The studies on some biological and ecological aspects of Chilocorus nigritus (Fabricius) (Coleoptera:Coccinellidae) and adaptation on environment

ABSTRACTPhD THESISTHE STUDIES ON SOME BIOLOGICAL AND ECOLOGICAL ASPECTSOF Chilocorus nigritus (FABRICIUS) (COLEOPTERA: COCCINELLIDAE)AND ADAPTATION ON ENVIRONMENTDerya ŞENALDEPARTMENT OF PLANT PROTECTIONINSTITUTE OF NATURAL AND APPLIED SCIENCESUNIVERSITY OF ÇUKUROVASupervisor: Prof. Dr. Nedim UYGUNYear: 2006, Pages: 127Jury : Prof. Dr. Nedim UYGUN: Prof. Dr. İsmail KARACA: Prof. Dr. M. Rifat ULUSOY: Prof. Dr. Neşet KILINÇER: Assoc. Prof. Cengiz KAZAKAonidiella aurantii (Maskell) (Homoptera: Diaspididae) is one of the most importantpests on citrus. Although the scale insect have natural enemies they are not sufficient enoughon suppressing of the pest in the East Mediterranean Region of Turkey. In the need ofeffective natural enemy, Chilocorus nigritus (Fabricius) (Coleoptera: Coccinellidae) wasimported from California to Turkey. In this study, some unknown bio-ecological propertiesand adaptation of C. nigritus to citrus orchards were investigated in the East MediterraneanRegion of Turkey.Biology of C. nigritus was studied at 18, 22, 26, 30, 34 ˚C constant and 20-32 ˚Ccycling temperatures. Development time of C. nigritus decreased with increasingtemperatures. Immature stages of C. nigritus were not completed at 18 ˚C and the highestmortality rate of immature stages 87.07 % was determined at 34 ˚C. As a result of studies ondifferent humidity levels (40, 60 and 80 %), the development period of preadult stages of C.nigritus were completed in a very short time (ne kadar) at the low humidity level and thehighest mortality rate, 69.64 % was found at 80 % RH. Development time of preadults fedon A. aurantii and Aspidiotus nerii (Bouché) (Homoptera: Diaspididae) was 27.36 and 27.37days, respectively. According to comparison of C. nigritus adult longevity prey on A.aurantii and A. nerii; the longevity was shorter and few number of eggs laid on A. aurantii.R0 values of C. nigritus that feed on A. nerii were 130.31 and 82.12; rm values were 0.66 and0.70; T values were 74.01 and 63.25 days at 26 and 30˚C. R0, rm and T values of predatorwere respectively 179.59, 0.079 and 65.62 days at 40% RH. These values were 48.50, 0.056and 69.31 days respectively when C. nigritus fed on A. aurantii.To determine adaptation of C. nigritus to orchards, adult and egg stages of predatorwere released to citrus orchards infested with both A. aurantii and P. pergandii, andfurthermore, predator was observed that mass-releases was carried out on A. aurantii and A.nerii within cages in semi-field conditions. As a result of releases, it did not over winter andadapted to East Mediterranean Region of Turkey.Key words: Chilocorus nigritus, biology, life table, change of diet, adaptation innature.II