Laboratory sprayer for testing of microbial biocontrol agents: design and calibration

Abstract

6The lack of commercially available low-cost laboratory spraying equipment for testing 7 microbial control agents can hinder advancement in the field of biocontrol. This study 8 presents an inexpensive, portable sprayer that is calibrated utilizing laboratory 9 consumables. The computer aided design files are made available so that it is freely 10 modifiable and can be used for machine routing or 3D printing. Bioassay data was 11 obtained by spraying Myzus persicae with spores of entomopathogenic fungi. Observed 12 variation in droplet deposition within tested pressure and volume settings, and spore 13 deposition within sprayed concentrations were low. Bioassay results show reproducible 14 mortality for the tested doses.15

Manipulating multi-level selection in a fungal entomopathogen reveals social conflicts and a method for improving biocontrol traits

“…The cohorts of 13 aphids were sprayed with 400 µl of conidia suspension using a precision micro sprayer in a 55 mm Petri dish as described by Erdos, Halswell (84). After treatment, aphids were maintained on single leaves of Chinese cabbage in plastic cups with mesh covered vents at 20±1 °C and a 14:10 L:D regime.…”

Controlling insecticide resistant clones of the aphid, Myzus persicae, using the entomopathogenic fungus Akanthomyces muscarius: fitness cost of resistance under pathogen challenge

“…The median lethal concentration (LC 50 ) for A. muscarius was calculated as 4 × 10 6 conidia mL −1 for the aphid clone O based on a dose response bioassay using seven doses and 18–20 insects per dose 55 . Furthermore, 20–22 even‐aged adult apterous aphids were treated in a 55 mm Petri dish with the LC 50 of A. muscarius conidial suspension.…”

“…Fungal suspensions were applied with a microspray tower consisting of an acrylic cylindrical tube, a top cap and artist airbrush (HP‐SBS ECL3500 with standard nozzle, ANEST Iwata‐Medea, USA), similar to those in other EPF studies 56,57 . Precise specifications and validation of the consistency of this set‐up have been described previously 55 . The volume and pressure settings after calibration were determined as 400 μL and 83 kPa.…”

“…The median lethal concentration (LC 50 ) for A. muscarius was calculated as 4 × 10 6 conidia mL −1 for the aphid clone O based on a dose response bioassay using seven doses and 18-20 insects per dose. 55 Furthermore, 20-22 even-aged adult apterous aphids were treated in a 55 mm Petri dish with the LC 50 of A. muscarius conidial suspension. Fungal suspensions were applied with a microspray tower consisting of an acrylic cylindrical tube, a top cap and artist airbrush (HP-SBS ECL3500 with standard nozzle, ANEST Iwata-Medea, USA), similar to those in other EPF studies.…”

“…56,57 Precise specifications and validation of the consistency of this set-up have been described previously. 55 The volume and pressure settings after calibration were determined as 400 μL and 83 kPa. Bioassays were carried out at 4 × 10 6 and 4 × 10 7 conidia mL −1 resulting in an applied dose of 615 and 1237 spores per mm 2 , respectively.…”