Influência de aldicarbe e fosetyl-AL sobre Selenaspidus articulatus (Morgan) (Homoptera: Diaspididae) em plantas de citros com e sem sintomas de clorose variegada dos citros

Estudou-se a relação entre a presença de sintomas da clorose variegada dos citros, doença causada pela bactéria Xilella fastidiosa (Wells), e a ação do inseticida aldicarbe e do fungicida fosetyl-AL sobre a cochonilha pardinha, Selenaspidus articulatus (Morgan) em plantas de citros. O ensaio foi realizado em pomar de laranja variedade Valência com cinco anos de idade, As pulverizações de fosetyl-AL foram realizadas quatro vezes com intervalo de três meses, e o aldicarbe foi aplicado no solo uma única vez. A ocorrência de S. articulatus foi avaliada quinzenalmente. Observou-se que: a) A clorose variegada dos citros (CVC) não interferiu na ação de aldicarbe, aplicado no solo, na dose utilizada sobre S. articulatus; b) A dose de aldicarbe empregada para o controle da referida praga em plantas com CVC pode ser a mesma indicada em plantas sem a doença; c) O poder residual de aldicarbe mostrou-se o mesmo em plantas com e sem sintomas de CVC; d) A associação de aldicarbe e fosetyl-AL não interferiu na ação do primeiro sobre a praga.

Exigências Térmicas e Previsão de Picos Populacionais de Lipaphis erysimi (Kalt.) (Homoptera: Aphididae)

Experimentos de laboratório e de campo foram realizados de outubro de 1998 a agosto de 1999, visando estimar as exigências térmicas de Lipaphis erysimi (Kalt). Para isso, o desenvolvimento do afídeo foi estudado em condições de laboratório em couve, Brassica oleracea L. var. acephala, usando câmaras climatizadas reguladas a 10, 15, 20, 25 e 30°C, fotofase de 14h e UR de 70±10%. O limite térmico inferior de desenvolvimento de L. erysimi foi de 3,04°C e a constante térmica 132,21 graus-dia. A previsão de ocorrência de adultos no campo foi feita usando-se o método da triangulação; o pico populacional foi previsto para 0-1 dia antes da data em que o mesmo foi observado no campo.

Oviposition preference of Bemisia tabaci (Genn.) biotype B (Homoptera: Aleyrodidae) for bean genotypes containing arcelin in the seeds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antibiosis effects of wild bean lines containing arcelin on Bemisia tabaci (Genn.) biotype B (Homoptera: Aleyrodidae)

A biologia de Bemisia tabaci biótipo B (Genn.) foi avaliada em genótipos de feijoeiro (Phaseolus vulgaris L.) que contêm arcelina em suas sementes. Foi também realizada análise bioquímica de proteínas, em sementes e em folhas dos genótipos de feijoeiro, a fim de verificar se haveria traços de arcelina nas folhas dos materiais a serem avaliados. Os testes foram conduzidos em condições de casa de vegetação, nas épocas das águas e da seca, em dois anos consecutivos, com os seguintes genótipos: ARC 3s, ARC 5s (genótipos selvagens portadores de arcelina); ARC 1, ARC 2, ARC 3, ARC 4 (linhagens quase-isogênicas portadoras de arcelina - Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)), Porrillo 70, Bolinha e IAPAR MD 808 (genótipos sem arcelina). Os genótipos selvagens, ARC 3s e ARC 5s, apresentaram altos níveis de antibiose, com ênfase para o ARC 5s (as ninfas tiveram alta mortalidade, em torno de 90%). O prolongamento do ciclo de desenvolvimento dos insetos provenientes do genótipo ARC 5s podem sugerir uma resistência do tipo antibiose e/ou não-preferência para alimentação. A resistência dos genótipos selvagens não está relacionada com a presença de arcelina nas sementes, já que nenhum traço dessa proteína foi encontrado nas folhas destes.

Use of Rubidium to Label Lysiphlebus testaceipes (Hymenoptera: Braconidae), a Parasitoid of Greenbugs (Homoptera: Aphididae), for Dispersal Studies

A reliable method of labeling is needed to study dispersal of the braconid parasitoid, Lysiphlebus testaceipes (Cresson), an important biological control of greenbugs, Schizaphis graminum (Rondani), on grain sorghum, Sorghum bicolor (L.) Moench. The feasibility of using aqueous solutions of rubidium chloride (RbCl) applied as a foliar spray or soil drench to label greenbugs and L. testaceipes developing within greenbugs was studied. Laboratory and field studies were conducted to identify the minimal concentration of RbCl to assure labeling of greenbugs and wasps, persistence of Rb throughout the wasp's life span, mobility of Rb to unsprayed sorghum leaves, and feasibility of studying dispersal using a release-recapture technique with Rb-labeled wasps. Both greenbugs and wasps could be labeled using RbCl at concentrations of 2,500-10,000 ppm. Rubidium content in labeled wasps did not significantly vary during the first 7 d after emergence. Greenbugs feeding on unsprayed leaves were labeled up to 4 wk after leaves were sprayed. Rb-labeled wasps were found at the maximum trap distance from the release site (60 m) within 1 d after release.

Parasitism of Greenbugs (Homoptera: Aphididae) by Lysiphlebus testaceipes (Hymenoptera: Braconidae) in Grain Sorghum: Implications for Augmentative Biological Control

Field cage studies were conducted to describe the relationship between the percentage of Lysiphlebus testaceipes (Cresson) parasitism (as measured by aphid mummies) and densities of greenbug, Schizaphis graminum Rondani, on grain sorghum, Sorghum bicolor L. In 1993 and 1994, a biotype E-susceptible grain sorghum hybrid was grown in field cages and L. testaceipes adults were released after each plant was infested with 20 biotype E greenbugs. The release rates were 0, 0.5, 1.0, and 2.0 wasps per plant in 1993, and 0, 0.16, 0.33, and 0.5 wasps per plant in 1994. Greenbugs and mummies were counted 1-2 times a week on all leaves of 2-4 randomly selected plants per cage. A release rate of 0.33-0.5 wasps per plant infested with 20 greenbugs maximized the number of mummies produced and prevented the greenbugs from reaching an economic threshold of 1,000 greenbugs per plant. Peak numbers of mummies occurred ≈400-500 DD (10°C base) after the initial wasp release. Regression analyses showed that the greenbug population started decreasing when the percentage of parasitism (as measured by mummies) reached 20-30 %. Greenbugs in the absence of wasps significantly reduced yield in 1994, but not in 1993.

Chromosome analysis of two species of sugar cane pests of the genus Mahanarva (Homoptera, Cercopidae)

Studies on the cytogenetics of Homoptera are scarce. Some references in the literature have reported a chromosome number for the genus ranging from n=5 to 19 and 2n=10 to 2n=39 chromosomes. The genus Mahanarva includes two species of agricultural importance as pests of sugar cane culture in Brazil. We report here the first data concerning the chromosome number and morphology of the species Mahanarva fimbriolata and M. posticata. The chromosome number observed for the two species was 2n=19 for males and 2n=20 for females. The sex determining mechanism of these species was of the XX/X0 type (for males and females, respectively), with chromosome X being the smallest in the complement.

Little cicada of sugarcane Mahanarva posticata (Homoptera: Cercopidae). A Brazilian agricultural pest. Morpho-histological study of salivary glands

Little cicadas are homopteran insect pests of sugarcane plantations. As these insects suck out the sap from the leaf parenchyma, they inoculate a toxic saliva that damages the plant vessels, thus promoting the loss of glucose by the affected plant. The morphological and histological analyses of the salivary glands of the little cicada Mahanarva posticata, revealed that these glands are formed by 2 portions: one portion comprises a group of acini and has been denominated as the principal gland; the second portion is filamentous in nature and has been denominated as the accessory gland; it is formed by very long and fine filaments. The acinous portion of the gland can be subdivided into 2 lobes: an anterior lobe formed by 3 lobules (I, II, III), and a posterior lobe formed by lobule IV and the excretory duct. Histologically, the salivary glands showed that the filaments are empty sutructures composed by several internal channels with secretion granules being observed in the cytoplasm of the cells of the secretory filaments. Lobules I and II of the principal gland are characterized by being highly basophilic and for accumulating a large amount of secretion in both the cytoplasm of the cells and inside secretion vesicles. Histochemically, we verified that the secretion produced by these glands is lipidic and protein in nature, with the production of polysaccharides being very low. The differences in stain and appearance of the different regions of the salivary gland lead us to believe that the final glandular product is lipoproteic in nature.

Reciprocal interference between ants and stingless bees attending the honeydew-producing homopteran Aetalion reticulatum (Homoptera: Aetalionidae)

We evaluated the reciprocal effects between foragers of the ants Camponotus crassus and of the stingless bees Trigona hyalinata on aggregations of the honeydew-producing treehopper Aetalion reticulatum. The interactions were observed in Bauhinia variegata (Caesalpiniaceae) and Mangifera indica (Anacardiaceae) trees. We recorded the presence/absence of each attendant species in homopteran aggregations to test if the observed co-occurrence is lower than that expected by chance. An exclusion experiment was performed in which each attendant species was excluded from aggregations in order to test if an attendant species is more likely to occupy aggregations where the other attendant is not present. We also recorded the number of individuals of each attendant species in homopteran aggregations to search for any correlation between homopteran and attendant abundances. Additionally, we performed experiments using termites (Termitidae, Isoptera) as models to verify if the attendant species have the potential to defend A. reticulatum against natural enemies. The co-occurrence of attendant species was lower than that expected by chance. Homopteran aggregations without stingless bees were more visited by ants than those in which T. hyalinata was present, and vice-versa. The abundance of stingless bees was proportional to homopteran abundance, while ants abundance was not correlated to homopteran abundance. Both attendant species attacked the natural enemies models when we glued the termites ca. 1 cm away from homopteran aggregations, but only ants removed termites glued 5-7 cm away from aggregations. We suggest that the effects of non-formicid attendants should be included as another factor influencing the costs and benefits of ant-homopteran interactions, since honeydew availability for ants also depends on the presence and behavior of interspecific attendants.

Biologia comparada de Trialeurodes vaporariorum (West.) (Hemiptera - Homoptera: Aleyrodidae) em soja e cinco cultivares de feijão

With the development of greenhouse grown crops, the whitefly Trialeurodes vaporariorum (West.) has become an important pest. Aiming at verifying the effect of host on the development of this species, the biology of the whitefly was studied on bean (Phaseolus vulgaris L.) cultivars IAC-Carioca Pyatã, IAPAR-57, Jalo Precoce, IAC-Bico de Ouro, IAC-Maravilha and on soybean (Glycine max L.) cultivar Cristalina. The study was conducted at the Laboratório de Entomologia Agrícola - FCA-UNESP, at 25 ± 3°C temperature, 80 ± 10% RH and 14h photophase. The biological parameters assessed were duration, viability and number of nymphal instars; male and female longevity, oviposition period, number of eggs per female and sex ratio; egg viability and incubation period and the life cycle duration. Based on data obtained, fertility life tables were constructed to allow a comparative analysis of the effect of cultivars on the biological development and consequent population growth of this species. The bean cultivars IAC-Maravilha and Jalo Precoce negatively influenced T. vaporariorum development, whereas, the other bean cultivars studied, as well as the soybean cultivar Cristalina, provided good conditions for development of this pest.

Evaluación de extractos cetónicos de paraíso, eucalipto y ricino sobre Myzus persicae (Homoptera: Aphididae)

En el cultivo de pimiento, Myzus persicae es una plaga cuyo manejo se basa en el uso de agroquímicos de síntesis. Una alternativa de menor impacto ambiental para su control es la aplicación de extractos naturales. El objetivo del trabajo fue evaluar el efecto de extractos provenientes de Melia azedarach, Eucalyptus globulus y Ricinus communis sobre este pulgón. Se escogió la técnica del film residual en papel de filtro, manteniendo los individuos sobre hojas de pimiento ornamental. Se utilizaron extractos acetónicos a una dilución de 10 000 ppm, con 5 individuos en cada una de las 10 réplicas de los tratamiento. Se efectuaron lecturas para mortalidad a los 30 minutos y 24, 48 y 72 horas. Los resultados se analizaron mediante ANOVA de medidas repetidas y prueba de Tukey. El extracto de eucalipto produjo una mortalidad significativa, alcanzando un máximo cercano al 50 % en promedio, para la lectura a las 72 horas. Asimismo se observó un efecto sobre la reproducción, generado por los extractos de eucalipto y ricino, aunque no pudo probarse esto estadísticamente. Para el ricino, se infiere un probable efecto de repelencia. Se propone continuar con los ensayos de extractos, ampliando la evaluación de su efecto sobre el potencial reproductivo del organismo blanco.

Respuesta funcional de diferentes instares larvales de Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) sobre ninfas de Bactericera cockerelli (Sulc) (Homoptera: Psyllidae)

Bactericera cockerelli (Sulc) (Homoptera: Psyllidae) es una plaga importante de solanaceas en México; para su control, la utilización de plaguicidas es el principal método, por lo que el uso de enemigos naturales bajo un sistema de manejo integrado, ha sido poco utilizado. Tal es el caso de Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), agente de control biológico reportado para esta plaga; sin embargo, se carece de estudios para conocer su potencial. El objetivo del presente trabajo consistió en determinar el tipo y los parámetros de respuesta funcional de C. carnea sobre ninfas de B. cockerelli. El análisis de regresión logística reveló que la respuesta funcional de los tres instares larvales de C. carnea sobre ninfas de B. cockerelli fue de tipo II. Los tres instares consumieron ninfas de B. cockerelli, sin embargo el tercer instar tuvo mayor consumo, menor tiempo de manipuleo y mayor coeficiente de ataque. Estos resultados demostraron que C. carnea fue voraz y su capacidad depredadora está en función de su estado de desarrollo. El tercer instar reveló altas posibilidades para reducir las poblaciones de esta plaga, lo que sugiere que puede ser incluido en sistemas de manejo integrado de plagas basados en el control biológico aumentativo.

Bibliography of the Cicadelloidea (Homoptera: Auchenorhyncha).

"Supersedes the Bibliography of the Homoptera Auchenorhyncha (Metcalf 1944a) as far as references to the Cicadelloidea are concerned."

A bibliography of the Homoptera (Auchenorhyncha).

1. Authors' list A-Z -- 2. List of journals and topical index.

Check list of the Cicadellidae (Homoptera) of America, north of Mexico,

A revision of the list of the North American Cicadellidae, published in 1937, by DeLong and Caldwell. cf. Introd.