Some Biological and Population Density Aspects of Predator Armored Scale Ladybird Beetle, Chilocorus Bipustulatus and Oriental Yellow Scale, Aonidiella Orientalis in Citrus Orchards of Iraq
Laboratory and field studies were conducted to investigate some biological and population densities of predator Armored scale ladybird beetle(ASLB) Chilocorus bipustulatus and Oriental yellow Scale (OYS) Aonidiella orientalis in Iraqi citrus orchards during 2013- 2014. Study was implemented in citrus orchards of mixed citrus varieties: Bergamot, Citrus aurantium; Mandarin, C. reticulata and Orange, C. sinensis. Population densities of C. bipustulatus were measured according to stages (larvae, Pupae and adults) per leaf and fruit; OYS calculated per 1cm2 in leaf and fruit. Biological parameters were studied under controlling conditions (27 C0 ± 2, 70% ± 5 RH, and 16: 8 h light: dark photo period). Results indicated that the population density of YOS in 1 cm2/ leaf: fruit were 10.6: 11.2, 3.0: 5.6 and 0.2: 0.3 in C. aurantium, C. reticulata and C. sinensis, respectively. While, population densities of ASLB were 22: 27, 4.5: 8 and 0: 0 per 100 leaves: 100 fruit in C. aurantium, C. reticulata and C. sinensis, respectively. The body parameters of width: length of last instar larvae, prepupa, pupa, male and female adult were: 2.32: 4.75, 2.69: 4.77, 3.49: 4.92, 3.13: 3.75, 3.60: 4.24 cm, respectively. The duration of egg, larva, pupa, preovipostion period development were: 10.1, 22.3, 8.1, 7.9 days, respectively. Total period was 40.6 day and survivorship 85.3%, 72.2% and 97.7%, respectively and 55.1% total premaginal development. The study results demonstrate the dispersal of C.bipustulatus as a biological control agent in Iraqi environment for YOS in citrus orchards.
Keywords— Population density, Biology, Chilocorus bipustulatus, Aonidella orientalis, Citrus.