For a grower who is applying a biocontrol agent to protect his crop, performance is effectivity in pest control. This of course is to be measured under field conditions. The effectivity may be expressed as compared to not applying the biocontrol agent, but more generally as compared to applying alternative (chemical) control measures. Ideally the comparison between the different pest control options also covers differences in costs and crop revenues. Unfortunately, the latter is more difficult to asses, so too often only the former is included in the evaluations.
For a researcher studying a potential biocontrol agent, performance is more generally expressed as detailed numerical expressions of the biological characteristics of a species. Examples of such characteristics are development time, the rate of reproduction, prey consumption rates, and so on. These values are typically studied under controlled conditions in the laboratory.
The projects within this BINGO Work Package are faced with a special challenge: they need to meet to both types of performance. Within the projects varieties of existing natural enemies are bred using selective breeding. In the end, these will have to perform in the field at the perception of the grower. But to get there, a lot of detailed measuring of specific performance traits is required.
Breeding for specific traits is common practice in domestic animals and both food and ornamental plants. It is a multibillion industry! In that respect it is perhaps surprising that selective breeding has hardly received attention for biocontrol agents. The reason for this, at least in my opinion, might come down to the same special challenge: how to asses the performance?
In order to selectively breed for certain desirable traits, there must be variation in these traits amongst the individuals, the variation must be heritable, and the phenotypes for the variable traits must be determined at the individual level. But how do you determine the phenotype of an individual insect or mite? Especially if the traits we are interested in are typically complex traits that are not seen with a single look at the animal. Instead assessment of these traits requires bioassays.
The key to successful selective breeding of biocontrol agents is clever bioassays. Therefore Tom Groot expects that we will talk a lot about bioassays in this Work Package. The clever bioassay targets the specific trait at the most important life stage of the individual and puts a numerical value for the phenotype on each individual. In addition, the selected individuals must survive the bioassay to produce the next generation, and finally, the time required per individual must be relatively short to allow sufficient numbers of individuals to be tested.
The bioassays are an essential tool for the selective breeding. The bioassays are now being developed and future newsletter may explain how they operate. But in the end, also the performance in the field needs to be assessed, because also growers need to be convinced that the breeding has improved their performance!