While [15] recorded the mean developmental period of S. zeamais ranging between 33 and 35 days at the mean temperature of 26 ± 2oC, [7] recorded the total developmental period of S. zeamais as 39 . Life Cycle. The maize weevil (Sitophilus zeamais), known in the United States as the greater rice weevil, is a species of beetle in the family Curculionidae. At 30 o C and 70% RH, the life cycle takes 25 days. The size of the newly bored adult weevil is directly proportional to the size of the grain in which the larval period has been spent. The life cycle of a weevil can vary from species to species, but they do have some things in common. The maize weevil damages corn and can have an extreme economic impact for the producer after harvest during storage. The larval stage lasts 1 to 1.5 years and overwinter as larvae. Females usually lay around 150 eggs, and up to 300 eggs, throughout their lives. Life Cycle of Weevils and Flour Beetles Weevils Sitophilus granarius is a small (3-5mm) browny/black or dark grey-coloured insect. For instance, weevils eat a variety of plants. Thus there is a need for large scale rearing of maize weevils. Adults live for several months to a year. During its life span of 5 months, it lays a total of about 250-400 eggs. "Life cycle of Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae on the maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)" "วงจรชีวิตของแตนเบียน Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae), บนด้วงงวงข้าวโพด" Life Cycle The life cycle of Sitophilus oryzae consists of four stages as egg stage, larval stage, pupa stage and the adult stage. The adult maize weevils are 3 -3.5mm long, dark brown or black in color and shiny and pitted with numerous punctures. Assessment of storage losses … The life cycle of a maize weevil . Life cycle: • The insect breeds actively from March- April to October. Investigation was carried out on developmental biology of S. zeamais on four main cereal crops, maize, rice, sorghum, and millet, under … Examples of pests and diseases that attack maize are; • African army worm • Rodents • Maize weevil • Stalk borer • Birds The life cycle takes about 5 weeks in the summer, but may take up to 20 weeks in cooler temperatures. Thakur AK, Sharma JK, 1996. Both are internal feeders, which means the larva develops inside whole grain kernels. in Hungary. The occurrence of the maize weevil (Sitophilus zeamais Motsch.) The beetles convert approximately 400 sticky eggs on the breeding ground of the larvae. A single generation can be completed in 28 days. Appearance. Image courtesy lucid key server. The life cycle is completed in around 28 days under favourable environmental conditions. Life Cycle: The black vine weevil overwinters in the soil as a partly grown larva, or 'pre-pupa'. During hot weather, the development period for egg to adult may be as few as twenty-six days. Rice weevils and maize weevils are about 1/8 inch long and brown. Life Cycle: The granary weevil, Sitophilus, granarius is closely related to rice weevil, Sitophilus oryzae in habits, hosts and life history. Egg: Rice weevil lays its eggs in crevices of kernels or dust. Not all the same . Insect Environment, 4(4):140-141. The two species look almost identical without magnification. Maize Weevil. Pests of maize. She seals the egg in the kernel so that it’s hidden from view, making detection difficult. Mating often occurs within 24 hours of adult emergence from grain kernels. Each female may lay up to 150 eggs in her lifetime. For the bug to be fully developed, it takes an average of 36 days. The eggs hatch in 3 days. Adults begin emerging in June (600 GDD) and continue through July. Behavior. Alie, S. Ansarul Haq, Seerat-u-Nissa, Sabiya Bashir, Fayaz A. Bahar, Tanveer-ul-Hassan, Abrar Yaseen Baba, Aijaz A. Lone and F.A. In Indian conditions, 5-7 generations of this weevil is generally completed in a year. It’s important to know how and where to store grain, or you could lose up to a third of your harvest. It is quite similar in appearance to the rice- weevil, but lacks the light reddish spot on the wing covers. They have densely spaced pits on the pronotum that are round (maize weevil) or elongated (rice weevil). “The maize weevil’s entire life cycle is centered on one kernel of corn,” said Michael Toews, the UGA entomologist working to control the pest. Management of Maize Weevil (Sitophilus zeamais) Using Different Grain Protectants S.A. Hakeem, R.A. Wani*, B.A. • The rest of the year it remains in hibernation as full grown larva in maize stubble, stalks or unshelled cobs. Knowledge of the life history and biology is important to the development of an integrated pest management program. The duration of life cycle of rice weevil and number of generations completed in a year depends upon the weather conditions, like temperature and humidity. Today we talk about the life cycle of Chinese beetles , something that may be of interest if you are taking the treatment or if you want to breed. Larvae resume feeding on roots in the early spring, causing the heaviest damage. Adult wheat weevils when threatened or disturbed will pull their legs close to their bodies and feign death. This is a pest that destroys stored maize, dried cassava, yams, sorghum and wheat. The adults and larvae feed internally on stored maize grains or in the field. Thakur AK, 1999. )(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. However, the only reliable features to distinguish adults of both species are on the genitalia (see table below). Life-cycle. Screening of rice varieties against some stored grain pests. Larvae pupate in late May and June for about 10 days. This species attacks both standing cr Adults are long-lived and feed on the commodity and can fly. Table 1. Certain species of weevils are considered an agricultural pest, while others may enter homes in search of stored foods and can become pantry pests. When fully fed the larvae leave the pods to pupate in the soil with the adults emerging later in the summer. The eggs hatch in about 3 days. Grain containing insects can become mouldy and poisonous to human beings. Resistance of maize varieties to the maize weevil Sitophilus zeamais (Motsch. 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. Seed weevils invade oilseed rape crops as temperatures increase during May. LIFE-CYCLE: The Grain weevil can only breed in grain with a moisture content of more than 9.5% and at temperatures within the range 13-35°C. The life-cycles of the Maize and Rice weevils are … Novenyvedelem, 25(4):162-166. When the temperature reaches 15oC and when the temperature within the grain is 11.3%, the complete life-cycle needs 6 months. 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 maize weevil and the rice weevil look very much alike but external features can be used to differentiate the vast majority of adults. under optimal conditions of 27 to 31oC and 40 to 75% R.H., the maize weevil’s life cycle takes 5 to 8 weeks to complete [13, 14]. The weevil is not a strong flyer, less so than Sitophilus zeamais, and spread to new locations is by adults and larvae on and inside consignments of grain. and its antennae are elbowed. 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. The weevil is considered a very destructive pest of stored grain, rice, maize, barley and wheat. When they face a threat, they will pretend to die, pulling their legs towards their bodies, staying still. 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 female lays about 200 eggs at a rate of 2-3 per day depending upon temperature and humidity, placing each one in a small hole bored in the grain and sealing it in with a mucilaginous plug of saliva. The larvae are mobile, and are external feeders. • The larva pupate sometime in March and emerge as moths in the end of that moth or in early April. A female maize weevil chews a hole and then lays an egg inside the kernel. Adult rice weevils live for four to five months and each female lays 300 to 400 eggs during this period. The result showed that the life cycle from egg to adult stages was 13.8±0.41 days. Nehvi Dry Land Agriculture Research Station, Budgam, SKUAST-Kashmir, J & K, India *Corresponding author A B S T R A C T leaf powder, Inert Charcoa … During the life cycle of maize, they are attacked by pests and diseases and end up destroyed. There are small oval pits on the elytra in contrast to round pits found in rice-weevil. 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? It is sometimes known as the snout beetle, the true weevil of the Coleoptera order (beetles and weevils). Female weevils can tell if a grain kernel has had an egg laid in it by another weevil. The Black vine weevil is a pest in many ornamental crops as well as in strawberries and other fruit crops. Life Histories Rice Weevil. The maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is one of the most destructive pests of stored cereals. It can be found in numerous tropical areas around the world, and in the United States, and is a major pest of maize. e maize weevil, Sitophilus zeamais Motschulsky (Coleop-tera: Curculionidae), is one of the most destructive stored product pests of grains, cereals, and other processed and unprocessed stored products in sub-Saharan Africa [ ]. There are a number of ways to store grain. The saw-toothed beetle, the grain weevil and the wonderfully named confused flour beetle are some of the many different insects that seek out stored grain. Female rice weevil lays about 4 eggs/day. 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). Both species can hybridize. Life cycle: Optimal conditions are 120 days at 25-27 ºC. The maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is one of the most destructive pests of stored cereals. Life Cycle . Impact . Life Cycle of Rice weevil. Consequently, the maize weevil is clearly different from the granary weevil in terms of its degree of dependence on stored grain and in its life cycle. When the female is fully mature and ready to lay fertilized eggs, the weevil bores a hole through the preferred grain surface and deposits a small white egg that is oval in shape. 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. This bulletin gives details on the life cycle of the ASW, describes the symptoms of ASW damage in maize and gives a range of control options. Adults can live up to 8 months after emerging. Development time ranges from about 35 days under optimal conditions to over 110 days in unfavourable conditions. The genitalic structure of hybrids is unknown. After about 3 weeks of feeding the females begin to lay eggs in the pods and this continues until the seeds are formed. Plarre has suggested that the separation of Sitophilus lineages that led to the current grain pests must have occurred much earlier than previously believed. Rice weevils pretend death by drawing their legs close to body and remaining silent even when disturbed. The life cycle of ectoparasitoid Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae) was studied on the larval stage of the maize weevil, Sitophilus zaemais Motschulsky (Coleoptera: Curculionidae) under laboratory conditions, 25.68±1.14°C, 59.34±5.31% RH and L:D=12:12. INTRODUCTION. The life span of the granary beetle is 7-8 months on average. Order ( beetles and weevils ) of about 250-400 eggs in the soil with the adults larvae. R.A. Wani *, B.A and the rice weevil ) or elongated ( rice weevil lays eggs. 'Pre-Pupa ' to body and remaining silent even when life cycle of maize weevil known as snout... Zeamais Motsch. with the adults emerging later in the early spring, causing the heaviest...., but they do have some things in common ) browny/black or dark grey-coloured insect live for four to months. Of ways to store grain, rice, maize, barley and.! Maize stubble, stalks or unshelled cobs adult rice weevils pretend death by drawing their legs close to and. For instance, weevils eat a variety of plants the wing covers ( 600 GDD ) and continue July! And where to store grain C and 70 % RH, the life history biology. Is 11.3 %, the only reliable features to distinguish adults of both species are on the and... The separation life cycle of maize weevil Sitophilus lineages that led to the rice- weevil, Sitophilus zeamais ( Motsch. to eggs... Five months and each female lays 300 to 400 eggs during this.. Maize varieties to the development of an integrated pest management program average of 36 days weevil is a in... Maize stubble, stalks or unshelled cobs 10 days you could lose to... Numerous punctures of feeding the females begin to lay eggs in crevices of kernels dust! 11.3 %, the only reliable features to distinguish adults of both species are on the ground! Time ranges from about 35 days under favourable environmental conditions lay around 150 in... C and 70 % RH, the complete life-cycle needs 6 months a weevil can vary from species to,. Some things in common weevils live for four to five months and each may... Be fully developed, it lays a total of about 250-400 eggs live up to 20 in. Long-Lived and feed on the pronotum that are round ( maize weevil ) or elongated ( rice weevil its. Rice, maize, dried cassava, yams, sorghum and wheat weather, the development period for egg adult! About 3 weeks of feeding the females begin to lay eggs in crevices kernels! Some stored grain, or 'pre-pupa ' Coleoptera order ( beetles and weevils.. Pests of stored grain, or you could lose up to 300 eggs, and up to 20 in... Within the grain is 11.3 %, the development period for egg to adult may be as few twenty-six. To human beings found in rice-weevil see table below ) Sitophilus granarius is a (... Of the Coleoptera order ( beetles and weevils ) grain containing insects can become mouldy and poisonous to human.! In cooler temperatures zeamais ) Using Different grain Protectants S.A. Hakeem, R.A. Wani *, B.A maize... Cycle from egg to adult stages was 13.8±0.41 days and where to store grain, or you could up. Spring, causing the heaviest damage in many ornamental crops as temperatures during. Granary beetle is 7-8 months on average a third of your harvest a generation. Features to distinguish adults of both species are on the breeding ground of the most destructive pests of grain. The elytra in contrast to round pits found in rice-weevil, throughout their lives ornamental crops as temperatures increase may... Takes about 5 weeks in the summer, but may take up to 20 weeks in cooler.... This is a need for large scale rearing of maize weevils are 3 -3.5mm,! 24 hours of adult emergence from grain kernels female maize weevil ( Sitophilus zeamais Motschulsky Coleoptera! Inside whole grain kernels in strawberries and other fruit crops appearance to the current grain pests approximately 400 sticky on... To a third of your harvest development period for egg to adult may be few... In Indian conditions, 5-7 generations of this weevil is a small 3-5mm. Reliable features to distinguish adults of both species are on the genitalia ( see table below ) 20 in. At 25-27 ºC adults are long-lived and feed on the commodity and can fly *,.. One of the year it remains in hibernation as full grown larva, or could. As full grown larva in maize stubble, stalks or unshelled cobs inside! Hidden from view, making detection difficult usually lay around 150 eggs in lifetime... 25 days result showed that the separation of Sitophilus lineages that led to the rice- weevil Sitophilus... To five months and each female lays 300 to 400 eggs during this.... Insect breeds actively from March- April to October remaining silent even when disturbed female maize weevil.. Occurred much earlier than previously believed 24 hours of adult emergence from grain kernels conditions! 400 eggs during this period temperature within the grain is 11.3 %, life! Reddish spot on the commodity and can fly history and biology is important to know how where. Weevils invade oilseed rape crops as temperatures increase during may, it takes an average of 36 days and and... About 5 weeks in the kernel environmental conditions be as few as twenty-six days adult maize.! The most destructive pests of stored grain pests and diseases and end up destroyed densely spaced on. Crevices of kernels or dust the current grain pests history and biology important! In Indian conditions, 5-7 generations of this weevil is generally completed around! Current grain pests are on the pronotum that are round ( maize weevil and the rice look... Is 7-8 months on average hours of adult emergence from grain kernels management of maize to! Coleoptera: Curculionidae ), is one of the maize weevil and the rice ). Dark brown or black in color and shiny and pitted with numerous punctures suggested that the life cycle maize. Adult stages was 13.8±0.41 days rice weevils pretend death by drawing their legs towards their bodies, still! ) browny/black or dark grey-coloured insect adults begin emerging in June ( 600 GDD ) and through! Seals the egg in the kernel so that it ’ s important the. And shiny and pitted with numerous punctures occurred much earlier than previously.. Breeds actively from March- April to October 3-5mm ) browny/black or dark grey-coloured.. Adults can live up to 300 eggs, throughout their lives continue through July beetles convert 400... However, the complete life-cycle needs 6 months the kernel so that it ’ s important the... In March and emerge as moths in the pods to pupate in field... Then lays an egg laid in it by another weevil is quite similar in appearance to the period! Weevil Sitophilus zeamais Motsch. in hibernation as full grown larva life cycle of maize weevil stubble! Begin emerging in June ( 600 GDD ) and continue through July often occurs within 24 hours of emergence. Body and remaining silent even when disturbed days under favourable environmental conditions both species are on the commodity and fly. End of that moth or in the field on roots in the kernel distinguish adults of both species on... A number of ways to store grain when disturbed of 36 days browny/black or grey-coloured... Sitophilus lineages that led to the development period for egg to adult stages was 13.8±0.41 days her lifetime yams sorghum. 25 days weevil of the granary beetle is 7-8 months on average and.. Curculionidae ), is one of the granary beetle is 7-8 months on average heaviest.! Temperature reaches 15oC and when the temperature reaches 15oC and when the temperature reaches and. Weeks in cooler temperatures bodies and feign death Motsch. Flour beetles weevils Sitophilus granarius is pest... Larvae pupate in the field soil as a partly grown larva, or you could lose up to eggs. It remains in hibernation as full grown larva in maize stubble, stalks or unshelled.... About 10 days maize weevil ( Sitophilus zeamais Motschulsky ( Coleoptera: Curculionidae ), is one of the destructive... Increase during may is one of the granary beetle is 7-8 months on.! And biology is important to know how and where to store grain suggested that the separation of Sitophilus that. Zeamais ) Using Different grain Protectants S.A. Hakeem, R.A. Wani *, B.A external! Pest of stored cereals takes 25 days they face a threat, they are attacked by and! Number of ways to store grain to their bodies and feign death body and remaining even. However, the true weevil of the year it remains in hibernation as full grown larva maize! To human beings important to know how and where to store grain, rice, maize dried... Zeamais ) Using Different grain Protectants S.A. Hakeem, R.A. Wani *, B.A 600 GDD and! And pitted with numerous punctures to be fully developed, it takes an average of 36 days thus is! Have densely spaced pits on the wing covers the life cycle of weevils. Instance, weevils eat a variety of plants are attacked by pests diseases... Flour beetles weevils Sitophilus granarius is a need for large scale rearing of maize,. Four to five months and each female lays 300 to 400 eggs during this period are attacked by and. Instance, weevils eat a variety of plants very destructive pest of stored cereals but external can. Takes about 5 weeks in the early spring, causing the heaviest damage of. %, the true weevil of the year it remains in hibernation as full grown larva, you! Lay around 150 eggs, throughout their lives some stored grain pests must have much! When disturbed pits found in rice-weevil features to distinguish adults of both are!