Performance of trichogrammatids as biocontrol agents of Pseudoplusia includens Walker (Lepidoptera: Noctuidae)

Este estudo objetivou selecionar as linhagens de tricogramatídeos mais adequadas ao controle da lagarta falsa-medideira, Pseudoplusia includens Walker. Foram avaliados os parâmetros biológicos e a taxa de parasitismo de 11 linhagens de Trichogramma pretiosum Riley, uma linhagem de Trichogramma atopovirilia Oatman & Platner e uma linhagem de Trichogrammatoidea annulata De Santis, criadas em ovos de P. includens. Entre as espécies/linhagens avaliadas, a linhagem T. pretiosum RV, coletada em Rio Verde, GO, apresentou o ciclo de desenvolvimento mais rápido e a maior porcentagem de parasitismo em ovos de P. includens. Não houve diferença no parasitismo e no número de parasitóides emergidos por ovo entre as espécies e linhagens de parasitóides avaliadas. De acordo com a análise de agrupamento (cluster analysis), a linhagem RV criada em ovos de P. includens teve o melhor desempenho. Apresentou maior taxa de parasitismo, menor duração do ciclo biológico, alta sobrevivência e predominância de fêmeas, sendo a mais indicada a ser utilizada em liberações de campo visando ao controle de P. includens.This research aimed to point out the most suitable trichogrammatid strains to control the soybean looper Pseudoplusia includes Walker. Biological parameters and parasitism ratio of 11 Trichogramma pretiosum Riley, one Trichogramma atopovirilia Oatman & Platner and one Trichogrammatoidea annulata De Santis strains reared on P. includens eggs were evaluated. Among all tested strains/species, T. pretiosum strain RV, collected in Rio Verde, GO, had the fastest development cycle and the highest percentage of parasitism of P. includens eggs. There was no difference in the parasitism and in the number of parasitoid emerged per egg among the tested parasitoid species and strains. Accordingly to the cluster analysis, T. pretiosum strain RV reared on P. includens eggs had the best performance. Considering the higher parasitism rate, shorter biological cycle, higher survival and sex ratio, T. pretiosum strain RV is the most appropriated to be used in field releases aiming at P. includens control

Parasitismo natural de <i>Spodoptera frugiperda</i> em milho

Avaliou-se a freqüência e diversidade de parasitoides associados a larvas de Spodoptera frugiperda. Para tanto, foram realizadas amostragens em campos experimentais de milho da Embrapa Soja (Londrina, PR, Brasil), no ano agrícola 2013. Duas áreas foram amostradas, e em cada uma delas foram coletadas aproximadamente de 230 larvas, compreendendo os estádios fenológicos V3 a V12. As larvas foram criadas em laboratório a 25±2ºC, UR 70±10% e fotoperíodo de 14 horas, sendo alimentadas com dieta artificial e observadas diariamente. Os parasitoides mais freqüentes foram: Chelonus insulares (Cresson) (Hymenoptera: Braconidae), Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) e Archytas marmoratus (Townsend) (Diptera: Tachinidae). Foi observado que o parasitismo total foi de 26% na área 1 e 31,7% na área 2. Os parasitoides pertencentes a ordem Diptera foram mais abundantes na área 1 (76,5%), em contrapartida, na área 2, foram mais abundantes os parasitoides da ordem Hymenoptera (98,6%).We evaluated the frequency and diversity of parasitoids associated with Spodoptera frugiperda larvae. For both, samples were collected in experimental corn fields of Embrapa Soja (Londrina, PR, Brazil), in the agricultural year 2013. Two areas were sampled, and each were collected approximately of 230 larvae, comprising the phenological stages V3-V12. The larvae were reared in the laboratory at 25±2°C, RH: 70±10% and photoperiod: 14 hours, being fed with artificial diet and observed daily. The most frequent parasitoids were Chelonus insulares (Cresson) (Hymenoptera: Braconidae), Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) and Archytas marmoratus (Townsend) (Diptera: Tachinidae). It was observed that the total parasitism was 26% in area 1 and 31.7% in the area 2. Parasitoids belonging to order Diptera were more abundant in the area 1 (76.5%), on the other hand, in area 2, were more abundant parasitoids of the order Hymenoptera (98.6%).Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Parasitismo natural de <i>Spodoptera frugiperda</i> em milho

Avaliou-se a freqüência e diversidade de parasitoides associados a larvas de Spodoptera frugiperda. Para tanto, foram realizadas amostragens em campos experimentais de milho da Embrapa Soja (Londrina, PR, Brasil), no ano agrícola 2013. Duas áreas foram amostradas, e em cada uma delas foram coletadas aproximadamente de 230 larvas, compreendendo os estádios fenológicos V3 a V12. As larvas foram criadas em laboratório a 25±2ºC, UR 70±10% e fotoperíodo de 14 horas, sendo alimentadas com dieta artificial e observadas diariamente. Os parasitoides mais freqüentes foram: Chelonus insulares (Cresson) (Hymenoptera: Braconidae), Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) e Archytas marmoratus (Townsend) (Diptera: Tachinidae). Foi observado que o parasitismo total foi de 26% na área 1 e 31,7% na área 2. Os parasitoides pertencentes a ordem Diptera foram mais abundantes na área 1 (76,5%), em contrapartida, na área 2, foram mais abundantes os parasitoides da ordem Hymenoptera (98,6%).We evaluated the frequency and diversity of parasitoids associated with Spodoptera frugiperda larvae. For both, samples were collected in experimental corn fields of Embrapa Soja (Londrina, PR, Brazil), in the agricultural year 2013. Two areas were sampled, and each were collected approximately of 230 larvae, comprising the phenological stages V3-V12. The larvae were reared in the laboratory at 25±2°C, RH: 70±10% and photoperiod: 14 hours, being fed with artificial diet and observed daily. The most frequent parasitoids were Chelonus insulares (Cresson) (Hymenoptera: Braconidae), Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) and Archytas marmoratus (Townsend) (Diptera: Tachinidae). It was observed that the total parasitism was 26% in area 1 and 31.7% in the area 2. Parasitoids belonging to order Diptera were more abundant in the area 1 (76.5%), on the other hand, in area 2, were more abundant parasitoids of the order Hymenoptera (98.6%).Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Parasitismo natural de <i>Spodoptera frugiperda</i> em milho

Avaliou-se a freqüência e diversidade de parasitoides associados a larvas de Spodoptera frugiperda. Para tanto, foram realizadas amostragens em campos experimentais de milho da Embrapa Soja (Londrina, PR, Brasil), no ano agrícola 2013. Duas áreas foram amostradas, e em cada uma delas foram coletadas aproximadamente de 230 larvas, compreendendo os estádios fenológicos V3 a V12. As larvas foram criadas em laboratório a 25±2ºC, UR 70±10% e fotoperíodo de 14 horas, sendo alimentadas com dieta artificial e observadas diariamente. Os parasitoides mais freqüentes foram: Chelonus insulares (Cresson) (Hymenoptera: Braconidae), Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) e Archytas marmoratus (Townsend) (Diptera: Tachinidae). Foi observado que o parasitismo total foi de 26% na área 1 e 31,7% na área 2. Os parasitoides pertencentes a ordem Diptera foram mais abundantes na área 1 (76,5%), em contrapartida, na área 2, foram mais abundantes os parasitoides da ordem Hymenoptera (98,6%).We evaluated the frequency and diversity of parasitoids associated with Spodoptera frugiperda larvae. For both, samples were collected in experimental corn fields of Embrapa Soja (Londrina, PR, Brazil), in the agricultural year 2013. Two areas were sampled, and each were collected approximately of 230 larvae, comprising the phenological stages V3-V12. The larvae were reared in the laboratory at 25±2°C, RH: 70±10% and photoperiod: 14 hours, being fed with artificial diet and observed daily. The most frequent parasitoids were Chelonus insulares (Cresson) (Hymenoptera: Braconidae), Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) and Archytas marmoratus (Townsend) (Diptera: Tachinidae). It was observed that the total parasitism was 26% in area 1 and 31.7% in the area 2. Parasitoids belonging to order Diptera were more abundant in the area 1 (76.5%), on the other hand, in area 2, were more abundant parasitoids of the order Hymenoptera (98.6%).Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Does the Establishment of Sustainable Use Reserves Affect Fire Management in the Humid Tropics?

Tropical forests are experiencing a growing fire problem driven by climatic change, agricultural expansion and forest degradation. Protected areas are an important feature of forest protection strategies, and sustainable use reserves (SURs) may be reducing fire prevalence since they promote sustainable livelihoods and resource management. However, the use of fire in swidden agriculture, and other forms of land management, may be undermining the effectiveness of SURs in meeting their conservation and sustainable development goals. We analyse MODIS derived hot pixels, TRMM rainfall data, Terra-Class land cover data, socio-ecological data from the Brazilian agro-census and the spatial extent of rivers and roads to evaluate whether the designation of SURs reduces fire occurrence in the Brazilian Amazon. Specifically, we ask (1) a. Is SUR location (i.e., de facto) or (1) b. designation (i.e. de jure) the driving factor affecting performance in terms of the spatial density of fires?, and (2), Does SUR creation affect fire management (i.e., the timing of fires in relation to previous rainfall)? We demonstrate that pre-protection baselines are crucial for understanding reserve performance. We show that reserve creation had no discernible impact on fire density, and that fires were less prevalent in SURs due to their characteristics of sparser human settlement and remoteness, rather than their status de jure. In addition, the timing of fires in relation to rainfall, indicative of local fire management and adherence to environmental law, did not improve following SUR creation. These results challenge the notion that SURs promote environmentally sensitive fire-management, and suggest that SURs in Amazonia will require special attention if they are to curtail future accidental wildfires, particularly as plans to expand the road infrastructure throughout the region are realised. Greater investment to support improved fire management by farmers living in reserves, in addition to other fire users, will be necessary to help ameliorate these threats