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Galls are plant neoformations induced by specialized parasites. Since gall inducers rely on reactive plant sites for gall development, variations in abiotic factors that affect plant phenology are expected to impact the life cycle of gall inducers. To test the hypothesis that different light conditions affect both host plant and gall inducer life cycles, we studied the system Eugenia uniflora (Myrtaceae) - Clinodiplosis profusa (Cecidomyiidae), comparing plants occurring in sunny and shaded environments. We mapped phenological differences among individuals of E. uniflora occurring in the two environments and related them to the influence of luminosity on the life cycle of the gall inducer. Shade plants showed lower intensity of leaf sprouting throughout the year compared to sun-exposed plants, especially during the rainy season. Young and mature galls are synchronized with the peak of leaf sprouting at the beginning of the rainy season, lasting longer in sun-exposed plants - approximately two months longer compared to shade plants. The greater light intensity positively impacts the formation and growth of leaves and galls, with an extended period available for their induction and growth. Thus, light is an important factor for the development of gallers, considering that variations in luminosity influenced not only the phenology of the host plant, but also determined the life cycle of gall inducers. Furthermore, changes in plant-environment interactions are expected to affect the life cycle and richness of other host plant-gall inducer systems.

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The concept of Ecosystem Services (ES) recognizes the importance of natural ecosystems in supporting human well-being. Hymenoptera, a diverse group of insects including ants, bees, and wasps, play crucial roles in providing ESs. Despite their significance, the provision of ESs by Hymenoptera is often undervalued, leading to ecosystem degradation and loss of important services. This study focuses on the association between Hymenoptera and a rupicolous bromeliad species (Encholirium spectabile) and explores the ESs promoted directly and indirectly by these insects. The study area is located in the Caatinga region of Brazil, characterized by irregular rainfall and a dry season. The results show that Hymenoptera, particularly bees, ants, and wasps, provide a range of ESs including pollination, honey production, pest control, cultural symbolism, and educational value. These services are vital for plant reproduction, food production, and ecosystem functioning in both seasons; there are no differences in species richness between seasons, but rather in species composition. Understanding the importance of Hymenoptera for ESs is crucial for informing conservation and management practices to ensure the sustainability of natural ecosystems. The study highlights the need for conservation actions to protect the intricate ecological relationships between Hymenoptera and bromeliads, which indirectly support ESs by providing habitat and resources, especially during droughts when resources are scarce in the region. By recognizing the importance of bromeliads in supporting Hymenopteran communities, conservation efforts can focus on preserving these critical ecological interactions and maintaining ES provision.

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Bromeliads play a vital role in preserving biodiversity in the Neotropical region. To understand their impact on arthropod diversity in Brazil's semi-arid region, we studied the rupicolous bromeliad Encholirium spectabile. From 2011 to 2018, we observed the arthropod fauna in E. spectabile clumps, documenting the associated taxa, their abundance, and interactions. We also investigated how seasonality affects arthropod richness and composition during the dry and rainy seasons. Over the observation period, 15 orders and 57 arthropod families were recorded in association with E. spectabile. Insecta dominated, followed by predatory chelicerates. Eight usage categories were identified, with Shelter being the most prevalent, followed by Predators, Nesters, and Nectarivores. Significant differences in taxonomic richness were noted between rainy and dry seasons, with the rainy season exhibiting higher diversity. Seasonal variation was also observed in species composition. Clumps of E. spectabile emerged as crucial habitats for surrounding arthropod fauna. This research underscores the importance of non-phylotelm bromeliads, particularly in high abiotic stress environments like semi-arid regions. The taxonomic diversity observed aligns with findings from diverse environments, shedding light on the relevance of E. spectabile for associated arthropod fauna. These results prompt further exploration of non-phylotelm bromeliads in semi-arid settings, providing a fresh perspective on their significance in shaping arthropod communities.

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Culex pipiens (Linnaeus, 1758) mosquitoes search plant sources of sugars to cope with the energetic demand of various physiological processes. The crop as part of the digestive system is devoted to the storage of sugar-based meal obtained from various nectars sources. The profiling of sugars and metabolites in the Culex pipiens' crop is scarce, and only few studies used Liquid Chromatography - Mass Spectrometry (LC-MS), which provides broad detection for biomonitoring environmental substances and even contaminants in the sugar diet of mosquitoes populations. Therefore, sugar and metabolite profiling were performed on crops obtained from mosquitoes exposed to plant nectar under laboratory or natural conditions by Ultra High-Performance LC-MS (UHPLC-MS). This method allowed us a precise quantitative and qualitative identification of sugar diet and associated environmental compounds in the crop of the mosquito C. pipiens. Under laboratory condition, mosquitoes were allowed to feed on either glucose solution, commercially-available flowers or field collected flowers. In addition, we collected mosquitoes from the field to compare those crop metabolomes with metabolome patterns occurring after nectar feeding in the lab. The sugar quantities and quality obtained from the crops of mosquitoes collected in the field were similar to those crops obtained from mosquitoes that fed on commercially-available flowers and from field collected flowers with a limit of detection of 10 µg/L for sucrose, glucose and sucrose. Next to sugar compounds, we identified 2 types of amino acids, 12 natural products, and 9 pesticides. Next to the diversity of sugar compounds, we could confirm that secondary metabolites and environmental pollutants are typically up taken from floral nectar sources by C. pipiens. The in-depth knowledge on mosquito-plant interactions may inspire the development and further optimization of mosquito trap systems and arboviral surveillance systems.

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Beneficial associations are very important for plants and soil-dwelling microorganisms in different ecological niches, where communication by chemical signals is relevant. Among the chemical signals, the release of phytohormones by plants is important to establish beneficial associations with fungi, and a recently described association is that of the entomopathogenic ascomycete fungus Metarhizium with plants. Here, we evaluated the effect of four different phytohormones, synthetic strigolactone (GR24), sorgolactone (SorL), 3-indolacetic acid (IAA) and gibberellic acid (GA3), on the fungus Metarhizium guizhouense strain HA11-2, where the germination rate and hyphal elongation were determined at three different times. All phytohormones had a positive effect on germination, with GA3 showing the greatest effect, and for hyphal length, on average, the group treated with synthetic strigolactone GR24 showed greater average hyphal length at 10 h of induction. This work expands the knowledge of the effect of phytohormones on the fungus M. guizhouense, as possible chemical signals for the rapid establishment of the fungus-plant association.

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In several montane forests around the world, epiphytes coexist in mats, sharing the rhizosphere and forming histosol-type soils rich in nutrients. The role of these epiphytes in the formation of canopy soil and the fitness costs that epiphytes face when cohabiting in these mats are unknown. In a lower montane cloud forest in central Veracruz, Mexico, a 2-year factorial experiment was carried out with the presence/absence of ramets of Phlebodium areolatum (Polypodiaceae), Tillandsia kirchhoffiana, T. multicaulis and T. punctulata (Bromeliaceae). We examined (i) which epiphyte species contribute to the formation of canopy soil, (ii) the role of epiphyte composition in the soil nutrient composition, and (iii) the fitness costs faced by epiphytes when cohabiting. Canopy soil formation highest when P. areolatum is present. Soil nutrient content does not change with epiphyte composition, is influenced by the microbiota, and P content decreases with the presence of epiphytes. The fitness costs show that the species compete, decreasing their survival and growth, but the competitive capacity differs between the species. We conclude that P. areolatum is an ecosystem engineer that promotes the creation of canopy soil but is a poor competitor. The results coincide with the model of succession by facilitation. Canopy soil is a slow-created component whose nutrient content does not depend on the epiphytic flora. In epiphyte mats, the dominant interactions are competitive, but there is also facilitation.

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Mabea fistulifera, a species pollinated mainly by diurnal and nocturnal vertebrates, presents pendulous inflorescences with approximately 70 pairs of nuptial nectaries (NNs). These NNs exude voluminous nectar drops that defy gravity, remaining exposed at the inflorescence for more than a day. We aimed to investigate the NN secretory process and the unique nectar presentation of M. fistulifera. NNs and their exudate were collected at different secretory stages and submitted to structural studies and chemical analysis. The epidermis is devoid of stomata and constitutes the main site of synthesis for non-sugar metabolites found on nectar and nectar-coating film. Nectary parenchyma presents few small starch grains, and vascular strands are distributed until the nectary parenchyma cells close to the epidermis. Vascular tissues at the nectary parenchyma seem to provide sugar and water for the nectar. A film composed of lipids, alkaloids, and proteins covers the nectar drops. The film guarantees the nectar offering for several hours, as it minimizes water loss and prevents falls by gravitational action. The release of large nectar drops is intrinsically linked to the NN anatomical traits and the exudate composition. Low sugar concentration and predominance of hexoses in M. fistulifera nectar are essential for maintaining nectar exudation for many hours, which results in the visitation of a broad spectrum of pollinators.

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ABSTRACT Perennial ryegrass is one of the most important food sources in animal production. However, several pests affect this crop, and one of the primary control strategies is the symbiotic relationships between ryegrass endophyte fungi. This fungus produces alkaloids that exhibit toxic activity against arthropods. Furthermore, the effect of fungi may extend to higher trophic levels, including predators (spiders and/or insects), decreasing their abundance and diversity. Given the importance of spiders and insects as predators, whether the symbiotic interaction between perennial ryegrass and endophyte fungus reduces the abundance and diversity of predators pose an important question. To address this question, natural enemies in perennial ryegrass were collected and analyzed over a year, and the percentage of endophyte fungus was evaluated by the presence of hyphae from two ryegrass cultivars, Jumbo (E-) and Alto AR1 (E+). We observed an 80% endophyte infection rate for (E+) and 0% for (E-). Moreover, 222 individual spiders corresponding to 10 families were identified in both perennial ryegrasses, including 209 individuals for (E-) and 13 for (E+). The most abundant spider family was Lycosidae, representing 71.17% of the total spiders. In addition, 65 insects were collected, corresponding to 6 families, with Carabidae being the most abundant. Furthermore, the Simpson index indicated the dominance of the family Lycosidae. Overall, spider and insect abundance and diversity were reduced in (E+), suggesting a negative effect of the endophyte on predator populations.

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ABSTRACT Gall-inducing insects are highly specialized herbivores as they have the ability to control and redirect the development of host plants to obtain food and shelter. The distribution of galls on plants can be influenced by seasonality and phenological events, which determines the reproductive success of these insects. The species Manihot caerulescens Pohl (Euphorbiaceae) has a great diversity of gall-inducing insects in the Cerrado of Western Bahia. Our study aimed to (1) study the fauna associated with M. caerulescens Pohl (Euphorbiaceae) and (2) evaluate the phenological events of this host plant species. We performed gall collections between July 2018 and June 2020 and monitored 30 individuals of the host species to study the phenology in the Serra da Bandeira, Bahia, Brazil. The emerged insects in the laboratory were mounted on permanent slides and identified. We found galls on the stems, leaves and inflorescences. Stem galls were induced by lepidopterans (Alucitidae), and leaf and inflorescence galls by Iatrophobia brasiliensis Rübsaamen, 1915 (Cecidomyiidae). Further, we showed that I. brasiliensis preferentially induced galls on the leaves, however during the dry season, galls were induced on the inflorescences. Although the induction of galls on the leaves by I. brasiliensis has already been reported in the literature, here for the first time we record the presence of galls on the inflorescences induced by the same gall-inducing species. Our study constitutes an important contribution towards the knowledge of the insect-plant interaction between M. caerulescens and I. brasiliensis in the Cerrado of Bahia.

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Abstract Understanding the diversity of insect galls is pivotal to the establishment of conservation planning in different Brazilian ecosystems. Here, we (1) characterize the insect galls found on plant host species, (2) identify the gall-inducing insects to the lowest possible taxonomic level, and (3) record the presence of gall-associated fauna. Our study was carried out monthly from August, 2017 to July, 2018 along nine trails in Serra da Bandeira, which is located in an area of Cerrado stricto sensu over a year. We found 48 distinct gall morphotypes, belonging to 12 botanical families. The most morphotypes commonly found were globoid (27.1%), lenticular (27.1%) and cylindrical (25%). The plant organs most affected by galling insects were the leaves (73%), followed by the stem (19%), flower (4%), inflorescence (2%) and fruits (2%). The host botanical families holding the highest number of galls were Fabaceae (26), Malpighiaceae (5) and Anacardiaceae, Combretaceae and Euphorbiaceae (3). We observed that the genus Copaifera Lindl. (Fabaceae) had the greatest diversity of gall morphotypes, harboring 19 morphotypes distributed in three species that occur sympatrically - Copaifera sabulicola J. Costa (Fabaceae), Copaifera depilis Dwyer (Fabaceae) and Copaifera luetzelburgii Harms (Fabaceae). For the first time in Brazil, we recorded the occurrence of galls on flowers of Manihot caerulescens (Euphorbiaceae), on inflorescences of Mimosa acutistipula (Fabaceae) and flower buds of Anacardium humile (Anacardiaceae), which were induced by Cecidomyiidae. Inducers of the order Diptera (Family Cecidomyiidae) were the most abundant, found in 14 morphotypes of galls. Regarding the associated fauna, we found insects primarily belonging the order Hymenoptera, and identified them as parasitoids. The information provided can be used highly by decision makers for conservation programs, as well as in other strategies for the conservation of biological diversity in the Brazilian Cerrado.

Resumo Compreender a diversidade de galhas de insetos é fundamental para o estabelecimento de planos de conservação em diferentes ecossistemas brasileiros. Aqui, nós (1) caracterizamos as galhas de insetos encontradas em espécies de plantas hospedeiras, (2) identificamos os insetos indutores de galhas até o nível taxonômico mais baixo possível e (3) registramos a presença de fauna associada a galhas. Nosso estudo foi realizado mensalmente de agosto de 2017 a julho de 2018 ao longo de nove trilhas na Serra da Bandeira, que está localizada em uma área de Cerrado stricto sensu ao longo de um ano. Encontramos 48 morfotipos distintos de galhas, pertencentes a 12 famílias botânicas. Os morfotipos mais comumente encontrados foram globoide (27,1%), lenticular (27,1%) e cilíndrico (25%). Os órgãos vegetais mais afetados pelos insetos galhadores foram as folhas (73%), seguidas do caule (19%), flor (4%), inflorescência (2%) e frutos (2%). As famílias botânicas hospedeiras com maior número de galhas foram Fabaceae (26), Malpighiaceae (5) e Anacardiaceae, Combretaceae e Euphorbiaceae (3). Observamos que o gênero Copaifera Lindl. (Fabaceae) apresentou a maior diversidade de morfotipos de galhas, abrigando 19 morfotipos distribuídos em três espécies que ocorrem simpatriicamente - Copaifera sabulicola J. Costa (Fabaceae), Copaifera depilis Dwyer (Fabaceae) e Copaifera luetzelburgii Harms (Fabaceae). Pela primeira vez no Brasil, registramos a ocorrência de galhas em flores de Manihot caerulescens (Euphorbiaceae), em inflorescências de Mimosa acutistipula (Fabaceae) e em botões florais de Anacardium humile (Anacardiaceae), induzidas por Cecidomyiidae. Indutores da ordem Diptera (Família Cecidomyiidae) foram os mais abundantes, encontrados em 14 morfotipos de galhas. Em relação à fauna associada, encontramos insetos pertencentes principalmente à ordem Hymenoptera, e os identificamos como parasitóides. As informações fornecidas podem ser utilizadas por tomadores de decisão para programas de conservação, bem como em outras estratégias para a conservação da diversidade biológica no Cerrado brasileiro.

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Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a polyphagous pest species capable of feeding on almost all forage and grain crops, although the food quality for the larvae likely varies among plant species and cultivars. The cultivation of grass forage species with grains has increasingly been adopted in Brazil, within both no-tillage and crop-livestock integration systems. In this study, we evaluated the performance of S. frugiperda larvae on 14 forage cultivars of Brachiaria, Panicum, and Cynodon, which are widely used in integrated cropping systems in Brazil. The biological performance of S. frugiperda varied among the cultivars. The larval survival rates were lower on Panicum maximum 'Massai' and P. maximum 'Tamani' cultivars. The insects had the highest performance indexes on Brachiaria brizantha 'Paiaguás', B. brizantha 'Marandu', and B. brizantha 'Xaraés' cultivars, followed by Brachiaria ruziziensis, previously proposed as a standard grass forage for comparisons with other species. On P. maximum, the insect had the lowest performance indexes, with values equal to zero when feeding on the P. maximum 'Massai' and 'Tamani' cultivars. These results will help make management decisions when cultivating grass forage plants in crop production systems in which S. frugiperda infestation is of concern.

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The genus Nacobbus, known as the false root-knot nematode, is native to the American continent and comprises polyphagous species adapted to a wide range of climatic conditions. Alone or in combination with other biotic and abiotic factors, Nacobbus spp. can cause significant economic yield losses on main food crops such as potato, sugar beet, tomato, pepper and bean, in South and North America. Although the genus distribution is restricted to the American continent, it has quarantine importance and is subject to international legislation to prevent its spread to other regions, such as the European Union. The management of Nacobbus spp. remains unsatisfactory due to the lack of information related to different aspects of its life cycle, survival stages in the soil and in plant material, a rapid and reliable diagnostic method for its detection and the insufficient source of resistant plant genotypes. Due to the high toxicity of chemical nematicides, the search for alternatives has been intensified. Therefore, this review reports findings on the application of environmentally benign treatments to manage Nacobbus spp. Biological control strategies, such as the use of different organisms (mainly bacteria, fungi and entomopathogenic nematodes) and other eco-compatible approaches (such as metabolites, essential oils, plant extracts, phytohormones and amendments), either alone or as part of a combined control strategy, are discussed. Knowledge of potential sources of resistance for genetic improvement for crops susceptible to Nacobbus spp. are also reported. The sustainable strategies outlined here offer immediate benefits, not only to counter the pathogen, but also as good alternatives to improve crop health and growth.

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The transference of metals from water irrigation and soil to plants is a possible pathway of contamination for the trophic chain. This research is focused on the distribution of 16 analytes in the water-soil-tree (Pyrus malus) interaction in an agricultural region in the state of Chihuahua in Mexico from August 2019 (first sampling) to August 2020 (second sampling). The apple variety under investigation was Golden Delicious; it was found that the trace elements of As (0.18-0.34 mg·kg-1) and Cd (0.11-0.14 mg·kg-1) in the apple were above the corresponding permissible limit, according to FAO/WHO, and Cr (0.08-0.86 mg·kg-1) was below the limit. Furthermore, the health risk implications were estimated by the Hazard Quotients (HQ) and carcinogenic risk (CR). For carcinogenic risk, As, Cd, and Cr exceeded the risk limit (CR > 10-4). This investigation as well provides a link for similar research around the globe. Major and trace elements detection was performed with the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) technique, along with a prior homogenization of samples and microwave acid digestion. To obtain the statistical behavior, an analysis of variance and correlation was performed.

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Abstract The genus Capsicum, native to tropical and subtropical America, belongs to the Solanaceae family, which includes commercially important vegetables such as chilies and green peppers. The silverleaf whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), causes losses to vegetables including Capsicum species. Among the alternatives of pest control, an effective, economical, and environmentally compatible method is the resistance of the host plant. Infestation by B. tabaci was evaluated in 73 Capsicum genotypes, corresponding to the species C. annuum, C. baccatum, C. sinense, C. frutescens and C. pubescens from an Ecuadorian genebank. Eighty-four percent of the C. baccatum genotypes evaluated showed the highest population densities of B. tabaci, while all the genotypes of C. sinense and C. frutescens had the lowest values (p < 0.05). The non-preference of adults and the scarce oviposition of B. tabaci on genotypes of C. sinense and C. frutescens suggests resistance due to antixenosis. These results could guide breeding programs for the resistance of Capsicum species to B. tabaci infestations.

Resumen El género Capsicum es nativo de América tropical y subtropical, pertenece a la familia Solanaceae e incluye ajíes y pimientos, que son hortalizas comercialmente importantes. La mosca blanca Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) ocasiona pérdidas en hortalizas incluyendo especies de Capsicum. Entre las alternativas de control de plagas, un método eficaz, económico y ambientemente compatible es la resistencia de la planta hospedera. Se evaluó la infestación por B. tabaci en 73 genotipos de Capsicum nativos de Ecuador, correspondientes a las especies C. annuum, C. baccatum, C. chinense, C. frutescens y C. pubescens, provenientes de un banco de germoplasma ecuatoriano. El 84% de los genotipos de C. baccatum evaluados mostraron las mayores densidades poblacionales de B. tabaci, mientras que los menores valores los tuvieron todos los genotipos de C. sinense y C. frutescens (p < 0.05). La no preferencia de adultos y la escasa oviposición de B. tabaci sobre genotipos de C. sinense y C. frutescens sugiere resistencia por antixenosis. Estos resultados podrían orientar programas de mejoramiento genético para la resistencia de especies de Capsicum ante infestaciones por B. tabaci.

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Spodoptera frugiperda (fall armyworm - FAW) is an important polyphagous agricultural pest feeding on nearly 350 host plants. FAW is undergoing incipient speciation with two well-characterized host-adapted strains, the "corn" (CS) and "rice" (RS) strains, which are morphologically identical but carry several genes under positive selection for host adaptation. We used non-targeted metabolomics based on gas chromatography/mass spectrometry to identify differences in metabolite profiles of the larval gut of CS and RS feeding on different host plants. Larvae were fed on artificial diet, maize, rice, or cotton leaves from eclosion to the sixth instar, when they had their midgut dissected for analysis. This study revealed that the midgut metabolome of FAW varied due to larval diet and differed between the FAW host-adapted strains. Additionally, we identified several candidate metabolites that may be involved in the adaptation of CS and RS to their host plants. Our findings provide clues toward the gut metabolic activities of the FAW strains.

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Two of the main causes of losses in tomato production are the greenhouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), and drought, which is becoming a central problem in agriculture due to global climate change. The separate effects of whitefly infestation and drought have been amply studied in many crop systems. However, less is known about their combined effects. To evaluate whether drought stress (DS) affects plant defense against whiteflies, we assessed the joint effects of whitefly infestation and DS on plant vegetative and reproductive performance in four tomato cultivars, and assessed the effects of DS on plant resistance and tolerance (compensatory ability) to whiteflies in a greenhouse experiment. Generally, we found negative effects of DS and whiteflies on plant performance, but the combined effects of DS and herbivory were not worse than those of either stress alone. In fact, plant performance under the combined effect of both stresses was usually similar to that in the presence of whiteflies without DS. Plants growing under DS had greater trichome density. However, plant resistance-as measured by whitefly population growth-decreased under DS in two cultivars and was unaffected in the other two. Compensatory ability decreased under DS in all but one cultivar. These cultivar-specific responses suggest genetic variation in resistance and tolerance to whiteflies and could be associated with differences in drought tolerance among cultivars. Our findings underscore the difficulty in predicting the combined effects of DS and herbivory and point to the need for a better understanding of the mechanisms underlying plant responses to both stresses at the molecular, cellular, and organismal levels.

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Plant resistance is a key strategy for the management of Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae), an important pest in South American rice paddies. The present study investigated the resistance of rice cultivars in terms of feeding and oviposition preference, growth, development, and biological performance of O. oryzae under natural conditions of field infestation during two consecutive rice seasons. There were no effects of the six cultivars on the feeding and oviposition preferences of O. oryzae as evaluated 5, 8, and 11 d After Flooding (DAF) of the plots, indicating the absence of antixenosis. Cultivars did not differ in terms of egg viability and larval density of first instars on the roots at 15 DAF. Significant differences were found 25 and 35 DAF when larval density per sample was high on 'BRS Pampa CL' (up to 24.5), intermediate on 'BRS Querência' and 'BRS Ligeirinho' (up to 16.1), and low on 'BRS Atalanta', 'BRS Firmeza', and 'Dawn' (up to 8.8). The cultivars 'BRS Atalanta', 'BRS Firmeza', and 'Dawn' caused malnutrition and inhibition of larval growth. These effects, typical of antibiosis, resulted in delayed pupation and emergence of adults; in addition, emerged females had body weight decreased strongly. The cultivars BRS Pampa CL, BRS Querência, and BRS Ligeirinho are susceptible, resulting in high larval populations and more suitable development of O. oryzae; antibiosis, as indicated for 'BRS Atalanta', 'BRS Firmeza', and 'Dawn', probably is the key mechanism of rice resistance to O. oryzae.

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ABSTRACT The garden fleahopper, Microtechnites bractatus (Say) (Hemiptera: Miridae), is associated with several cultivated plant species and, despite its economic importance, little is known about its development and performance in such hosts. We described here, the morphology of immature stages, and evaluated the biology of M. bractatus in beans, potatoes, white clover, alfalfa, and wheat. The bioassays were carried out in the laboratory under controlled temperature (25±2ºC), humidity (UR70±15%), and photoperiod (12L:12D). The eggs of M. bractatus are elongated and slightly curved, without respiratory projections and light yellow in color, becoming dark at the end of the incubation period. Nymphs present an oval-shaped body, a reddish color that intensifies along with the development and dimorphic wing pads in the fifth instar. In the bioassays, the host plants influenced the biological aspects of M. bractatus, both in the immature and adult stages. Nymph survival was higher in clover and alfalfa, while in wheat, it was lower. Clover-fed insects had the longest longevity. The fecundity parameters and egg viability were favored in insects that fed on clover and alfalfa. The fertility life table showed that feeding M. bractatus with clover provides a higher net reproduction rate (R0) and a higher finite ratio of population increase (ʎ). This study contributes to bioecological and behavioral studies on M. bractatus and provides data for the recognition and characterization of individuals in the immature stage.

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In a general way, galling insects can induce only one gall morphotype on the host plant species. However, some taxa of galling insects such as Eriococcidae can induce sexually dimorphic galls on the same host. In the present study, Lopesia mataybae (Diptera: Cecidomyiidae) induced two gall morphotypes on the leaflets of Matayba guianensis (Sapindaceae), a rare evidence of sexual dimorphism in galls induced by Cecidomyiidae. We investigated the adult emergence of galling insects and the morphological, histological, and histochemical attributes of the gall morphotypes. Both gall morphotypes showed the galling insect in the larval or pupal stage, and the insect adult emergence from different morphotypes was sexually distinct. Galls occupied by females (Globoid) were significantly larger (average height = 4.67 mm. S = 0.43/average width = 4.59 mm. S = 0.70) than galls occupied by males (cylindrical) (average height = 2.95 mm. S = 0.46/average width = 2.34 mm. S = 0.45). Both gall types were composed of elongated cells in the inner cortex and rounded cells in the outer cortex of the vessel-like structure. The globoid galls showed 42 cell layers (14 of them cylindrical, S = 3.86; 28 rounded, S = 5.89) and cylindrical galls showed 29 layers. There were no differences between morphotypes in the histochemical compounds detected. We have shown here significant morphological and histological differences between male and female galls possibly due to the different nutritional requirements of Lopesia mataybae sexes. Therefore, the expression of sexual dimorphism in gall morphotypes may be associated with developmental pathway differentiation between the sexes of L. mataybae.

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Echinopsis chiloensis is an endemic cactus from Chile, distributed in a temperature and rainfall gradient between 30° and 35° South latitude, with mean temperatures increasing and precipitation decreasing toward the north. It is the main host of the mistletoe Tristerix aphyllus, a holoparasite completely dependent on the cactus for water, carbon, and minerals. In this study, we investigated the consequences of parasitism over the fitness and physiology of this cactus throughout its distribution range and how it is affected by the environment. We measured five functional traits in eight populations latitudinally distributed, the first three only for the host: reproductive fitness, stomatal traits (density and size), and photosynthesis (during winter and summer); and the last two for the host and parasite: stable isotopes (∂13C and ∂15N), and nutrients (carbon and nitrogen content). The results showed a negative effect of parasitism over fitness of infected cacti. However, the higher nitrogen concentrations in cactus tissues toward the south improved overall fitness. Regarding photosynthesis, we only observed a negative effect of parasitism during the dry season (summer), which is also negatively affected by the increase in summer temperatures and decrease in winter rainfall toward the north. There were no differences in nutrient concentration or in the isotopic signature of healthy and infected cacti. Conversely, we observed a higher carbon and lower nitrogen concentration in mistletoes than in cacti regardless of latitude. The loss of temperature seasonality toward the north increases the C:N ratio, and the values between the parasite and its host diverge. ∂15N was similar between parasites and hosts while ∂13C of the parasite was enriched when compared to its host. Overall, the infection by T. aphyllus affects Echinopsis chiloensis fitness but showed no strong effects over the cactus physiology, except for the summer photosynthesis. Therefore, our data revealed that E. chiloensis response to T. aphyllus infection is sensitive to environmental changes in a way that could be strongly impacted by the desertification projected for this area due to climate change.