Effects of the availability of floral resources and neighboring plants on nectar robbery in a specialized pollination system.

Many plants pollinated by nectar-foraging animals have to maintain a balance between legitimate visitor attraction strategies and mechanisms that minimize illegitimate visits. This study investigated how floral display and neighboring species composition influences nectar robbing by hummingbirds in the tropical ornithophilous herb Heliconia spathocircinata. We tested the role of inflorescence display, flower abundance, and neighboring species in the reduction of nectar robbing in H. spathocircinata. Our results indicate that nectar robbing hummingbird activity was higher in moderately large inflorescence displays and that the frequency of nectar robbing in H. spathocircinata decreases with increased flower abundance and the presence of neighboring plant species. Neighboring non-ornithophilous plants decreased the frequency of nectar robbing in H. spathocircinata flowers to a greater extent than ornithophilous ones. These results suggest that nectar robbing hummingbirds are attracted to similar conditions that attract legitimate visitors and that spatial aggregation and mixed-species displays may represent a mechanism to dilute nectar robbing effects at an individual level.

Morphological and stomatal characterization of Heliconia chartacea Var. sexy pink induced polyploidy / Caracterização morfológica e estomática de heliconia chartacea var. sexy pink induzidas a poliploidia

The growth of the tropical flower market has demanded a consistent search for new varieties, primarily those endowed with an exotic profile, but that are also beautiful and durable. The genusHeliconia, naturally found in the Amazon region, is among the most prominent of tropical flowers. Looking to augment the genetic variability available in Heliconia chartacea var. Sexy Pink, biotechnological research was conducted with the application of colchicine to induce polyploidy in plants from this species. With that in mind, this study was undertaken to evaluate the establishment of plants in the field drawn from in vitro polyploidy induction assay and to determine the morphological and physiological characteristics of 38 H. chartacea var. Sexy Pink clones. The characterization analyzes were performed through 49 morphological descriptors and a stomatal density evaluation using microscopy. The genotype 35 exhibited the greatest morphological variations, with alterations in the position and coloring of the inflorescence, in addition to having the edges of the entire limbus. Genotype 18 featured the lowest amounts for plant height and inflorescence size, showing promise for research geared towards use in reduced environments. Some genotypes did not have any flowering and arerecommended exclusively for landscape composition such as foliage, since their exotic characteristics allow for this. The genotypes that were evaluated displayed stomata with tetracytic morphology and guard cells that had no significant changes. However, genotypes with greater equatorial diameter and stomatal density were obtained in relation to the mother-plant. Overall, the induction of polyploidy allowed for clones to be obtained with a high variability for the characteristics of the leaf, pseudostem and inflorescence, with various attributes that confer a more efficient post-harvest management to some genotypes, in addition to favorable aspects for commercialized purposes as a cut flower.

A expansão do mercado de flores tropicais tem demandado uma constante procura por novas variedades, principalmente aquelas dotadas de perfil exótico, mas ainda apresentando beleza e durabilidade. Dentre as flores tropicais de maior destaque, se encontram as do gênero Helicônia, sendo estas naturalmente encontradas na região Amazônica. Visando aumentar a variabilidade genética disponível em Heliconia chartacea var. Sexy Pink, pesquisas biotecnológicas foram realizadas com a aplicação de colchicina para indução a poliploidia em plantas da espécie. Deste modo, o objetivo do presente trabalho foi avaliar as plantas estabelecidas em campo, provenientes dos ensaios de indução à poliploidia in vitro para determinar as características morfológicas e fisiológicas de 38 clones de H. chartacea var. Sexy Pink. As análises de caracterização foram realizadas por meio de 49 descritores morfológicos e avaliação da densidade estomática por microscopia. O genótipo 35 foi o que apresentou as maiores variações morfológicas, com alterações na posição e coloração da inflorescência, além de possuir as bordas do limbo foliar inteiras. O genótipo 18 apresentou os menores valores para altura da planta e tamanho das inflorescências, mostrando-se promissor para pesquisas voltadas ao uso em ambientes reduzidos. Alguns genótipos não tiveram floração, sendo recomendada a sua utilização exclusivamente para composição paisagística como folhagens, já que sua exoticidade permite esta finalidade. Os genótipos avaliados apresentaram estômatos com morfologia tetracítica e células-guarda sem alterações significativas, porém, foram obtidos genótipos com maior diâmetro equatorial e densidade estomática em relação a planta matriz. De modo geral, a indução a poliploidia permitiu a obtenção de clones com alta variabilidade para características da folha, pseudocaule e inflorescência, sendo vários os atributos que conferiram a alguns genótipos um manejo pós-colheita mais eficiente, além de aspectos favoráveis para comercialização como flor de corte.

Different levels of shade on population of grasshoppers and its oviposition preference on heliconias / Diferentes níveis de sombreamento na população de gafanhotos e sua preferência para oviposição em helicônias

Grasshoppers of the families Acrididae and Romaleidae (Orthoptera) are among the insects that defoliate heliconias and have been gaining status as pests of commercial crops of these plants in Brazil. The objectives of the present study were to identify the grasshopper defoliating heliconias in the municipality of Santo Antônio de Pádua, RJ (Brazil), to evaluate the effect of different levels of shade on the population of this grasshopper and the production parameters of heliconias, and to determine if this grasshopper has an oviposition preference among the heliconias evaluated. The experiment was in a completely randomized block design, in subdivided plots (four levels of shade in the plot, 0%, 30%, 50% and 80%, and four species of Heliconia: H. psittacorum, H. stricta, H. wagneriana and H. psittacorum x H. spathocircinata Golden Torch in the subplot), with four replications. The grasshopper was identified as Cornops frenatum frenatum (Acrididae). An increase in shade resulted in a decrease in the number of oviposition holes from the grasshopper and the number of lateral buds. Shade did not influence the number of C. f. frenatum nymphs and adults and the number of flower stems. H. wagneriana was the most preferred species for oviposition by C. f. frenatum. Results suggested using screens to shade heliconia plants can help control C. f. frenatum populations, however, the light requirements of the heliconias should be considered to guarantee productivity.(AU)

Os gafanhotos das famílias Acrididae e Romaleidae (Orthoptera) estão entre os insetos desfolhadores de helicônias, e vem ganhando status de pragas em cultivos comerciais dessas flores no Brasil. O presente estudo objetivou identificar o gafanhoto de ocorrência no município de Santo Antônio de Pádua, RJ (Brasil) causador de desfolhamento em helicônias; avaliar o efeito de diferentes níveis de sombreamento sobre a população desse gafanhoto e parâmetros produtivos de helicônias; e se existe preferência do gafanhoto para oviposição entre as helicônias avaliadas. O experimento foi em delineamento em blocos ao acaso, em esquema de parcelas subdivididas (quatro níveis de sombreamento: 0%, 30%, 50% e 80% na parcela e quatro espécies de Heliconia: H. psittacorum, H. stricta, H. wagneriana e H. psittacorum x H. spathocircinata Golden Torch na subparcela), com quatro repetições. O gafanhoto desfolhador foi identificado como Cornops frenatum frenatum (Acrididae). À medida que o sombreamento se tornou mais denso, diminuíram o número de orifício de oviposição do gafanhoto e o número de brotações laterais. O sombreamento não influenciou o número de ninfas e adultos de C. f. frenatum e o número de hastes florais. H. wagneriana foi a espécie mais preferida para oviposição por C. f. frenatum. Os resultados sugerem que o uso de tela para sombreamento das plantas de helicônia pode auxiliar no controle da população de C. f. frenatum, porém, deve-se observar o padrão de exigência de luminosidade das helicônias para garantir a produtividade.(AU)

Different levels of shade on population of grasshoppers and its oviposition preference on heliconias / Diferentes níveis de sombreamento na população de gafanhotos e sua preferência para oviposição em helicônias

ABSTRACT: Grasshoppers of the families Acrididae and Romaleidae (Orthoptera) are among the insects that defoliate heliconias and have been gaining status as pests of commercial crops of these plants in Brazil. The objectives of the present study were to identify the grasshopper defoliating heliconias in the municipality of Santo Antônio de Pádua, RJ (Brazil), to evaluate the effect of different levels of shade on the population of this grasshopper and the production parameters of heliconias, and to determine if this grasshopper has an oviposition preference among the heliconias evaluated. The experiment was in a completely randomized block design, in subdivided plots (four levels of shade in the plot, 0%, 30%, 50% and 80%, and four species of Heliconia: H. psittacorum, H. stricta, H. wagneriana and H. psittacorum x H. spathocircinata 'Golden Torch' in the subplot), with four replications. The grasshopper was identified as Cornops frenatum frenatum (Acrididae). An increase in shade resulted in a decrease in the number of oviposition holes from the grasshopper and the number of lateral buds. Shade did not influence the number of C. f. frenatum nymphs and adults and the number of flower stems. H. wagneriana was the most preferred species for oviposition by C. f. frenatum. Results suggested using screens to shade heliconia plants can help control C. f. frenatum populations, however, the light requirements of the heliconias should be considered to guarantee productivity.

RESUMO: Os gafanhotos das famílias Acrididae e Romaleidae (Orthoptera) estão entre os insetos desfolhadores de helicônias, e vem ganhando status de pragas em cultivos comerciais dessas flores no Brasil. O presente estudo objetivou identificar o gafanhoto de ocorrência no município de Santo Antônio de Pádua, RJ (Brasil) causador de desfolhamento em helicônias; avaliar o efeito de diferentes níveis de sombreamento sobre a população desse gafanhoto e parâmetros produtivos de helicônias; e se existe preferência do gafanhoto para oviposição entre as helicônias avaliadas. O experimento foi em delineamento em blocos ao acaso, em esquema de parcelas subdivididas (quatro níveis de sombreamento: 0%, 30%, 50% e 80% na parcela e quatro espécies de Heliconia: H. psittacorum, H. stricta, H. wagneriana e H. psittacorum x H. spathocircinata 'Golden Torch' na subparcela), com quatro repetições. O gafanhoto desfolhador foi identificado como Cornops frenatum frenatum (Acrididae). À medida que o sombreamento se tornou mais denso, diminuíram o número de orifício de oviposição do gafanhoto e o número de brotações laterais. O sombreamento não influenciou o número de ninfas e adultos de C. f. frenatum e o número de hastes florais. H. wagneriana foi a espécie mais preferida para oviposição por C. f. frenatum. Os resultados sugerem que o uso de tela para sombreamento das plantas de helicônia pode auxiliar no controle da população de C. f. frenatum, porém, deve-se observar o padrão de exigência de luminosidade das helicônias para garantir a produtividade.

A new species of Heliconia (Heliconiaceae) with pendent inflorescence, from Chucantí Private Nature Reserve, eastern Panama.

Heliconia berguidoi (Heliconiaceae), a new species from premontane forest of eastern Panama, is described, illustrated and its conservation status evaluated. Heliconia berguidoi bears pink flowers, an uncommon color in this group. It differs from the Colombian species Heliconia rhodantha and Heliconia sanctae-theresae, the most similar taxa, by the combination of a petiole glabrous except for the woolly base, a very long peduncle, the perianth pubescent at the apex and staminode with cuspidate apex. Heliconia berguidoi is also similar to Heliconia pogonantha in all four of its varieties and to Heliconia ramonensis in two of its four varieties, but differs by a combination of the long peduncle, pink flowers and staminode with cuspidate apex. Fifty-six Heliconia species have been found in Panama, eighteen of them endemic.

ResumenHeliconia berguidoi (Heliconiaceae), una nueva especie de bosque premontano del este de Panamá, es descrita, ilustrada y su estado de conservación evaluado. Heliconia berguidoi tiene flores rosadas, color poco común en este grupo. Difiere de las especies de Colombia Heliconia rhodantha y Heliconia sanctae-theresae, taxones más similares, por la combinación de un pecíolo glabro aunque lanudo en la base, pedúnculo muy largo, ápice del perianto pubescente y estaminoide con el ápice cuspidado. Heliconia berguidoi es también similar a Heliconia pogonantha en sus cuatro variedades y a Heliconia ramonensis en dos de sus cuatro variedades, pero difiere por la combinación de su largo pedúnculo, el color rosado de las flores y el estaminoide con ápice cuspidado. En Panamá se han encontrado cincuenta y seis especies de Heliconia, dieciocho de ellas endémicas.

Phytoseiid mites (Acari: Phytoseiidae) associated with tropical ornamental plants, with a checklist and a key to the species of Bahia, Brazil.

Twenty-four papers refer to phytoseiid mites from different plant species in the state of Bahia, northeastern Brazil, but none of those refer to taxonomic surveys on ornamental plants. The aim of this study was to determine phytoseiids from tropical ornamentals in the southern coastal region of Bahia state, as well as to present a checklist and an identification key to the species recorded in that state. Samples were collected at eight localities of five municipalities. A total of seventeen species in nine genera was found on fifteen plant species of the families Costaceae, Heliconiaceae, Musaceae and Zingiberaceae. The most frequent and abundant phytoseiid species were Iphiseiodes metapodalis (El-Banhawy), Amblyseius operculatus De Leon and Iphiseiodes zuluagai Denmark & Muma, respectively. The checklist and the identification key to the Phytoseiidae species of Bahia were prepared based on the published literature.

Infestation of Raoiella indica Hirst (Trombidiformes: Tenuipalpidae) on Host Plants of High Socio-Economic Importance for Tropical America.

The mite Raoiella indica Hirst was recently introduced into America, where it has shown amazing ability to disseminate and broaden its range of hosts. An experiment was conducted in Cancún, Mexico, to determine infestation levels of this mite on plants recorded as hosts: coconut palm (Cocos nucifera) of cultivars Pacific Tall and Malayan Dwarf, oil palm (Elaeis guineensis) hybrids Deli x Ghana and Deli x Nigeria, Dwarf Giant banana (Musa acuminata, AAA subgroup Cavendish), Horn plantain (M. acuminata x Musa balbisiana, AAB subgroup Plantain), lobster claw (Heliconia bihai), and red ginger (Alpinia purpurata). Nursery plants of these host species or cultivars were artificially infested with R. indica in February 2011. In the four replications of 10 plants, each plant was infested with 200 R. indica specimens, and the numbers of infesting mites were recorded for 6 months. A maximum of 18,000 specimens per plant were observed on coconut Pacific Tall and Malayan Dwarf, followed by lobster claw, with a maximum of 1000 specimens per plant. Infestations were minimal for the remaining plants. Mite numbers on all plants declined naturally during the rainy season. All plant materials sustained overlapping mite generations, indicating that they are true hosts. Complementarily, infestation level was determined in backyard bananas and plantains. Correlations of infestation with plant height, distance from coconuts, and exposure to direct sunlight were estimated. Both bananas and plantains were infested by R. indica even when situated far from infested coconut palms. A Spearman correlation was found between infestation and plant height, although it was significant only for Silk plantain.

Interaction intimacy of pathogens and herbivores with their host plants influences the topological structure of ecological networks in different ways.

UNLABELLED: • PREMISE OF THE STUDY: Over the past two decades an interest in the role that plant-animal mutualistic networks play in the organization and dynamic of biodiversity has steadily risen. Despite the ecological, evolutionary, and economic importance of plant-herbivore and plant-pathogen antagonistic relationships, however, few studies have examined these interactions in an ecological network framework.• METHODS: We describe for the first time the topological structure of multitrophic networks involving congeneric tropical plant species of the genus Heliconia (Heliconiaceae, Zingiberales) and their herbivores and pathogens in the state of Pernambuco, Brazil. We based our study on the available literature describing the organisms (e.g., insects, mites, fungi, and bacteria) that attack 24 different species, hybrids, and cultivated varieties of Heliconia.• KEY RESULTS: In general, pathogen- and herbivore-Heliconia networks differed in their topological structure (more modular vs. more nested, respectively): pathogen-Heliconia networks were more specialized and compartmentalized than herbivore-Heliconia networks. High modularity was likely due to the high intimacy that pathogens have with their host plants as compared with the more generalized feeding modes and behavior of herbivores. Some clusters clearly reflected the clustering of closely related cultivated varieties of Heliconia sharing the same pathogens.• CONCLUSIONS: From a commercial standpoint, different varieties of the same Heliconia species may be more susceptible to being attacked by the same species of pathogens. In summary, our study highlights the importance of interaction intimacy in structuring trophic relationships between plants and pathogens in the tropics.

Notes on the ecology of rolled-leaf hispines (Chrysomelidae, Cassidinae) at La Gamba (Costa Rica).

A total of 301 adult hispine beetles of the genera Cephaloleia and Chelobasis were found in rolled leaves of plants of 17 species of Zingiberales (families Costaceae, Heliconiaceae, Maranthaceae, Musaceae, and Zingiberaceae) during a field study at La Gamba, Golfito region, Costa Rica. Of these beetles, Cephaloleia belti was recorded from 12 potential host plant species, C. distincta from 7, C. dilaticollis from 5, C., Chelobasis bicolor, C. championi, and C. histrionica from 3, Chelobasis perplexa and C. instabilis from 2, whereas C. trivittata from only one. Of the plant species, Heliconia latispatha had 7 beetle species in its leaf rolls, Calathea lutea had 5, H. imbricata and H. rostrata had 4, H. stricta and Musa paradisiaca had 3, H. wagneriana had 2, while on H. vaginalis, H. danielsiana, H. densiflora, H. longiflora, Calathea crotalifera, C. platystachya, Goeppertia lasiophylla, Alpinia purpurata, Costus pulverulentus and Costus barbatus, H. densiflora, H. vaginalis, and H. danielsana only hispines of one species were found. Cephaloleia belti occurred together with beetles of six other hispine species, whereas Cephaloleia trivittata never shared a leaf roll with another hispine species. The remaining beetle species aggregated with one to four other hispines. Adults of C. belti and C. championi were frequently seen, occasionally also with C. dilaticollis, C. histrionica, and Chelobasis perplexa, to co-occur with the carabid Calophaena ligata in the same leaf roll without any sign of interspecific aggression. A comparison of host choices and the phylogeny of the hispines and of their host plants revealed no signs that beetles used species level phylogenetic relationships within the Zingiberales to select food plants. Obviously, within this plant order, rolled-leaf hispines choose their plant hosts in a nearly opportunistic manner. Seemingly, they use differences among plants at higher taxonomic levels but within the Zingiberales, the availability of young - rolled - leaves might be the actual decisive factor.