Impact of lambdacyhalothrin on arthropod natural enemy populations in irrigated rice fields in southern Brazil

Abstract

Abstract. The present study aimed to determine the selectivity of the pyrethroid lambdacyhalothrin on arthropod natural enemy populations in irrigated rice fields in Rio Grande do Sul, Brazil. The study was conducted at three sites: districts of Cachoeira do Sul, Eldorado do Sul and Capivari do Sul during the crop years of 2007/2008 and 2008/ 2009. Each site consisted of two subareas divided into four plots. One of the subareas received a spray application of 150 ml/ha of lambdacyhalothrin CS 50, while the other subarea was untreated. Arthropods were collected at 2, 15, 30 and 45 days after the application of the insecticide to assess its impact on natural enemy populations. The results indicated consistent differences in natural enemy populations between the treated and untreated areas, especially within the first 2 weeks after the application of the insecticide. Principal components analysis together with x 2 analysis revealed differences in the populations of Tetragnathidae, Anyphaenidae, Araneidae, Coccinellidae, Phytoseiidae and Coenagrionidae between the treated and untreated areas. This study indicated the existence of a great diversity of arthropod natural enemies in irrigated rice fields in a subtropical environment similar to that reported previously from rice fields in tropical environments. In addition, lambdacyhalothrin was shown to be a rapid acting insecticide, with a significant initial decrease in natural enemy populations followed by a rapid recovery beginning at 2 weeks after the application of the insecticide. Especially disconcerting is the severe impact of the insecticide on Phytoseiidae and Araneidae, which are considered key natural enemies for the management of rice pests in southern Brazil.

Diversity of Major Predators Under Different Insecticide Regimes in Two Important Growth Stages of Rice

“…Least diversity was recorded in lambda cyhalothrin 5%EC and chlorpyriphos 20%EC treated plots. Similar trend was observed in case of evenness index and emamectin benzoate 5%SG showed the (Fritz 2013). In the present study, the spider population was more in sulfoxaflor 25%SC followed by pymetrozine 50%WG and emamectin benzoate 5%EC.…”

Sensitivity of spiders from different ecosystems to lambda‐cyhalothrin: effects of phylogeny and climate

“…7 Among them are the pyrethroid insecticides, which may affect spider survival, 8,9 feeding behavior 9,10 and locomotor activity, 11 even at concentrations below the recommended field dose. One widespread pyrethroid insecticide is lambda-cyhalothrin, which is known to reduce the abundance and diversity of natural enemies, including spiders, in field scenarios 12,13 and to cause spider mortality under laboratory conditions. 8 Moreover, lambda-cyhalothrin is cataloged as a bioaccumulative and toxic substance for non-target organisms, and is currently classified as a candidate for substitution in the EU.…”

Effect of IPM Modules on Major Pests and their Natural Enemies in King Chilli <i>Capsicum Chinense</i> in Northeast India

“…Similar results were obtained by Sechser et al (2003), Seal et al (2006) and Khani et al (2012) with imidacloprid proved to be harmful to coccinellids. Karthikeyan et al (2008), Fritz et al (2013) and Rodrigues et al (2013) observed that spiders were significantly reduced with lambda cyhalothrin was sprayed in rice. Sasikumar and Kumar (2012) also observed that the spiders are reduced with foliar application of lambda cyhalothrin and imidacloprid in sesame crop and Sherawat et al (2015) with imidacloprid on spiders in Pakistan.…”