These weevils are very destructive grain pests. Commonly, loss of weight is up to 5%, but severe infestations increase the losses up to 40%. Before grain is placed in a bin, it should be screened to eliminate fine The procedure is carried out by certified operators. Development is about 35 days under optimal cnmditions. However, its coloring is generally darker than that of the rice weevil. Photo 2  Georg Goergen, IITA-Benin. Bt: Some success has been reported using Bt. narrow strip extending down the middle of the dorsal (top) side. insecticides to get the control job accomplished safely. The repellent effect of neem may keep grains free from infestations for several months. Maize weevils carried a great collection of other fungi including A. niger, A. glaucus, A. candidus, Penicillium islandicum, P. citrinum, Paecilomyces, Acremonium, Epicoccum, F. semitectum, yeasts and many others. Use a flashlight or Insect resistant maize: recent advances and utilization. The maize weevil (Sitophilus zeamais) adult. Note that many storage pests are resistant to malathion. suspected, first eliminate other possible causes. carefully. Both insects are less coldhardy than the Grain weevil and will not normally overwinter in unheated premises or grain stored at normal temperatures. The maize weevil is found in all warm and tropical parts of the world. Motschulsky (Coleoptera:Curculionidae) is an important pest of maize in storage in term of losses caused in food quality and quantity in Nepal. IMPORTANCE AS A PEST: Grain weevils are important pests of farm-stored grain. Relationship among aspergillus flavus infection, maize weevil damage, and ear moisture loss in exotic x adapted maize. Pyrethrins: Used as a grain protectant (sometimes with piperonyl butoxide). For extra protection, some treat seeds or grains before Development is about 35 days under optimal cnmditions. Key pests: Almond moth, angoumois grain moth, confused flour beetle, flat grain beetle, granary weevil*, Indian meal moth, lesser grain borer, maize weevil*, red flour beetle*, rice moth, rice weevil*, rusty grain beetle*, sawtoothed grain beetle* *Suppressed to low levels (Please see label for complete list of pests.) Perhaps a method to avoid if seed is for growing. The mobile application is available from the Google Play Store and Apple iTunes. Maize weevil, Sitophilus zeamais; adult side view. Keep grain storage rooms, sheds, houses, or "cribs" clean. Corrêa AS, Vinson CC, Braga LS, Guedes RN, de Oliveira LO. The visible damage to the trial’s stored maize grain was also far more evident in the untreated samples, averaging 68%, compared with 14% damage in the treated samples. There are many pantry pests which can infest homes and businesses. The maize weevil has fully developed wings, and is a stronger flyer than the rice weevil, Sitophilus oryzae, and spreads more widely this way. Look for the characteristic large emergence holes in the grain with irregular edges. Infested grain will usually be found heating at the surface, and it may be damp, sometimes to such an extent that sprouting occurs. The eggs hatch into larvae, which eat the plant material surrounding them. The female has a … NIH 5. is an important pest of maize that attacks the grain both in the field and during storage. The rate of development and pupal stages. storage with dusts or sprays of synergized pyrethrins, labelled for this CULTURAL CONTROLIt is most important to dry the grain properly, to keep the storage area clean, and to monitor the grain often and regularly. intervals during cooler months for the presence of hotspots, moldy Storing maize on the cob with husks on re­duces weevil infestation. necessarily more susceptible to maize weevil damage than it is the normal endosperm type of the commercial corn available on the market. Maize weevil, Sitophilus zeamais; adult, view from above. The maize weevil Sitophilus zeamais Motsch. other light source to examine all food storage areas and food products The maize weevil has fully developed wings, and is a stronger flyer than the rice weevil, Sitophilus oryzae, and spreads more widely this way. Maize weevil, Sitophilus zeamais Motschulsky, is a spite of these precautions, fumigation of the grain will be necessary. If using sacks, do not reuse those that stored previous harvests. An egg The Maize weevil will breed on maize in the field, but the Rice weevil only breeds in stored grain. Malathion: i) as a spray; treat grain and do not use for food within 90 days of treatment; ii) as a dust; treat grain and do not use for food within 14 days of treatment. should be contacted to perform the fumigation. Heat damaged maize kernels may have a discolored, wrinkled, and blistered, be puffed and/or swollen, or their seed coats may be peeling off Heat damage most likely comes from drying of grain. Photo 2. Insecticides are supplementary to sanitation and proper Collect and dispose of spilled grain in or around the storage area. The larvae cause damage by boring into the grain, making holes and grinding it to a fine powder. It is difficult to detect the weevil unless populations are high as it spends most of its life inside grain. introduction of the larger grain borer. Thereafter, weevil damage was heavy in infested plots and negligible in controls. Maize weevil Sitophilus zeamais Motschulsky Classification. checked at two week intervals during warm months and at one month for garbage removal, or bury deep in the soil. Prevention is the best strategy; but if resistance is around doorways and other places where insects could hide or enter. Worldwide. The maize weevil is very similar to the rice weevil, Sitophilus oryzae (see Fact Sheet no. Secondary damage is caused by moulds, insects and mites. Asia, Africa, North, South and Central America, the Caribbean, Europe, Oceania. Other pests Sucking pests. minimum of thirty days is required for passing through the egg, larval Maize Weevils are small and easy to kill, but they can complete their life cycle quickly. In sub-tropical and tropical countries. ), Angoumois grain moths (Sitotroga cerealella), and the larger grain borer (Prostephanus truncatus). Mating often occurs within 24 hours of adult emergence from grain kernels. From the The reddish markings on the wing covers are more clearly defined. The maize weevil also infests other types of stored, processed cereal products such as pasta, cassava, an If the problem is an important pest of maize that attacks the grain both in the field and during storage. Look for the adults, with long snouts (about 1 mm). Of the three, the Both adults and larvaefeed on internally on maize grains and an infestation can start in the field (when the cob is still on the plant) but most damage occurs in storage. It is a subset of damage including broken or cracked kernels but is identified as its own type of damage by the USDA. Key words : Genetic resistance, stored grain pest, QPM corn It is slightly larger, up to 1/8-inch long, and like the rice weevil, it is dull reddish brown to black with four red-yellow spots on its back. Various neem products were compared with copra oil, palm oil and 0.25% diazinon dust for protection of stored maize against the grain weevil, Sitophilus zeamais Motsch. Long thought to be simply a larger strain of rice weevil, the maize weevil looks very similar. is slightly slower for the maize weevil than for the rice weevil. must fumigate. Treatment of grains for human consumption or for animal feed [make sure the product is labelled for use on rice, maize and small grains (barley, oats, wheat)]. 3.1.3. The two species look almost identical without magnification. Note that identification of Sitophilus zeamais is difficult because of its similarity with Sitophilus oryzae, and needs to be done by a taxonomist. If you detect an Avoid sowing new ground with maize after pasture in areas that have a known history of white grubs. ples of internal feeders include maize weevil, rice weevil, granary weevil, lesser grain borer, bean weevil, cowpea weevil, and larvae of Angoumois grain moth. It is possible to confuse the maize weevil with other storage insect pests such as the larger grain borer - LGB (Prostephanus truncatus). Approximately, 500 g of Maize Kernels in glass jars were moisture equilibrated in an incubator for a period of one week before infesting with 300 unsexed weevils (Miller et al.,; 1969). packages. materials and broken kernels. AUTHOR Grahame Jackson1Information from Swaine G (1971) Agricultural Zoology in Fiji. Maize weevils (known as Sumpwa sumpwa in Nyanja language) cause large losses in maize grains. Maize weevil, Sitophilus zeamais, clearly showing four light reddish to yellowish spots at the corners of the wing case. By November 12, 2020 Uncategorized 0 comments Tainting with white, dusty excreta which contaminate the product as well as rendering it unpalatable. Cereal Research Communications. After the grain If using bins, remove any grains that remain (and, if possible, spray with insecticide). light reddish or yellowish spots. Females lay up to 150 eggs placed in holes chewed into the grain and plugged with a gelatinous substance. Similar cautions apply as for pyrethroids (above). should be aerated to lower the moisture level and temperature. Weevil migration and reproduction in control plots reduced treatment differences in damage during the first 3 yr. feeds on the interior of the grain kernel. Their larvae hatch from eggs laid on to grains by weevils. They frequently cause almost complete destruction of grain in elevators or bins, where conditions are favorable and the grain is undisturbed for some length of time. Type of damage: These weevils are very destructive grain pests. Proceedings of an International Symposium held at the International Maize and Wheat Improvement Center, 27 November-3 December 1994., 91-95; [11 ref]. Adults are 3-4 mm long, reddish-brown to black (Photos 1&2), with four light reddish to yellowish spots at the corners of the wing cases (Photo 3&4). This weevil is a cosmopolitan pest of grain, preferring whole grain Treatments can be source of infestation and quickly get rid of it. Damage by S. zeamais causes food loss, … Grain that is to be stored for longer than six months may need a Sieving has been used as a method of removing adult weevils, but it is very labour intensive. Damage of Maize Weevil on Maize Varieties on Weight Basis. materials. The maize weevil, known in the United States as the greater rice weevil, is a species of beetle in the family Curculionidae. S. oryzae is universally regarded as one of the most destructive primary pests of stored cereals. lack of. Maize weevil, Sitophilus zeamais; another view of the four (very) faint, reddish spots at the corner of the wing case. 32:371-378. The thorax is densely et al., 2008; Baidool et al., 2010). The grub changes to a naked The damage caused by the maize weevil S. zeamais on maize landraces, Amarelo Antigo, Asteca, Caiano, Carioca, and Ferrinho, was evaluated by no-choice tests under laboratory conditions. A Infestations can start in the field, but most damage occurs in storage. If practical and regulations allow, dispose of heavily insects from entering the grain on the surface. It can be found in numerous tropical areas around the world, and in the United States, and is a major pest of maize. 328). Interpretive Summary: Natural sources of resistance to diseases and insects of corn are very valuable in corn production. In order to obtain test insects of known or similar age, these weevils were … Maize kernels treated with neem oil or ash were damaged less than the control. The eggs hatch into white, legless larvae, which remain inside the grain, and pupate there. London; and CABI (2015) Sitotroga zeamais (greater grain weevil) Crop Protection Compendium (www.cabi.org/cpc); and from BioNET-EAFRINET Keys and Fact Sheets (http://keys.lucidcentral.org/keys/v3/eafrinet/maize_pests/key/maize_pests/Media/Html/Sitophilus_zeamais_Motschulsky_1855_-_Maize_Weevil.htm). Malathion: apply to walls, floors, and inside of bins used to store the grain. Infestations can start in the field, but most damage occurs in storage. Note care must be taken to ensure that the treated seed does not contaminate that used for human consumption. During large infestations, heat and moisture are produced, leading to colonisation by moulds and mites. Remove old kernels, and sweep floors, walls, doors, and vents to collect seeds, grain powder and dust, and burn them before storing the new harvest. Low moisture content (10 % or less) and low tempera­tures (below 15 °C) will prevent weevil development. Though Meal Moths, Grain Beetles and Flour Beetles are very common, Maize Weevils are just as likely to be the unwanted insect in such areas. In contrast, his treated samples revealed an average of only 36 maize weevils/500g maize grain, just 11% of the average weevil numbers in the untreated samples. red-brown to nearly black and is usually marked on the back with four weevil, but larger Accessed 26 September 2007. Maize weevil is among pests of storage sorghum in Ethiopia (Temesgen and Waktole, 2013). Because of the high toxicity of registered fumigants and technical For small infestations, freezing for several days and then heating for 24 hours is affective. Maize weevil, greater grain weevil, greater rice weevil. They have densely spaced pits on the pronotum that are round (maize weevil) or elongated (rice weevil). Overall, control is similar to that recommended for the rice weevil (see Fact Sheet no. It must not be used for animal consumption, poultry feed or mixed with animal feed. Heating grain to 60C can kill larvae; however, this may Neonicotinoids: e.g., imidocloprid. After the bin is cleaned, and all needed repairs have been made, the Note, toys can sometimes be filled with grain and act as a source of infestation; so too can dried flowers. Her Majesty's Stationery Office. The simplest and most effective measure is to locate the Exposed adults. Apple iOS Edition. Weevils were shown to carry significant A. flavus contamination, as floor and wall surfaces both inside and outside the bin should be treated. storage. knowledge needed for their proper use, a qualified pesticide applicator Mechanisms of resistance in maize grain to the maize weevil and the larger grain borer. Attempt made to review bionomics and management practices of this pest gleaning published literatures/papers on national and international journals, proceedings, reports, newsletter and books. wings beneath its wing covers and can fly readily. Description. Android Edition It is recorded from Australia, Fiji1, New Caledonia, Papua New Guinea, Solomon Islands, and Tonga. Maize is the is also shorter comparatively (Raina, 1970). Identification of host kairomones from maize, Zea mays, for the maize weevil, Sitophilus zeamais. ( Tribolium spp has fully developed wings beneath its wing covers and can fly readily rice weevils maize... Products carefully similarity with Sitophilus oryzae is universally regarded as one of the rice weevil ( Fact! Less ) and low tempera­tures ( below 15 °C ) will prevent weevil development and are most in! Tarpaulin or in other ways sealed for the characteristic large emergence holes in the family Curculionidae or! Detect an infestation, locate it by putting sticky traps around the room or warehouse where it.! ) or elongated ( rice weevil is more rounded than that of the grain.! Inside grain around doorways and other places where insects could hide or enter body the. Kernels but is identified as its own type of the maize and granary weevils ( known Sumpwa. The red and confused flour beetles ( Tribolium spp low tempera­tures ( below 15 )! Was heavy in infested plots and negligible in controls than it is the normal endosperm type of female... ) and low tempera­tures ( below 15 °C ) will prevent weevil development than it is recorded from Australia Fiji1! On the cob with husks on re­duces weevil infestation were damaged less than grain. Guedes RN, de Oliveira LO also dried stored products, including pasta previous harvests and! Grain feeder Order: Coleoptera family: Curculionidae Acronym: SZE always CHECK WHETHER the product is for grain. A pest of stored maize, dried cassava, yam, common sorghum and wheat sometimes with piperonyl ). After harvest, and also dried stored products, including pasta grain kernels these are! 5 %, but most damage occurs in storage is slightly slower for maize... Pupal ), Angoumois grain moths ( Sitotroga cerealella ), you must fumigate distributed... From entering the grain with irregular edges is more rounded than that of the maize weevil damage, inside. For human consumption stored cereals treated grain can be applied to prevent insects from entering the on...: SZE kairomones from maize, Zea mays, for the maize weevil, rice! Has been reported using bt: CHEMICAL CONTROLIf pesticides are needed, the. ( Raina, 1970 ) Waktole, 2013 ) pupate there other light source to examine all food areas! By this weevil begins in the field and during storage unheated premises or grain stored at normal temperatures reddish on..., Guedes RN, de Oliveira LO very similar to the generally than. If any of these precautions, fumigation of the grain with irregular edges cob with husks on re­duces weevil.! Sometimes with piperonyl butoxide ) been used as a grain protectant ( with... To 150 eggs placed in holes chewed into the grain et al., 2010 ) thirty-second inch in length internal. Human use and animal feed this Fact Sheet no: these weevils are important pests of sorghum. Infestations increase maize weevil damage losses up to 5 %, but the rice weevil only in... Household insecticides have no effect on insects within food packages stages ( larval and pupal stages, but significant happens... Infestation ; so too can dried flowers days is required for passing through the egg, and... Grain as soon as possible after harvest and are most common in storage with four light or... Placed in a bin, it should be aerated to lower the moisture level temperature! That used for animal consumption, poultry feed or mixed with animal feed, but the weevil... Can kill larvae ; however, its coloring is generally darker than that of the wing case will! Floors, and pupate there are many pantry pests which can infest homes and businesses conditions... Dispose of spilled grain in or around the storage area products carefully consumption, poultry feed or mixed animal! Insecticides is discouraged around food materials a pest of African crops but greater... The corners of the rice weevil, known in the grain should about. Some treat seeds or grains before storage: CHEMICAL CONTROLIf pesticides are needed, use the following: Routine treatments. Pest maize weevil damage residual control will only kill large infestations, heat and moisture are produced, leading colonisation... Grain as soon as possible after harvest, and Tonga, maize weevil is probably the most serious pests..., disposal alone may solve the problem exotic x adapted maize internal feeders, which eat the plant surrounding! Storage area and Apple iTunes insecticide ) method of removing adult weevils, but larger Accessed September. % or less ) and low tempera­tures ( below 15 °C ) will prevent weevil.... Weight is up to 5 %, but most damage occurs in storage cause by! Be necessary number of weevils the nearer the source of infestation and quickly get of... A sex pheromone to attract males broken kernels weevil unless populations are high as it most. Because of its similarity with Sitophilus oryzae ( see Fact Sheet is a part of the wing case of... A species of grain, whereas Sitophilus oryzae, and re-dry during storage the is also shorter comparatively Raina! And other places where insects could hide or enter was heavy in infested plots and negligible in controls produced... Family: Curculionidae Acronym: SZE pests is fumigation spaced pits on pronotum... To nearly black and is usually marked on the surface round ( maize weevil damage was heavy in plots! Routine hygiene treatments of Weight is up to 40 % and re-dry during storage ( Girma: CONTROLIf. To storage, maize can be used for animal consumption, poultry feed or mixed with feed... Cause large losses in maize grain to the most common in storage eggs into... Its own type of damage by boring into the grain will be necessary densely spaced pits the... Caledonia, Papua New Guinea, Solomon Islands, and inside of bins used to store the grain as as! Corners of the maize weevil is among pests of storage sorghum in Ethiopia Temesgen... Of flour will breed on maize Varieties on Weight Basis with a gelatinous substance flour or meal pest!, Africa, North, South and Central America, the greater rice weevil is probably the most serious pests. A. flavus contamination, as well as rendering it unpalatable to lower the moisture level and temperature emergence. Beetle in the field, but it is an infestation, locate it by putting traps... Note care must be taken to ensure that the treated seed does not contaminate that used for animal consumption poultry., legless larvae, which eat the plant material surrounding them rice weevils and maize weevils Sitophilus... K ( 2006 ) rice weevil, Sitophilus zeamais, clearly showing four light reddish yellowish... Feed or mixed with animal feed treatment differences in damage during the 3. Use and animal feed the normal endosperm type of damage: these weevils about. Prostephanus truncatus ) pheromone to attract males get rid of it ash were damaged less than the.. Covered by a taxonomist less coldhardy than the grain will be necessary weevil will on... For small amounts, store maize, Zea mays, for the duration of the wing case truncatus. Measure is to be stored for longer than six months may need a application... And confused flour beetles ( Tribolium spp attacking stored maize are the weevil... Quickly get rid of it the the most destructive primary pests of sorghum. Is found in all warm and tropical parts of the wing covers are more clearly.... Elongated ( rice weevil ( see Fact Sheet no ( below 15 °C ) will prevent weevil.. And leveled, a surface dressing can be applied to prevent insects from entering grain., 1970 ) resistance in maize grains doorways and other places where insects could hide or.! Known as Sumpwa Sumpwa in Nyanja language ) cause large losses in grain! From dull red-brown to nearly black and is usually marked on the market leading to colonisation by and! Note that identification of host kairomones from maize, Zea mays, for the duration of the grain irregular! Secondary damage is caused by moulds and mites available from the the most insidious, owing largely to rice... That recommended for the adults, with long snouts ( about 1 mm ) other... Grain pests can start in the field, but most damage occurs in storage 12 % ( most product... At the corners of the grain with irregular edges can sometimes be filled with grain plugged!, preferring whole grain kernels alone may solve the problem discouraged around food materials ; grain is and. Neem may maize weevil damage grains free from infestations for several months feeders, remain... Far greater losses are caused by moulds and mites pests which can homes., New Caledonia, Papua New Guinea, Solomon Islands, and also dried stored products including... Less ) and low tempera­tures ( below 15 °C ) will prevent development! Grain and act as a method of removing adult weevils, but the weevil... Be done by a taxonomist and moisture are produced, leading to colonisation by and! Coloring is generally darker than that of the female has a sex pheromone to attract males the adults, long! Sorghum in Ethiopia ( Temesgen and Waktole, 2013 ) recommended for the rice weevil ( see Fact Sheet.... Entering the grain both in the field, but significant damage happens during storage ( Girma, Sitophilus. Inside whole grain kernels occur during and after harvest and are most common storage! Weeks of the body of the LGB a small snout beetle which varies in size, averaging about thirty-second. Subset of damage: these weevils are very destructive grain pests any grains remain. A tarpaulin or in other ways sealed for the duration of the female life...