Biological, morphological, and ecological parameters of Harmonia axyridis (Col.: Coccinellidae); effect of color polymorphism, location, and generation

Distribution of Harmonia axyridis as an invasive predator, newly appeared in Iran, was investigted in northern provinces of Iran. Some biological and morphological traits were studied, including color morphs, sex ratio, and adults body length. Samples were collected from four regions in north and east-north of Iran as well as two generations of Rasht population to assess the effect of geographical location and insect’s generation. Reproductive potential of females of two main color morphs (melanic and non-melanic) was also investigated in overwintering and summer generations. Sampling were succesful in Guilan, Mazandaran, Golestan, and North Khorasan. Proportion of melanic individuals in Heyran, Shaft, Bojnourd, Rasht (overwintering population), and Rasht (spring population) was 11.51, 12.64, 10.57, 12.17, and 11.63, respectively. Sex ratios ranged from 38 to 44% showing no difference among the obovevmentioned populations. Mean length of adult insect body in individuals from Bojnord (6.57±0.029 mm) was larger than others. There was no difference between females of the two main color morphs in terms of oviposition potential. However, overwintering females laid significantly more eggs than summer females, regardless of color morphs. This study confirmed progress of H. axyridis distribution towards new areas. Moreover, it was indicated that sampling location and generation have no effect on color morphs ratio in newly invaded areas, and oviposition rate cannot be a regulating factor for color morphs ratio in next generation.