Red spider in jackfruit: bioecology and biological efficacy of acaricides

Abstract

Jackfruit (Artocarpus heterophyllus) has become an important fruit and represents a production option for tropical areas of Mexico. However, due to its recent introduction, information on its associated pests and diseases and management recommendations is still limited. In 2017, deformation of the leaves, discoloration of the beam and the presence of spider webs on the underside caused by an unknown mite were observed. The objective of this research was to identify the associated mite, determine its population distribution and fluctuation and evaluate the biological efficacy of acaricides. The study was conducted during 2018-2019 in Nayarit, Mexico. The identified mite is Tetranychus pacificus known as the red spider. It is distributed in all producing areas of jackfruit in Nayarit. It was mainly detected from November to June with greater infestation in the Tecuitata producing area (0.86 mites’ leaf-1) and Jalcocotan (0.57 mites’ leaf-1) of the municipality of San Blas. On average in September and October its presence is imperceptible; however, in El Capomo only in July was detected which probably indicates an initial stage of dispersal of the mite. Significant correlation was observed (β= 0.0489, r= -0.73, F= 0.0345, α= 0.05) of the population with the temperature, with a decrease in the population at a higher temperature and accentuated from 26 ° C. No correlation was observed with relative humidity. The highest temperature (27.9 °C) and relative humidity (88.2%) occurred in the month of July and September, respectively, months in which the lowest mite population was observed. The acaricides evaluated exercised significant control. At 21 days after application, differences occurred between treatments and the absolute control (Pr>F= 0.0245). With the application of azadirachtin (1.9 g of ia L-1 of water) and mineral oil (16.9 g of ia L-1 of water) a control of 75.9% and 72.5%, respectively, was obtained.