What is the level of fruit infestation by pulp-feeding insects?: An overview of their meaning and measurement

Abstract

Despite the economic, ecological, and evolutionary importance of the fruit infestation level by pulp-feeding insects, its meaning and measurement are confusing yet. We show the first overview of the fruit infestation level, which emphasizes the problems to define its biological meaning and estimation ways. Employing a literature search concerning the fruit infestation level, we identify different concepts, estimations, and assumptions. This exercise reveals that commonly the interpretation of the infestation level is confusing. We highlight that the data use of the infestation level may drag interpretation problems that depend on (1) the study objectives, (2) the developmental insect stage, and (3) the sampling management. Also, jargon problems arise concerning the research field and the complexity level of the study. Lastly, we explain how to calculate and report the fruit infestation level taking into account the sampling design and measurement scales. Using fruit flies as a model, we show the main topics and guidelines for better study design of the infestation level, either in agricultural, ecological, and evolutionary contexts.