Valuation of quality parameters for rearing Aceria malherbae Nuzzaci (Acari: Eriophyidae), a biological control agent of field bindweed, Convolvulus arvensis L.

ABSTRACT

Field bindweed (Convolvulus arvensis) is one of the 10 most problematic weeds in the world. Its control using chemical herbicides is not completely effective. Aceria malherbae is a mite used successfully as a biological agent to control field bindweed. Effective implementation of this kind of biocontrol requires high-quality production of these mites. The purpose of this study was to investigate different quality indicators for effectively rearing A. malherbae under greenhouse conditions. The indicators considered were number of gallmites (adults, immature stages, and eggs), number of developed stems per plant, and number of galls per stem. We used 25 plots with 10 pots per plot, testing a sub-sample from one-fourth of these pots. The Shewhart chart or process–behavior chart was applied to determine basic statistics (means and range) and acceptance and rejection limits. Rejection limits for inferior plots were set at 3.9 developed stems per plant, 5.2 galls per stem, 7.4 adults, 32 nymphs, and 11 eggs, per plot. We also propose for quality control that the number of developed stems per plant and the number of galls per stem be routinely counted to detect any reduced quality of mite production. The results suggest that these indicators could be used for assessing quality control in large-scale reproduction of A. malherbae.

Key words:

• Eriophyidae
• Aceria malherbae
• field bindweed
• Convolvulus arvensis
• biological control
• rearing
• quality control.

ACKNOWLEDGEMENTS

The authors wish to thank Dr. Alec McClay, McClay Ecoscience, 15 Greenbriar Crescent, Sherwood Park, AB, Canada; Dr. John A. Goolsby, Research Entomologist, Biological Control of Pests and Weeds, United States Department of Agriculture, Agricultural Research Service, Washington, DC, USA, in Kika de la Garza, Subtropical Agricultural Research Center, Beneficial Insects Unit, Weslaco, TX 78596, USA, and Dr. Vikram Prasad, West Bloomfield, MI, USA, for their many suggestions on the manuscript.