Pear rust mite, Epitrimerus pyri (Acari: Eriophyidae) oviposition and nymphal development on Pyrus and non-Pyrus hosts.
The ovipositional response of deutogynes of Epitrimerus pyri and the rate of development of nymphs of E. pyri differed according to the host plant to which mites were exposed. Among the 14 Pyrus hosts examined, leaves from the Clapp's Favorite cultivar of P. communis [pears] elicited the strongest egg laying response and the fastest rate of nymphal development, whereas egg laying was least and nymphal development slowest on leaves from P. calleryana. Among the 3 non-Pyrus hosts, E. pyri oviposited and completed nymphal development on leaves of apple and quince (Cydonia oblonga), but would not deposit eggs on leaves of apricot. Antixenosis appeared to be the primary mechanism of resistance, although antibiosis may be operating to a lesser extent. The results are discussed in relation to the resistance of Pyrus to other arthropod pests.