insects Article Comparative Efficacy of Residual Insecticides against the Turkestan Cockroach, Blatta lateralis, (Blattodea: Blattidae) on Different Substrates Sudip Gaire 1 and Alvaro Romero 2,* 1 Department of Entomology, University of Kentucky, Lexington, KY 40546, USA; [email protected] 2 Department of Entomology, Plant Pathology and Weed Science, New Mexico State University, Las Cruces, NM 88003, USA * Correspondence: [email protected]; Tel.: +1-575-646-5550 Received: 19 June 2020; Accepted: 24 July 2020; Published: 28 July 2020 Abstract: The Turkestan cockroach, Blatta lateralis (Walker) is an invasive urban pest prevalent throughout the Southwestern United States. Despite the presence of this cockroach in peridomestic areas, there is limited information on strategies that can be utilized by pest management professionals (PMPs) to effectively manage populations of this pest. We evaluated the efficacy of dry residues of liquid insecticides commonly used for household and structural insect pest control: Tandem (0.10% thiamethoxam, 0.03% lambda-cyhalothrin), Transport GHP (0.05% acetamiprid, 0.06% bifenthrin), Temprid SC (0.10% imidacloprid, 0.05% beta-cyfluthrin), Demand CS (0.06% lambda-cyhalothrin), Talstar P (0.06% bifenthrin), and Phantom (0.5% chlorfenapyr) on three different substrates against Turkestan cockroach nymphs. Except for Phantom and Talstar P, all insecticide formulations killed 100% of the cockroaches on concrete, 89–100% on tile, and 77–100% on wood within 4 days. The rate of cockroach mortality varied according to the substrates to which they were exposed. Temprid SC and Transport GHP killed cockroaches faster on tile than wood. Tandem provided a faster mortality rate than Transport GHP and Temprid SC on concrete. Demand CS and Tandem killed cockroaches at similar rates on the three substrates. This study provides information to guide PMPs in their selection of insecticide formulations for the management of Turkestan cockroach infestations. Keywords: peridomestic cockroach; invasive urban pest; insecticide efficacy; dry residues; substrate type 1. Introduction The Turkestan cockroach, Blatta lateralis (Walker) (Blattodea: Blattidae) is a peridomestic cockroach that inhabits arid and semi-arid areas of the world. It is native to Saudi Arabia, Afghanistan, Uzbekistan, Southern Russia, and some parts of Africa [1–3]. In the last few decades, this cockroach species has expanded from their native range to other Asiatic countries and other continents [4]. In the United States, Turkestan cockroaches were first detected in 1978 at a military base in Lathrop, California, and it is believed that initial infestation occurred when military equipment was brought back from Middle East and Asian military bases [5]. Since then, infestations of this cockroach have established in desert regions of most other southern states, such as Arizona [6], New Mexico [7], Texas [8], and Georgia [9]. Anecdotal accounts by extension entomologists and pest management professionals (PMPs) indicate that Turkestan cockroaches are the most common outdoor cockroach species in many urban areas in the Southwestern United States. In Southern California, the Turkestan cockroach is a prevalent outdoor nuisance pest occupying similar habitats to that of the Oriental cockroach (Blatta orientalis, L.) [10]. Recent studies suggested that Oriental cockroaches are being displaced as major outdoor pests Insects 2020, 11, 477; doi:10.3390/insects11080477 www.mdpi.com/journal/insects Insects 2020, 11, x 2 of 10 prevalentInsects 2020, 11outdoor, 477 nuisance pest occupying similar habitats to that of the Oriental cockroach (Blatta2 of 9 orientalis, L.) [10]. Recent studies suggested that Oriental cockroaches are being displaced as major outdoor pests in this area due to the faster development and reproduction of Turkestan cockroaches [11].in this A arearising due concern to the is faster the expansion development of Turkestan and reproduction cockroaches of Turkestan to areas cockroachesoutside the southwestern [11]. A rising Unitedconcern States is the through expansion pet of stores Turkestan selling cockroaches them as a feeder to areas species outside [11]. the The southwestern spread of the United Turkestan States cockroachthrough pet may stores also selling facilitate them the as co a feeder‐introduction species [of11 the]. 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Laboratorymanagement and (IPM) field strategies evaluations for conducted controlling by Turkestanthe University cockroaches of California is just [10 ]beginning showed that to bait-basedemerge [10,20]. programs Laboratory can be anand eff ectivefield evaluations tool for the conductedmanagement by ofthe Turkestan University cockroaches of California in [10] environmental showed that sensitive bait‐based areas. programs Similarly, can Alkan be an eteffective al. [20] toolshowed for the that management diatomaceous of Turkestan earth (DE) cockroaches is very eff ectivein environmental when used sensitive against Turkestan areas. Similarly, cockroaches. Alkan etCurrently,there al. [20] showed is no that information diatomaceous available earth on the (DE) residual is very effect effective of insecticides when onused Turkestancockroaches. against Turkestan cockroaches.Since insecticide Currently, efficacy there can varyis no depending information on available the substrate on the [21 residual], we evaluated effect of in insecticides this study theon Turkestanmortality of cockroaches. Turkestan cockroaches Since insecticide exposed efficacy to various can insecticide vary depending formulations on the on commonsubstrate harborage [21], we evaluatedmaterials. Thein this results study from the this mortality laboratory of studyTurkestan might cockroaches help PMPs select exposed insecticide to various formulations insecticide for formulationstargeted application on common when harborage managing Turkestanmaterials. cockroachThe results