Biology of Mononychelus planki (Acari: Tetranychidae) on Calopogonium mucunoides (Plantae: Fabaceae)

Abstract

The spider mite Mononychellus planki (McGregor) has been considered a threat to soybean in Brazil, where it is referred to as soybean-green-mite. It has been reported from several countries in the American continent and in the Caribbean, attacking 68 plant species of 12 families, but mostly Fabaceae and Malvaceae. Calopogonium mucunoides Desv. is a common plant of spontaneous occurrence in Brazil, where it is often attacked by M. planki. Both the mite and C. mucunoides seem to be of American origin. The objective of this work was to evaluate the importance of C. mucunoides as a host for M. planki. Duration of the immature phase (11.5 ± 0.9 – 11.9 ± 0.2 days) was comparable to values reported for the mite on soybean, but total fecundity (18.1 ± 0.5 – 18.7 ± 2.3 eggs) was much lower. Values of life table parameters (rm, R0 and λ) were relatively low, reflecting the reduced ability of M. planki to reach high numbers on this plant, possibly as a result of their co-evolution. Yet, the present study suggests the importance of C. mucunoides in maintaining M. planki population under natural conditions, in the absence of soybean, a plant introduced to the Americas.