance ◽

Bioenergetics Models ◽

Many Particles

Larvae of many marine invertebrates must capture and ingest particulate food in order to develop to metamorphosis. These larvae use only a few physical processes to capture particles, but implement these processes using diverse morphologies and behaviors. Detailed understanding of larval feeding mechanism permits investigators to make predictions about feeding performance, including the size spectrum of particles larvae can capture and the rates at which they can capture them. In nature, larvae are immersed in complex mixtures of edible particles of varying size, density, flavor, and nutritional quality, as well as many particles that are too large to ingest. Concentrations of all of these components vary on fine temporal and spatial scales. Mechanistic models linking larval feeding mechanism to performance can be combined with data on food availability in nature and integrated into broader bioenergetics models to yield increased understanding of the biology of larvae in complex natural habitats.

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Propagation of Pistacia lentiscus var. Chia Genotypes and Determination of Their Ornamental Traits Combined with a Genetic Analysis Using ISSR Markers

Agronomy ◽

10.3390/agronomy11020205 ◽

2021 ◽

Vol 11 (2) ◽

pp. 205

Author(s):

Stefanos Kostas ◽

Stefanos Hatzilazarou ◽

Elias Pipinis ◽

Anastasios Vasileiadis ◽

Panagiotis Magklaras ◽

...

Keyword(s):

Genetic Analysis ◽

Germination Rate ◽

Leaf Traits ◽

Issr Markers ◽

Pistacia Lentiscus ◽

Natural Habitats ◽

Indolebutyric Acid ◽

Single Male ◽

Asexual Propagation

Pistacia lentiscus L. is a dioecious shrub or small tree with high drought resistance, native in the entire Mediterranean basin. The variety ‘Chia’ (mastic tree) is cultivated for the production of mastic gum (a resin produced after wounding of the trunks and thick branches) in the Island of Chios (Greece), but it also has a significant ornamental value. In the present study, ten male and ten female genotypes of P. lentiscus var. Chia from the natural habitats of Chios were selected and examined with respect to the rooting efficiency of their shoot cuttings. The germination ability of the seeds was also tested. The 20 plants were morphologically described, mainly with respect to traits related to their ornamental value. Furthermore, leaves were collected from the 20 genotypes, from which genomic DNA (gDNA) was isolated, followed by amplification of gDNA fragments using the polymerase chain reaction (PCR) and inter simple sequence repeat (ISSR) primers. This was done aiming both at the determination of their genetic distance and the establishment of possible correlations between the amplified bands and certain morphological traits. The results of the study showed that there were differences among the genotypes for both methods of propagation. Regarding the rooting of the shoot cuttings, the best genotype was 8M (cv. ‘Psilophyllos’), achieving a rooting rate of 62.5% in winter with the application of indolebutyric acid (potassium salt of IBA), while regarding the seed germination capacity the genotype 2F exhibited the highest germination rate (57%). Genetic analysis using ISSRs separated the plants into four groups, one group consisting of male genotypes, one of the female genotypes, one consisting of members from both genders and a fourth containing a single male genotype. The genetic analysis of the male genotypes only produced a dendrogram showing the cultivars clustering in three different groups. Regardless of the genetic analysis, it seems that there were correlations between the ISSR markers and the leaf traits and also the gender and the asexual propagation. These correlations can assist future breeding programs of P. lentiscus var. Chia.

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Anthonomus rubi on Strawberry Fruit: Its Biology, Ecology, Damage, and Control from an IPM Perspective

Insects ◽

10.3390/insects12080701 ◽

2021 ◽

Vol 12 (8) ◽

pp. 701

Author(s):

Lorenzo Tonina ◽

Giulia Zanettin ◽

Paolo Miorelli ◽

Simone Puppato ◽

Andrew G. S. Cuthbertson ◽

...

Keyword(s):

Feeding Activity ◽

Host Feeding ◽

Mass Trapping ◽

Natural Habitats ◽

Potential Control ◽

North East ◽

Monitoring Tools ◽

Anthonomus Rubi ◽

And Control

The strawberry blossom weevil (SBW), Anthonomus rubi, is a well-documented pest of strawberry. Recently, in strawberry fields of Trento Province (north-east Italy), new noteworthy damage on fruit linked to SBW adults was observed, combined with a prolonged adult activity until the autumn. In this new scenario, we re-investigated SBW biology, ecology, monitoring tools, and potential control methods to develop Integrated Pest Management (IPM) strategies. Several trials were conducted on strawberry in the laboratory, field and semi-natural habitats. The feeding activity of adult SBW results in small deep holes on berries at different stages, causing yield losses of up to 60%. We observed a prolonged survival of newly emerged adults (>240 days) along with their ability to sever flower buds without laying eggs inside them in the same year (one generation per year). SBW adults were present in the strawberry field year-round, with movement between crop and no crop habitats, underlying a potential role of other host/feeding plants to support its populations. Yellow sticky traps combined with synthetic attractants proved promising for both adult monitoring and mass trapping. Regarding control, adhesive tapes and mass trapping using green bucket pheromone traps gave unsatisfactory results, while the high temperatures provided by the black fabric, the periodic removal of severed buds or adults and Chlorpyrifos-methyl application constrained population build-up. The findings are important for the development of an IPM strategy.

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Identification of Phytoplasmas Representing Multiple New Genetic Lineages from Phloem-Feeding Leafhoppers Highlights the Diversity of Phytoplasmas and Their Potential Vectors

Pathogens ◽

10.3390/pathogens10030352 ◽

2021 ◽

Vol 10 (3) ◽

pp. 352

Author(s):

Wei Wei ◽

Valeria Trivellone ◽

Christopher H. Dietrich ◽

Yan Zhao ◽

Kristi D. Bottner-Parker ◽

...

Keyword(s):

Host Range ◽

Quantitative Polymerase Chain Reaction ◽

Rflp Analysis ◽

Natural Habitats ◽

Genetic Lineages ◽

Genetic Subgroup ◽

Polymerase Chain ◽

Phloem Feeding ◽

Fresh Insight

Phytoplasmas are obligate transkingdom bacterial parasites that infect a variety of plant species and replicate in phloem-feeding insects in the order Hemiptera, mainly leafhoppers (Cicadellidae). The insect capacity in acquisition, transmission, survival, and host range directly determines the epidemiology of phytoplasmas. However, due to the difficulty of insect sampling and the lack of follow-up transmission trials, the confirmed phytoplasma insect hosts are still limited compared with the identified plant hosts. Recently, quantitative polymerase chain reaction (qPCR)-based quick screening of 227 leafhoppers collected in natural habitats unveiled the presence of previously unknown phytoplasmas in six samples. In the present study, 76 leafhoppers, including the six prescreened positive samples, were further examined to identify and characterize the phytoplasma strains by semi-nested PCR. A total of ten phytoplasma strains were identified in leafhoppers from four countries including South Africa, Kyrgyzstan, Australia, and China. Based on virtual restriction fragment length polymorphism (RFLP) analysis, these ten phytoplasma strains were classified into four distinct ribosomal (16Sr) groups (16SrI, 16SrIII, 16SrXIV, and 16SrXV), representing five new subgroups (16SrI-AO, 16SrXIV-D, 16SrXIV-E, 16SrXIV-F, and 16SrXV-C). The results strongly suggest that the newly identified phytoplasma strains not only represent new genetic subgroup lineages, but also extend previously undiscovered geographical distributions. In addition, ten phytoplasma-harboring leafhoppers belonged to seven known leafhopper species, none of which were previously reported insect vectors of phytoplasmas. The findings from this study provide fresh insight into genetic diversity, geographical distribution, and insect host range of phytoplasmas. Further transmission trials and screening of new potential host plants and weed reservoirs in areas adjacent to collection sites of phytoplasma harboring leafhoppers will contribute to a better understanding of phytoplasma transmission and epidemiology.

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Predation on Drosophila suzukii within Hedges in the Agricultural Landscape

Insects ◽

10.3390/insects12040305 ◽

2021 ◽

Vol 12 (4) ◽

pp. 305

Author(s):

Alexandra Siffert ◽

Fabian Cahenzli ◽

Patrik Kehrli ◽

Claudia Daniel ◽

Virginie Dekumbis ◽

...

Keyword(s):

Agricultural Landscape ◽

Vital Role ◽

Agricultural Landscapes ◽

Gut Content ◽

Drosophila Suzukii ◽

Natural Habitats ◽

Host Fruit ◽

Molecular Gut Content Analysis ◽

Wild Fruits ◽

Diverse Community

The invasive Drosophila suzukii feeds and reproduces on various cultivated and wild fruits and moves between agricultural and semi-natural habitats. Hedges in agricultural landscapes play a vital role in the population development of D. suzukii, but also harbor a diverse community of natural enemies. We investigated predation by repeatedly exposing cohorts of D. suzukii pupae between June and October in dry and humid hedges at five different locations in Switzerland. We sampled predator communities and analyzed their gut content for the presence of D. suzukii DNA based on the COI marker. On average, 44% of the exposed pupae were predated. Predation was higher in dry than humid hedges, but did not differ significantly between pupae exposed on the ground or on branches and among sampling periods. Earwigs, spiders, and ants were the dominant predators. Predator communities did not vary significantly between hedge types or sampling periods. DNA of D. suzukii was detected in 3.4% of the earwigs, 1.8% of the spiders, and in one predatory bug (1.6%). While the molecular gut content analysis detected only a small proportion of predators that had fed on D. suzukii, overall predation seemed sufficient to reduce D. suzukii populations, in particular in hedges that provide few host fruit resources.

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Influence of competition and intraguild predation between two candidate biocontrol parasitoids on their potential impact against Harrisia cactus mealybug, Hypogeococcus sp. (Hemiptera: Pseudococcidae)

Scientific Reports ◽

10.1038/s41598-021-92565-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

María B. Aguirre ◽

Octavio A. Bruzzone ◽

Serguei V. Triapitsyn ◽

Hilda Diaz-Soltero ◽

Stephen D. Hight ◽

...

Keyword(s):

Intraguild Predation ◽

Interference Competition ◽

Biocontrol Agents ◽

Parasitoid Species ◽

Temporal Window ◽

Response Models ◽

Potential Impact ◽

Functional Response Models ◽

Fully Bayesian ◽

Release Strategy

AbstractWhen two or more parasitoid species, particularly candidates for biocontrol, share the same target in the same temporal window, a complex of behaviors can occur among them. We studied the type of interactions (competition and intraguild predation) that existed between the nymphal parasitoids Anagyrus cachamai and A. lapachosus (Hymenoptera: Encyrtidae), two candidate neoclassical biocontrol agents against the Puerto Rican cactus pest mealybug, Hypogeococcus sp. (Hemiptera: Pseudococcidae). The surrogate native congener host in Argentina, the cactus mealybug Hypogeococcus sp., was studied to predict which species should be released; in the case that both should be released, in which order, and their potential impact on host suppression. In the laboratory we conducted experiments where different densities of the host mealybug were exposed to naive females of A. cachamai and A. lapachosus sequentially in both directions. Experiments were analyzed by combining a series of competitive behavioral and functional response models. A fully Bayesian approach was used to select the best explaining models and calculate their parameters. Intraguild predation existed between A. cachamai, the species that had the greatest ability to exploit the resource, and A. lapachosus, the strongest species in the interference competition. The role that intraguild predation played in suppression of Hypogeococcus sp. indicated that a multiple release strategy for the two biocontrol agents would produce better control than a single release; as for the release order, A. lapachosus should be released first.

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Evaluation of the Antioxidant, Anti-Inflammatory and Cytoprotective Activities of Halophyte Extracts against Mycotoxin Intoxication

Toxins ◽

10.3390/toxins13050312 ◽

2021 ◽

Vol 13 (5) ◽

pp. 312

Author(s):

Nolwenn Hymery ◽

Xavier Dauvergne ◽

Halima Boussaden ◽

Stéphane Cérantola ◽

Dorothée Faugère ◽

...

Keyword(s):

Antioxidant Activities ◽

Protective Action ◽

Dry Weight ◽

Cell Protection ◽

Natural Habitats ◽

Total Antioxidant ◽

Mdbk Cells ◽

Dpph Scavenging ◽

T2 Toxin

Twelve halophyte species belonging to different families, widely represented along French Atlantic shoreline and commonly used in traditional medicine, were screened for protective activities against mycotoxins, in order to set out new promising sources of natural ingredients for feed applications. Selected halophytic species from diverse natural habitats were examined for their in vitro anti-mycotoxin activities, through viability evaluation of Madin-Darby Bovine Kidney (MDBK) and intestinal porcine enterocyte (IPEC-J2) cell lines. Besides, the in vitro antioxidant activities of plant extracts were assessed (total antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH)-scavenging bioassays). Of the 12 species, Galium arenarium, Convolvulus soldanella and Eryngium campestre exhibited the most protective action on MDBK and IPEC-J2 cells against zearalenone (ZEN) or T2 toxin contamination (restoring about 75% of cell viability at 10 μg·mL−1) without inflammation response. They also had strong antioxidant capacities (Inhibitory concentration of 50% (IC50) < 100 μg·mL−1 for DPPH radical and total antioxidant capacity (TAC) of 100 to 200 mg Ascorbic Acid Equivalent (AAE)·g−1 Dry Weight), suggesting that cell protection against intoxication involves antioxidant action. A bio-guided study showed that fractions of G. arenarium extract protect MDBK cells against T2 or ZEN toxicity and several major compounds like chlorogenic acid and asperuloside could be involved in this protective effect. Overall, our results show that the halophytes G. arenarium, C. soldanella and E. campestre should be considered further as new sources of ingredients for livestock feed with protective action against mycotoxin intoxication.

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Identity of mass-flowering crops moderates functional trait composition of pollinator communities

Landscape Ecology ◽

10.1007/s10980-021-01261-3 ◽

2021 ◽

Author(s):

Nicole Beyer ◽

Felix Kirsch ◽

Doreen Gabriel ◽

Catrin Westphal

Keyword(s):

Faba Bean ◽

Management Practices ◽

Functional Trait ◽

Flower Morphology ◽

Landscape Diversity ◽

Floral Resources ◽

Wild Bees ◽

Natural Habitats ◽

Mass Flowering ◽

Wild Bee

Abstract Context Pollinator declines and functional homogenization of farmland insect communities have been reported. Mass-flowering crops (MFC) can support pollinators by providing floral resources. Knowledge about how MFC with dissimilar flower morphology affect functional groups and functional trait compositions of wild bee communities is scarce. Objective We investigated how two morphologically different MFC, land cover and local flower cover of semi-natural habitats (SNH) and landscape diversity affect wild bees and their functional traits (body size, tongue length, sociality, foraging preferences). Methods We conducted landscape-level wild bee surveys in SNH of 30 paired study landscapes covering an oilseed rape (OSR) (Brassica napus L.) gradient. In 15 study landscapes faba beans (Vicia faba L.) were grown, paired with respective control landscapes without grain legumes. Results Faba bean cultivation promoted bumblebees (Bombus spp. Latreille), whereas non-Bombus densities were only driven by the local flower cover of SNH. High landscape diversity enhanced wild bee species richness. Faba bean cultivation enhanced the proportions of social wild bees, bees foraging on Fabaceae and slightly of long-tongued bumblebees. Solitary bee proportions increased with high covers of OSR. High local SNH flower covers mitigated changes of mean bee sizes caused by faba bean cultivation. Conclusions Our results show that MFC support specific functional bee groups adapted to their flower morphology and can alter pollinators` functional trait composition. We conclude that management practices need to target the cultivation of functionally diverse crops, combined with high local flower covers of diverse SNH to create heterogeneous landscapes, which sustain diverse pollinator communities.

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