Fig. 1

A Ventral drawings of adult bulb mites (Rhizoglyphus robini). From left to right: female, male fighter and male scrambler. Morphological characteristics useful for identification are highlighted: black arrows indicate the third leg pair (thickened and sharply terminated in fighters), and dotted blue ellipses highlight the genitalia (including the anal discs in the males), which differ distinctly between males and females [42]. The idiosoma length is indicated with a red arrow (between the two dashed red lines; 42, 43) on the drawing of the female. Mite drawings by F. Rhebergen. B Workflow for pheromone quantifications: (1) females, male fighters and male scramblers were randomly selected from rich (dark grey) and poor (light grey) stock populations, and housed individually in plastic tubes, (2) the idiosoma length of the collected mites was measured as a proxy for body size, (3) mites from the same stock population and of the same sex or ART, were pooled based on idiosoma length, totaling 60 pools, and (iv) the α-acaridial production of each pool was quantified by performing hexane extractions followed by gas chromatography (GC) analysis