Biodiversity of insects in paddy plots planted under the System of Rice Intensification (SRI) using some flowering plants as biological control agents against paddy pests: a case study at Kesang Tasek, Ledang, Johor

A study was conducted to determine the biodiversity of insects in the organic rice plots planted under the System of Rice Intensification (SRI), and using the flowering plants, viz. Big-Sage or Bunga Tahi Ayam (Lantana camara), Sunflower (Helianthus annuus) and Zinnia (Zinnia elegans) as biological control agents against paddy pests in the rice fields of Kesang Tasek, Ledang District, Johor. Insect samplings were conducted on three occasions from November 2013 to January 2014 at two study plots, one of which was cultivated under SRI, while the other plot was conventionally planted to serve as the control plot. Samplings were done using six different methods, namely the light trap, malaise trap, pitfall trap, yellow pan trap, sticky trap and the sweeping net. A total of 3319 individual specimens were sampled and identified, representing 49 species in 29 families and 7 orders of insects. The most predominant pests represented by 460 individuals belonged to the family Cicadellidae (order Hemiptera), followed by Pyralidae (order Lepidoptera, with 369 individuals), and Coengrionidae (order Odonata) with 223 individuals sampled, respectively. Members of the family Staphylinidae (order Coleoptera) comprised the most dominant group of predators, represented by 176 individuals sampled in the study area. The Shannon-Weiner Diversity Index (H'), Shannon-Weiner Evenness Index (E') and Margalef Richness Index (R') gave higher values for the SRI organic plot compared to the control plot, i.e. H'=3.25, E'=0.84 and R'=7.47, respectively. However, one-way ANOVA showed no significant differences (p>0.05) in insect diversity between the three phases of rice growth in both plots. Using some flowering plants, i.e. Big-Sage or Bunga Tahi Ayam (Lantana camara), Sunflower (Helianthus annuus) and Zinnia (Zinnia elegans) as a protective plants or biological control agents against paddy pests instead of applying commercial chemical pesticides can restore the biological diversity and population abundance of parasitoids and predators (beneficial insects) in the SRI organic rice ecosystem.