The survey of Orius (Hemiptera: Anthocoridae) species in Antalya province and biology and diapause of Orius majusculus (Reuter)

In this study, biology and diapause of Orius majusculus Reuter, a predator of western flower thrips Frankliniella occidentalis (Pergande) that is a polyphagous pest of greenhouse-grown vegetable and ornamental plants, was investigated. In addition, Orius species were surveyed in Antalya province.The effect of photoperiod on the development, reproduction and diapause of O. majusculus were investigated under the various day-lenght conditions (11.5, 12, 12.5, 13.5, 14.5 and 16 h) and a light intensity of 2400 lux at 60% r.h.and 26±10C. Results showed that the critical day-length was between 11.5 and 12 h, all the adults entered in to reproductive diapuse at a day-length of 11.5 h, and the development time was also longer at 11.5 h day-length.The effect of light intensity on the development, reproduction and diapause of O. majusculus was determined under various light intensities (10, 25, 50, 100, 200 and 2400 lux) and a day-lenght of 12.5 h at %60±10 r.h. and 26±10C. The results of this study demonstrated that development times of various nymphal stages were longer at 200 lux than other light intensities. Fecundity and diapause rates were not affected by the light intensities.In order to determine the effect of high temperature (30 on the diapause of O. majusculus at short day-length condition, the insects were exposed to 30±10C, 11.5 h day-length and 2400 lux. Under these conditions, the diapause of no female was not terminated.Various biological stages of O. majusculus were exposed to two different constant temperatures (18 and 26±10C) and to fluctuating thermoperiods (26 0C (12 h)/ 10 0C (12 h) at 11.5 h day-length and 2400 lux to determine the biological stage which is sensitive to short day. In experiments, 11.5 h as short day and 12.5 h as long day was used. The results showed that nymph+adult stages should be exposed to short day to induce a 100% diapause at 18 and 260C .In order to asses the potential for storing O. majusculus in diapause the insects were exposed to 11.5 h day-length and 180C beginning with the egg stage and survival rate of diapausing adults were determined after 1, 2 and 3 months storage temperature with no mortality. Mortalities of 17, 45 and 90% were found after 1, 2 and 3 months, respectively. live In order to determine the effect of storage conditions on the reproductive performance of O. majusculus, 25 females were taken at the end of the 1st and 2nd months and then exposed to 12.5 h day-length and 260C. Diapause of 7 and 18% of the females was not terminated after 1 and 2 months storage, respectively.No significant difference was found between the fecundities of females stored for the indicated periodsIn order to determine Orius species, their thysanopteran preys on host plant species, surveys were carried out in Antalya province from February 2009 to April 2010. According to the results, the most common Orius species were Orius laevigatus (Fieber) (66.2%), and Orius niger (Wolff) (33.3%). These species were commonly encountered on the Vicia faba. Additionally, these two Orius species were commonly seen together with Thrips major Uzel ve Frankliniella occidentalis(Pergande).