Host Plant Diversity Research Articles

How Plants Synthesize Pyrethrins: Safe and Biodegradable Insecticides.

Natural pyrethrin insecticides produced by Dalmatian pyrethrum (Tanacetum cinerariifolium) have low mammalian toxicity and short environmental persistence, providing an alternative to widely used synthetic agricultural insecticides that pose a threat to human health and the environment. A recent surge of interest in the use of pyrethrins as agricultural insecticides coincides with the discovery of several new genes in the pyrethrin biosynthetic pathway. Elucidation of this pathway facilitates efforts to breed improved pyrethrum varieties and to engineer plants with improved endogenous defenses or hosts for heterologous pyrethrin production. We describe the current state of knowledge related to global pyrethrum production, the pyrethrin biosynthetic pathway and its regulation, and recent efforts to engineer the pyrethrin pathway in diverse plant hosts.

Ectomycorrhizal fungi induce systemic resistance against insects on a nonmycorrhizal plant in a CERK1-dependent manner.

Below-ground microbes can induce systemic resistance against foliar pests and pathogens on diverse plant hosts. The prevalence of induced systemic resistance (ISR) among plant-microbe-pest systems raises the question of host specificity in microbial induction of ISR. To test whether ISR is limited by plant host range, we tested the ISR-inducing ectomycorrhizal fungus Laccaria bicolor on the nonmycorrhizal plant Arabidopsis thaliana. We used the cabbage looper Trichoplusia ni and bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pto) as readouts for ISR on Arabidopsis. We found that root inoculation with L.bicolor triggered ISR against T.ni and induced systemic susceptibility (ISS) against the bacterial pathogen Pto. We found that L.bicolor-triggered ISR against T.ni was dependent on jasmonic acid signaling and salicylic acid biosynthesis and signaling. Heat-killed L.bicolor and chitin were sufficient to trigger ISR against T.ni and ISS against Pto. The chitin receptor CERK1 was necessary for L.bicolor-mediated effects on systemic immunity. Collectively our findings suggest that some ISR responses might not require intimate symbiotic association, but rather might be the result of root perception of conserved microbial signals.

Potential Biological Control Agents for Soilborne Fungal Pathogens in Tennessee Snap Bean Farms

Fungi isolated from snap bean roots and rhizosphere soil where fungicides are not used included Fusarium oxysporum, Fusarium equiseti, Fusarium subglutinans, Fusarium camptoceras, Fusarium chlamydosporum, Fusarium verticillioides, Fusarium proliferatum, Fusarium acuminatum, Fusarium solani, Peyronellaea pinodella, Macrophomina phaseolina, and Glomerella guttata. Only P. pinodella, M. phaseolina, and F. oxysporum were isolated on symptomatic plants. These soilborne fungi are common pathogens of diverse host plants. Pathogenicity tests under controlled environment demonstrated that these fungi were pathogenic on snap beans. Subsequently, bacterial endophytes isolated from snap bean roots, papaya roots and stems, and dogwood stems were evaluated as potential biological control agents against these diverse fungi. All bacteria isolated, including Bacillus vallismortis (PS), Bacillus amyloliquefaciens (Psl), Bacillus subtilis (Prt), Bacillus thuringiensis (Y and IMC8), Enterobacter sp. (E), Stenotrophomonas sp. (B17A), and Serratia sp. (B17B) suppressed growth of the fungal pathogens in vitro and formed clear inhibition zones in petri dish dual cultures. Growth media taken from the inhibition zones suppressed growth of the fungal pathogens in the absence of the bacterial cells, suggesting that the bacteria released unidentified antagonistic biochemical substances into the media. This study constitutes an initial screening of endophytes as biological control agents against diverse fungal pathogens and forms a basis for the discovery of novel strains that can be further developed and integrated into disease management systems for diverse fungal pathogens. Isolates B. vallismortis (PS), B. amyloliquefaciens (Psl), B. subtilis (Prt), and B. thuringiensis (Y IMC8) exhibited the best performance as potential biological control agents paving the way for larger-scale in vivo studies and characterization of their interactions with fungal pathogens.

Disentangling the steps of the infection process responsible for juvenile disease susceptibility

Abstract Juveniles of diverse host taxa, including vertebrates, invertebrates and plants, are more susceptible to parasitic infections than adults, a phenomenon still poorly understood. To shed light on the mechanisms underlying this host age effect, we investigated its expression during different steps of the infection process of a bacterial parasite of the planktonic crustacean Daphnia. To do so, we infected juvenile and adult Daphnia magna with the bacterium Pasteuria ramosa and monitored parasite development in experiments specific to different steps of the infection process. We did not find an effect of host age on parasite attachment, but found a strong increase in the penetration time of the parasite into hosts with increasing age. Host age at exposure also affected within‐host parasite development, which was delayed in old adult D. magna in comparison to young adults and juveniles. Furthermore, parasite clearance was observed only in old adults, suggesting that old hosts have a better immune response than young adults and juveniles. Our results reveal a step‐specific effect of host age on disease progression, giving support for different hypotheses explaining high juvenile disease susceptibility. While these mechanisms are likely to work independently from each other, earlier steps of the infection process influence later steps, and thus may respond more readily to selection than later steps. Our results also highlight that clearance can occur both during early parasite establishment and surprisingly at progressed infection phases, an undocumented phenomenon in invertebrates, where late infections are often considered chronic, lasting until host death. A free Plain Language Summary can be found within the Supporting Information of this article.

Diversity of indigenous arbuscular mycorrhizal fungi in rhizosphere of upland rice (Oryza sativa L.) varieties in Southwest Nigeria

Diversity of indigenous arbuscular mycorrhizal fungi in rhizosphere of upland rice (Oryza sativa L.) varieties in Southwest Nigeria

Ecological Green Space Planning for Butterflies Habitat in Residential Area

Development a residential area cause fragmentation both green space and wildlife habitat as well. Moreover, the landscape design orientation in housing areas usually focusing on the aesthetic value and less attention to the ecological function as well as the health of the ecosystem. Butterflies are the indicators of environmental and ecosystem health. Areas rich in butterflies and moths indicate the richness of other invertebrates. These collectively provide a wide range of environmental benefits, including pollination and natural pest control. Therefore the presence of ecological orientation of green space in a residential area as a habitat for butterflies and other wildlife is one of the solution. The purpose of this study is to create an ecological green space plan for a butterflies habitat in the residential area. The study was conducted consist of preparation, data collection, data analysis, synthesis and planning. The aspect analyzed in this study are biophysical aspect and quality of ecological aspect that contains butterflies diets and a host plants, proximity to the water resource, vegetation cover and the interspersion of habitat components. The result show that the butterflies on the site, qualitatifly, indicate quite diverse lack of diversity of host plants and the vegetation for the butterflies diets. The as green space plan for butterfly habitat was arranged based on the development of the ecological space concept, the vegetation concept and the animal activities concept. Each green space unit (patches) has functions as sink and source and also as steping stone and connecting corridor between sinks and source. A plant selection is proposed for each green space unit.

Effects of Epichloë gansuensis Endophyte on the Root and Rhizosphere Soil Bacteria of Achnatherum inebrians Under Different Moisture Conditions.

This study was conducted to explore effects of the systemic fungal endophyte Epichloë gansuensis on root and rhizosphere soil bacterial diversity of Achnatherum inebrians host plants growing under different moisture conditions. Soil properties of different treatments were compared using standard techniques. A total of 4371379 16S rRNA gene sequences were obtained and assigned to 5025 operational taxonomic units (OTUs). These OTUs in roots and rhizosphere soil were divided into 13 and 17 phyla, respectively, and the Actinobacteria and Proteobacteria were the most abundant phyla both in roots and rhizosphere soil. Shannon diversity and Chao1 richness index of bacteria in rhizosphere soil was significantly higher than in roots. E. gansuensis decreased the Shannon diversity of the root-associated bacterial community, and increased Shannon diversity and Chao1 richness index of the rhizosphere soil bacterial community of A. inebrians. Meanwhile, Chao1 richness of the rhizosphere soil bacterial community of A. inebrians significantly increased with the increase of the soil moisture level. Structural equation modeling also emphasized that E. gansuensis decreased the diversity of the root-associated bacterial community and increased the diversity of the rhizosphere soil bacterial community through decreasing soil available N. Additionally, soil moisture increased the diversity of the rhizosphere soil bacterial community through increased soil pH, C/N, and NN, and decreased soil AP. The E. gansuensis endophyte and soil moisture effects on root and rhizosphere soil bacterial diversity were likely to be from responses to modifications of the rhizosphere soil properties.

Biodiversity and Updated Checklist of Moth Caterpiliar-Fauna (Lepidoptera), Damaging Host Tree and Plant Species of Jammu, Kashmir and Ladakh (India)

This paperdeals with 54 species under44 genera ofmoth caterpillars of Jammu, Kashmir and Ladakh regions of lndia, belonging to 19 families under 11 Super-families, affecting more than 52 diverse host tree and plant species, including valuable agricultural crops, trees and plant species. The various Super-families, with total number of caterpillar species are: Bombycoids (13 spp.), Cossoids (2), Gelechoids (11), Geometroids (5), Gracillaroids (2), Lasiocompoids (2), Noctuoids (7), Pyraloids (6), Sesioid (1), Tineoids (2), Yponomeutoids (3) The highest number of caterpillar species i.e. 7, has been found to damage plum fruit tree, followed by 6 spp. each, affecting apple and poplar trees, and 5 spp. damaging willow trees. 4 species each of caterpillar, are known to severely damage peach and mulberry trees respectively. Rest of the host tree/plant species are affected either by 3 spp. or 2 spp. or 1 sp. of moth caterpillars. An up-to-date systematic/annotated checklist of caterpillar-fauna has been provided. In addition to this, biodiversity of caterpillars affecting hosts of different kinds from vast localities and areas of Jammu, Kashmir and Ladakh, has briefly been discussed.

Different Plant Viruses Induce Changes in Feeding Behavior of Specialist and Generalist Aphids on Common Bean That Are Likely to Enhance Virus Transmission.

Bean common mosaic virus (BCMV), bean common mosaic necrosis virus (BCMNV), and cucumber mosaic virus (CMV) cause serious epidemics in common bean (Phaseolus vulgaris), a vital food security crop in many low-to-medium income countries, particularly in Sub-Saharan Africa. Aphids transmit these viruses “non-persistently,” i.e., virions attach loosely to the insects' stylets. Viruses may manipulate aphid-host interactions to enhance transmission. We used direct observation and electrical penetration graph measurements to see if the three viruses induced similar or distinct changes in feeding behaviors of two aphid species, Aphis fabae and Myzus persicae. Both aphids vector BCMV, BCMNV, and CMV but A. fabae is a legume specialist (the dominant species in bean fields) while M. persicae is a generalist that feeds on and transmits viruses to diverse plant hosts. Aphids of both species commenced probing epidermal cells (behavior optimal for virus acquisition and inoculation) sooner on virus-infected plants than on mock-inoculated plants. Infection with CMV was especially disruptive of phloem feeding by the bean specialist aphid A. fabae. A. fabae also experienced mechanical stylet difficulty when feeding on virus-infected plants, and this was also exacerbated for M. persicae. Overall, feeding on virus-infected host plants by specialist and generalist aphids was affected in different ways but all three viruses induced similar effects on each aphid type. Specifically, non-specialist (M. persicae) aphids encountered increased stylet difficulties on plants infected with BCMV, BCMNV, or CMV, whereas specialist aphids (A. fabae) showed decreased phloem ingestion on infected plants. Probing and stylet pathway activity (which facilitate virus transmission) were not decreased by any of the viruses for either of the aphid species, except in the case of A. fabae on CMV-infected bean, where these activities were increased. Overall, these virus-induced changes in host-aphid interactions are likely to enhance non-persistent virus transmission, and data from this work will be useful in epidemiological modeling of non-persistent vectoring of viruses by aphids.

A Whole-Plant Culture Method to Study Structural and Functional Traits of Extraradical Mycelium.

An in vivo whole-plant bi-dimensional experimental system has been devised and tested with different host plants, in order to obtain extraradical mycelium (ERM) produced by different arbuscular mycorrhizal fungi (AMF). In this system, a host plant germling is inoculated with AMF to establish mycorrhizal symbiosis, and, after colonization, newly formed extraradical hyphae and spores are removed. Then the mycorrhizal root system is wrapped in a nylon net and placed between membranes in a Petri dish, allowing ERM to grow on the membrane surface. Such extraradical hyphae may be used for in situ morphometric analyses or collected for molecular or biochemical assays: in the latter case, the plant with its root sandwich may be reassembled to renew mycelium production. In this experimental system, which was tested with diverse host plant species and lines, values of explored membrane surface areas and densities of ERM showed wide ranges of variation, and its length ranged from 9.7±2.0 to 48.8±9.9m per plant, depending on host and AMF identity. Across the different plant-AMF combinations tested, the whole-plant system produced 2.0±0.6 to 5.3±0.3mg of ERM fresh biomass per plant per harvest. This experimental system can be used for a wide range of AMF and host plants species, either establishing arbuscular mycorrhizas or other mycorrhizal interactions. ERM produced and collected in the whole-plant system is suitable for morphological, physiological, and molecular analyses, facilitating studies on the different aspects of mycorrhizal symbiotic interactions.

Chemosensation and Evolution of Drosophila Host Plant Selection

The ability to respond to chemosensory cues is critical for survival of most organisms. Among insects, Drosophila melanogaster has the best characterized olfactory system, and the availability of genome sequences of 30 Drosophila species provides an ideal scenario for studies on evolution of chemosensation. Gene duplications of chemoreceptor genes allow for functional diversification of the rapidly evolving chemoreceptor repertoire. Although some species of the genus Drosophila are generalists for host plant selection, rapid evolution of olfactory receptors, gustatory receptors, odorant-binding proteins, and cytochrome P450s has enabled diverse host specializations of different members of the genus. Here, I review diversification of the chemoreceptor repertoire among members of the genus Drosophila along with co-evolution of detoxification mechanisms that may have enabled occupation of diverse host plant ecological niches.

Independent Evolution with the Gene Flux Originating from Multiple Xanthomonas Species Explains Genomic Heterogeneity in Xanthomonas perforans.

Xanthomonas perforans is the predominant pathogen responsible for bacterial leaf spot of tomato and X. euvesicatoria for that of pepper in the southeast United States. Previous studies have indicated significant changes in the X. perforans population collected from Florida tomato fields over the span of 2 decades, including a shift in race and diversification into three phylogenetic groups driven by genome-wide homologous-recombination events derived from X. euvesicatoria In our sampling of Xanthomonas strains associated with bacterial spot disease in Alabama, we were readily able to isolate X. perforans from symptomatic pepper plants grown in several Alabama counties, indicating a recent shift in the host range of the pathogen. To investigate the diversity of these pepper-pathogenic strains and their relation to populations associated with tomatoes grown in the southeast United States, we sequenced the genomes of eight X. perforans strains isolated from tomatoes and peppers grown in Alabama and compared them with previously published genome data available from GenBank. Surprisingly, reconstruction of the X. perforans core genome revealed the presence of two novel genetic groups in Alabama that each harbored a different transcription activation-like effector (TALE). While one TALE, AvrHah1, was associated with an emergent lineage pathogenic to both tomato and pepper, the other was identified as a new class within the AvrBs3 family, here designated PthXp1, and was associated with enhanced symptom development on tomato. Examination of patterns of homologous recombination across the larger X. euvesicatoria species complex revealed a dynamic pattern of gene flow, with multiple donors of Xanthomonas spp. associated with diverse hosts of isolation.IMPORTANCE Bacterial leaf spot of tomato and pepper is an endemic plant disease with a global distribution. In this study, we investigated the evolutionary processes leading to the emergence of novel X. perforans lineages identified in Alabama. While one lineage was isolated from symptomatic tomato and pepper plants, confirming the host range expansion of X. perforans, the other lineage was isolated from tomato and acquired a novel transcription activation-like effector, here designated PthXp1. Functional analysis of PthXp1 indicated that it does not induce Bs4-mediated resistance in tomato and contributes to virulence, providing an adaptive advantage to strains on tomato. Our findings also show that different phylogenetic groups of the pathogen have experienced independent recombination events originating from multiple Xanthomonas species. This suggests a continuous gene flux between related xanthomonads associated with diverse plant hosts that results in the emergence of novel pathogen lineages and associated phenotypes, including host range.

Multiple components of plant diversity loss determine herbivore phylogenetic diversity in a subtropical forest experiment

Abstract Plant diversity loss can alter higher trophic‐level communities via non‐random species interactions, which in turn may cascade to affect key ecosystem functions. These non‐random linkages might be best captured by patterns of phylogenetic diversity, which take into account co‐evolutionary dependencies. However, lack of adequate phylogenetic data of higher trophic levels hampers our mechanistic understanding of biodiversity relationships in species‐rich ecosystems. We used DNA barcoding to generate data on the phylogenetic diversity of lepidopteran caterpillars in a large‐scale forest biodiversity experiment in subtropical China. We analysed how different metrics of lepidopteran phylogenetic diversity (Faith's PD, MPD, MNTD) and taxonomic diversity were influenced by multiple components of tree diversity (taxonomic, functional, phylogenetic). Our data from six sampling periods represent 7,204 mitochondrial cytochrome c oxidase subunit I (COI) sequences of lepidopteran larvae, clustered into 461 molecular operational taxonomic units. Lepidopteran abundance, the effective number of species (irrespective of the focus on rare or common species) and Faith's PD and MPD (reflecting basal evolutionary splits), but not MNTD (reflecting recent evolutionary splits), significantly increased with experimentally manipulated tree species richness. Lepidopteran MNTD decreased with increasing tree MNTD. Path analyses showed that tree phylogenetic and functional diversity explained part, but not all of the effects of tree species richness on lepidopteran diversity. Importantly, tree diversity effects on lepidopteran diversity were to a large extent indirect, operating via changes in lepidopteran abundance. Synthesis. Our study shows that evolutionary dependencies determine the response of herbivore communities to changes in host plant diversity. Incorporating a wider range of diversity metrics both at the level of producers and consumers can thus help to develop a more comprehensive understanding of the functional consequences of biodiversity change across trophic levels. Moreover, the dependence of trophic linkages on herbivore abundances underlines the need to address the consequences of current declines in insect abundances for ecosystem structure and functioning.

Whole-Genome Sequence of the Phlox Powdery Mildew Pathogen Golovinomyces magnicellulatus Strain FPH2017-1

Powdery mildew (PM) fungi are obligate biotrophs capable of infecting diverse plant hosts, ranging from monocotyledonous agricultural crops to dicotyledonous ornamental crops. The PM lifestyle poses significant challenges for studying these pathogens in isolation from their host. We present a draft genome of Golovinomyces magnicellulatus, a host-specific PM on Phlox species.

Host Potential and Adaptive Responses of Drosophila suzukii (Diptera: Drosophilidae) to Barbados Cherries.

Biological invasions are a global threat to agricultural crops worldwide. In the Neotropical region, the spotted-wing Drosophila [Drosophila suzukii (Matsumura)] has rapidly expanded its geographical range spreading throughout South America in recent years. Besides climatic factors, the remarkable success of its establishment and subsequent distribution in this region is closely dependent on the diversity and availability of host plants. We evaluated the host potential (e.g., as food and oviposition sources) of fruits of jabuticaba [Plinia cauliflora (Mart.) Kausel (Myrtales: Myrtaceae)], Barbados cherry (Malpighia emarginata DC) (Malpighiales: Malpighiaceae), bonnet pepper (Capsicum chinense Jacq.) (Solanales : Solanaceae), and coffee (Coffea arabica L.) (Gentianales : Rubiaceae) and their effects on the biological and physiological traits of D. suzukii. For the fruit types where fly emergence occurred, we assessed the biological and physiological performance of the flies and compared these parameters with those recorded for flies reared on strawberries (Fragaria × ananassa Duchesne) (Rosales : Rosaceae) and an artificial diet. Our results revealed that oviposition into fruits and completion of the life cycle occurred on Barbados cherries only. Furthermore, field surveys revealed a higher emergence rate of D. suzukii on undamaged ripe Barbados cherries than damaged ones. Moreover, flies developing on Barbados cherries and an artificial diet presented earlier emergence, shorter developmental time, lower number of adults per female, and a female-biased sex ratio compared to flies developing on strawberries. Overall, our findings demonstrated suitability of Barbados cherry as a host for D. suzukii, which renders management of D. suzukii in Neotropical region an even more challenging task.

New Ca. Liberibacter psyllaurous haplotype resurrected from a 49-year-old specimen of Solanum umbelliferum: a native host of the psyllid vector

Over the last century, repeated emergence events within the Candidatus Liberibacter taxon have produced pathogens with devastating effects. Presently, our knowledge of Ca. Liberibacter diversity, host associations, and interactions with vectors is limited due to a focus on studying this taxon within crops. But to understand traits associated with pathogen emergence it is essential to study pathogen diversity in wild vegetation as well. Here, we explore historical native host plant associations and diversity of the cosmopolitan species, Ca. L. psyllaurous, also known as Ca. L. solanacearum, which is associated with psyllid yellows disease and zebra chip disease, especially in potato. We screened tissue from herbarium samples of three native solanaceous plants collected near potato-growing regions throughout Southern California over the last century. This screening revealed a new haplotype of Ca. L. psyllaurous (G), which, based on our sampling, has been present in the U.S. since at least 1970. Phylogenetic analysis of this new haplotype suggests that it may be closely related to a newly emerged North American haplotype (F) associated with zebra chip disease in potatoes. Our results demonstrate the value of herbarium sampling for discovering novel Ca. Liberibacter haplotypes not previously associated with disease in crops.

Characterization of insect galls from a vegetation area in Altinópolis, São Paulo State, Brazil

Herein, we studied the occurrence of insect galls from natural vegetation around the Itambé Cave, Altinópolis, SP, Brazil. A sampling effort of 7.5 hours resulted in 41 gall morphotypes on 21 host plant species from 14 families. The richest families of host plants in morphotypes were Fabaceae (N = 11), Euphorbiaceae (N = 7), and Malpighiaceae (N = 5). Copaifera langsdorffii Desf. (N = 8), Croton floribundus Spreng. (N = 7), Diplopterys pubipetala (A. Juss.) W.R. Anderson & C.C. Davis (N = 5), and Bauhinia holophylla (Bong.) Steud. (N = 4) were the super host plant species. Among the gall makers obtained, cecidomyiids were reared in 81% of cases and Hemiptera (Diaspididae), Hymenoptera (Eurytomidae), Coleoptera (Apion sp./Apionidae), and Lepidoptera in 4.5% of cases, each. The parasitoids belong to the Chalcidoidea superfamily (Hymenoptera). One new species of Camptoneuromyiia (Cecidomyiidae) was found in Smilax oblongifolia Pohl ex Griseb. (Smilacaceae) as inquiline and a new species of Lestodiplosis in Diplopterys pubipetala (Malpighiaceae) was a predator. We also present the first register of Bauhinia holophylla as host plants of Cecidomyiidae, and we expand the occurrence of Rochadiplosis tibouchinae Tavares and Couridiplosis vena to São Paulo State. The results of this paper are a continuation of the description of gall morphotypes from the vegetation in Northeastern São Paulo State, and they also increase knowledge about the diversity of host plant and gall-maker associations in the Neotropical region.

Host plants and edaphic factors influence the distribution and diversity of ectomycorrhizal fungal fruiting bodies within rainforests from Tshopo, Democratic Republic of the Congo

AbstractEctomycorrhizal fungi constitute an important component of forest ecosystems that enhances plant nutrition and resistance against stresses. Diversity of ectomycorrhizal (EcM) fungi is, however, affected by host plant diversity and soil heterogeneity. This study provides information about the influence of host plants and soil resources on the diversity of ectomycorrhizal fungal fruiting bodies from rainforests of the Democratic Republic of the Congo. Based on the presence of fungal fruiting bodies, significant differences in the number of ectomycorrhizal fungi species existed between forest stand types (p < 0.001). The most ectomycorrhizal species‐rich forest was the Gilbertiodendron dewevrei‐dominated forest (61 species). Of all 93 species of ectomycorrhizal fungi, 19 demonstrated a significant indicator value for particular forest stand types. Of all analysed edaphic factors, the percentage of silt particles was the most important parameter influencing EcM fungi host plant tree distribution. Both host trees and edaphic factors strongly affected the distribution and diversity of EcM fungi. EcM fungi may have developed differently their ability to successfully colonise root systems in relation to the availability of nutrients.

Correspondence of butterfly and host plant diversity: foundation for habitat restoration and conservation

Abstract At a spatial scale, the diversity of butterflies varies with numerous factors including the availability of the host plant species. In parity with this proposition, the correspondence of diversity of butterfly and plant in the background of the urban–rural gradient was evaluated using Kolkata, India, as a model study area. The results reveal significant positive correlation between the diversity of butterflies and the plants, with the different values for the suburban, rural, and urban areas. Identification of the butterfly loads for the plants in the respective areas can be useful in enhancing the conservation of the butterflies through enhanced plantation of the concerned plant species. Alternatively, the disclosure of the generalist and specialist pattern of the plant species preference by the butterflies may be useful in enhancing the population of the respective species in the concerned areas. The conservation strategy for butterfly species may be refined through the use of both or any one of the quantitative assessment of the butterfly–plant links in the urban–rural gradient in Kolkata, India, and similar places in the world.

Host plants for mealybugs (Hemiptera: Pseudococcidae) in grapevine crops

ABSTRACT Mealybugs (Hemiptera: Pseudococcidae) are considered pest insects of economic importance in grapevine crops. They are highly polyphagous, feeding on host plants of about 250 families. This study aimed to identify host plants for mealybugs in grapevine crops, in the São Francisco Valley region, Brazil. The samples included weeds, ornamentals, windbreaks, fruit trees and native plants of the Caatinga biome. A total of 37 species of host plants for mealybugs were identified, distributed in 18 families. The Malvaceae family was the most frequent one, with eigth host species identified, followed by Fabaceae with four and Euphorbiaceae with three. Most of these host plants are being recorded here for the first time in association with mealybugs species. From the identified plant species, 24 are hosts for Maconelicoccus hirsutus, 16 for Phenacoccus solenopsis, one for Ferrisia virgata, one for Dysmicoccus brevipes and one for Planococcus citri. The obtained results are important to better understand the host plant diversity for mealybugs, in order to implement integrated pest management programs.