RESUMO
Abstract The red gum lerp psyllid, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), an insect pest originating in Australia and which feeds only on Eucalyptus L'Hér. (Myrtales: Myrtaceae) plants, has spread to several countries. The populations of this insect commonly reach high populations on Eucalyptus plants since its entry into Brazil, and also indicated an unrecorded behavioral. The objectives of this study were to describe a peculiar adaptation in the feeding habit of G. brimblecombei and to register the new habit. The oviposition and feeding by G. brimblecombei, commonly, on the leaves of Eucalyptus, started to occur, also, on lignified twigs. This suggests a not yet recorded adaptation of this insect to reduce insect × plant intraspecific competition.
Resumo O psilídeo de concha, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), um inseto praga originário da Austrália e que se alimenta apenas de plantas de Eucalyptus L'Hér. (Myrtales: Myrtaceae), se espalhou por vários países. Esse inseto, geralmente, atinge grandes populações em plantas de Eucalyptus desde sua entrada no Brasil e, também, indicou um comportamento diferente. Os objetivos deste estudo foram descrever uma adaptação peculiar no hábito alimentar de G. brimblecombei e registrar o novo hábito. A oviposição e alimentação por G. brimblecombei, geralmente, nas folhas de Eucalyptus, passaram a ocorrer, também, em ramos lignificados. Isso sugere uma adaptação diferente desse inseto para reduzir a competição intraespecífica inseto × planta.
RESUMO
The red gum lerp psyllid, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), an insect pest originating in Australia and which feeds only on Eucalyptus L'Hér. (Myrtales: Myrtaceae) plants, has spread to several countries. The populations of this insect commonly reach high populations on Eucalyptus plants since its entry into Brazil, and also indicated an unrecorded behavioral. The objectives of this study were to describe a peculiar adaptation in the feeding habit of G. brimblecombei and to register the new habit. The oviposition and feeding by G. brimblecombei, commonly, on the leaves of Eucalyptus, started to occur, also, on lignified twigs. This suggests a not yet recorded adaptation of this insect to reduce insect × plant intraspecific competition.
O psilídeo de concha, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), um inseto praga originário da Austrália e que se alimenta apenas de plantas de Eucalyptus L'Hér. (Myrtales: Myrtaceae), se espalhou por vários países. Esse inseto, geralmente, atinge grandes populações em plantas de Eucalyptus desde sua entrada no Brasil e, também, indicou um comportamento diferente. Os objetivos deste estudo foram descrever uma adaptação peculiar no hábito alimentar de G. brimblecombei e registrar o novo hábito. A oviposição e alimentação por G. brimblecombei, geralmente, nas folhas de Eucalyptus, passaram a ocorrer, também, em ramos lignificados. Isso sugere uma adaptação diferente desse inseto para reduzir a competição intraespecífica inseto × planta.
Assuntos
Animais , Oviposição , Comportamento , Eucalyptus/parasitologia , Hemípteros/crescimento & desenvolvimentoRESUMO
ABSTRACT Some psyllids transmit 'Candidatus Liberibacter solanacearum' (Lso), the causal agent of devastating plant diseases of cultivated Solanaceae and Apiaceae. The recent detection of Bactericera cockerelli and Lso in Ecuador seriously threatens these crops in South America. There, neither the role of native psyllids in the Lso epidemiology nor the psyllid fauna of vegetables are known. With the aim to identify potential vectors and risk scenarios for the spread of Lso in South America, a survey of the psyllid fauna of Solanaceae and Apiaceae crops and associated weeds was conducted in Brazil. Samples were taken at 29 localities in four states. A total of 2857 specimens were sampled, representing at least 37 species of 23 genera and seven families. The most frequent species on carrot, chilli pepper and potato were Russelliana solanicola, R. capsici and Isogonoceraia divergipennis, respectively. Immatures of R. capsici were found on chilli pepper and of R. solanicola on carrot and potato, confirming these plants as hosts. The two psyllid species have been suspected previously to transmit plant pathogens of unknown identity. Russelliana solanicola is one of the few polyphagous species. Here the species is reported for the first time from carrot. Recent collections in Rio Grande do Sul suggest that Solanum laxum represents the original host of R. capsici, which subsequently shifted to chilli pepper. Both, adaptation to agricultural crops and the possibility of ability to transmit pathogens, make the two Russelliana species dangerous potential vectors of Lso and other plant pathogens in South America.
RESUMO
The survival of eggs and nymphs of Diaphorina citri Kuwayama (Hemiptera: Liviidae) was estimated on young plants (< 1 year) of Citrus sinensis (cultivar Valencia) grafted on Citrus limonia in 3 seasons (Winter and Spring 2013; and Autumn 2014) in Ribeirão Preto, São Paulo State, Brazil. Young shoots with eggs were selected from natural or artificial infestations. Eggs, small nymphs (1st to 3rd instar), and large nymphs (4th and 5th instar) were counted every 3 days. Shoots with large nymphs were caged until the emergence of the adults. The lowest eggs and nymph survival were observed during Winter (0.0%), and Autumn (0.4%); the highest survival rates were recorded during Spring (12.2%). The biotic factor of mortality identified was the parasitism of large nymphs by Tamarixia radiata Waterston (Hymenoptera: Eulophidae), observed in all seasons. Air temperatures (minimum and maximum), and air relative humidity (minimum) could not explain the immature survival differences between Spring (12.2%) and Autumn (0.4%). Rainfall during Spring (165 mm) was higher than during Autumn (48 mm) and may have favored the survival of D. citri in the Spring. Adverse abiotic factors seem to be more important on immature D. citri survival than the biotic factor (parasitism).(AU)
A sobrevivência de ovos e ninfas de Diaphorina citri Kuwayama (Hemiptera: Liviidae) foi estimada em plantas jovens (< 1 ano) de Citrus sinensis (cultivar Valencia) enxertadas em Citrus limonia em 3 estações (inverno e primavera de 2013, e outono de 2014) em Ribeirão Preto, estado de São Paulo, Brasil. Ramos novos com ovos foram selecionados a partir de infestações naturais ou artificiais. Ovos, ninfas pequenas (ínstar 1 ao 3) e ninfas grandes (ínstar 4 e 5) foram contados a cada 3 dias. Ramos com ninfas grandes foram colocados em gaiolas até a emergência dos adultos. As menores sobrevivências de ovos e ninfas foram observadas no inverno (0,0%) e no outono (0,4%), e a maior sobrevivência ocorreu na primavera (12,2%). O principal fator biótico de mortalidade identificado foi o parasitismo de ninfas grandes por Tamarixia radiata Waterston (Hymenoptera: Eulophidae), observado em todas as estações. As temperaturas (mínima e máxima) e umidade relativa (mínima) do ar não explicaram as diferenças nas sobrevivências de imaturos entre a primavera (12,2%) e o outono (0,4%). As chuvas na primavera (165 mm) foram maiores que no outono (48 mm) e podem ter favorecido a sobrevivência de D. citri na primavera. Fatores abióticos adversos parecem ser mais importantes na sobrevivência de imaturos de D. citri que o fator biótico (parasitismo).(AU)
Assuntos
Mortalidade , Citrus , Ninfa , Citrus sinensis , HemípterosRESUMO
Thermal hygrometric requirements for the rearing and release of Tamarixia radiata (Waterston) (Hymenoptera, Eulophidae). Tamarixia radiata is the main agent for the biological control of Diaphorina citri in Brazil with a parasitism rate ranging from 20 to 80%. This study investigated the influence of temperature on the development, fecundity and longevity of adults of T. radiata and the effect of relative humidity (RH) on their parasitism capacity and survival rate in the pre-imaginal period. The effect of temperature was assessed in the range between 15 and 35 ± 1ºC, 70 ± 10% RH, and a 14-h photophase. The RH effect was evaluated in the range from 30 to 90 ± 10%, temperature at 25 ± 1ºC, and photophase of 14-h. At 25ºC, circa 166.7 nymphs were parasitized, the highest parasitism capacity observed compared to other treatments. The longest longevity of females was observed at 25ºC, although the rate did not differ in the 20-30ºC temperature range. The threshold temperature (TT) was 7.2ºC, and 188.7 degrees-day were required for the development (egg-to-adult period). The parasitism rate and longevity were higher at 50 and 70% of RH. This shows that temperature and RH may affect the parasitism capacity of T. radiata on nymphs of D. citri, which can explain the great parasitism variation for D. citri observed in citrus groves in São Paulo State, Brazil.
RESUMO
The psyllid Diaphorina citri Kuwayama 1908 has become the main citrus pest species in the state of São Paulo, Brazil, after the introduction of the huanglongbing or citrus greening. This study evaluated the parasitism of 3rd, 4th and 5th instar D. citri nymphs by Tamarixia radiata (Waterston, 1922) in citrus groves under a regimen of regular insecticide applications in ten producing regions: Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins and São João da Boa Vista. Sixty-nine samples of new branches infested with nymphs of D. citri were collected from 2005 to 2008 in orange groves ranging from 1 to 20 years old, of the varieties Hamlin, Pera, Valencia and Natal. The parasitoid T. radiata is widely distributed in São Paulo orange groves, and was identified in 50 (72%) of the samples, showing a mean parasitism rate of 12.4%. The highest parasitism rate was observed in the "summer" (from January through March), with a mean of 25.7%. Nymphal parasitism was above 90% in two samples. The probable causes of the variations in parasitism of D. citri by T. radiata are discussed.
O psilídeo Diaphorina citri Kuwayama 1908 tornou-se a principal praga dos citros no estado de São Paulo após a introdução do huanglongbing ou grenning dos citros. Este estudo avaliou as proporções de ninfas de terceiro a quinto ínstares de D. citri parasitadas por Tamarixia radiata (Waterston, 1922) em pomares de laranja submetidos a pulverizações constantes de inseticidas em dez regiões produtoras, Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins e São João da Boa Vista. Foram coletadas 69 amostras de ramos jovens infestados com ninfas de D. citri obtidas entre 2005 e 2008 em pomares de 1 a 20 anos de idade, das cultivares Hamilin, Pera, Valencia e Natal. O parasitóide T. radiata encontra-se amplamente distribuído em pomares de São Paulo, tendo sido observado em 50 amostras (72%), com taxa média de parasitismo de 12.4%. O maior parasitismo foi verificado no "verão" (janeiro a março) com média de 25.7%. O parasitismo de ninfas superou 90% em duas amostras. São discutidas as causas próváveis das variações entre o parasitismo de D. citri por T. radiata.
RESUMO
An experimental test of rainfall as a control agent of Glycaspis brimblecombei Moore (Hemiptera, Psyllidae) on seedlings of Eucalyptus camaldulensis Dehn (Myrtaceae). Glycaspis brimblecombei is one the greatest threats to eucalyptus plantations in Brazil. The effects of rainfall to reduce the abundance of lerp of Glycaspis brimblecombei on experimentally infested seedlings of Eucalyptus camaldulensis were assessed. The number of lerps on the adaxial and abaxial surfaces of every leaf of 60 seedlings was recorded, before and after submission to the following treatments: "artificial rain", "leaf wetting" and control. A drastic reduction in lerp abundance per plant was observed after the treatments "leaf wetting" and artificial rain (F = 53.630; p < 0.001), whereas lerp abundance remained roughly constant in the control treatment along the experiment (F = 1.450; p = 0.232). At the end of the experiment, lerp abundance was significantly lower in both the "artificial rain" and "leaf wetting" than in the control treatment. Two days of rainfall simulation were sufficient to decrease more than 50% of the lerp population, with almost 100% of effectiveness after 5 days of experiment. Our results indicate that lerp solubilization and mechanical removal by water are potential tools to the population regulation of G. brimblecombei on E. camaldulensis seedlings.
Teste experimental da chuva como agente de controle de Glycaspis brimblecombei Moore (Hemiptera, Psyllidae) em mudas de Eucalyptus camaldulensis Dehn (Myrtaceae). Glycaspis brimblecombei é uma das maiores ameaças das plantações de eucalipto do Brasil. Foram avaliados os efeitos da água na redução da abundância de conchas desse inseto em mudas de Eucalyptus camaldulensis infestadas experimentalmente. Foi quantificado o número de conchas nas superfícies adaxial e abaxial de todas as folhas de 60 mudas, antes e após a aplicação dos seguintes tratamentos: "chuva artificial", "molhamento das folhas" e controle. Foi observada uma drástica redução na abundância de conchas nos tratamentos "chuva artificial" e "molhamento das folhas" (F = 53,630; p < 0,001), o que não ocorreu para o tratamento controle ao longo do experimento (F = 1,450; p = 0,232). Ao final do experimento, a abundância de conchas foi significativamente menor no tratamento "chuva artificial" e "molhamento das folhas" do que no tratamento controle. Dessa forma, dois dias de chuva mostraram ser eficientes para diminuir mais que 50% da população de conchas, com quase 100% de eficiência após 5 dias de experimento. Nossos resultados indicam que a solubilização das conchas e a remoção mecânica pela água são potenciais ferramentas para regulação populacional de G. brimblecombei em mudas de E. camaldulensis.
RESUMO
Eucalyptus are hosts of several psyllid species. Among them, Ctenarytaina eucalypti (Maskell) is considered the most harmful to Eucalyptus globulus plantations. In Brazil, this pest has been observed in the state of Parana, and in 2005, it was found causing damage to plantations of E. globulus in Arroio Grande and Piratini cities, RS. The monophagous endoparasitoid Psyllaephagus pilosus Noyes was also observed parasitizing nymphs of C. eucalypti. This parasitoid has been shown to be highly efficient in controlling this psyllid species, making unnecessary the use of any other control method.
Assuntos
Animais , Eucalyptus/parasitologia , Hemípteros/fisiologia , Himenópteros/fisiologia , BrasilRESUMO
Spiromesifen is an insecticide that inhibits the synthesis of lipids and, in Mexico, its use against the Tomato-Potato Psyllid, Bactericera cockerelli (Sulc), on chili pepper (Capsicum annum), tomato (Lycopersicon sculentum) and potato (Solanum tuberosum) began in 2005; however more information is needed to understand its toxicity on this insect pest. The aim of this research was to determine the toxicity of spiromesifen against each of the biological stages of tomato-potato psyllid, its effect on fertility and viability of eggs deposited by treated females, as well as the female preference to lay eggs on treated and non treated plants. The relative toxicity at 95 percent mortality (highest LC95 value /LC95 value of the respective biological stage) of spiromesifen in egg, nymph 1, nymph 2, nymph 3, nymph 4, and nymph 5 were 517.5; 31316.2; 2950.1; 315.6; 18.2 and 1-fold, respectively. There were no differences in the toxicity of spiromesifen between adult males and females. The number of laid eggs was reduced as the spiromesifen concentration used to treat female increased and egg hatch was reduced in all tested doses. In the "no choice" test, females deposited 38.6 ± 2.01 eggs by leaf of non treated chili pepper type jalapeño, while in the treated with 360 mg L-1 we observed 0.3 ± 0.08 eggs by leaf. In the "choice" test, the oviposition decreased as the dose increased. There were no eggs on plants treated with 2400 mg L-1 of spiromesifen.
Assuntos
Animais , Feminino , Masculino , Hemípteros/efeitos dos fármacos , Hemípteros/crescimento & desenvolvimento , Estágios do Ciclo de Vida/efeitos dos fármacos , Compostos de Espiro/toxicidadeRESUMO
Feeding and oviposition preferences of Ctenarytaina spatulata Taylor (Hemiptera, Psyllidae) for Eucalyptus spp. and other Myrtaceae in Brazil. The Australian psyllid, Ctenarytaina spatulata Taylor (Hemiptera, Psyllidae), was first detected in Brazil in 1994, where it was found on drought-affected shoots of Eucalyptus grandis in a plantation located in the northern part of Paraná State. The oviposition and feeding preferences of this psyllid were examined on 19 Eucalyptus species, one Eucalyptus hybrid (Cambiju), three Corymbia species and four native Myrtaceae species (Hexaclames edulis, Marlieria edulis, Plinia trunciflora, and Psydium sp.) under greenhouse conditions. The largest populations of C. spatulata were found on E. robusta and E. pellita, while sizeable infestations were also found on E. urophylla, E. grandis, and the Cambiju hybrid. The plants with the greatest symptoms of damage were E. grandis and E. resinifera. Eucalyptus cinerea, E. benthamii, E. pilularis, and E. dunnii were not infested and E. cloeziana was minimally infested. Among the Corymbia species, the number of eggs of C. spatulata was very low on C. citriodora and C. torelliana. No eggs and nymphs of C. spatulata were found on native Brazilian Myrtaceae. The number of eggs on plants was highly correlated with the subsequent levels of nymphs, suggesting that egg counts can be used as a viable monitoring tool to assist with the integrated management of this pest.
Ctenarytaina spatulata Taylor, 1997 (Hemiptera, Psyllidae), originária da Austrália, foi detectada no Brasil em 1994. Sua ocorrência foi inicialmente observada em E. grandis no Norte do Paraná associada à seca dos ponteiros. Com o objetivo de verificar a preferência deste psilídeo para postura e alimentação foram analisadas, em casa de vegetação, um híbrido e dezenove espécies do gênero Eucalyptus, três do gênero Corymbia e cinco mirtáceas nativas (Hexaclames edulis, Marlieria edulis, Plinia trunciflora and Psydium sp.). As maiores populações de C. spatulata ocorreram em E. robusta e E. pellita. No entanto, foram as espécies E. grandis e E. resinifera que apresentaram o maior número de plantas com sintomas de danos. As espécies E. cinerea, E. cloeziana, E. dunnii, E. benthamii, E. nitens, E. viminalis, E. pilularis e E. camaldulensis não apresentaram infestação por C. spatulata. Nas espécies de Corymbia foi observado um número muito reduzido de ovos de C. spatulata em C. citriodora e C. torelliana. Em nenhuma das espécies de Myrtaceae nativas foram observados ovos ou ninfas de C. spatulata. O número de ovos na planta foi altamente correlacionado com o número de ninfas, sugerindo que a contagem de ovos possa ser usada como uma ferramenta viável no monitoramento desta praga.
RESUMO
Glycaspis brimblecombei Moore is an Australian native pest of Eucalyptus detected in Brazil in 2003. Since then, it has spread fast and colonized plantations in several states of the country. This study aimed to investigate the influence of cerrado remnants on the abundance and biological control of G. brimblecombei. We placed yellow sticky card traps to capture insects in four plantations of hybrid clones of Eucalyptus urophylla x Eucalyptus grandis ("Urograndis") and four plantations of E. urophylla x Eucalyptus camaldulensis ("Urocam"). Traps were placed in three areas of these plantations: center, border with cerrado and border without cerrado. We also collected leaves from the same clones to estimate psyllid egg and lerp abundance. The abundance of G. brimblecombei was lower in the plantation-cerrado border, and the inverse pattern was observed for microhymenopterans. The leaf abaxial surface showed a higher abundance of eggs and nymphs, probably as a consequence of a lower parasitism rate and mechanical removal by wind and rain. Egg number was higher on Urograndis than in Urocam clones, but the number of psyllid lerps was higher in the latter. Thus, the establishment of first instars is probably a critical event to psyllid infestation, and these differences may be caused by morphological, anatomical and biochemical leaf features of distinct clones. Our results suggest that the maintenance of native vegetation around plantations is a promising management practice to promote the natural biological control of G.brimblecombei, a strategy that would also enhance the preservation of cerrado remnants.
Assuntos
Animais , Eucalyptus/genética , Eucalyptus/parasitologia , Hemípteros/fisiologia , Genótipo , Controle de Insetos , Densidade DemográficaRESUMO
Biologia do psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera, Psyllidae) em Eucalyptus spp.. Glycaspis brimblecombei Moore também conhecido por psilídeo-de-concha, se caracteriza por ser uma espécie específica ao gênero Eucalyptus L'Her. Este trabalho teve por objetivo determinar o ciclo biológico de G. brimblecombei em Eucalyptus spp. O trabalho foi conduzido em câmara climatizada (BOD), sob a temperatura de 26 ºC e fotofase de 12 horas. As espécies de Eucalyptus utilizadas para o experimento foram: Eucalyptus camaldulensis, E. tereticornis, E. urophylla, E. grandis, Corymbia citriodora e um híbrido de E. grandis x E. urophylla ('urograndis'). Inicialmente foram utilizados 100 repetições (ninfas) tratamento (espécies de Eucalyptus). As avaliações foram diárias. Os parâmetros biológicos avaliados foram a duração e viabilidade do estágio ninfal, longevidade dos adultos, número de posturas/fêmea, duração do período embrionário, número e viabilidade ovos, longevidade dos adultos e duração do ciclo total. Os resultados obtidos demonstraram que salvo C. citriodora que apresentou ser letal ao desenvolvimento ninfal de G. brimblecombei as demais espécies de Eucalyptus testadas oferecem condições ao desenvolvimento biológico deste psilídeo, sendo que neste trabalho E. camaldulensis mostrou-se a mais adequada.
Glycaspis brimblecombei Moore, also known as red gum lerp psyllid, is characterized to be specific to the genus Eucalyptus. This work aimed to evaluate G. brimblecombei biological cycle in Eucalyptus spp. The work was accomplished in acclimatized chamber (BOD), with temperature of 26 ºC and photophase of 12 hours. Eucalyptus species used in this study were: Eucalyptus camaldulensis, E. tereticornis, E. urophylla, E. grandis, Corymbia citriodora and E grandis x E. urophylla hybrid ('urograndis'). Initially 100 replications (nymphs) per treatment (Eucalyptus species) were prepared. The evaluations were daily and the following biological parameters were measured: nymph phase duration and viability, adult longevity, number of eggs/female, duration of incubation period, egg number and viability, total cycle, longevity and duration of adults. The results demonstrated that, except for C. citriodora, the other eucalypt species offer conditions to G. brimblecombei biological development, being E. camaldulensis the most adequate species.