Banker Plant Bonuses? The Benefits and Risks of Including Brassicas in Field Margins to Promote Conservation Biocontrol of Specialist Pests in Oilseed Rape.

European agri-environment schemes include the use of flower-rich field margins to promote on-farm biodiversity, but species mixtures rarely include Brassicaceae. As pests of oilseed rape (OSR; Brassica napus) and their parasitoids are mostly brassica specialists, including brassica 'banker plants' in the mixtures would help support these important biocontrol agents and improve pest control throughout the crop rotation. We assessed the potential of six brassicaceous plants (replicated plots grown in the field) to enhance populations of parasitoids of OSR pests whilst minimising proliferation of their pest hosts. Fodder radish (Raphanus sativus) facilitated high production of parasitoids of the pollen beetle pest (Brassicogethes aeneus) but may proliferate Ceutorhynchus weevil pests due to low parasitism. Turnip rape (B. rapa) and the B. rapa hybrid 'Tyfon' showed potential to perform a trap cropping function for pests, but their early flowering phenology resulted in B. aeneus larvae escaping parasitisation, potentially assisting proliferation of this pest. Forage rape B. napus exhibited similarly high B. aeneus parasitoid production characteristics to R. sativus but did not potentiate problems with other pests, indicating that it would be a favourable banker plant option. Careful selection of plants in field margin mixtures is therefore needed to maximise their benefits and ideally the whole crop pest-beneficial complex needs to be studied, as focus on a single major pest risks unintended consequences with other pest problems.

The potential of decision support systems to improve risk assessment for pollen beetle management in winter oilseed rape.

BACKGROUND: The reliance on and extensive use of pyrethroid insecticides have led to pyrethroid resistance in pollen beetle (Meligethes aeneus). Widespread adoption of best practice in pollen beetle management is therefore needed. Decision support systems (DSSs) that identify the risk period(s) for pest migration can help to target monitoring and control efforts, but they must be accurate and labour efficient to gain the support of growers. Weather data and the phenology of pollen beetles in 44 winter oilseed rape crops across England over 4 years were used to compare the performance of two risk management tools: the DSS proPlant expert, which predicts migration risk according to a phenological model and local weather data, and 'rule-based advice', which depends on crop growth stage and a temperature threshold. RESULTS: Both risk management tools were effective in prompting monitoring that would detect breaches of various control thresholds. However, the DSS more accurately predicted migration start and advised significantly fewer days of migration risk, consultation days and monitoring than did rule-based advice. CONCLUSION: The proPlant expert DSS reliably models pollen beetle phenology. Use of such a DSS can focus monitoring effort to when it is most needed, facilitate the practical use of thresholds and help to prevent unnecessary insecticide applications and the development of insecticide resistance.

Temperature-activity relationships in Meligethes aeneus: implications for pest management.

BACKGROUND: Pollen beetle (Meligethes aeneus F.) management in oilseed rape (Brassica napus L.) has become an urgent issue in the light of insecticide resistance. Risk prediction advice has relied upon flight temperature thresholds, while risk assessment uses simple economic thresholds. However, there is variation in the reported temperature of migration, and economic thresholds vary widely across Europe, probably owing to climatic factors interacting with beetle activity and plant compensation for damage. The effect of temperature on flight, feeding and oviposition activity of M. aeneus was examined in controlled conditions. RESULTS: Escape from a release vial was taken as evidence of flight and was supported by video observations. The propensity to fly followed a sigmoid temperature-response curve between 6 and 23 °C; the 10, 25 and 50% flight temperature thresholds were 12.0-12.5 °C, 13.6-14.2 °C and 15.5-16.2 °C, respectively. Thresholds were slightly higher in the second of two flight bioassays, suggesting an effect of beetle age. Strong positive relationships were found between temperature (6-20 °C) and the rates of feeding and oviposition on flower buds of oilseed rape. CONCLUSION: These temperature relationships could be used to improve M. aeneus migration risk assessment, refine weather-based decision support systems and modulate damage thresholds according to rates of bud damage.

Blow-out fractures: patterns of ocular motility and effect of surgical repair.

The decision to repair an orbital blow-out fracture depends on several factors, but evidence for the optimum timing of surgery is not clear. We retrospectively studied all patients with orbital injuries who were referred to the eye department at a Scottish teaching hospital over a 10-year period from 1997 to 2006. We aimed to document the incidence and pattern of disturbances of ocular motility after blow-out fractures, and identify the rates of early and late resolution of these deficits, both spontaneously and after surgical repair. We found that most patients with blow-out fractures had a motility defect for an acute phase; approximately one third of which resolved spontaneously within 2 weeks. Recovery of motility after orbital surgery occurred in less than half the patients, and was not immediate. Continuing recovery also occurred in those who did not undergo surgery. Entrapment of muscle or tissue is not the only cause of motility disturbance after blow-out fractures, and orbital surgery is only one aspect of management in those patients with persistent motility defects.

Infective endocarditis presenting with Parinaud's dorsal midbrain syndrome.

We present a case of vertical gaze palsy in a 13-year-old girl caused by underlying infective endocarditis, secondary to an infected navel piercing. This case illustrates that infective endocarditis does not always present with classic signs.