Journal of Agricultural, Food and Environmental Sciences UDC 633.1-276(564.3-17) 632.76:633.1(564.3-17) Original scientific paper ____________________________________________________________________________________________________ THE DISTRIBUTION AND POPULATION DENSITY OF THE CEREAL WEEVIL, PACHYTYCHIUSHORDEI (BRULLÉ) (COLEOPTERA: CURCULIONIDAE) IN CEREAL FIELDS IN NORTHERN CYPRUS M. Güllü 1* , C. Gözüaçik 2 , A. Konuksal 3 , H. Hekimhan 4 , H. Fidan 1 1 Biological Control Research Institute, Department of Entomology, P. O. BOX: 21, 01321 Adana/Turkey 2 Iğdır University, Faculty of Agriculture, Department of Plant Protection Iğdır/Turkey 3 Agricultural Research Institute, Lefkoşa (Nicosia)/TRNC 4 Egean Agricultural Research Institute, Menemen-İzmir/Turkey * corresponding author: mgullu83@hotmail.com Abstract The Cereal weevil, Pachytychiushordei (Brulle) (Coleoptera: Curculionidae) is an important pest of barley and wheat. This study was conducted to determine the distribution areas and the population density of P. hordeiin Northern Cyprus. The sampling were conducted in 57 cereal fields of 46 villages in Lefkoşa, Girne, Güzelyurt, Gazimağusa and İskele districts in 2012-2013 years. Sweep net were used in samplings. At the end of the study, P. horde ihas been found common all in regions and the highest population densities were 379 adults/100 sweepnet and 247 adults/100 sweep net in Hisarköy/Girne in the years 2012-2013 respectively. In addition, damage states of P. hordeiwas evaluated. Key words: Cereal, Cereal weevil, Pachytychiushordei, distribution, population density, Northern Cyprus. Introduction Cereals are the leading agricultural products in Northern Cyprus agriculture with 84,163 hectares of cultivated land. Barley is cultivated in 92.7% of the total cereal fields, whereas wheat is cultivated in 6.4% and oat and triticale are cultivated in 0.9%, which in total yield 134,149 tons of grain (Anonymous, 2011). Most of the cultivated barley is used as feed in animal farming industry, and wheat is utilized as human nutrition. Thus, cereal production is of utmost importance for North Cypriot farmers, especially the barley. As in any product, there are various species of pests that affect cereals both in pre-harvest and post- harvest periods, causing different levels of harm. One of these pests is the Cereal weevil, Pachytychius hordei (Brullé, 1832) (Coleoptera: Curculionidae) that harms the fields before the harvest. It was reported that the Cereal weevil, P. hordei which is a prevalent and significant pest in Palearctic region, has two sub-species: Pachytychius hordei hordei (Brullé, 1835) and P. hordei squamosus (Waltl, 1836) (Caldara, 2010). It was reported that P. hordeihordei sub-species exist in Cyprus fauna and spread across the whole island; in addition Pachytychius basimaculatus Voss, 1964 sub-species exists as well, albeit limited to Paphos and Larnaca regions (Alziar, 1995; Alziar, 2010). Cereal weevil, P. hordei adults are 2-4 mm long, bright black or brown insects with whitish- cream hairs or scales on its elytra (Anonymous, 2008; Alziar, 2010) (Fig. 1a). Adult individuals exit from the soil during the days when weather temperature is 12-14⁰C and relative humidity is 57-80% in barley and wheat fields and feed on the cereal stem and leaves (Şimşek, 1993). Three adjacent characteristic small round holes similar to staple holes occur on the leaf surface as a result of the feeding of P. Hordeiadults (Fig. 1b). It was reported that adults also feed on flowers during heading stage, destroying them and preventing fertilization in barley and wheat by 4.4% and 2.7%, respectively (Şimşek, 1998a). While male and female adults feed, they also mate (Fig. 1c) and leave their whitish translucent eggs (Fig.1d) between spikelet husks in the spikes (Fig. 1e). Each female could leave a total of 40-50 eggs, one