Manipulating the community structure of arthropods in rice fields with floral resources plants

Abstract

Conservation biological control encourages natural enemies to suppress target pests through manipulation of environmental factors that influence natural enemy survival and effectiveness, including microclimates, availability of food for adults and alternative prey, and shelter from adverse environmental conditions. This study aimed to identify selective flowering plants that could be used to manipulate the arthropod community structure in rice fields. Three rice fields (a field without resources of flowering plants, a field with vegetable crop, and a field with ornamental plant) were used in this experiment. The flowering plants included Helianthus sp., Catharanthus roseus, and Cosmos sulphureus while the vegetable plants included eggplant, cucumber, and long beans. Arthropod recording was carried out by direct observation and yellow pan traps from 14 to 98 days after planting. We recorded 33,728 arthropods representing 153 species in 68 families, 13 orders, and 2 classes. The presence of flowering plant significantly affects abundance, species richness, diversity index, and evenness of arthropods both in dry and wet seasons. The rice field surrounded with ornamental plants or vegetables showed the lowest abundance of phytophagous arthropods, the highest abundance of parasitoid and predatory arthropods. Therefore, vegetable crops such as cucumber, long beans and eggplant have great opportunities as refugia in rice fields.