LIFE CYCLE OF IMMATURE STAGES OF ORYCTES AGAMEMNON ARABICUS FAIRMAIRE (1896) (COLEOPTERA: SCARABAEIDAE) UNDER SIMILAR NATURAL CONDITIONS OF SOUTHWEST TUNISIA

Few biographies on the biology of Oryctes agamemnon arabicus exist in the world. The aimof this work is to study the developmental cycle of immature stages of this pest in breedingtrials conducted under natural conditions. Biological cycle of O. a. arabicus was composedof egg, three larval, pupal and adult stages. Results showed that incubation of eggs lasted for12.95±0.16 days and larval periods of 1^st, 2^nd and 3^rd instar were 35.24±4.33, 60.42±39.2 and189.15±44.47 days, respectively. Larval development prolonged for 284.94 days. Pupalperiod lasted for 20.78±2.69 days. Development of one generation, from eggs to adultemergence, lasted for 318.6±17.82 days which indicated that it was univoltine species.Detailed statistical analysis showed that developmental time within the same stage washighly affected by climatic conditions particularly temperature. Thus, we distinguishedbetween adults developed from summer eggs and autumn eggs.