RESUMEN
The lethal yellowing (LY) is a major phytoplasma causing disease seriously threatening coconut plantations worldwide, with imminent risk of entering Brazil. The LY phytoplasma is restricted to the phloem and transmitted by the planthopper Haplaxius crudus (Van Duzee) (Cixiidae). In this study, Auchenorrhyncha were collected on the leaves of Dwarf vs. Dwarf hybrids and Brazilian Green Dwarf Jiqui in the Brazilian northern state of Para using yellow adhesive traps in May of 2016. The planthopper H. crudus was found in coconut plantations of Brazilian Green Dwarf Jiqui, accounting for 87% of the individuals captured. This is the first report of vector H. crudus in Brazilian coconut plantations. These findings are of great scientific relevance since H. crudus could negatively impact the Brazilian coconut industry and this knowledge could be used in contingency measures in the case of LY be introduced in the country.
Asunto(s)
Cocos , Hemípteros , Animales , Brasil , Insectos Vectores , Phytoplasma , Enfermedades de las Plantas/microbiología , Hojas de la PlantaRESUMEN
In many tropical landscapes, agroforestry systems are the last forested ecosystems, providing shade, having higher humidity, mitigating potential droughts, and possessing more species than any other crop system. Here, we tested the hypothesis that higher levels of shade and associated humidity in agroforestry enhance coffee ant richness more during the dry than rainy season, comparing ant richness in 22 plots of three coffee agroforestry types in coastal Ecuador: simple-shade agroforests (intensively managed with low tree species diversity), complex-shade agroforests (extensively managed with intermediate tree species diversity) and abandoned coffee agroforests (abandoned for 10-15 yr and resembling secondary forests). Seasonality affected responses of ant richness but not composition to agroforestry management, in that most species were observed in abandoned coffee agroforests in the dry season. In the rainy season, however, most species were found in simple-shade agroforests, and complex agroforestry being intermediate. Foraging coffee ants species composition did not change differently according to agroforestry type and season. Results show that shade appears to be most important in the dry seasons, while a mosaic of different land-use types may provide adequate environmental conditions to ant species, maximizing landscape-wide richness throughout the year.
Asunto(s)
Hormigas , Biodiversidad , Agricultura Forestal , Estaciones del Año , Árboles , Animales , Coffea , Ecuador , LluviaRESUMEN
The flat-mite Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae) is considered important in citrus (Citrus spp.) and coffee plants (Coffea spp.) in Brazil, and is known as the leprosis and coffee ring spot mite, as being a vector of the Citrus Leprosis Rhabdovirus - CitLV and Coffee Ring Spot Virus - CoRSV. The objective of this work is to find out about the reproductive success of B. phoenicis on citric fruits and coffee leaves by fertility life table parameters and its biology. The experiments were carried out in laboratory conditions at 25 +/- 2 degrees C, 70 +/- 10% of relative humidity and 14 h of photophase. The lengths of embryonic and post-embryonic periods were different due to the host where the mite was reared. B. phoenicis showed better development and higher survival and fecundity in citric fruits than coffee leaves. The intrinsic rate of the population increase (r(m)) was 0.128 and 0.090 - females/female/day on citric fruits and coffee leaves, respectively. The citric fruits were more appropriate for the development of B. phoenicis than coffee leaves.
Asunto(s)
Vectores Arácnidos/fisiología , Citrus/parasitología , Café/parasitología , Estadios del Ciclo de Vida/fisiología , Ácaros/fisiología , Animales , Vectores Arácnidos/clasificación , Vectores Arácnidos/crecimiento & desarrollo , Fertilidad/fisiología , Interacciones Huésped-Parásitos , Tablas de Vida , Ácaros/clasificación , Ácaros/crecimiento & desarrollo , Factores de TiempoRESUMEN
The flat-mite Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae) is considered important in citrus (Citrus spp.) and coffee plants (Coffea spp.) in Brazil, and is known as the leprosis and coffee ring spot mite, as being a vector of the Citrus Leprosis Rhabdovirus - CitLV and Coffee Ring Spot Virus - CoRSV. The objective of this work is to find out about the reproductive success of B. phoenicis on citric fruits and coffee leaves by fertility life table parameters and its biology. The experiments were carried out in laboratory conditions at 25 ± 2 °C, 70 ± 10 percent of relative humidity and 14 h of photophase. The lengths of embryonic and post-embryonic periods were different due to the host where the mite was reared. B. phoenicis showed better development and higher survival and fecundity in citric fruits than coffee leaves. The intrinsic rate of the population increase (r m) was 0.128 and 0.090 - females/female/day on citric fruits and coffee leaves, respectively. The citric fruits were more appropriate for the development of B. phoenicis than coffee leaves.
O ácaro Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae) é considerado importante em citros (Citrus spp.) e cafeeiro (Coffea spp.) no Brasil, sendo conhecido como ácaro da leprose e da mancha-anular, por ser vetor dos vírus causadores da leprose em citros,Citrus Leprosis Rhabdovirus - CitLV, e da mancha-anular em cafeeiro,Coffee Ring Spot Virus - CoRSV. O objetivo deste trabalho foi avaliar o sucesso reprodutivo de B. phoenicis, em frutos cítricos e em folhas de cafeeiro, por meio de parâmetros calculados a partir da tabela de vida,de fertilidade e da biologia. Os experimentos foram realizados em laboratório a 25 ± 2 °C, 70 ± 10 por cento de umidade relativa e 14 h de fotofase. Os períodos embrionário e pós-embrionário apresentaram diferenças em função do hospedeiro em que o ácaro foi criado.B. phoenicis teve melhor desenvolvimento, maior sobrevivência e maior fertilidade específica em frutos cítricos do que em folhas de cafeeiro. A taxa intrínseca de crescimento populacional (rm) foi de 0,128 e 0,090 fêmeas/fêmea/dia em frutos cítricos e em folhas de cafeeiro, respectivamente. Os frutos cítricos mostraram-se mais adequados ao desenvolvimento de B. phoenicis do que as folhas de cafeeiro.