Does frequency-dependence determine male morph survival in the bulb mite Rhizoglyphus robini?

作者：Deere Jacques A^*; Smallegange Isabel M

来源：Experimental and Applied Acarology, 2014, 62(4): 425-436.

DOI：10.1007/s10493-013-9751-1

• Alternative reproductive tactics
• Male dimorphic mite
• Frequency-dependence
• Threshold trait
• Polymorphism

Alternative reproductive phenotypes (ARPs) represent discrete morphological variation within a single sex; as such ARPs are an excellent study system to investigate the maintenance of phenotypic variation. ARPs are traditionally modelled as a mixture of pure strategies or as a conditional strategy. Most male dimorphisms are controlled by a conditional strategy, where males develop into a particular phenotype as a result of their condition which allows them to reach a certain threshold. Individuals that are unable to reach the threshold of a conditional strategy are considered to 'make the best of a bad job'; however, these individuals can have their own fitness merits. Given these fitness merits, condition-dependent selection alone is not sufficient to maintain a conditionally determined male dimorphism and other mechanisms, most likely frequency-dependent selection, are required. We studied in an experiment, the male dimorphic bulb mite Rhizoglyphus robini-where males are fighters that can kill other males or benign scramblers-to assess the strength of frequency-dependent survival in a high and low-quality environment. We found that male survival was frequency-dependent in the high-quality environment but not the low-quality environment. In the high-quality environment the survival curves of the two morphs crossed but the direction of frequency-dependence was opposite to what theory predicts.

• 出版日期2014-4