Huseyin Cetin

The German cockroach, Blattella germanica (Linnaeus) (Blattodea: Ectobiidae), is a major urban pest that can cause allergic reactions and mechanically carry pathogenic microorganisms. Its control has become increasingly difficult because of widespread resistance to commonly used insecticides, particularly synthetic pyrethroids. This study compared the efficacy of six commercial gel bait formulations containing imidacloprid, dinotefuran, clothianidin, indoxacarb, spinosad, or fipronil against four field populations of B. germanica from Antalya, Türkiye, previously characterized and routinely monitored as pyrethroid-resistant. Adult females, adult males, and nymphs were tested separately, and mortality was recorded at 24 h intervals over a 120 h exposure period. Mortality data were analyzed using one-way ANOVA followed by Duncan’s multiple-range test, while univariate ANOVA was used to evaluate the effects of gel bait formulation, population, developmental stage, and exposure time. Mortality differed significantly among the tested formulations, populations, developmental stages, and exposure times (p < 0.001). The dinotefuran-containing formulation produced the highest and most consistent mortality across all populations and developmental stages. The indoxacarb-containing formulation also showed high efficacy, although mortality developed more gradually during the early observation periods. The formulation containing imidacloprid showed the lowest efficacy, whereas those containing clothianidin, spinosad, and fipronil produced intermediate and population-dependent responses. Nymphs were significantly less susceptible than adult females and males. Overall, the efficacy of the tested gel bait formulations was influenced by formulation, field population, developmental stage, and exposure time. These findings provide comparative efficacy data that may support the selection and rotation of gel bait formulations in resistance-aware management programs for B. germanica.

Spinosad is a naturally derived insecticide obtained from a soil-dwelling bacterium and is widely used against various agricultural and public-health pests. Although resistance to spinosad has been reported in several pest groups—including thrips, fruit flies, beetles, lepidopterans, and even mosquitoes—no study to date has evaluated its resistance status in the house fly, Musca domestica L. (Diptera: Muscidae). The present study provides the first field-based assessment of spinosad resistance in larvae of M. domestica, based on field-collected populations from Türkiye, and offers the first baseline data on larval susceptibility for this species. House fly larvae collected from seven provinces were exposed to a series of spinosad doses, and LD₅₀ values were calculated using probit analysis. According to the results, LD₅₀ values showed variability of up to approximately 18-fold, ranging from 0.002 g a.i./m² in the Adana population to 0.036 g a.i./m² in the Şanlıurfa population. The corresponding resistance ratio (RR₅₀) values calculated based on the most susceptible population (Adana) ranged from 1.0 to 18.0, indicating low-to-moderate variation in baseline tolerance among the tested field populations. Despite these differences at low doses, the minimum operational dose of 0.25 g a.i./m² consistently produced 97–100% emergence inhibition in all populations. Overall, no high or very high resistance levels were detected across the tested populations. These findings indicate that, despite detectable differences in baseline tolerance, spinosad remains a highly effective larvicide for house fly management. The establishment of these baseline data is essential for future resistance-monitoring programs, and continued surveillance is strongly recommended to detect early shifts in susceptibility before operational resistance emerges.

In this study, we investigated the potential use of housefly Musca domestica (Linnaeus, 1758) (Diptera: Muscidae) larvae as an alternative feed for mass-rearing Calosoma sycophanta (Linnaeus, 1758) (Coleoptera: Carabidae), a species utilized in biological control against forest pests. Our research focused on the egg production efficiency of Calosoma adults when fed housefly larvae and the growth and development of first-instar Calosoma larvae under laboratory conditions. We compared these groups with Calosoma individuals fed on pine processionary moth (PPM), Thaumetopoea wilkinsoni (Tams, 1926) (Lepidoptera: Thaumetopoeidae). The results indicated a significant increase in weight for first-instar C. sycophanta larvae after 16 days: a 52.9-fold increase when fed PPM and a 16-fold increase when fed housefly larvae. In terms of length growth, PPM-fed larvae demonstrated a 4.52-fold increase, whereas housefly-fed larvae showed a 3.06-fold increase. Although the larvae consumed M. domestica larvae, the adult Calosoma did not produce eggs, and the larvae did not pupate. In contrast, Calosoma adults fed with T. wilkinsoni produced eggs, with their larvae successfully maturing to adulthood. Fifty percent of larvae fed with PPM and eighty percent fed with houseflies survived to 16 days. The findings suggest that while Calosoma larvae raised on houseflies are smaller and lighter than those fed with PPM, feeding them houseflies for a minimum of two weeks and subsequently releasing them in their larval stage could aid in the biological control of PPM.

Cockroaches, particularly the German cockroach (Blattella germanica Linnaeus, Blattodea: Ectobiidae) and the American cockroach (Periplaneta americana (Linnaeus), Blattodea: Blattidae), are major public health pests due to their ability to transmit pathogens and develop resistance to chemical insecticides, including synthetic pyrethroids, which are widely used worldwide. Given the increasing resistance, entomopathogenic nematodes (EPNs) have emerged as a potential biological control alternative. This study evaluates the efficacy of three EPN species, Steinernema carpocapsae (Weiser), S. feltiae (Filipjev), and Heterorhabditis bacteriophora Poinar, against B. germanica and P. americana collected from different regions of Antalya, Türkiye. Laboratory bioassays were conducted under controlled conditions, testing five EPN concentrations (100, 250, 500, 750, and 1000 IJs/mL). The results showed that S. carpocapsae was the most effective, causing mortality rates of 46.7% to 100% in adult German cockroaches and 20% to 66.7% in nymphs, while S. feltiae and H. bacteriophora exhibited lower efficacy. American cockroaches showed higher resistance, with S. carpocapsae achieving a maximum mortality of 33.3% at the highest concentration, whereas S. feltiae and H. bacteriophora had no significant lethal effect. These findings suggest that S. carpocapsae could be a promising biological control agent for B. germanica, particularly in pyrethroid-resistant populations.

This study aimed to investigate the non-target toxicity (insecticidal activity) of various herbicides (bentazone+MCPA, bispyribac sodium, cyhalofop butyl, quinclorac, oxadiazon, and clomazone) used in rice cultivation on Aedes aegypti L. and Culex pipiens L. mosquitoes. Given the ecological significance of rice cultivation areas (paddy fields) and the public health importance of these mosquito species, the research sought to understand how exposure to varying herbicide doses affects mosquito survival. The research utilized a laboratory strain of Ae. aegypti and both laboratory and field strains of Cx. pipiens mosquitoes, exposing them to three distinct doses of herbicides: the recommended application rate, and doses that were two and four times higher. Toxicity tests were conducted following the World Health Organization guidelines. Adult emergence inhibition rates (%) were recorded after exposing larvae of different developmental stages; early (first-second instar) and late (third-fourth instar) to the tested herbicides. Oxadiazon consistently showed higher toxicity to mosquitoes compared to other herbicides across all tested doses, causing up to 91.67% inhibition of adult emergence. Quinclorac also demonstrated notable toxicity, but to a lesser extent and primarily in Ae. aegypti. The remaining herbicides exhibited low or no significant insecticidal effects. Notably, early-stage larvae were more susceptible across the experiments. These findings suggest that while some herbicides used in paddy fields have a minimal impact on mosquitoes, oxadiazon, in particular, poses a significant risk. Understanding these interactions can aid in developing integrated pest management strategies that consider both crop protection and mosquito control, emphasizing the need for judicious herbicide use in ecologically sensitive environments.

The lesser mealworm (Alphitobius diaperinus) is a significant pest in poultry facilities, transmitting pathogens such as Salmonella and causing structural damage in poultry operations. Challenges such as insecticide resistance and environmental concerns associated with the widespread use of traditional insecticides underscore the need for sustainable alternatives. This review examines biological and sustainable management strategies for managing the lesser mealworm, including entomopathogenic fungi, bacteria, nematodes, plant essential oils-extracts, pheromones, and diatomaceous earth. These eco-friendly approaches highlight fungi and nematodes for their effectiveness in larval control and essential oils for their insecticidal and repellent properties. The application of pheromones and diatomaceous earth further complements other methods within integrated pest management (IPM) systems. Integrating these biological tools into IPM offers a sustainable and effective solution for reducing A. diaperinus populations, addressing both health and environmental concerns.

The house fly, Musca domestica L., 1758 (Diptera: Muscidae), is a public health pest commonly found on animal farms, manure heaps, and garbage dumps. In agricultural and livestock areas, house flies are frequently exposed to pesticides used against various pests, which leads to the development of insecticide resistance. This resistance complicates their control and has prompted researchers and insecticide manufacturers to explore alternative control strategies and methods. This study examines the effects of insect growth regulators (IGRs), specifically diflubenzuron and pyriproxyfen, used as larvicides, on egg yield, egg-laying index, and egg-to-adult transition rates in six different house fly populations. These populations were collected and cultured from five Turkish provinces (Antalya, Bursa, Edirne, Gaziantep, and İzmir) between June 2020 and August 2021, as well as from a susceptible population provided by the World Health Organization (WHO). The adult house flies were fed sugar solutions (40%) containing either 5% or 10% concentrations of diflubenzuron and pyriproxyfen. Our findings show an 80% reduction in egg yield and a 90% reduction in adult emergence rates across all populations compared to the control group. Although exposure to IGRs significantly decreased egg area indices, it did not affect the egg to adult transition rate.

In the veterinary field, particularly in the poultry farming sector, Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae) is a significant pest that causes economic losses and acts as a vector for various pathogens. This study is the first to evaluate the efficacy of the entomopathogenic nematode Steinernema feltiae Filipjev, 1934 against both the larval (fifth instar) and imago (adult) of A. diaperinus from various Turkish populations. The insects were collected from six poultry farms in the provinces of Balikesir, Bolu, Canakkale, Manisa, and Izmir in Türkiye, bred, and then tested at concentrations ranging from 25 to 200 infective juveniles (IJs) per milliliter. Mortality was monitored over a five-day period. The findings revealed that larvae were much more susceptible to S. feltiae nematodes compared to adults, with LC₅₀ values of larvae ranging from 33.17 to 83.12 IJs/mL. The Manisa population was the most susceptible, while the Izmir population was the most resistant. These results suggest that S. feltiae could be an effective biological control agent for managing A. diaperinus in Turkish poultry farms, reducing the reliance on chemical insecticides.