RESUMO
The microlepidoptera, Bedellia somnulentella (Zeller), is an important pest of sweetpotato, Ipomoea batatas (L.) Lam. Damage by B. somnulentella occurs in the larval stage and when consuming the foliar mesophyll of I. batatas make the leaves brown, wrinkled, and reducing the photosynthetic area and the yield. The detection and management of this pest depends on knowing its biological cycle and identifying its natural enemies. The objectives of this study were to determine the life history of B. somnulentella feeding on I. batatas leaves and to survey parasitoids of this pest in the field. The duration and viability of B. somnulentella egg, larva, prepupa, pupa, and adult stages were evaluated under laboratory conditions. Cephalic capsule width was measured to determine the number of B. somnulentella instars, based on the Dyar rule and analyzed by the Akaike statistical model (AIC). The developmental period of B. somnulentella was 32.5 ± 0. 21 d with a viability of 75, 84, 100, and 84% for the egg, larva, prepupa, and pupa stages, respectively. The identification of this pest on the plants is possible from the third instar and in the pupal and adult stages. The parasitoid Conura sp. (Hymenoptera: Chalcididae) was identified parasitizing pupae of B. somnulentella and could be considered a potential natural enemy for the integrated management of this pest.
Assuntos
Convolvulaceae , Ipomoea batatas , Lepidópteros , Animais , Brasil , Larva , Controle Biológico de Vetores , Folhas de Planta , Pupa , SolanalesRESUMO
The potato psyllid Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) is a pest of solanaceous crops (order Solanales), including potato (Solanum tuberosum L.) and tomato (S. lycopersicum L.). Feeding by high populations of nymphs causes psyllid yellows while adults and nymphs are vectors of the plant pathogen 'Candidatus Liberibacter solanacearum'. Foliar symptoms that were consistent with either 'Ca. L. solanacearum' infection or psyllid yellows were observed in 2019 on tomatillo (Physalis ixocarpa Brot.; family Solanaceae) grown within an experimental plot located near Saltillo, Mexico. This study had three primary objectives: 9i) determine whether the foliar symptoms observed on tomatillo were associated with 'Ca. L. solanacearum' infection, (ii) identify the haplotypes of 'Ca. L. solanacearum' and potato psyllids present in the symptomatic plot, and (iii) use gut content analysis to infer the plant sources of 'Ca. L. solanacearum'-infected psyllids. Results confirmed that 71% of symptomatic plants and 71% of psyllids collected from the plants were infected with 'Ca. L. solanacearum'. The detection of 'Ca. L. solanacearum' in plants and psyllids and the lack of nymphal populations associated with psyllid yellows strongly suggests that the observed foliar symptoms were caused by 'Ca. L. solanacearum' infection. All infected plants and insects harbored the more virulent 'Ca. L. solanacearum' haplotype B but one psyllid was also coinfected with haplotype A. The potato psyllids were predominantly of the central haplotype but one psyllid was identified as the western haplotype. Molecular gut content analysis of psyllids confirmed the movement of psyllids between noncrop habitats and tomatillo and indicated that 'Ca. L. solanacearum' infection of psyllids was associated with increased plant diversity in their diet.
Assuntos
Physalis , Rhizobiaceae , Solanum tuberosum , Liberibacter , México , Doenças das Plantas , Rhizobiaceae/genética , SolanalesAssuntos
Animais , Vespas , Solanum lycopersicum , Himenópteros , Lepidópteros , Mariposas , Óvulo , Brasil , Controle Biológico de Vetores , SolanalesRESUMO
BACKGROUND: The South American tree Solanum mauritianum Scopoli (Solanaceae) is a problematic invasive plant in numerous tropical, subtropical and temperate regions around the globe. Because conventional management approaches are not cost-effective, biological control provides an alternative approach. Gargaphia decoris Drake (Tingidae) is currently used as a biological control agent in South Africa and New Zealand. Considering the importance of climate in the establishment and success of a biological control agent, this study used ecological niche models (ENM) to identify areas where S. mauritianum is a problematic invader and where suitable conditions exist for G. decoris. Additionally, the climate niche dynamics of G. decoris were investigated and ENMs projected worldwide for the year 2050 were built. RESULTS: Our results indicate that most of the countries where S. mauritianum is problematic have suitable climatic conditions for G. decoris, and that the species can survive in climates with temperatures lower than those in its native range. For future climates, ENMs predict wider regions with favourable climatic conditions for G. decoris. CONCLUSION: Considering the results of this study, the prospects of using G. decoris as a biological control agent are good under current and future climates. Introduction of this agent could be considered in affected countries where it has not been released. © 2019 Society of Chemical Industry.