Advanced trap design of Metarhizium anisopliae spore release for controlling date palm horned beetle Oryctes elegans

The aim of this study was to investigate the potential of traps for releasing Metarhizium anisopliae Metsch in a population of date palm horned beetle Oryctes elegans Prell. The structure used in the trap consisted of an absorber section, stopper plates, pickup hopper, and trap chamber. In order to study different pheromone and dietary compounds in the trap predation rate, three treatments in three replications were cumulative pheromone, integration (cumulative pheromone and nutrient absorber) and nutrient absorber containing 20 g of date palm meristem. Insect retention time and concentration of inoculum were standardized to achieve maximum trap efficiency in adult insemination. Hence, five times of 20, 30, 40, 50 and 60 seconds and 5 concentrations of 104, 105, 106, 107 and 108 spore/mL were considered. The final dimensions of 350×350×650 mm trap were made using standard workshop methods. The results showed that the type of attractant had significant effects on trapping efficiency of adults. The highest rate of insect trapping was observed in the combination of cumulative pheromone and date meristem and the lowest was found in the date meristem alone. The highest rate of trapping occurred at 8 pm. The best time and concentration for maximum male and female inoculation were 54.3 and 55.7 seconds as well as 4.14×104 and 4.36 104 104 spores/ml, respectively. The results of the present research showed that the smart releasing trap of M. anisopliae as a pathogenic agent of the population of palm horned beetles possess the required efficiency in laboratory conditions.