Population dynamics of Stenoma catenifer Walsingham (Lepidoptera: Depressariidae) on Hass avocado orchards in México

Abstract

• Population peaks of Stenoma catenifer occurred during fruiting-flowering stages. • Avocado fruit infestation ranged between 0.0 and 65.0% • Temperature and relative humidity delineates a comfort zone. • Risk of occurrence was modeled as a bivariate kernel distribution. Avocado production in Mexico represents an income of more than $3.2 billion dollars per year in foreign exchange. Unfortunately, several factors can limit the export of this fruit. One of such limiting factor is the avocado seed moth, Stenoma catenifer ; however, its population dynamics is barely known. Therefore, is relevant to study the environmental factors affecting population changes, aimed to improve its management. In this study, we monitored the population fluctuations of S. catenifer males and explored its relationship with temperature and relative humidity by using pheromone-baited traps in Hass avocado orchards in the state of Colima, Mexico. From June 2018 to June 2019, a total of 6,836 males of the avocado seed moth were collected, with two population peaks. The first in June-August, during the fruiting stage, and the second in December-January, coinciding with the end of fruiting and flowering stages. Fruit infestation ranged from 0.0 to 65.0% in the orchards examined. Cluster analysis and principal coordinate analysis indicated that sampling time and relative humidity group together but differ from temperature. The effect of relative humidity and temperature on catches was analyzed by relating non-parametric bivariate distributions. The highest male catches were recorded at temperatures greater than 15.8 °C and relative humidity greater than 60% while low relative humidity did not favor moth catches. These results may be useful to predict bioecological conditions for the occurrence of populations of this pest.