scholarly journals Intraspecific interaction of host plant influences local distribution of specialist herbivores through metabolic alterations in leaves

2021 ◽  
Author(s):  
Haruna Ohsaki ◽  
Atsuko Miyagi ◽  
Maki Kawai-Yamada ◽  
Akira Yamawo
Keyword(s):  
Population Density ◽  
Condensed Tannins ◽  
Total Phenolics ◽  
Local Population ◽  
Leaf Traits ◽  
Leaf Beetle ◽  
Resource Utilisation ◽  
Intraspecific Interaction ◽  
Specialist Herbivore ◽  
Leaf Beetles

Recent studies suggest that changes in leaf traits due to interactions between plants affect the resource utilisation and distribution of herbivores. However, this has not yet been confirmed experimentally. Here, we investigated the effects of phenotypic plasticity in leaf traits of Rumex obtusifolius (host plant) in response to the intra and interspecific interaction on distribution of two leaf beetles, Gastrophysa atrocyanea (specialist herbivore) and Galerucella grisescens (generalist herbivore). We investigated the local population density of R. obtusifolius plants and the presence of leaf beetles on the plants at five study sites. Leaf chemicals (condensed tannins and total phenolics) were compared between aggregated and solitary R. obtusifolius plants. To clarify the effects of the interaction environment of R. obtusifolius plants on their leaf traits and resource utilisation by leaf beetles, we conducted cultivation and preference experiments. Leaf chemicals (chlorophylls, organic acids, primary metabolites, condensed tannins and total phenolics) and preferences of adult leaf beetles were compared between intraspecific, interspecific plant interaction, or no-interaction treatments. Finally, we evaluated the effects of interaction between R. obtusifolius on leaf beetle distribution in mesocosm experiments. In the field, the presence of the specialist leaf beetle, G. atrocyanea, was positively correlated with the local population density (rosette overlap ratio) of R. obtusifolius plants; however, no correlation was observed in the case of the generalist leaf beetle, G. grisescens. In the cultivation experiment, plants in the intraspecific interaction treatment increased their leaf contents of condensed tannins and total phenolics, and G. atrocyanea consumed more of these leaves than leaves in other treatments. Similar results were observed in the field. In the mesocosm experiment, larger numbers of G. atrocyanea were distributed on R. obtusifolius plants exposed to below-ground intraspecific interaction than on plants not exposed to intraspecific interaction. Our results provide experimental evidence that leaf trait changes in response to intraspecific interaction between host plants influence specialist herbivore distribution. This highlights the need to integrate plant plant interactions into our understanding of plant animal interactions.

scholarly journals Changing Land Use and Population Density Are Degrading Water Quality in the Lower Mekong Basin

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1948
Author(s):  
Flavia Tromboni ◽  
Thomas E. Dilts ◽  
Sarah E. Null ◽  
Sapana Lohani ◽  
Peng Bun Ngor ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Population Density ◽  
Local Population ◽  
Reference Conditions ◽  
Mekong River ◽  
Land Use Impacts ◽  
Wet Season ◽  
Mekong Basin ◽  
Lower Mekong Basin

Establishing reference conditions in rivers is important to understand environmental change and protect ecosystem integrity. Ranked third globally for fish biodiversity, the Mekong River has the world’s largest inland fishery providing livelihoods, food security, and protein to the local population. It is therefore of paramount importance to maintain the water quality and biotic integrity of this ecosystem. We analyzed land use impacts on water quality constituents (TSS, TN, TP, DO, NO3−, NH4+, PO43−) in the Lower Mekong Basin. We then used a best-model regression approach with anthropogenic land-use as independent variables and water quality parameters as the dependent variables, to define reference conditions in the absence of human activities (corresponding to the intercept value). From 2000–2017, the population and the percentage of crop, rice, and plantation land cover increased, while there was a decrease in upland forest and flooded forest. Agriculture, urbanization, and population density were associated with decreasing water quality health in the Lower Mekong Basin. In several sites, Thailand and Laos had higher TN, NO3−, and NH4+ concentrations compared to reference conditions, while Cambodia had higher TP values than reference conditions, showing water quality degradation. TSS was higher than reference conditions in the dry season in Cambodia, but was lower than reference values in the wet season in Thailand and Laos. This study shows how deforestation from agriculture conversion and increasing urbanization pressure causes water quality decline in the Lower Mekong Basin, and provides a first characterization of reference water quality conditions for the Lower Mekong River and its tributaries.

Species delimitation in the leaf beetle genus Macroplea (Coleoptera, Chrysomelidae) based on mitochondrial DNA, and phylogeographic considerations

2006 ◽  
Vol 37 (4) ◽  
pp. 467-479 ◽  
Author(s):  
Gregor Kölsch ◽  
Bo Vest Pedersen ◽  
Olof Biström
Keyword(s):  
Phylogenetic Analysis ◽  
Mitochondrial Dna ◽  
Species Delimitation ◽  
Mitochondrial Gene ◽  
Leaf Beetle ◽  
Genetic Distances ◽  
Amino Acid Substitutions ◽  
Species Status ◽  
Leaf Beetles ◽  
Gene Coding

AbstractThe genus Macroplea Samouelle, 1819 is a group of highly specialized aquatic leaf beetles occurring in the Palaearctic. Since the members of this genus are morphologically very similar, we addressed the question of species identification and delimitation by analysing the second half of the mitochondrial gene coding for the cytochrome oxidase I (COI) subunit. Species limits are inferred from the multimodal frequency distribution of genetic distances between specimens: low genetic distances within a species are clearly set apart from distances between species. The species status of the hitherto controversial species M. japana (Jacoby, 1885) is confirmed. The pattern of nucleotide and amino acid substitutions is discussed in the light of functional domains of the COI molecule. Although the data are preliminary, the results provide new data on the distribution of the species. Together with the phylogenetic analysis they allow for a discussion of the phylogeography of the genus.

scholarly journals Investigating leaf beetles (Coleoptera, Chrysomelidae) on the west coast islands of Sabah via checklist-taking and DNA barcoding

2018 ◽  
Author(s):  
Kam-Cheng Yeong ◽  
Haruo Takizawa ◽  
Thor-Seng Liew
Keyword(s):  
Dna Barcoding ◽  
West Coast ◽  
Leaf Beetle ◽  
Coi Gene ◽  
Beetle Species ◽  
Dna Barcodes ◽  
The West ◽  
Leaf Beetles ◽  
Baseline Knowledge ◽  
Island Habitats

Sabah, northern Borneo is one of the world’s most well-recognized biodiversity hotspots famous for the incredible diversity of its flora and fauna. Plenty of studies of leaf beetle fauna from this region have been conducted over the past 30 years. Yet, our knowledge of the leaf beetle fauna from island habitats remains scarce despite Sabah having the highest number of islands in Malaysia (ca. 500 islands). In this study, we collected leaf beetle fauna from 13 islands off the west coast of Sabah between January 2016 and March 2017. All specimens were identified to species level. Species names were assigned when the specimens fitted the description of species in the literature and morpho-species were assigned when the species names could not be determined. In addition, DNA barcodes – mitochondarial COI gene – of the species were sequenced. A total of 68 species from 31 genera and 5 subfamilies were collected with 12 species name being determined. From the data it was established that Pulau Gaya has the highest species richness (42 species), followed by Pulau Tiga (22 species) and Pulau Sapangar (18 species). Furthermore, a total of 64 Barcode Index Numbers consisting of 101 DNA barcodes were obtained from 60 leaf beetle species. The mean intraspecific and interspecific distances were determined as 0.77 % and 16.11 %, respectively. In addition, DNA barcoding also reveals phenotypic variation in leaf beetle species, particularly in the case of the subfamily Galerucinae. This study provides baseline knowledge and information about the DNA barcodes of leaf beetle species on Sabah’s island habitats for use in future studies.

scholarly journals IDENTIFIKASI MORFOLOGI BAKTERI ASAM LAKTAT PADA NIRA SEGAR LONTAR (Borassus flabellifer Linn)

2019 ◽  
Vol 1 (2) ◽  
pp. 47-52
Author(s):  
Surenshy Bulu ◽  
Novi Ivonne Bullu ◽  
Anggraeni Dian Naomi Rupidara
Keyword(s):  
Mortality Rate ◽  
Experimental Method ◽  
Leaf Beetle ◽  
Biological Agents ◽  
Distilled Water ◽  
Metabolic System ◽  
Leaf Beetles

Entomopathogen is one of the biological agents that infects the insects and can damage the body's metabolic system of insects. This objective of the study were to determine the entomopathogenic activity of S. marcescens on mortality of coconut leaf beetles larvae (B. longissima), and the time needed to reach LT50. The study used an experimental method with 6 treatments of varying S.marcescens volumes, consisting of A (distilled water as a control), B (5 ml), C (7.5 ml), D (10 ml), E (12.5 ml), and F (15 ml) with 4 replications. The data were analyzed using ANOVA and Probit LT50 test. The results showed that the volume of S.marcescens had an effect on mortality of coconut leaf beetle B. longissimi larvae. The best mortality rate at treatment E is 78% with the value of LT50 in treatment F is 42.15 hours. S.marcescens has entomopathogenic activity in coconut leaf beetles (B. longissima) Gestro larvae.

Adjustment of fecundity and sex ratio in response to social environments in a haplodiploid mite

2022 ◽  
Author(s):  
Nuwan Weerawansha ◽  
Qiao Wang ◽  
Xiong Zhao He
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Population Size ◽  
Local Population ◽  
Female Offspring ◽  
Social Environments ◽  
Positive Interaction ◽  
Offspring Sex Ratio ◽  
Offspring Sex ◽  
Large Populations

Animals can adjust reproductive strategies in favour of corporation or competition in response to local population size and density, the two key factors of social environments. However, previous studies usually focus on either population size or density but ignore their interactions. Using a haplodiploid spider mite, Tetranychus ludeni Zacher, we carried out a factorial experiment in the laboratory to examine how ovipositing females adjust their fecundity and offspring sex ratio during their early reproductive life under various population size and density. We reveal that females laid significantly more eggs with increasing population size and significantly fewer eggs with increasing population density. This suggests that large populations favour cooperation between individuals and dense populations increase competition. We demonstrate a significant negative interaction of population size and density that resulted in significantly fewer eggs laid in the large and dense populations. Furthermore, we show that females significantly skewed the offspring sex ratio towards female-biased in small populations to reduce the local mate competition among their sons. However, population density incurred no significant impact on offspring sex ratio, while the significant positive interaction of population size and density significantly increased the proportion of female offspring in the large and dense populations, which will minimise food or space competition as females usually disperse after mating at crowded conditions. These results also suggest that population density affecting sex allocation in T. ludeni is intercorrelated with population size. This study provides evidence that animals can manipulate their reproductive output and adjust offspring sex ratio in response to various social environments, and the interactions of different socio-environmental factors may play significant roles.

scholarly journals Host Specificity of the Parasitic Wasp Anaphes flavipes (Hymenoptera: Mymaridae) and a New Defence in Its Hosts (Coleoptera: Chrysomelidae: Oulema spp.)

Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 175
Author(s):  
Alena Samková ◽  
Jiří Hadrava ◽  
Jiří Skuhrovec ◽  
Petr Janšta
Keyword(s):  
Biological Control ◽  
Czech Republic ◽  
Host Specificity ◽  
Parasitic Wasp ◽  
Leaf Beetle ◽  
Host Defence ◽  
Pest Species ◽  
New Host ◽  
Leaf Beetles ◽  
Study Laboratory

The parasitic wasp Anaphes flavipes (Förster, 1841) (Hymenoptera: Mymaridae) is an important egg parasitoid of cereal leaf beetles. Some species of cereal leaf beetle co-occur in the same localities, but the host specificity of the wasp to these crop pests has not yet been examined in detail. A lack of knowledge of host specificity can have a negative effect on the use of this wasps in biological control programs addressed to specific pest species or genus. In this study, laboratory experiments were conducted to assess the host specificity of A. flavipes for three species of cereal leaf beetles (Oulema duftschmidi Redtenbacher, 1874, Oulema gallaeciana Heyden, 1879 and Oulema melanopus Linnaeus, 1758) in central Europe. For the first time, a new host defence against egg parasitoids occurring in O. gallaeciana from localities in the Czech Republic, a strong dark sticky layer on the egg surface, was found and described. The host specificity of A. flavipes was studied in the locality with the presence of this defence on O. gallaeciana eggs (the dark sticky layer) (Czech Republic) and in a control locality (Germany), where no such host defence was observed. Contrary to the idea that a host defence mechanism can change the host specificity of parasitoids, the wasps from these two localities did not display any differences in that. Respectively, even though it has been observed that eggs with sticky dark layer can prevent parasitization, the overall rate of parasitization of the three species of cereal beetles has not been affected. However, in our view, new host defence can influence the effects of biological control, as eggs of all Oulema spp. in the locality are protected against parasitization from the wasps stuck on the sticky layer of the host eggs of O. gallaeciana.

scholarly journals Changes of tannin and nutrients during decomposition of branchlets of Casuarina equisetifolia plantation in subtropical coastal areas of China

2013 ◽  
Vol 59 (No. 2) ◽  
pp. 74-79 ◽  
Author(s):  
Zhang LH ◽  
Zhang SJ ◽  
Ye GF ◽  
Shao HB ◽  
Lin GH ◽  
...  
Keyword(s):  
Condensed Tannins ◽  
Total Phenolics ◽  
Current Knowledge ◽  
Dry Weight ◽  
Phosphorus Concentration ◽  
Casuarina Equisetifolia ◽  
Nitrogen And Phosphorus ◽  
Litterbag Experiment ◽  
Time Required

A litterbag experiment was conducted to investigate the changes of tannins and nutrients in branchlets at different decomposition stages of Casuarina equisetifolia in southern subtropical coastal zone, China, using the colorimetric assays. The time required for the loss of half of the initial dry weight (t<sub>50</sub>) was 9.13 months. Total phenolics (TP), extractable condensed tannins (ECT), protein-bound condensed tannins (PBCT), total condensed tannins (TCT) and protein precipitation capacity (PPC) of branchlets litter decreased rapidly, while fibre-bound condensed tannins (FBCT) increased during decomposition. Nitrogen and phosphorus concentration of the branchlet litter both increased gradually during decay. Negative correlations between TP and nitrogen or phosphorus, as well as TCT and nitrogen or phosphorus were found. These chemical changes enhanced the current knowledge on the potential ecological role of nutrient transformation in tannins in C. equisetifolia plantations.

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