A standardised bioassay method using a bench‐top spray tower to evaluate entomopathogenic fungi for control of the greenhouse whitefly, Trialeurodes vaporariorum

BACKGROUND: Bioassays evaluating entomopathogenic fungi (EPF) isolates for effective microbial control of whitefly are a fundamental part of the screening process for bioprotectants, but development of repeatable, robust bioassays is not straightforward. Currently, there is no readily available standardised method to test the efficacy of EPF on whitefly. Here, we describe the calibration and use of a spray tower to deliver a standardised protocol to assess EPF activity; the method was validated using 18 EPF from four genera in tests against greenhouse whitefly, Trialeurodes vaporariorum (Westwood). RESULTS: At 138 kPa, the sprayer delivered 0.062 mL mm−2 (620 L ha−1) and an even deposition of spray across the central 1590 mm2 of the spray area. Average conidial deposition for all EPF was 252 conidia mm−2 and equivalent to 2.5 × 1012 conidia ha−1 at an application concentration of 1 × 107 conidia mL−1. Conidial deposition of a test Beauveria bassiana suspension increased with increasing application concentration. Egg laying by T. vaporariorum adults was restricted to 177 mm2 using clip cages specifically designed to ensure that third‐instar T. vaporariorum received a uniform spray coverage. Nymphs occupied 373 ± 5 mm2 of the leaf after migrating during the first instar. Average T. vaporariorum mortality totaled 8–89% 14 days after application of 1 × 107 conidia mL−1 of each EPF isolate. CONCLUSION: Combining the calibrated sprayer and bioassay method provides a reliable, standardised approach to test the virulence of EPF against whitefly nymphs. This laboratory‐based assay is affordable, replicable and allows the user to alter the dose of conidia applied to the target

Diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is the most common acute hyperglycaemic emergency in people with diabetes mellitus. A diagnosis of DKA is confirmed when all of the three criteria are present — ‘D’, either elevated blood glucose levels or a family history of diabetes mellitus; ‘K’, the presence of high urinary or blood ketoacids; and ‘A’, a high anion gap metabolic acidosis. Early diagnosis and management are paramount to improve patient outcomes. The mainstays of treatment include restoration of circulating volume, insulin therapy, electrolyte replacement and treatment of any underlying precipitating event. Without optimal treatment, DKA remains a condition with appreciable, although largely preventable, morbidity and mortality. In this Primer, we discuss the epidemiology, pathogenesis, risk factors and diagnosis of DKA and provide practical recommendations for the management of DKA in adults and children

First host record and description of female Halictophagus calcaratus Pasteels (Strepsiptera: Insecta) from South Africa

The strepsipteran, Halictophagus calcaratus, was described from South Africa by Pasteels in 1958, but no host record/s or females were included. Here we record that H. calcaratus parasitizes the cicadellid, Molopopterus theae Theron 1978, an important pest of the commercially produced shrub, Aspalathus linearis (Fabaceae), from which ‘Rooibos’ tea is produced. We provide a redescription of the male and a description of the female and the male cephalotheca. A checklist of South African Strepsiptera is included

First host record and description of female Halictophagus calcaratus Pasteels (Strepsiptera: Insecta) from South Africa

The strepsipteran, Halictophagus calcaratus, was described from South Africa by Pasteels in 1958, but no host record/s or females were included. Here we record that H. calcaratus parasitizes the cicadellid, Molopopterus theae Theron 1978, an important pest of the commercially produced shrub, Aspalathus linearis (Fabaceae), from which ‘Rooibos’ tea is produced. We provide a redescription of the male and a description of the female and the male cephalotheca. A checklist of South African Strepsiptera is included