Life Cycle of Weevils and Flour Beetles Weevils Sitophilus granarius is a small (3-5mm) browny/black or dark grey-coloured insect. During the life cycle of maize, they are attacked by pests and diseases and end up destroyed. This is a pest that destroys stored maize, dried cassava, yams, sorghum and wheat. The adult maize weevils are 3 -3.5mm long, dark brown or black in color and shiny and pitted with numerous punctures. After about 3 weeks of feeding the females begin to lay eggs in the pods and this continues until the seeds are formed. In Indian conditions, 5-7 generations of this weevil is generally completed in a year. Thakur AK, Sharma JK, 1996. On-going studies are being done to see what can be improved to diminish the population and the effects that maize weevils have on the grain. The end of the body of the maize weevil is also more rounded that of the LGB and its head is elongated into a distinctive “beak-like snout? Rice weevils pretend death by drawing their legs close to body and remaining silent even when disturbed. The maize weevil (Sitophilus zeamais), known in the United States as the greater rice weevil, is a species of beetle in the family Curculionidae. She seals the egg in the kernel so that it’s hidden from view, making detection difficult. The life-cycles of the Maize and Rice weevils are … Development time ranges from about 35 days under optimal conditions to over 110 days in unfavourable conditions. Females usually lay around 150 eggs, and up to 300 eggs, throughout their lives. The life span of the granary beetle is 7-8 months on average. Both species can hybridize. The female uses her strong mandibles to chew a hole in the grain kernel where she deposits a single egg and seals the hole with a gelatinous fluid. Adults can live up to 8 months after emerging. )(Coleoptera: Curculionidae) ... of damage during storage depends upon the number of emerging adults during each generation and the duration of each life cycle and seeds permitting more rapid and higher levels of adult emergence will be more seriously damaged. There are a number of ways to store grain. During hot weather, the development period for egg to adult may be as few as twenty-six days. Females chew into maize grains where they lay their eggs throughout most of their adult life of up to one year, although 50% of their eggs may be laid in the first 4-5 weeks. Life Cycle of Rice weevil. Pests of maize. adult maize weevil significantly lived longest on maize and millet (122.3±1.87 and 126±3.20 days) than on rice and sorghum (120.3±3.24 and 117.6±2.07 days), respectively (Table 1). The adult female rice weevil lays an average of 4 eggs per day and may live for four to five months (producing 250-400 eggs). It can be found in numerous tropical areas around the world, and in the United States, and is a major pest of maize. Adults are long-lived and feed on the commodity and can fly. Argentine stem weevil (Listronotus bonariensis) ASW occurs throughout New Zealand and is a major insect pest of grasses and cereals including maize.It is responsible for a substantial decrease in plant populations in some maize crops. Rice weevils and maize weevils are about 1/8 inch long and brown. When fully fed the larvae leave the pods to pupate in the soil with the adults emerging later in the summer. Life Cycle: The granary weevil, Sitophilus, granarius is closely related to rice weevil, Sitophilus oryzae in habits, hosts and life history. Assessment of storage losses … However, the only reliable features to distinguish adults of both species are on the genitalia (see table below). 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