Biological characteristics of Orthonama obstipata (Fabricius, 1794) (Lepidoptera: Geometridae), an emerging defoliator of mint (Mentha spicata L., 1753) in Morocco

The looper caterpillar, O. obstipata is one of the defoliator species of cultivated mint in Morocco. Its identification and its biology constitute the preliminary step for the development of a program aiming at its integrated management. The larvae were collected from a plot of mint grown in a region of northern central Morocco, and reared in the laboratory. The identification of the species was based on comparing the male aedeagus and the female spermatheca to the reference slides. In this study, the elements of biology and morphological characteristics of the different ecophases of O. obstipata are clarified and discussed. The life cycle of the species, from egg to egg, is completed in 31.3 ± 2.16 days. The emergence occurs linearly in time after the 27th and 28th days of oviposition according the sex. The sex ratio (Male/Female) is 0.88:1. The fecundity of the females is positively correlated with their lifespan. Females have an average fecundity of 210 eggs and a fertility rate of 97%. Adults live on average 22.0 ± 6.27 days. The highest mortality rates occur in the last larval instar and pupa. Keywords: Orthonama obstipata, Biology, Reproduction, Mentha spicata