Effects of the nematode Phasmarhabditis hermaphrodita and of venom from the endoparasitic wasp Pimpla hypochondriaca on survival and food consumption of the pest slug Deroceras reticulatum; implications for novel biocontrol strategies

BACKGROUND: Controlling pests through disruption of biochemical pathways by physiologically active compounds/factors from animals and plants represents an expanding field of research. The authors investigated whether such factors in venom from the wasp Pimpla hypochondriaca (Retzius) can affect the viability and food consumption of the slug Deroceras reticulatum (Müller), and whether they can improve the efficacy of nematode-induced slug mortality. RESULTS: Exposure of slugs to 4 mL of water containing 500, 1000 and 5000 Phasmarhabditis hermaphrodita (Schneider) resulted in significant increases in mortality (with hazard ratios of 3.5, 3.9 and 5.8 respectively) and significant reductions in total food consumption and mean food consumption each day for 21 days. Injection of slugs with 4, 8 or 12 microL of P. hypochondriaca venom resulted in significant increases in mortality (with hazard ratios of 3.3, 4.5 and 9.0 respectively) and significant reductions in total food consumption compared with the controls. However, there was no significant effect of venom on the mean food consumption on individual days of the 21 day assay period, although significant reductions occurred for the 8 and 12 microL doses up to day 10. Injecting slugs with 4 microL of venom prior to exposure to 500 nematodes had no synergistic effect on either mortality or food consumption compared with either of the individual treatments. CONCLUSIONS: Pimpla hypochondriaca venom contains factors capable of killing and reducing food consumption by D. reticulatum. The utilization of these factors as components of integrated pest management strategies is discussed.     

绿色生态豪宅——著名室内设计大师提摩西·克里根专访

提摩西·克里根(Timothy Corrigan)被国外多家媒体称为当今时尚先锋,他一直致力于创造一个融合了浓郁的欧式典雅风格与加州的休闲舒适氛围的居住环境。他在洛杉矶和巴黎都设有办事处,负责世界各地的建筑项目。除了提供设计服务之外,     

New invasion of <Emphasis Type="Italic">Bemisia tabaci</Emphasis> Mediterranean species in Brazil associated to ornamental plants

In Brazil, the first major invasion event of Bemisia tabaci was that of Middle East–Asia Minor 1 (MEAM1) species, formerly termed as B biotype, which commenced in the 1990s mainly by ornamental plants in São Paulo State. More than two decades after this invasion, the presence of the Mediterranean (MED) species of B. tabaci, formerly Q biotype, was reported in Rio Grande do Sul, the southernmost State of Brazil, and now in São Paulo and Paraná States, in southeastern Brazil. Specimens of whiteflies collected from commercial begonia, hydrangea, petunia and poinsettia greenhouses in São Paulo, and also from begonias and poinsettias collected in flower shops in Paraná, were all identified as belonging to MED species. Furthermore, the secondary endosymbionts Arsenophonus, Hamiltonella and Rickettsia of MED from São Paulo and Paraná were detected by PCR and their presence confirmed by sequencing and FISH analysis, and those results differed from MED detected in Rio Grande do Sul that harbored only Hamiltonella and Cardinium. Our results suggest a new MED invasion into Brazil and is associated with ornamental plants. The two MED populations are genetically different and suggest that they are separate invasions.     

Development of a new humane toxin for predator control in New Zealand

The endemic fauna of New Zealand evolved in the absence of mammalian predators and their introduction has been responsible for many extinctions and declines. Introduced species including possums (Trichosurus vulpecula Kerr), ship rats (Rattus rattus L.) and stoats (Mustela erminea L.) are targeted to protect native birds. Control methodologies currently rely largely on labor-intensive trapping or the use of increasingly unpopular poisons, or poisons that are linked with low welfare standards. Hence, the development of safer humane predator toxins and delivery systems is highly desirable. Para-aminopropiophenone (PAPP) is being developed as a toxin for feral cats (Felis catus L.) and stoats. Carnivores appear to be much more susceptible to PAPP than birds, so it potentially has high target specificity, at least in New Zealand. Pen trials with 20 feral cats and 15 stoats have been undertaken using meat baits containing a proprietary formulation of PAPP. A PAPP dose of 20–34 mg kg⁻¹ was lethal for feral cats and 37–95 mg kg⁻¹ was lethal for stoats. Our assessments suggest that PAPP, for the control of feral cats and stoats, is a humane and effective toxin. PAPP causes methaemoglobinaemia, resulting in central nervous system anoxia, lethargy and death.     

Insecticidal activity of scorpion toxin (ButaIT) and snowdrop lectin (GNA) containing fusion proteins towards pest species of different orders

BACKGROUND: The toxicity of a fusion protein, ButalT/GNA, comprising a venom toxin (ButaIT) derived from the red scorpion, Mesobuthus tamulus (F.), and Galanthus nivalis agglutinin (GNA), was evaluated under laboratory conditions against several pest insects. Insecticidal activity was compared with SFI1/GNA, a fusion comprising a venom toxin (SFI1) derived from the European spider Segestria florentina (Rossi) and GNA, which has been previously demonstrated to be effective against lepidopteran and hemipteran pests, and to GNA itself. RESULTS: Injection assays demonstrated that both fusion proteins were toxic to lepidopteran larvae, dipteran adults, coleopteran adults and larvae and dictyopteran nymphs. ButalT/GNA was more toxic than SFI1/GNA in all cases. GNA itself made a minor contribution to toxicity. Oral toxicity of ButalT/GNA towards lepidopteran pests was confirmed against neonate Spodoptera littoralis (Boisd.), where incorporation at 2% dietary protein resulted in 50% mortality and > 85% reduction in growth compared with controls. ButaIT/GNA was orally toxic to Musca domestica L. adults, causing 75% mortality at 1 mg mL^?1 in aqueous diets and, at 2 mg g^?1 it was orally toxic to Tribolium castaneum (Herbst.), causing 60% mortality and a 90% reduction in growth. CONCLUSIONS: Toxicity of the ButaIT/GNA recombinant fusion protein towards a range of insect pests from different orders was demonstrated by injection bioassays. Feeding bioassays demonstrated the potential use of the ButaIT/GNA fusion protein as an orally active insecticide against lepidopteran, dipteran and coleopteran pests. These experiments provide further evidence that the development of fusion protein technology for the generation of new, biorational, anti‐insect molecules holds significant promise. © Crown Copyright 2009. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.     

Mapping genomic regions for reproductive traits in beef cattle: Inclusion of the X chromosome

Although the second largest chromosome of the genome, the X chromosome is usually excluded from genome-wide association studies (GWAS). Considering the presence and importance of genes on this chromosome that are involved in reproduction, the aim of this study was to evaluate the effect of its inclusion in GWAS on reproductive traits (scrotal circumference [SC], early pregnancy [P16] and age at first calving [AFC]) in a Nelore herd. Genotype data from 3,263 animals with the above-mentioned phenotypes were used. The results showed an increase in the variances explained by the autosomal markers for all traits when the X chromosome was not included. For SC, there was an increase of more than 10% for the windows on chromosomes 2 and 6. For P16, the effect was increased by almost 20% for windows on chromosome 5. The same pattern was found for AFC, with an increase of more than 10% for the most important windows. The results indicate that the noninclusion of the X chromosome can overestimate the effects of autosomes on SC, P16 and AFC not only because of the additive effect of the X chromosome itself but also because of its epistatic effect on autosomal genes.     

Impacts of the nitrogen application on productivity and nutrients concentrations of the corn-Congo grass intercropping system in the dry season

ABSTRACT

The corn-grass intercropping system began to be used in the dry season, as it provides increased straw production for the no-tillage system. However, corn and grass are plants demanding in nitrogen. The corn cultivated in the dry season is called out-of-season corn in Brazil. The objective of this study was to evaluate the productivity and nutrients concentrations of out-of-season corn and Congo-grass intercropped in the no-tillage system, as a function of the nitrogen rates applied in sidedressing. The treatments were four nitrogen rates, 0, 30, 60 and 90?kg?ha^?1. The experimental design was randomised complete blocks with four replicates. The experimental period corresponded to the harvests of 2015 and 2016. There were evaluated: corn grain yield, dry mass production and nutrient concentration in the shoots of the plants intercropped. The evaluations were carried out at the physiological maturity stage of the corn and at the time of desiccation of the grass. Nitrogen increased grain yield and dry mass production of the plants intercropped. Nitrogen maximised the magnesium concentration in out-of-season corn and the nitrogen, calcium, magnesium and sulphur concentrations in Congo grass. Excess nitrogen promoted reduction of the phosphorus in the Corn-Congo grass intercropping system in the dry season.