For the future, keep all such items in airtight containers. Clean your home: As with any pest, cleaning up will discourage them. Corners and walls were most productive. ), Encyclopedia of Food Grains, second ed. Rice weevils are a serious stored product pest, and if left unchecked, they have the ability to compromise food supplies on a massive scale. Infestations by grain weevils and Angoumois grain moth are the most reported with infestation usually commencing in the field (McFarlane, 1989; Beta et al., 2016). The population increase of S. zemais was completely suppressed at 10°C, while that of S. oryzae was completely suppressed at 15°C (Throne 1994). The most effective way to control rice weevils in your home is through the help of a professional pest control expert. Cribs, bins, sealed bunkers, pits, pots, bags, Underground pits, bins, tightly stacked bags. Make sure to store grains in sealed plastic or glass containers with tight-fitting lids, and regularly rotate dry goods in your pantry, getting rid of older or expired items. In another study, with fumigation periods of 15 and 20 days, the concentrations of 40, 50, and 60% eliminated all stages of the insects. Sitophilus oryzae (Rice weevil) Sitophilus zeamais (Maize Weevil) Each of these species varies considerably in size but has a distinctive elongated snout which is adapted to the size of its preferred grain. Where grain is stored on small farms, S. zeamais is thus more likely than S. oryzae to fly to the ripening crop in the field and establish an infestation in the grain before harvest. have a low susceptibility to synthetic pyrethroids but are readily killed by organophosphorus compounds such as fenitrothion and pirimiphos-methyl. Carbonyl sulfide (as gas), carbon disulfide (as liquid), and ethyl formate (aqueous solution) were tested as fumigants in silos of wheat in Australia. The efficacy of CdS, nano-Ag, and nano-TiO2 nanoparticles against the larvae has been tested successfully (Chakravarthy et al., 2012). Some secondary insects feed on the mould rather than the food product. Grain stocks may be fumigated with phosphine to eliminate existing infestation, but these treatments provide no protection against reinfestation. Development of pest management strategies that favor the action of natural parasites may have some potential. Get a Quote. Adapted from McFarlane, J.A., 1989. A strain of aposymbiotic S. oryzae, was also used in this study. In Korea, the classification of the Sitophilus weevil group occurring in stored grains has been confused, resulting in its misidentification in most references reporting Sitophilus oryzae (Linnaeus). During the course of grain storage, different pest control methods may be applied depending on the types of storage devices used (Table 4.5). Adapted from McFarlane, J.A., 1989. with weevils and throw them out, along with any dry products that were nearby. By continuing you agree to the use of cookies. Although both species are capable of flight, S. zeamais has a greater ability and tendency to fly (Giles 1969). It is also a good idea to make sure that screens in windows and doors are intact. Weevils prefer warm, moist environments. Primary insects are uniquely adapted both anatomically and physiologically to attack the specific food supply they have evolved with over time. When females chew holes in food and insert an egg inside, they also seal up the hole with a gelatinous secretion; this can make it much more difficult to detect infestations before they’ve become obvious and distressing. ODNRI Bulletin No. Both the white legless larvae and adults of weevils feed on grain. They are named because when first discovered they were mainly associated with whole grain rice. According to De Carmago Casella et al (1998), effective control of Sitophilus was achieved with a synthetic atmosphere and 0.5 or 0.75 g of phosphine per cubic meter, for an exposure period of 120 h. Good storage hygiene plays an important role in limiting infestation by S. zeamais. (1) Bulwark employees may not work with any sign of illness. The average lifespan of a weevil is about 5–6 months (McFarlane, 1989; Beta et al., 2016). Sitophilus is naturally infected with the bacterial endosymbiont Sodalis pierantonius. (5) We offer online pay and online signature service to entirely eliminate the need for customers to touch pens, credit cards, or service agreements. Individual trap catches were as high as 333 for the rice weevil and 32 for the sawtoothed grain beetle. Typically, they reach 2-4mm in length and have a long cylindrical body which is dark brown or nearly black in colour. In southern states, adults may infest crops out in the fields and contaminate food processing facilities when the infested crops are brought in. Guidelines for Pest Management Research to Reduce Stored Food Losses Caused by Insects and Mites. Throw out the infested product: Take any bags of flour, dried corn, etc. S. oryzae was more susceptible to gamma radiation than S. granarius, and irradiation of S. zeamais by microwave and gamma radiation has been studied (Franco et al 1997). A perforated plastic probe trap can be used to monitor insect activity in grain under laboratory conditions (Trematerra 1998). The source of diatomaceous earth, insect species, grain moisture content, temperature, method of application, and duration of exposure are all factors that influence the mortality of stored-product insects. Manually separated wheat kernels (kernels crease facing down), uninfested and infested by different life stages of the insects, were x-rayed at 15 kV potential and 65 μA current. Santos et al (1999) described the use of a carbon dioxide controlled atmosphere in Brazil for the control of S. zeamais on maize and wheat. They are named because when first discovered they were mainly associated with whole grain rice. The largest family is Curculionoidae. The female rice weevil will lay (on average) 4 eggs per day over her lifespan of 4-5 months. Aegypti when the immersion method was used for various larval stages (Morejon et al., 2018). Several plant extracts have been tested for activity against Sitophilus spp. Rice weevils are a species of stored product pest that are found living throughout the world; in the United States they are mainly found in southern states that have warmer climates. After some sanitation efforts were made and a perimeter treatment given, a significant reduction in catch was visible. The removal of infested residues from last season’s harvest is essential. You should also caulk gaps found around exterior windows and doors to help prevent adults from flying into your home. The parasitoid Theocolax elegans has also been recorded (Flinn et al 2006) as attacking S. zeamais. In a U.S. study, a combination of controlled ambient aeration in the autumn and chilled aeration during summer storage was found to have significant potential as a nonchemical preventive pest management technique (Maier et al 1996). We are confident we can control your pest problems following CDC regulations. Heat treatment of grains such as smoking them over an open fire can destroy pests almost immediately (McFarlane, 1989), although such practices may introduce smoke flavor to the kernels depending on the length of treatment. The tamarind weevil is only known for eating tamarind. Rice weevils are winged and capable of flight. Since rice weevils are so small, it might be challenging to know for sure if those are the insects you’re dealing with. Sitophilus spp. Weevil larvae and nymphs grow naturally inside wheat grains. While they are not pleasant to have around, you can at least be relieved that they are not dangerous or harmful. The infestations by C. ferrugineus pupae and adults were identified with more than 96% accuracy, and 97% of kernels infested by P. interpunctella larvae were identified by both the linear-function parametric classifier and BPNN. Among different methods (acoustic method, near infrared spectroscopy and imaging, thermal imaging, and visible light imaging) used to detect insect infestations in grain, the soft x-ray method is considered as the simple and fast method to detect hidden insects in grain(Keagy and Schatzki, 1991, 1993; Schatzki et al., 1993; Karunakaran et al., 2004b, 2005; Neethirajan et al., 2007). The linear-function parametric classifier and back-propagation neural network (BPNN) identified more than 84% of infestations caused by C. ferrugineus and T. castaneum larvae (Table 16.3). ODNRI Bulletin No. Control. Most colder areas, such as northern Europe, have wheat weevils instead, which are more tolerant of the cold. Dry heat treatment has been found to be an effective control against all developmental stages of S. zeamais (Hasan and Khan 1998). For these reasons, they also enjoy dry corn and seeds. Adult lifespan is approximately 6 months. Detection and Inspection (for general aspects see S. granarius). Other common secondary insects are: Tribolium castaneum (Herbst), Tribolium confusum Jacquelin du Val, Cryptolestes sp., Plodia interpunctella (Huebner) and Ephestia cautella (Walker). In: Wrigley, C., Corke, H., Seetharaman, K., Faubion, J. Secondary insects are opportunistic insects that feed on the grain only after the seed coat has been broken either mechanically or by a primary insect. The physical appearance of the weevil is based on the species. Scientific classification: Weevils belong to the superfamily Curculionoidea of the order Coleoptera. Available at: They are known to contaminate bird seed (specifically sunflower seeds), corn, wheat, rice, beans, nuts, cereals, stored cotton, along with grapes, apples, and pears. A total of 57 extracted features were used to identify uninfested and infested kernels using statistical and neural network classifiers (Karunakaran et al., 2003a,b,c, 2004b,c,d,e). In order to prevent your pantry and home from becoming infested with these stored product pests, you should always inspect food and food packaging for signs of rice weevil activity before purchasing them from the store. Admixing with a grain protectant can also effectively protect sorghum and millet kernels for a relatively long time (McFarlane, 1989). (Eds. After completing their metamorphosis with an ultimate insect molt (UIM), the adults remain inside the grains for three more days before emerging. (2014) demonstrated the larvicidal and pupicidal activity of silver nanoparticles using Leucas aspera leaf extract and recorded LC₅₀ and LC₉₀ values against the first to fourth instar larvae and pupae of the mosquito vectors, Aedes aegypti and Anopheles stephensi. Beauveria bassiana can be an effective microbial control agent if used as a preventive treatment (Adane et al 1996). An adult female weevil bores a hole in the grain and lays an egg inside the kernel (McFarlane, 1989; Beta et al., 2016). A good example of this would be the saw toothed grain beetle (Oryzaephilus surinamensis), which is typically found as a secondary infester of cereal grain, flour and dry fruits and vegetables.