ABSTRACT
The phloem-limited bacteria, "Candidatus Liberibacter asiaticus" and "Ca. L. americanus", are the causal pathogens responsible for Huanglongbing (HLB). The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the principal vector of these "Ca. Liberibacter" species. Though Tamarixia radiata Waterston (Hymenoptera: Eulophidae) has been useful in biological control programmes against D. citri, information on its global distribution remains vague. Using the Climate Change Experiment (CLIMEX) model, the potential global distribution of T. radiata under the 2050s, 2070s, and 2090s for Special Report on Emissions Scenarios A1B and A2 was defined globally. The results showed that habitat suitability for T. radiata covered Africa, Asia, Europe, Oceania, and the Americas. The model predicted climate suitable areas for T. radiata beyond its presently known native and non-native areas. The new locations predicted to have habitat suitability for T. radiata included parts of Europe and Oceania. Under the different climate change scenarios, the model predicted contraction of high habitat suitability (EI > 30) for T. radiata from the 2050s to the 2090s. Nevertheless, the distribution maps created using the CLIMEX model may be helpful in the search for and release of T. radiata in new regions.
Subject(s)
Citrus , Hemiptera , Rhizobiaceae , Wasps , Animals , Climate Change , Hemiptera/microbiology , Pest Control, Biological , Plant DiseasesABSTRACT
The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an efficient vector of "Candidatus Liberibacter" species, the causative agents implicated in citrus greening or huanglongbing (HLB). HLB is the most devastating citrus disease and has killed millions of citrus trees worldwide. Classical biological control using Tamarixia radiata Waterston (Hymenoptera: Eulophidae) against ACP has been successful in some regions. Climatic conditions are critical in determining suitable areas for the geographical distribution of T. radiata. However, paucity of information on climate change impacts on the global spread of T. radiata restricts international efforts to manage ACP with T. radiata. We investigated the potential global distribution of T. radiata using 317 native and non-native occurrence records and 20 environmental data sets (with correlation coefficients (|r| > 0.7)). Using the Maximum Entropy model, these data were analyzed for two shared socioeconomic pathways (SSPs) and two time periods (2030s and 2050s). We showed that habitat suitability for T. radiata occurred in all continents except Antarctica. However, the highly suitable areas for T. radiata were found in parts of the Americas, Asia, Africa and Oceania. The climate suitable areas would increase until the 2050s. The predictions showed that mean temperature of coldest quarter and precipitation of warmest quarter were the most important environmental variables that influenced the distribution of T. radiata. The model reliably predicted habitat suitability for T. radiata, which can be adapted in classical biological control programs to effectively manage ACP in an environmentally friendly manner.
Subject(s)
Climate Change , Wasps , Animals , Citrus , Hemiptera , Pest Control, Biological , Plant Diseases , TemperatureABSTRACT
Frankliniella schultzei (Trybom) is a serious pest of melon crops and is commonly found in the main producing areas of melon in Brazil (North and Northeast regions). This pest causes significant losses, damaging plants through feeding and tospovirus vectoring. Thus, the proper management of F. schultzei is crucial to prevent economic losses, and knowledge of the within-field distribution patterns of F. schultzei can be used to improve this pest management. This study aimed to determine the within-field distribution (through semivariogram modeling and kriging interpolation) and the factors associated with F. schultzei abundance in open-field yellow melon crops. We surveyed four yellow melon fields located in Formoso do Araguaia (Tocantins state, North Brazil) for thrips abundance in various crop stages (vegetative, flowering, and fruiting) in 2015 and 2016. Twelve models were fitted and it was determined that F. schultzei counts were strongly aggregated. The median spatial dependence was 4.79 m (range 3.55 to 8.02 m). The surface maps generated by kriging depicted an edge effect in fields 3 and 4. In addition, correlation analyses indicated that air temperature and presence of surrounding cucurbits are positively associated with F. schultzei abundance in yellow melon fields. Altogether, these insights can be combined for spatially based pest management, especially when the conditions (cucurbits in the surroundings and warmer periods) are favorable to F. schultzei.
Subject(s)
Cucurbitaceae , Thysanoptera , Tospovirus , Animals , Brazil , Pest ControlABSTRACT
Objetivo: descrever duas complicaçöes raras de otite média aguda tratada inadequadamente. Método: descriçäo de um caso de duas complicaçöes simultâneas de otite média aguda em um menino de 12 anos e realizaçäo de revisäo da literatura. Resultados: Um paciente masculino, branco, de 12 anos, veio encaminhado de outro serviço por apresentar quadro de otite há dois meses, näo responsivo ao tratamento clínico, evoluindo com massa cervical à direita. O exame clínico demonstrou membrana timpânica espessada e opacificada à direita, com discreto aumento da vascularizaçäo. O estudo radiológico evidenciou processo inflamatório/infeccioso, envolvendo regiäo mastóidea direita, com aspecto de múltiplos abscessos, estendendo-se extracranialmente para regiäo cervical e presença de alteraçöes sugestivas de flebite, envolvendo seios transverso e sigmóide direitos. Após ser submetido à cirurgia e antibioticoterapia endovenosa, o paciente apresentou boa evoluçäo, com baixa morbidade. Conclusäo: Apesar da baixa incidência de complicaçöes das otites médias, devido ao avanço e uma maior abrangência no espectro da antibioticoterapia, näo podemos nos abster da sua existência
