Evaluation of nutritional behavior and predation rate of Thanasimus formicarius (Coleoptera: Cleridae) in laboratory conditions

Abstract

Bark beetle is one of the most dangerous groups among forest pests. Periodic outbreaks of these species can cause very serious economic losses as well as negatively affect ecosystem processes and functions. Strategies developed in line with the specific objectives and continued efforts to control these pests are necessary. Environment-friendly and nature compatible methods are preferred to keep the population of pests at low levels. One of the effective methods of suppressing the bark beetle population is biological control. Thanasimus formicarius, a general predator of many bark beetle species, is an effective natural enemy of them. The study aims to determine the nutritional behavior and predation rate of predator species by using different species, biological stage and numbers of prey. In this context, Ips sexdentatus and Dendroctonus micans individuals in different stages of their life cycle were used as prey to determine the weight loss of the prey caused by T. formicarius, prey preference, and predation rates of predator beetle. T. formicarius adults caused an average weight loss of 0.0188 g of their prey within 24 h. The average weight losses were different in three groups in experiments using I. sexdentatus adults alone, D. micans larvae alone, and these two species together as prey. In experiments wherein only I. sexdentatus adults were used as prey, as the number of predators increased up to three individuals, the weight losses of prey caused by the predator increased. In the evaluations conducted without considering the differences in stages of life cycle and prey species, the predator caught the prey at a rate of 69%. In experiments wherein only I. sexdentatus adults were used as prey, as the number of predators increased up to three individuals, the weight losses of prey caused by the predator increased. Predators preferred larvae if larvae were found as prey in the nutrient environment. The average predation rate of T. formicarius in experiments using I. sexdentatus adults alone as prey was 68.9%, whereas this rate was 71.3% in experiments using D. micans larvae alone.