Use of a Lower-Volume, Surface Pesticide Spray Conserves Spider Assemblages in a Tea Field

Abstract

Since spiders are sensitive to pesticides, the use of lower-volume pesticide sprays that specifically target the plucking surface may help to preserve their assemblages. In this study, we investigated the effect of four pyrethroid pesticides on spider populations in tea (Camellia sinensis) fields when applied using a lower-volume sprayer. Abundance and composition at family level of spiders were assessed before and after treatments. We found that fewer spiders were eliminated when we used a lower-volume sprayer (40 liters/10 ares) rather than a conventional sprayer (200 liters/10 ares) due to the lower-volume treatment only covering the plucking surface (top layer) of the tea plants. These findings indicate that the tea leaf layer plays a good role in sheltering spiders during pesticide application and that the lower-volume treatment that specifically targets the plucking surface can enhance this protection. Therefore, to successfully maintain predatory spiders that prey on tea pests, tea farmers should reduce the volume of pesticides they use and try to restrict the spray to the plucking surface of the plants.

Structure of the Assemblages of Spiders in Mediterranean Pear Orchards and the Effect of Intensity of Spraying

“…Earlier authors reported a negative effect of pesticides on philodromids [ 74 ]; although, others have reported a certain resistance to pesticides in some Philodromus species [ 31 , 75 , 76 ]. Salticids have been reported as extremely susceptible to pesticides in orchards in warm regions worldwide [ 46 , 58 , 77 ]. The impact of pesticides on cheiracanthiids and particularly on Cheiracanthium species is little known, but some populations have been found to exhibit a certain resistance to insecticides [ 78 ].…”

Insights into the functional role of tea microbes on tea growth, quality and resistance against pests and diseases

“…Microbial pesticides increase growth of plants by suppressing the activities of tea pests and pathogenic agents (Bhattacharyya and Sarmah, 2018). Mites and pests cause damaging effects to tea plants (Yu et al, 2018) and Ectropis obliqua and Gyropsylla spegazziniana are prime mite and pests affecting the tea plants (Kakoki et al, 2018). The microbes were discovered as an important biological weapon to control the pests of tea around 1970.…”