Establishment, persistence and local dispersal of the entomopathogenic fungi Metarhizium anisopliae (ESALQ1037) and M. robertsii (ESALQ1426) (Ascomycota: Hypocreales) were investigated in the soil and rhizosphere following soil drench application in strawberries between 2012 and 2013 at a single location in Inconfidentes, Minas Gerais, Brazil. Metarhizium spp. isolates (n = 108) were collected using selective agar media and insect bait methods, and characterized by sequence analyses of the 5'-end of the translation elongation factor 1-a and the MzFG543igs intergenic region and by multilocus simple sequence repeat analysis. Both applied fungal isolates were frequently recovered from bulk soil and rhizosphere samples of the treated plots, suggesting that they were able to establish and disperse within the soil. Persistence within the soil and strawberry rhizosphere for both fungal isolates was observed up to 12 months after application with frequencies of 25% of haplotypes similar to isolate ESALQ1037 and 87.5% of haplotypes similar to isolate ESALQ1426, respectively. Overall, M. robertsii was the most abundant species in the agroecosystem studied representing 77.8% of the isolates recovered across all sample dates. 2016 Elsevier B.V. All rights reserved.

Insecticides derived from the bacterium Bacillus thuringiensis (Bt) and plants genetically modified (GM) to express B. thuringiensis toxins are important alternatives for insect pest control worldwide. Risk assessment of B. thuringiensis toxins to non-target organisms has been extensively studied but few toxicological tests have considered soil invertebrates. Oribatid mites are one of the most diverse and abundant arthropod groups in the upper layers of soil and litter in natural and agricultural systems. These mites are exposed to the toxic compounds of GM crops or pesticides mainly when they feed on vegetal products incorporated in the soil. Although some effects of B. thuringiensis products on Acari have been reported, effects on oribatid mites are still unknown. This study investigated the effects of the ingestion of Bt cotton Bollgard and of the B. thuringiensis commercial product Dipel WP on the pantropical species Scheloribates praeincisus (Scheloribatidae). Ingestion of Bollgard and Dipel did not affect adult and immature survivorship and food consumption (estimated by number of fecal pellets produced daily) or developmental time of immature stages of S. praeincisus. These results indicate the safety of Bollgard and Dipel to S. praeincisus under field conditions where exposition is lower and other food sources besides leaves of Bt plants are available. The method for toxicological tests described here can be adapted to other species of Oribatida, consisting on a new option to risk assessment studies.

The two-spotted spider mite Tetranychus urticae is an important pest of strawberry crops in Brazil and many other countries. Focus for biocontrol studies involving entomopathogenic fungi has been on three species from the genus Metarhizium: M. anisopliae sensu stricto (s.s.), M. brunneum and M. robertsii. Also, the species Beauveria bassiana has been studied for spider mite control and one isolate (ESALQPL63) is commercially available in Brazil. New and undescribed Metarhizium species have been found recently in Brazil and provide a pool of isolates with potential for biocontrol in Brazil and probably also elsewhere. The mortality of adult females of T. urticae when exposed to four new Brazilian species of Metarhizium was compared to the mortality when exposed to M. anisopliae s.s., M. brunneum, M. pingshaense, M. robertsii and Beauveria bassiana ESALQPL63. Fungal suspensions were sprayed onto mites at 10 conidia/mL with 0.05% Tween 80 in laboratory bio-assays. We measured total mortality and percentage sporulating cadavers 10 days after exposure and calculated median lethal time (LT). The lowest LT (4.0 ± 0.17) was observed for mites treated with Metarhizium sp. Indet. 1 (ESALQ1638), which also performed well with respect to mortality after 10 days and capacity to sporulate from cadavers. Among the other little studied species tested, M. pingshaense (ESALQ3069 and ESALQ3222) and Metarhizium Indet. 2 (ESALQ1476) performed well and were comparable to B. bassiana (ESALQPL63). The new Metarhizium isolates and species thus showed potential for biological control.

The objective of this study was to determine the effects of light intensity and duration (photoperiod) on the sporulation (discharge of primary conidia) and conidia germination (from non-infective primary conidia to infective capilliconidia) of Neozygites floridana isolates from Tetranychus urticae originating from Norway and Brazil. Two light intensities (40 and 208 μmolm(-2)s(-1)), three photoperiods (24 h of continuous light (24 h D), 12 h of darkness followed by 12 h of light (12 h D: 12 h L) and 24 h of continuous darkness (24 h D)) and two temperatures (18°C and 23°C) were tested. The fungus produced similar amounts of primary conidia and capilliconidia at 12 h D:12 h and 24 h D, indicating that the fungus discharges almost all of its conidia during the first 12 h of darkness. Light had less of an effect on the production of primary conidia than on capilliconidia formation. At 24 h L, capilliconidia formation was significantly lower for all tested light intensities, temperatures and isolates compared to 12 h D:12 h L and 24 h D. At both light intensities, 24 h L resulted in a significantly lower capilliconidia formation for the Norwegian isolate compared to the Brazilian isolate. Our data suggest that, even though 24 h L reduced sporulation, some capilliconidia formation may occur at the low light intensities found on the underside of strawberry leaves during parts of the day as well as the top of a non-shaded strawberry leaf during the dim evening and morning hours in the tropics and during the dim, long summer days in temperate regions.

Neozygites floridana is a pathogenic fungus and natural enemy of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), which is an important polyphagous plant pest. The aim of this study was to reveal and predict what combination of temperature, relative humidity (RH), and time that enables and promotes primary conidia production and capilliconidia formation in N. floridana (Brazilian isolate ESALQ 1420), in both a detached leaf assay mimicking climatic conditions in the leaf boundary layer and in a semi-field experiment. In the detached leaf assay, a significant number of conidia were produced at 90% RH but the highest total number of primary conidia and proportion of capilliconidia was found at 95 and 100% RH at 25 °C. Positive temperature and RH effects were observed and conidia production was highest in the 8 to 12 h interval. The semi-field experiment showed that for a >90% probability of N. floridana sporulation, a minimum of 6 h with RH >90% and 10 h with temperatures >21 °C, or 6 h with temperatures >21 °C and 15 h with RH >90% was needed. Our study identified suitable conditions for primary- and capilliconidia production in this Brazilian N. floridana isolate. This information provides an important base for building models of a Decision Support System (DSS) where this natural enemy may be used as a tool in Integrated Pest Management (IPM) and a base for developing in vivo production systems of N. floridana.

Foi objetivo avaliar a inclusão de coprodutos do crambe na dieta de bezerros sobre o consumo e digestibilidade dos nutrientes. Foram utilizados oito bezerros Nelore desmamados, fistulados no rúmen, com peso corporal médio inicial de 177±5,1 kg, mantidos em baias individuais e com acesso irrestrito a água ea mistura mineral. Os animais foram distribuídos em dois quadrados latinos 4×4, sendo testados a torta de crambe no quadrado latino 1 e o farelo de crambe no quadrado latino 2, incluídos nas proporções de 0, 5,10 e 15% na base da matéria seca em dietas contendo 73% de feno de tifton 85 e 27% de concentrado à base de fubá de milho, farelo de soja e torta ou farelo de crambe. O experimento foi constituído de quatro períodos experimentais, com 18 dias cada, sendo os cinco primeiros dias destinados à adaptação dos animais ao tratamento e do 6o ao 10o dia para coleta de amostras. O consumo de matéria seca, de matéria orgânica, de proteína bruta, de fibra detergente neutro e de carboidratos não fibrosos não diferiu entre os diferentes níveis de inclusão de torta ou farelo de crambe, mas houve redução da digestibilidade com aumento do farelo de crambe na maioria das vezes.

The aim of this study was to investigate the impact of reduced dietary non-phytate phosphorus (nPP) or nPP and calcium (Ca) concentrations in diets supplemented with phytase on performance, bone mineralisation and serum parameters of weaned piglets from 28 to 63 days of age. A total of 168 barrows and gilts, weaned at 28 days of age, with an average initial bodyweight of 8.11 ± 0.61 kg were randomly allocated in a completely randomised block design. Treatments consisted of a positive control and an additional six treatments, in a 3 × 2 factorial arrangement, totalling seven treatments (Trt). The positive control (PC) diet was formulated to meet or exceed the nutrient requirements of pigs weighing 8–30 kg bodyweight, without phytase supplementation, and the six other diets were formulated similar to the PC, except with a reduction in the nPP concentration of 0.065, 0.130 or 0.195% (Phase Feeding 1 (PF1), PF2 or PF3 respectively) or similar to PF1, PF2 and PF3 minus 0.16% Ca, supplemented with 2000 FTU/kg of phytase, with eight replicate pens/Trt of three piglets each, in a three-phase feeding program. From Day 28 to Day 35, the average daily gain was higher (P < 0.05) and the feed conversion rate was lower (P < 0.05) respectively for piglets fed the PC when compared with those fed PF3 and PC treatment minus 0.160% calcium and minus 0.195% nPP (PF6). In contrast, when evaluating the period from Day 28 to 49, piglets fed PC presented the highest average daily gain, but only differed (P < 0.05) to those fed PF3 and PF6. When considering the overall period, at 63 days of age, no significant difference was detected (P > 0.05) between the PF Trts tested and the PC regarding performance. As for bone mineralisation at 63 days, bone P (BP) decreased as nPP in the diet decreased, regardless of the Ca level. However, except for PF3 and PF6, BP and third metacarpal bone ash concentration were respectively higher for pigs fed the PF Trts, when compared with PC. All treatments containing phytase resulted in a lower bone Ca:BP ratio when compared with PC. Serum P concentrations decreased as nPP in the diet decreased, regardless of the level of dietary Ca. However, with the exception of PF3 and PF6, serum P was not significantly different than pigs fed the PC. In conclusion, reducing nPP or nPP and Ca in diets containing 2000 FTU Ronozyme® HiPhos/kg phytase had no adverse effects on growth performance and increased BP and third metacarpal bone ash concentration compared with pigs fed a nutritionally adequate control diet.

The insecticides/ acaricides abamectin and lambda-cyhalothrin at half concentrations and fenpropathrin and permethrin and the fungicide tebuconazole at the recommended concentrations resulted in the lowest impact on N. floridana. The fungicides with the active ingredients sulfur, cyprodinil + fludioxonil, azoxystrobin, azoxystrobin + cyproconazole, trifloxystrobin + tebuconazole and pyraclostrobin + epoxiconazole negatively affected N. floridana. © 2015 Society of Chemical Industry.