50 research outputs found

    Shelter-Building Behavior and Natural History of Two Pyralid Caterpillars Feeding on Piper stipulaceum

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    Shelter-building behavior by caterpillars provides a mechanism of defense against predators, microenvironment enhancement, and in some cases nutritional benefits. This study provides a detailed description of the life cycle and shelter-building process of caterpillars, and identifies constraints and factors influencing this adaptive behavior in Lepidomys n. sp. near proclea Druce (Pyralidae: Chrysauginae), a tropical dry forest pyralid. Five macroscopic larval instars were detected during the life cycle, and activities performed during shelter-building were categorized and timed. Caterpillar predators were identified, and 20% of all collected larvae died due to attack by parasitoid wasps. Shelter-building behavior was found to be constrained by the ontogenetic stage of caterpillars and influenced by leaf size of the host plant, Piper stipulaceum Opiz (Piperales: Piperaceae). A similar pattern of shelter- building behavior exhibited by Tosale n. sp. near cuprealis larvae that coexisted in the same host plant is also described. Larvae of the second species were significantly less abundant than those of Lepidomys and hatched one month later in the rainy season, which could indicate some competitive interactions between these two pyralid species

    Two New Species of \u3ci\u3eWockia\u3c/i\u3e Heinemann (Lepidoptera: Urodidae) from Coastal Dry-Forests in Western Mexico

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    Two new species of Wockia Heinemann, 1870 (Lepidoptera: Urodidae), W. chewbacca and W. mexicana, are described from primary dry-forests in western Mexico. A new host record is reported for the genus from larvae of W. chewbacca feeding on leaves of Casearia nitida (L.) Jacq. (Salicaceae). Several shared genitalic features and DNA barcode similarities suggest a congeneric relationship between the two Mexican species but uncertain generic placement within Urodidae. Scanning electron micrographs of the larva and illustrations of the larva and pupa of Wockia chewbacca are provided, along with illustrations of male and female genitalia of both Mexican species. Three unusual features found in the larval stage are documented for W. chewbacca include; a multi-lobed integument, recurved D2 seta on the shield of T1, and a ‘‘hydroid bush’’ consisting of multiple sensilla trichoidea on the apical turret of the antenna. Locality data indicate the existence of Neotropical elements of Wockia and an expanded distributional range for the genus

    Two New Species of \u3ci\u3eWockia\u3c/i\u3e Heinemann (Lepidoptera: Urodidae) from Coastal Dry-Forests in Western Mexico

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    Two new species of Wockia Heinemann, 1870 (Lepidoptera: Urodidae), W. chewbacca and W. mexicana, are described from primary dry-forests in western Mexico. A new host record is reported for the genus from larvae of W. chewbacca feeding on leaves of Casearia nitida (L.) Jacq. (Salicaceae). Several shared genitalic features and DNA barcode similarities suggest a congeneric relationship between the two Mexican species but uncertain generic placement within Urodidae. Scanning electron micrographs of the larva and illustrations of the larva and pupa of Wockia chewbacca are provided, along with illustrations of male and female genitalia of both Mexican species. Three unusual features found in the larval stage are documented for W. chewbacca include; a multi-lobed integument, recurved D2 seta on the shield of T1, and a ‘‘hydroid bush’’ consisting of multiple sensilla trichoidea on the apical turret of the antenna. Locality data indicate the existence of Neotropical elements of Wockia and an expanded distributional range for the genus

    Reorganization of interaction networks modulates the persistence of species in late successional stages

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    Ecological interaction networks constantly reorganize as interspecific interactions change across successional stages and environmental gradients. This reorganization can also be associated with the extent to which species change their preference for types of niches available in their local sites. Despite the pervasiveness of these interaction changes, previous studies have revealed that network reorganizations have a minimal or insignificant effect on global descriptors of network architecture, such as connectance, modularity and nestedness. However, little is known about whether these reorganizations may have an effect on community dynamics and composition.To answer the question above, we study the multi-year dynamics and reorganization of plant–herbivore interaction networks across secondary successional stages of a tropical dry forest. We develop new quantitative tools based on a structural stability approach to estimate the potential impact of network reorganization on species persistence. Then, we investigate whether this impact can explain the likelihood of persistence of herbivore species in the observed communities.We find that resident (early-arriving) herbivore species increase their likelihood of persistence across time and successional stages. Importantly, we demonstrate that, in late successional stages, the reorganization of interactions among resident species has a strong inhibitory effect on the likelihood of persistence of colonizing (late-arriving) herbivores.These findings support earlier predictions suggesting that, in mature communities, changes of species interactions can act as community-control mechanisms (also known as priority effects). Furthermore, our results illustrate that the dynamics and composition of ecological communities cannot be fully understood without attention to their reorganization processes, despite the invariability of global network properties

    Predictability of biotic stress structures plant defence evolution

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    To achieve ecological and reproductive success, plants need to mitigate a multitude of stressors. The stressors encountered by plants are highly dynamic but typically vary predictably due to seasonality or correlations among stressors. As plants face physiological and ecological constraints in responses to stress, it can be beneficial for plants to evolve the ability to incorporate predictable patterns of stress in their life histories. Here, we discuss how plants predict adverse conditions, which plant strategies integrate predictability of biotic stress, and how such strategies can evolve. We propose that plants commonly optimise responses to correlated sequences or combinations of herbivores and pathogens, and that the predictability of these patterns is a key factor governing plant strategies in dynamic environments.</p

    Local dispersal pathways during the invasion of the cactus moth, Cactoblastis cactorum, within North America and the Caribbean

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    Cactoblastis cactorum, a species of moth native to Argentina, feeds on several prickly pear cactus species (Opuntia) and has been successfully used as a biological control of invading Opuntia species in Australia, South Africa and native ruderal Opuntia species in some Caribbean islands. Since its introduction to the Caribbean its spread was uncontrolled, invading successfully Florida, Texas and Louisiana. Despite this long history of invasion, we are still far from understanding the factors determining the patterns of invasion of Cactoblastis in North America. Here, we explored three non-mutually exclusive explanations: a) a stepping stone model of colonization, b) long distance colonization due to hurricanes, and/or c) hitchhiking through previously reported commercial routes. Genetic diversity, genetic structure and the patterns of migration among populations were obtained by analyzing 10 nuclear microsatellite loci. Results revealed the presence of genetic structure among populations of C. cactorum in the invaded region and suggest that both marine commercial trade between the Caribbean islands and continental USA, as well as recurrent transport by hurricanes, explain the observed patterns of colonization. Provided that sanitary regulations avoiding humanmediated dispersal are enforced, hurricanes probably represent the most important agent of dispersal and future invasion to continental areas.Fil: Andraca Gómez, Guadalupe. Universidad Nacional Autónoma de México. Instituto de Ecología; MéxicoFil: Lombaert, Eric. Université CÎte d'Azur; Francia. Centre National de la Recherche Scientifique; FranciaFil: Ordano, Mariano Andrés. Fundación Miguel Lillo; Argentina. Universidad Nacional de Tucumån. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumån. Instituto de Ecología Regional; ArgentinaFil: Pérez Ishiwara, Rubén. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; MéxicoFil: Boege, Karina. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; MéxicoFil: Domínguez, César A.. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; MéxicoFil: Fornoni, Juan. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; Méxic

    Two New Species of \u3ci\u3e Compsolechia\u3c/i\u3e Meyrick (Lepidoptera: Gelechiidae) Associated with \u3ci\u3e Casearia\u3c/i\u3e (Flacourtiaceae) in Coastal Dry-Forests of Western Mexico

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    Two new species of Compsolechia Meyrick (Lepidoptera: Gelechiidae), C. camilotus Adamski and C. vittatiella Adamski, are described from dry-forests in western Mexico. Larvae of both species were collected on leaves of Casearia nitida (L.) Jacq. (Flacourtiaceae), a new host record for the genus. Photographs of larvae and their shelters and adult moths are provided. In addition, illustrations of the male and female genitalia of the adults, larval chaetotaxal maps, and scanning electron micrographs for both species are included. The pupa of only C. camilotus was available for description

    The ontogeny of plant indirect defenses

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    Plants frequently attract natural enemies of their herbivores, resulting in a reduction in tissue damage and often in enhanced plant fitness. While such indirect defenses can dramatically change as plants develop, only recently have ecologists begun to explore such changes and evaluate their role in mediating plant-herbivore-natural enemy interactions. Here we review the literature documenting ontogenetic patterns in plant rewards (i.e. extrafloral nectaries (EFNs), food bodies (FBs) and domatia) and volatile organic compounds (VOCs), and identify links between ontogenetic patterns in such traits and the attraction of natural enemies (ants). In the case of reward traits we concentrate in ant-plant studies, which are the most numerous. We report that all indirect defensive traits commonly vary with plant age but ontogenetic trajectories differ among them. Myrmecophytic species, which provide both food and shelter to their defenders, do not produce rewarding traits until a minimum size is reached. Then, a pronounced increase in the abundance of food rewards and domatia often occurs as plants develop, which explains the temporal succession or colony size increase of mutualistic ant species and, in some cases, leads to a reduction in herbivore damage and enhanced fitness as plants age. In contrast, ontogenetic patterns were less consistent in plant species that rely on VOC emissions to attract natural enemies or those that provide only food rewards (EFNs) but not nesting sites to their associated ants, showing an overall decline or lack of trend with plant development, respectively. Future research should focus on uncovering: (i) the costs and mechanisms underlying ontogenetic variation in indirect defenses, (ii) the relative importance of environmental and genetic components shaping these ontogenetic trajectories, and (iii) the consequences of these ontogenetic trajectories on plant fitness. Advances in this area will shed light on the context dependency of bottom-up and top-down controls of herbivore populations and on how natural selection actually shapes the ontogenetic trajectories of these traits.Fil: Quintero, Carolina. State University Of Colorado-boulder; Estados Unidos. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Patagonia Norte. Instituto de InvestigaciĂłn en Biodiversidad y Medioambiente; ArgentinaFil: Barton, Kasey E.. University Of Hawaii At Manoa; Estados UnidosFil: Boege, Karina. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xic

    Data from: Testing the Distraction Hypothesis: do extrafloral nectaries reduce ant‐pollinator conflict?

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    1. Ant guards protect plants from herbivores, but can also hinder pollination by damaging reproductive structures and/or repelling pollinators. Natural selection should favour the evolution of plant traits that deter ants from visiting flowers during anthesis, without waiving their defensive services. The Distraction Hypothesis posits that rewarding ants with extrafloral nectar could reduce their visitation of flowers, reducing ant-pollinator conflict while retaining protection of other structures. 2. We characterised the proportion of flowers occupied by ants and the number of ants per flower in a Mexican ant-plant, Turnera velutina. We clogged extrafloral nectaries on field plants and observed the effects on patrolling ants, pollinators and ants inside flowers, and quantified the effects on plant fitness. Based on the Distraction Hypothesis we predicted that preventing extrafloral nectar secretion should result in fewer ants active at extrafloral nectaries, more ants inside flowers and a higher proportion of flowers occupied by ants, leading to ant-pollinator conflict, with reduced pollinator visitation and reduced plant fitness. 3. Overall ant activity inside flowers was low. Preventing extrafloral nectar secretion through clogging reduced the number of ants patrolling extrafloral nectaries, significantly increased the proportion of flowers occupied by ants from 6.1% to 9.7%, and reduced plant reproductive output through a 12% increase in the probability of fruit abortion. No change in the numbers of ants or pollinators inside flowers was observed. This is the first support for the Distraction Hypothesis obtained under field conditions, showing ecological and plant fitness benefits of the distracting function of extrafloral nectar during anthesis. 4. Synthesis: Our study provides the first field experimental support for the Distraction Hypothesis, suggesting that extrafloral nectaries located close to flowers may bribe ants away from reproductive structures during the crucial pollination period, reducing the probability of ant-occupation of flowers, reducing ant-pollinator conflict, and increasing plant reproductive success

    Clogging Experiments Data

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    Includes in the tabs within the excel file the following datasets: 1) data short term clogging experiment; 2) data for long term clogging experiment; 3) fitness (seeds) data for short term clogging experiment; 4) details of ant species and abundance visiting flowers and EFN (used for supplementary material analyses)
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