Identification and Oviposition Response of Sitophilus oryzae (L.) (Coleoptera: Curculionidae: Dryophthorinae) on Various Food Grains

Abstract

In this study weevils were collected from the local areas of Tandojam and its surroundings. While further identification was performed at the Laboratory of postgraduate student, | department of Entomology, Faculty of Crop Protection, Sindh Agriculture University, Tandojam. The collected weevils from the local areas of Tandojam, were killed in a jar by applying potassium cyanide and were mounted through entomological pins on their right elytron. The specimens were also labeled, which contains information about the date of collection, name of collector, host of plant if was known. After that abdomen were separated and put at 10% potassium hydroxide for overnight at room temperature separately and were heavily sclerotized. The specimens were also heated for 10 minutes. In the next day these specimen were rushed in water for 5 minutes. During this experiment habitus images were taken with the help of camera fitted in microscope. The examination of gentile and other remaining parts were performed under the microscope for capturing of necessary images. For habitus images model of camera canon Power shot (sx510 HS) were utilized and for the gentile organ images USB camera fitted microscope 350k pixel (1) Kyowa Medilux (2) Labomed CSM2 20 to 40x were used. For the oviposition response on various grains, tested grains include; wheat, barley, oat, maize, gram, millet. A pair of newly emerged Sitophilus oryzae (Fabricius, 1775) from a laboratory colony was placed in plastic jars of 150 ml. There were 6 treatments, each treatment with 3 replications. Eggs were counted in each jar containing pair of weevils. Analysis was carried out through statistical software SXW 8.0, to categorize the preference of Sitophilus oryzae.