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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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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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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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This study reports Pachybrachis sp. association with a new host, Spermacoce verticillata L. (Rubiaceae). It synthesizes Brazil locality records and host plant records from literature. Specimens of adults and larvae were collected on the host in an urban area of Maceió, Alagoas, Brazil. Larvae and adults were reared on the host plant in the laboratory, using fresh plant tissue daily.

Este estudio presenta la asociación de Pachybrachis sp. con un nuevo huésped, Spermacoce verticillata L. (Rubiaceae). En este trabajo se dan a conocer las localidades registradas en Brasil para la especie y los registros de plantas huésped mencionados en la literatura. Se recolectaron especímenes de adultos y larvas sobre el huésped en un área urbana de Maceió, Alagoas, Brasil. Las larvas y los adultos se criaron en la planta huésped en el laboratorio, utilizando tejido vegetal fresco a diario.

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ABSTRACT Galls are structures of vegetal tissue modified by several biological agents, mainly dipterans of the Cecidomyiidae family. The galls are indicators of the gall inducers' presence, because of the species-specific interaction between the gall inducer and its host plant species. The aim of this study was to expand the geographical distribution of cecidomyiids - usually known only to the type-locality - in species of Andira Lam. (Fabaceae) distributed in Brazil, through the presence of their gall morphotypes in host plants. We searched for records of gall morphotypes in Andira species in all inventories of insect galls in Brazilian biomes and in virtual herbaria in Brazilian and abroad institutions. We found six species of Andira with forty-nine registers of 20 morphotypes of galls induced by cecidomyiids. They were from 35 localities; of those, 15 Municipalities, five States and the Federal District are new points of occurrence. We found three new registers for the fusiform gall in A. fraxinifolia, four registers for the fusiform gall in A. humilis, two new registers for the lenticular gall in A. nitida, and six new registers for three morphotypes in A. vermifuga. No new records were found for the morphotypes of A. cujabensis and A. surinamensis. These results indicate that digital tools, combined with well-illustrated inventory data, are capable to expand knowledge about the distribution of cecidomyiids through the recognition of their specific marker, the morphotypes.

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ABSTRACT Among the plant diversity of the Cerrado, the genus Copaifera is commonly associated with galling insects. Here, we expand the knowledge about insect galls on Copaifera sabulicola J.A.S Costa & L.P. Queiroz (Fabaceae) by characterizing their occurrence in a stricto sensu vegetation area of the Brazilian Cerrado, Western Bahia, Brazil throughout the year. We randomly sampled 60 branches (50 cm long) from individuals of C. sabulicola, from April 2015 to March 2016. We found 11 morphotypes for C. sabulicola, of which 5 are new records. Further, we identified six gall-inducing insects, all belonging to Cecidomyiidae family. Regarding other arthropods associated with C. sabulicola, we observed inquilines, successors, and parasitoids, belonging to the orders Collembola, Hemiptera, Hymenoptera and Acari. The parasitoid fauna included three families of the order Hymenoptera: Braconidae, Encyrtidae and Eulophidae.

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Abstract: An overview of insect galls on Asteraceae in Brazil is presented. We used the Web of Science database to find publications about insect galls from 1988 to 2020. We analyzed 88 publications and collected data from 51 of those. A total of 487 gall morphotypes were counted on 157 plant species of 42 genera. This value singled out Asteraceae as the richest plant family in number of gall morphotypes in Brazil. Most morphotypes were recorded in the Atlantic Forest (41%) and Cerrado (30.5%), the most surveyed biomes in Brazil. Baccharis L. supported the greatest gall richness (43.9%), which could be explained by the hypotheses of geographic area and taxon size. Baccharis concinna G.M. Barroso, B. dracunculifolia DC. and B. platypoda DC. were indicated as superhost species. Most galls were induced on stems (52.2%), a pattern known in Asteraceae for gall-inducing Tephritidae and Chloropidae, and extended in the present study to Cecidomyiidae. Most galls were fusiform (42.5%), which can be related to the highest number of gall on stems. Cecidomyiidae (Diptera) were the most frequent inducers, as observed worldwide. The presence of other dwellers - parasitoids, cecidophages, kleptoparasites, and successors - were reported in 8.8% of the gall morphotypes, being parasitoids the most frequent, as found in other Brazilian publications. Most host plants (58%) are endemic to Brazil, 14% are useful and few are vulnerable or endangered (six and four species, respectively). Due to the high host specificity, the gall-inducers associated with these plants can also be considered either endemic, important, vulnerable and/or endangered, respectively.

Resumo: Um panorama geral das galhas de insetos em Asteraceae no Brasil é apresentado. Usamos a base de dados "Web of Science" para encontrar publicações sobre galhas de insetos de 1988 a 2020. Analisamos 88 publicações no total, porém obtivemos dados de apenas 51. Um total de 487 morfotipos de galhas foi contabilizado em 157 espécies de plantas de 42 gêneros. Este valor indica as Asteraceae como a família botânica mais rica em número de morfotipos de galhas no Brasil. A maioria dos morfotipos foi registrada na Mata Atlântica (41%) e no Cerrado (30.5%), biomas mais investigados no Brasil. Baccharis L. suportou a maior riqueza de galhas (43.9%), o que poderia ser explicado pelas hipóteses de área geográfica e tamanho do táxon. Baccharis concinna G.M. Barroso, B. dracunculifolia DC. E B. platypoda DC. foram indicadas como as espécies super hospedeiras. A maioria das galhas foi induzida em caules (52.2%), um padrão conhecido em Asteraceae para Tephritidae e Chloropidae indutores de galhas, e estendido no presente estudo para Cecidomyiidae. A maioria das galhas foi fusiforme (42.5%), o que pode estar relacionado ao maior número de galhas em caule. Os Cecidomyiidae (Diptera) foram os indutores mais frequentes, como no mundo inteiro. A presença de outros ocupantes - parasitoides, cecidófagos, cleptoparasitas e sucessores - foi assinalada em 8.8% dos morfotipos de galhas, sendo os parasitoides os mais frequentes, como em outras publicações no país. A maioria das plantas hospedeiras são endêmicas do Brasil (58%), 14 são úteis e algumas são vulneráveis ou ameaçadas (seis e quatro, respectivamente). Devido à alta especificidade de plantas hospedeiras, os indutores de galhas associados a estas plantas podem ser considerados endêmicos, de importância econômica, vulneráveis e/ou ameaçados, respectivamente.

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Abstract: The Pantanal Biome occupies 20% of the Brazilian territory extending its distribution over two Brazilian States, Mato Grosso and Mato Grosso do Sul. This Biome is one of Brazil's poorly known regions concerning insect gall and their interactions with host plants. In this study, we characterized for the first time the gall morphology, identified host plants and the gall makers from an area of Brazilian wetlands from Mato Grosso State, known as Pantanal Matogrossense. We sampled Pantanal Biome areas in Poconé municipality, along the Transpantaneira Road, Mato Grosso State, Brazil, in two expeditions, July 2012 and January 2013, with a total effort of 2 hours. We characterized 91 morphotypes of insect galls in 54 host plant species; 28 gall makers in 24 host plant species; the richest host plant families are Fabaceae, Myrtaceae, and Sapindaceae. Psidium guineense Sw. is the super host species. This area in Pantanal Matogrossense is the second in the richness of gall morphotypes (N=91) and average morphotypes/plant species (1.7), comparing phytophysiognomies. Additionally, 15 plant species are new record as host in galler-host plant interaction in the world. This number represents 30% of the total of host plant species sampled in Poconé. This inventory is new knowledge to the Pantanal Matogrossense and representing a unique testimony of insect-plant interactions consumed by the unprecedented fire that occurred in Pantanal Biome in the dry season of 2020.

Resumo: O Bioma Pantanal ocupa 20% do território brasileiro estendendo sua distribuição sobre dois Estados brasileiros, Mato Grosso e Mato Grosso do Sul. Esta é uma das regiões menos estudadas do Brasil com relação aos insetos e suas interações. Neste estudo, caracterizamos pela primeira vez a morfologia de galhas, identificamos plantas hospedeiras e galhadores em áreas do Pantanal Norte, conhecido como Pantanal Matogrossense. As amostragens foram feitas em áreas do Bioma Pantanal, no município de Poconé, ao longo da Estrada Transpantaneira, Mato Grosso, Brasil em duas expedições, julho de 2012 e janeiro de 2013. Caracterizamos 91 morfotipos de galhas entomógenas em 54 espécies de plantas hospedeiras; identificamos 28 galhadores em 24 espécies de plantas hospedeiras; as famílias de plantas hospedeiras mais ricas em galhas são Fabaceae, Myrtaceae e Sapindaceae. Psidium guineense Sw. é a espécie superhospedeira. Esta área no Pantanal Matogrossense é a segunda tanto em riqueza de morfotipos de galhas (N=91) quanto na média de morfotipos por espécie de planta hospedeira (1,7), em fitofisionomias comparáveis. Além disso, 15 espécies de plantas são novos registros como hospedeiras para galhas de insetos no mundo. Esse número representa 30% do total de plantas amostradas em Poconé. Todos os dados deste inventário são conhecimentos novos para o Pantanal Mato-grossense e para o estado do Mato Grosso, representando um testemunho único das interações inseto-planta que foram consumidas pelo fogo sem precedentes ocorrido no Bioma Pantanal em sua estação seca de 2020.

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The Midwest region of Brazil possesses large areas dominated by the Cerrado that is poorly known concerning insect gall and their interactions. In this study, we inventory the gall morphology, host plants, and the gall makers from Parque Nacional da Chapada dos Guimarães, Mato Grosso State, in areas of natural vegetation from Cerrado, for the first time. Samplings occurred in two expeditions, July 2012 and January 2013. We characterized 295 morphotypes of insect galls in 140 host plant species, with 89 gall makers; the richest family in host plants was Fabaceae (16.7%), and the species was Protium heptaphyllum (Aubl.) Marchand (Burseraceae, 3.7%). Parque Nacional da Chapada dos Guimarães is the richest Brazilian cerrado area in gall morphotypes (295) and the second in average morphotypes/host plant species (2.1). Additionally, six genera and 38 species are new records as host plants; two of them, Bernardia similis Pax and K.Hoffm and Ormosia macrophylla Benth., are new occurrences for Mato Grosso State, and other two, Vochysia petraea Warm. and Talisia subalbens (Mart.) Radlk. are listed in the Red List of Threatened Species IUCN. This inventory data represents a testimony of insect-plant interactions in a Brazilian Cerrado area that was consumed by an unprecedented fire in the dry season of 2020.

A região Centro-Oeste do Brasil possui grandes áreas dominadas pelo Cerrado nas quais insetos e suas interações são pouco conhecidos. Neste estudo, fizemos o inventário de galhas, plantas hospedeiras e galhadores do Parque Nacional da Chapada dos Guimarães, Mato Grosso, uma área de vegetação natural de Cerrado. As amostragens foram realizadas em duas expedições, em julho de 2012 e janeiro de 2013. Caracterizamos 295 morfotipos de galhas de insetos em 140 espécies de plantas hospedeiras; com identificação de 89 galhadores; a família de plantas com maior número de espécies hospedeiras de galhas foi Fabaceae (16,7%) e a espécie com maior número de galhas, Protium heptaphyllum (Aubl.) Marchand (Burseraceae, 3,7%). Esta é a área mais rica em morfotipos de galhas do cerrado brasileiro (295) e a segunda na média de morfotipos/espécie de planta hospedeira (2,1). Além disso, seis gêneros e 38 espécies são registros novos de ocorrência de plantas hospedeiras para galhas de insetos; duas delas, Bernardia similis Pax and K.Hoffm and Ormosia macrophylla Benth., são registros novos para o Estado do Mato Grosso e outras duas, Vochysia petraea Warm. and Talisia subalbens (Mart.) Radlk. estão listadas na Lista Vermelha de Espécies Ameaçadas IUCN. Os dados desse inventário representam um testemunho das interações inseto-planta para o Cerrado no Brasil, em uma área que foi consumida por um incêndio sem precedentes na estação seca de 2020.

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Knowledge of the influence of evolutionary factors that promote either the differentiation or cohesion of pest insect populations is critical for the improvement of control strategies. Here, we explore the extent to which genetic differentiation occurs between populations of the Mexican fruit fly, Anastrepha ludens, in association with four plant hosts (Citrus sinensis, C. paradisi, Mangifera indica and Casimiroa edulis) in the Soconusco region of Chiapas (Mexico). Using variants from six enzymatic loci, we obtained measures of genetic diversity for three sample arrangements: (1) by sex per locality, (2) by locality and (3) by host. The extent of genetic differentiation in populations was assessed using the Analyses of Molecular Variance (AMOVA) method for each array of samples, and moderate to high levels of genetic variation were observed between the sexes, as well as among localities and host plants. A Bayesian approach was then used to assess any population structure underlying the genetic data we obtained, but this analysis showed no significant structuring due to locality or host plant. We also considered whether the observed genotypic frequencies in male and females matched those expected under a hypothesis of random mating. Here we found significant deviations from expected genotypic frequencies, suggesting that sexual selection is acting on these populations. Overall, our results indicate that sexual selection, along with the presence of some heterogeneity in environments provided by both geographical factors and availability of host plants, has influenced the evolution of pest populations in this region of Mexico. Implications for area-wide pest management strategies are discussed.

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Despite its broad host range, the spotted lanternfly Lycorma delicatula (White), is known to have a marked preference for Ailanthus altissima. However, whether this polyphagous phloem feeder can complete its life cycle in the absence of A. altissima is unknown. We examined the performance of L. delicatula with and without access to A. altissima by tracking development, survival, host tree species association, and oviposition in large enclosures planted with Salix babylonica and Acer saccharinum along with either A. altissima or Betula nigra. We monitored enclosures from late May 2019 through June 2020. Lycorma delicatula survival was slightly higher in enclosures with A. altissima and 50% of individuals in A. altissima enclosures reached the adult stage ~6.5 d earlier than in enclosures without A. altissima. In the presence of A. altissima, nymphs were most frequently observed on this host while adults were found at similar frequencies on A. altissima and A. saccharinum. In the absence of A. altissima, nymphs were most frequently associated with S. babylonica and A. saccharinum, while adults were most often found on A. saccharinum. Females laid a total of 46 and 6 egg masses in enclosures with and without A. altissima, respectively, before freezing temperatures killed the remaining adults. The proportion of eggs that hatched per egg mass did not differ between treatments. Although L. delicatula can complete development and reproduce on other host species without access to A. altissima, fitness was reduced. These findings have implications for management that relies exclusively on treatment of A. altissima.

Assuntos

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Little is known about the effects of genetically modified corn plants on the foraging of Spodoptera frugiperda (J.E. Smith). Therefore, this study examines whether singular herbicide-tolerant and insect-resistant plants and their stacked events interfere with food preference and oviposition of S. frugiperda. Two non-Bt corn hybrids and three Bt-hybrids, some of them with glyphosate tolerance (GT), were evaluated. Food preference of larvae and biological parameters were assessed. Oviposition preference bioassays involved choice and no choice condition in plants uninfested and previously infested by larvae in a greenhouse and in the field. The results indicate that there is no relationship between preference of larvae and adult moths. Adult females selected preferentially transgenic hybrids, while larvae selected non-Bt hybrid. Fall armyworm larvae avoid Bt-toxin-expressing leaf tissues, survived only on the non-Bt leaf tissues, and showed minor differences in other life-history traits reared on GT and non-transgenic corn leaf tissues. Female moths showed preference for transgenic plants to lay eggs, but with variable output between previously infested and uninfested plants with larvae. The fact that moths preferred Ag 3700RR2 and non-Bt hybrids for oviposition supports the refuge's strategy aiming at producing susceptible individuals. The use of this hybrid must be integrated with a program of control. The results showed also the importance of correct hybrid selection as part of insect resistance management to Bt-plants. The implications of these findings for understanding the impacts of plant-mediated cues on pest behavior in transgenic crop systems are discussed.

Assuntos

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Myrmecochory (seed dispersal by ants) is a unique seed dispersal syndrome among invertebrates. It comprises three main phases: seed removal, seed manipulation, and seed deposition. However, the contribution of each phase to seed and seedling fate remains unclear. Here, we experimentally quantified the effects of each phase of myrmecochory on seed germination and seedling establishment, the two most critical life history stages involved in plant recruitment. We established 30 sample points, and each included an adult Mabea fistulifera tree, an Atta sexdens nest entrance, and six seed depots. We monitored the germination of M. fistulifera seeds for 3 months and subsequently followed the growth and mortality of the resulting seedlings for 12 months. Only the dispersal distance influenced plant establishment, reducing seed germination and increasing seedling growth, but with no effect of seed manipulation and deposition site. Despite the contrasting effects of distance on seed germination and seedling growth, the positive effect of dispersal distance on seedling growth was ten times greater than the negative effect on seed germination. Moreover, A. sexdens behaved neither as granivore nor as herbivore of M. fistulifera seeds or seedlings, which suggests that seed dispersal by A. sexdens is advantageous to M. fistulifera. Thus, the joint occurrence of these two species in disturbed areas could have a positive effect on this pioneer plant population, which might promote forest regeneration.

Assuntos

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Coptoborus ochromactonus (Smith and Cognato) is one of the most common and important pests of balsa, Ochroma pyramidale (Cav. Ex Lam. Urb.), an economic pillar of the wood industry in Ecuador. Commercial balsa plantations have been expanded from humid to dry climate areas to limit insect damage, but basic knowledge is still lacking on the interaction of C. ochromactonus activity with variation in climate and plantation age. We investigated the effects of climate and host age on the seasonal flight activity of C. ochromactonus and its infestation rate and intensity, as well as the effect of age and individual infestation intensity on balsa dieback. Experiments were conducted in 1-, 2-, and 3-yr-old commercial balsa plantations located in areas of humid or dry climates. Seasonal flight activity (monitored with baited traps) differed between study sites and seasons. Increased flight activity was significantly correlated with higher relative humidity, higher mean temperature, and reduced precipitation during the dry season in the humid site and with increased mean and minimum temperature and increased precipitation during the rainy season in the dry site. Infestation rates by C. ochromactonus significantly increased with plantation age, especially in the humid site. Intensity of individual infestations (measured as number of successful insect entry holes per tree) was significantly influenced by both climate and plantation age, and it was particularly severe on 3-yr-old trees in the dry site. Percentage of foliage loss significantly increased with infestation intensity. Overall, our results can be relevant for devising preventive measures and suitable management strategies for this emerging pest in Ecuadorian wood plantations.

Assuntos