Initial and residual efficacy of insecticides on different surfaces against rice weevil Sitophilus oryzae (L.)

The aim of the study was to investigate how various types of storage facilities with, e.g., concrete, metal, and plywood surfaces interfere with the activity of different insecticide formulations used for rice weevil Sitophilus oryzae (L.) control: malathion (EC), pirimiphos-methyl (EC), and lambda-cyhalothrin (CS and WP). Initial and residual efficacy were determined in the laboratory. Knockdown data for the initial effects were processed by probit analysis and presented as knockdown time (KDT) parameters with kdt-p lines. Delayed effects were shown as knockdown efficacy (%) determined after 24 h of weevils’ contact with 7-, 14-, 30-, 60-, 90-, 120-, 150-, and 180-day-old deposits on each surface. Malathion (EC) and pirimiphos-methyl (EC) showed the highest initial knockdown efficacy on metal, while it was 3.6 (3.4)- and 4.4 (3.3)-fold lower on concrete and plywood, respectively. Lambda-cyhalothrin (CS and WP) showed the highest initial efficacy on concrete, and slightly lower (1.3 and 2.4) fold on metal and plywood, respectively. Both formulations of lambda-cyhalothrin and malathion on metal, as well as pirimiphos-methyl on plywood were 100 % efficient against S. oryzae 180 days after the treatment. Delayed efficacy of both formulations of lambda-cyhalothrin decreased on plywood after 120 days, and after 180 days the efficacy was 55 %. All insecticides, except lambda-cyhalothrin (CS), expressed low knockdown efficacy on concrete, while the deposit of lambda-cyhalothrin (CS) on concrete was 100 % efficient during 90 days, and after 120, 150, and 180 days the efficacy was 83, 65, and 17 %, respectively

Insect Pest Management in Stored Grain

Once cereal grain is harvested and put into storage, it provides a resource for a range of insect pests of stored grain. With few exceptions, these insects rarely attack grain in the field before harvest, but once the grain is in storage there is a degree of inevitability that insect infestation will occur. This means that methods are needed to either disinfest grain or to protect it from infestation during storage. The aim of this chapter is to review recent advances in insect pest management in stored grain, ranging from methods that are well established to those that are still being evaluated. This topic has been the subject of considerable laboratory and field research as evidenced by the large and growing body of published studies. Resistance to phosphine resistance and various insecticides, as well as the phase-out of methyl bromide as an ozone-depleting substance, continue to be major drivers for research on management of insects in stored products. Other research has focussed on improving the basic understanding of various methods or ways of improving methods currently in use. Despite extensive research on a wide variety of chemical and non-chemical treatments, very few have been commercialised. Two examples are spinosad, which has been registered as a grain protectant, and sulfuryl fluoride, which is now available as a grain fumigant. The interest in non-chemical treatments, especially aeration cooling, is encouraging. In general, integrated pest management is seen as the goal of entomologists, requiring the strategic integration of multiple methods to provide maximum effect with minimal health and environmental risks. Some of the chemical and non-chemical treatments reviewed in this chapter have great potential to be used as part of an integrated approach