1,917 research outputs found

    Biology of Maconellicoccus hirsutus (Hemiptera: Pseudococcidae) on Hibiscus rosa-sinensis.

    Get PDF
    Maconellicoccus hirsutus Green, 1908 (Hemiptera: Pseudococcidae) is an introduced pest that threatens fruit and ornamental plant production in Brazil. Reported in Brazil for the first time in 2010, in the state of Roraima, M. hirsutus, has spread rapidly to other regions of the country. The objective of this study was to investigate the biology of M. hirsutus on Hibiscus rosa-sinensis L. (Malvaceae) leaves in laboratory conditions with climatic parameters similar to those of the Brazilian North and Northeast (27 ± 1 °C, 60 ± 10% relative humidity and 12 hours light and 12 hours dark). Eighty M. hirsutus nymphs were individualized on rooted H. rosa-sinensis leaves and their survival, mortality, sex ratio, and egg numbers per female emerged were recorded. Maconellicoccus hirsutus can have up to nine generations per year, taking 6.5 days to double its population size. The female numbers of this pest are about three times higher than those for its male counterparts, with 98 eggs per female and 97% viability. The survival curve of the species is type I, that is, mortality rates are higher in adulthood. Maconellicoccus hirsutus, especially, a pest of fruit trees and ornamental plants, presents great potential for population growth in Brazilian tropical conditions

    Population fluctuations in the pink hibiscus mealybug and its natural enemies in Annona squamosa (Annonaceae) in Roraima, Brazil.

    Get PDF
    <div><p>ABSTRACT Maconellicoccus hirsutus (Hemiptera, Pseudococcidae), a species of economic interest, especially for fruit plants, is expanding on the South American continent. Information about the population dynamics of this pest associated with control by natural enemies and cultural practices is fundamental for its management. Our objective was to study the population fluctuations in M. hirsutus and its natural enemies in a sugar-apple (Annona squamosa) orchard in Roraima, northern Brazil. Trees were evaluated monthly over a 12-month period. Infestation rates by M. hirsutus and its parasitism were also estimated for potential host plants around the study area. Highest infestation occurred in August and February-March. Alternative hosts were infested during the off-season, mainly fruit. Lacewings and the parasitoid Anagyrus kamali (Hymenoptera, Encyrtidae) were abundant natural enemies. Average parasitism by A. kamali in fruits was 50%, with highest rates in periods of greatest infestation by M. hirsutus. Fruitification pruning reduced M. hirsutus populations.</p></div

    Pontos de colheita e características das cultivares de arroz de terras altas "BRSMG Curinga" e "BRS Liderança".

    Get PDF
    Este trabalho teve por objetivo determinar o momento ideal de colheita de duas cultivares de arroz de terras recentemente recomendadas pela Embrapa. Para tanto avaliou-se o rendimento de grãos inteiros no beneficiamento, tendo-se como base o número de dias após o florescimento médio e o teor de umidade dos grãos na colheita.bitstream/CNPAF/23003/1/comt_79.pd
    corecore