Population Parameters of Tetranychus merganser Boudreaux (Acari Tetranychidae) in Papayo (Carica papaya L.) at Different Temperatures
Tetranychus merganser is a mite species that causes greater economic damage in the papaya (Carica papaya) production area in the state of Veracruz, Mexico. Therefore, it was necessary to study their biology in order to make better decisions in their management. We obtained a colony of mites from a female collected in the municipality of Manlio F. Altamirano, and expanded their population on bean leaves (Phaseolus vulgaris) under greenhouse conditions. The objective was to evaluate the influence of temperature on the population parameters of this species and the duration of their developmental stages. For this purpose, we established cohorts starting with eggs, and exposed them to the following conditions: constant temperatures (19, 23, 27, 31, 33 and 35 °C); 60±2 % relative humidity, photoperiod of 14:10 h light:dark, and fed with papaya leaf discs. The duration of the life cycle of T. merganser decreased from 52.3 to 12.9 d with the increase of temperature. The net reproductive rate (Ro) was 37.40, 62.38, 43.98, 10.47 and 2.32 for 19, 23, 27, 31 and 33 °C; at 35 °C, the cohort was not viable. The intrinsic rate of population increase (rm) was 0.08, 0.19, 0.21, 0.18 and 0.12 at the temperatures recorded. Optimal development occurred between 23 and 27 C. Although papaya is not its best host compared to more favorable population parameters obtained by other authors in beans, T. merganser can behave like a pest in papaya under the environmental conditions prevailing in the area.