scholarly journals Spatiotemporal Distribution of Herbivorous Insects Along Always-Green Mountaintop Forest Islands

2021 ◽  
Vol 4 ◽  
Author(s):  
Juliana Kuchenbecker ◽  
Luiz Eduardo Macedo-Reis ◽  
Marcílio Fagundes ◽  
Frederico S. Neves
Keyword(s):  
Species Turnover ◽  
Southeastern Brazil ◽  
Herbivorous Insects ◽  
Campo Rupestre ◽  
Herbivorous Insect ◽  
Global Changes ◽  
Old Growth Forest ◽  
Xylophagous Insects ◽  
Insect Guilds ◽  
Forest Islands

Insects make up the bulk of terrestrial diversity and about half of insect species are herbivores that have direct relationships with their host plants and are the basis of the entire food chain, on which wildlife and humanity depend. Some herbivorous insect traits, such as their spatio-temporal distribution, are especially relevant in the current scenario of global changes, which are more pronounced in high elevation areas, helping to improve the effectiveness of conservation actions. Here we evaluated the influence that different spatiotemporal scales have on three free-feeding herbivorous insect guilds (fluid-feeding, leaf-chewing, and xylophagous insects) in montane forest islands immersed in a grassland-dominated matrix (campo rupestre). We assessed whether species turnover or nestedness was the main component determining both spatial and temporal species composition variation (β-diversity) of the herbivorous insect community. We also checked the temporal effect on herbivorous insect guilds composition between vertical strata. We sampled herbivorous insects during two summers and two winters in 14 forest islands of different sizes and shapes in a natural mountainous fragment located in southeastern Brazil. A total of 6597 herbivorous insects representing 557 morphospecies were sampled, 290 of which were fluid-feeding, 147 leaf-chewing and 120 xylophagous insects. We found a main contribution of time scale in the organization of the herbivorous insect composition sampled in this study, mainly by turnover, with small differences among guilds. Additionally, we could see that climate determined the local variation of species, corroborating that we have a highly variable always-green system over space and time where the understory community varies less in comparison to the canopy community. Our findings suggest that long-term ecological research on herbivorous community structure in relation to climatic variation is a key element for future investigations, which can be decisive for the conservation of herbivorous insect communities. We also suggest that the effects of anthropogenic pressures must be monitored in this system, since these forest islands may serve as warming refuges in a fragmented landscape holding an invaluable diversity of species that, without these old-growth forest reservoirs, would be doomed to disappear.

scholarly journals Root-associated entomopathogenic fungi manipulate host plants to attract herbivorous insects

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Belén Cotes ◽  
Gunda Thöming ◽  
Carol V. Amaya-Gómez ◽  
Ondřej Novák ◽  
Christian Nansen
Keyword(s):  
Host Plant ◽  
Entomopathogenic Fungi ◽  
Host Plants ◽  
Near Infrared ◽  
Delia Radicum ◽  
Host Plant Selection ◽  
Herbivorous Insects ◽  
Herbivorous Insect ◽  
Insect Performance ◽  
Leaf Reflectance

AbstractRoot-associated entomopathogenic fungi (R-AEF) indirectly influence herbivorous insect performance. However, host plant-R-AEF interactions and R-AEF as biological control agents have been studied independently and without much attention to the potential synergy between these functional traits. In this study, we evaluated behavioral responses of cabbage root flies [Delia radicum L. (Diptera: Anthomyiidae)] to a host plant (white cabbage cabbage Brassica oleracea var. capitata f. alba cv. Castello L.) with and without the R-AEF Metarhizium brunneum (Petch). We performed experiments on leaf reflectance, phytohormonal composition and host plant location behavior (behavioral processes that contribute to locating and selecting an adequate host plant in the environment). Compared to control host plants, R-AEF inoculation caused, on one hand, a decrease in reflectance of host plant leaves in the near-infrared portion of the radiometric spectrum and, on the other, an increase in the production of jasmonic, (+)-7-iso-jasmonoyl-l-isoleucine and salicylic acid in certain parts of the host plant. Under both greenhouse and field settings, landing and oviposition by cabbage root fly females were positively affected by R-AEF inoculation of host plants. The fungal-induced change in leaf reflectance may have altered visual cues used by the cabbage root flies in their host plant selection. This is the first study providing evidence for the hypothesis that R-AEF manipulate the suitability of their host plant to attract herbivorous insects.

One more piece to the puzzle: Diadorimia , a new monotypic genus in the Spermacoceae (Rubiaceae), endemic to the campo rupestre of Minas Gerais, southeastern Brazil

Taxon ◽  
2021 ◽  
Author(s):  
João A.M. Carmo ◽  
Marcelo Reginato ◽  
Javier E. Florentín ◽  
Mariela Nuñez Florentin ◽  
Roberto M. Salas ◽  
...  
Keyword(s):  
Minas Gerais ◽  
Southeastern Brazil ◽  
Campo Rupestre ◽  
Monotypic Genus

What We Don't Know About Diet-Breadth Evolution in Herbivorous Insects

2020 ◽  
Vol 51 (1) ◽  
pp. 103-122 ◽  
Author(s):  
Nate B. Hardy ◽  
Chloe Kaczvinsky ◽  
Gwendolyn Bird ◽  
Benjamin B. Normark
Keyword(s):  
Plant Species ◽  
Population Genetic ◽  
Genetic Architecture ◽  
Diet Breadth ◽  
Herbivorous Insects ◽  
Herbivorous Insect ◽  
Insect Diversity ◽  
Major Question ◽  
Genetic Environment ◽  
Species Ecology

Half a million species of herbivorous insects have been described. Most of them are diet specialists, using only a few plant species as hosts. Biologists suspect that their specificity is key to their diversity. But why do herbivorous insects tend to be diet specialists? In this review, we catalog a broad range of explanations. We review the evidence for each and suggest lines of research to obtain the evidence we lack. We then draw attention to a second major question, namely how changes in diet breadth affect the rest of a species’ biology. In particular, we know little about how changes in diet breadth feed back on genetic architecture, the population genetic environment, and other aspects of a species’ ecology. Knowing more about how generalists and specialists differ should go a long way toward sorting out potential explanations of specificity, and yield a deeper understanding of herbivorous insect diversity.

scholarly journals Thermal Tolerance of Fruit-Feeding Butterflies (Lepidoptera: Nymphalidae) in Contrasting Mountaintop Environments

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 278 ◽  
Author(s):  
Vanessa Diniz e Silva ◽  
Marina Vale Beirão ◽  
Danon Clemes Cardoso
Keyword(s):  
Climate Change ◽  
Critical Temperature ◽  
Thermal Tolerance ◽  
Global Climate ◽  
Campo Rupestre ◽  
Temperature Dependent ◽  
Physiological Constraints ◽  
Resistant Species ◽  
Complicated Task ◽  
Forest Islands

Ectothermic organisms, such as insects, are highly temperature dependent and are good models for studies that predict organisms’ responses to global climate change. Predicting how climate change may affect species distributions is a complicated task. However, it is possible to estimate species’ physiological constraints through maximum critical temperature, which may indicate if the species can tolerate new climates. Butterflies are useful organisms for studies of thermal tolerance. We tested if species have different thermal tolerances and if different habitats influence the thermal tolerance of the butterflies present in Brazil’s campo rupestre (open areas) and forest islands (shaded areas). A total of 394 fruit-feeding butterflies, comprising 45 species, were tested. The results separated the species into two statistically different groups: the resistant species with maximum critical temperature of 53.8 ± 7.4 °C, and the non-resistant species with maximum critical temperature of 48.2 ± 7.4 °C. The species of butterflies displayed differences in maximum critical temperature between the campo rupestre and forest islands that can be related to the two distinct habitats, but this did not correlate phylogenetically. Species from the forest islands were also divided into two groups, “resistant” and “non-resistant”, probably due to the heterogeneity of the habitat; the forest islands have a canopy, and in the understory, there are shaded and sunny areas. Species from forest islands, especially species that displayed lower thermal tolerance, may be more susceptible to global warming.

Effects of climate and forest age on plant and caterpillar diversity in the Yucatan, Mexico

2014 ◽  
Vol 30 (5) ◽  
pp. 419-434 ◽  
Author(s):  
Tijl Essens ◽  
Euridice Leyequién ◽  
Carmen Pozo ◽  
Henricus F. M. Vester ◽  
Hector A. Hernández-Arana
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Forest Type ◽  
Species Turnover ◽  
Herbivorous Insect ◽  
Forest Age ◽  
Forest Types ◽  
Humid Forest ◽  
Species Numbers ◽  
Explained Variation

Abstract:Understanding patterns in plant and herbivorous insect diversity across spatial and temporal scales is fundamental to ecology, but comparative multi-taxonomic studies in tropical seasonally dry forests remain scarce. In 36 sites, distributed over three forest age classes (5–10 y, 10–30 y, >100 y) and three seasonal forest types (dry, intermediate, humid), we sampled plants of different stem diameter classes while caterpillars were sampled across vertically distributed forest layers during three seasons over the year. We recorded 299 plant species and 485 caterpillar morphospecies. For large woody plants, species numbers showed a gradually increasing trend with forest age in the intermediate and humid forest types, while the main portion of explained variation in overall species turnover was accounted for by the forest type × forest age interaction (21.3–23.1% of 44.4–48.7%). Ordinations and multivariate pairwise comparisons suggested a faster but also very distinct successional development of species diversity of large plants in the driest compared with humid and intermediate forest types. In contrast, highest species numbers of small plants in the undergrowth was often found in the 5–10 y-old vegetation across forest types, whereas forest type was the major factor in overall species turnover (contributing 24.2% of 48.7% explained variation). Caterpillar species turnover was most correlated to species turnover of small plants; however, variation in caterpillar species diversity appears to be mostly regulated by seasonal cues, and to a lesser extent by patterns of regional turnover and local diversity of undergrowth plant species.

scholarly journals A review and meta-analysis of the enemy release hypothesis in plant–herbivorous insect systems

2016 ◽  
Author(s):  
Kim Meijer ◽  
Menno Schilthuizen ◽  
Leo Beukeboom ◽  
Christian Smit
Keyword(s):  
Native Species ◽  
Native Plants ◽  
Meta Analysis ◽  
Enemy Release Hypothesis ◽  
Enemy Release ◽  
Herbivorous Insects ◽  
Herbivorous Insect ◽  
Insect Diversity ◽  
Specific System ◽  
Community Approach

A suggested mechanism for the success of introduced non-native species is the enemy release hypothesis (ERH). Many studies have tested the predictions of the ERH using the community approach (native and non-native species studied in the same habitat) or the biogeographical approach (species studied in their native and non-native range), but results are highly variable, possibly due to large variety of study systems incorporated. We therefore focused on one specific system: plants and their herbivorous insects. We performed a systematic review and compiled a large number (68) of datasets from studies comparing herbivorous insects on native and non-native plants using the community or biogeographical approach. We performed a meta-analysis to test the predictions from the ERH for insect diversity (number of species), insect load (number of individuals) and level of herbivory for both the community and biogeographical approach. For both the community and biogeographical approach insect diversity was significantly higher on native than on non-native plants. Insect load tended to be higher on native than non-native plants at the community approach only. Herbivory was not different between native and non-native plants at the community approach, while there was too little data available for testing the biogeographical approach. Our meta-analysis generally supports the predictions from the ERH for both the community and biogeographical approach, but also shows that the outcome is importantly determined by the response measured and approach applied. So far, very few studies apply both approaches simultaneously in a reciprocal manner while this is arguably the best way for testing the ERH.

COMPARATIVE ANATOMY OF CALOLISIANTHUS SPECIES (GENTIANACEAE – HELIEAE) FROM BRAZIL: TAXONOMIC ASPECTS

2011 ◽  
Vol 68 (1) ◽  
pp. 139-155 ◽  
Author(s):  
M. N. Delgado ◽  
A. A. Azevedo ◽  
L. C. Silva ◽  
G. E. Valente ◽  
M. C. M. Kasuya
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Comparative Anatomy ◽  
Southeastern Brazil ◽  
Campo Rupestre ◽  
Leaf Margin ◽  
Adaptive Responses ◽  
High Luminosity ◽  
Leaf Base ◽  
Anatomical Characters ◽  
Stems And Leaves

This work aims to characterise the morphology and anatomy of roots, stems and leaves of Calolisianthus species (Gentianaceae – Helieae) to assist in the taxonomy and understanding of some adaptive responses to high luminosity, prolonged water deficit and nutritional stress in their environment. Samples of Calolisianthus speciosus and C. pendulus were collected in campo rupestre (rocky land) and samples of C. amplissimus were collected in cerrado (savanna) areas in southeastern Brazil. The roots have a cortex with Arum-type arbuscular mycorrhizae. The three species have winged and square stems and in Calolisianthus amplissimus the stem is hollow. Calolisianthus pendulus and C. speciosus have a pair of conspicuous extrafloral nectaries at the leaf base, which are absent in C. amplissimus. Calolisianthus pendulus has a dorsiventral mesophyll and a round leaf margin with parenchymatic cells. Calolisianthus amplissimus has a homogeneous mesophyll and a leaf margin with collenchyma. Calolisianthus speciosus leaves have a homogeneous mesophyll and a margin with sclerenchyma and collenchyma. Our results demonstrate that some anatomical characters are useful for the identification of Calolisianthus species and might be used to elucidate evolutionary relationships among Calolisianthus and their adaptive responses.

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