GSC Biological and Pharmaceutical Sciences, 2019, 06(01), 021–029 Available online at GSC Online Press Directory GSC Biological and Pharmaceutical Sciences e-ISSN: 2581-3250, CODEN (USA): GBPSC2 Journal homepage: https://www.gsconlinepress.com/journals/gscbps  Corresponding author E-mail address: Copyright © 2019 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. (R ESEARCH A RTICLE ) Laboratory evaluation of toxicity of spinosad tablets and tracer 48 SC insecticides against different stages of American cockroaches (Periplaneta americana L.), in Jeddah governorate Sharawi Somia 1, * , Mahyoub Jazem 1, 2 * and Assagaf Ahmad 1 1 Department of Biology Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia. 2 IBB University, Ibb, Republic of Yemen. Publication history: Received on 20 December 2018; revised on 14 January 2019; accepted on 18 January 2019 Article DOI: https://doi.org/10.30574/gscbps.2019.6.1.0163 Abstract Periplaneta americana is an important household insect pest worldwide and acts as a mechanical vector and reservoir for pathogenic agents. Fermented insecticides are biopesticide, derived from fermentation by the soil-dwelling actinomycete. The aim of this study was to test the susceptibility of Spinosad tablets and Tracer 48 SC against P. americana adults and nymphs using different concentrations. Bioassays were done by feeding and contact toxicity methods. Mortality was recorded after 48 hours of exposure. Mortality data from the replicates was assessed by probit analysis. All tested insects showed high susceptibility for spinosad compared with the control. The effectiveness of fermented insecticides against susceptible different stages of P. americana showed that these formulations can be strongly effective for the control of P. americana. Keywords: Spinosad; Tracer; Insecticides; Mortality; P. americana; Toxicity 1. Introduction American cockroaches (Periplaneta americana) (Linnaeus), order Dictyoptera, suborder Blattaria is an important insects in medical [1], they are the most notorious pests, found in kitchens [2]. It is one of the largest common cockroach species [3]. Out of 500, 30 species are considered as household pest [4]. A number of cockroaches pests live in/or around homes, and they are omnivorous scavengers [1]. They survive in warm weather with high moisture conditions as well as in unfavorable environments for humans [5]. P. americana can spread bacteria, fungi, and other pathogenic microorganisms from infected areas [6], and cause allergies to human [7]. They play important role in the transmission of different diseases by mechanical and biological ways [8, 9]. P. americana spends most of its time in sewage, sewer pipe which usually contains high density of pathogens [10]. Also, they feed on garbage and they have large opportunities to disseminate human pathogen [11, 12]. In addition, their nocturnal and filthy habits of eating their feces make them ideal carriers of numerous pathogenic microbes [13]. Cockroaches spread pathogens through their cuticle [14], because their nymphal cuticles go through ecdysis [15]. Therefore, they transfer pathogens in different ways such transmission routes may occur among populations with infected individuals such as vertical transmission which occurs when an infected mother passes on the pathogen or disease to her progeny [16]. All of these pathogens used as dangerous organisms targeting animal or human populations. A numerous pathogens such as bacteria, fungi and molds, helminths, protozoans and viruses, harmful to humans being are carried by cockroaches as well as they present in their faeces [12,17]. More than 100 species of bacteria have been