Pests
Pests have specialized in living in storage rooms, where the abundance of heat, moisture and food produces their mass multiplication. Some damage the field, and after harvesting they increase their population density in the storage rooms (rice weevil, grain moth). There are insects that have adapted to such an extent that their life outside the storage rooms is impossible (the grain weevil has degenerated wings).
Grain moth, dried fruit moth, gray flour moth are the most characteristic storage representatives of the order Lepidoptera (butterflies), damaging in mills, silos, homes. Storage moths fly around and infect only the surface of the stored material, after which they can migrate to other areas.
Nocturnal insects that rarely fly during the day and are often found perched on walls. Adult moths do not feed, but break down the nutrients in their bodies accumulated during the caterpillar stage.
The gray flour moth also forms cobwebs that clog elevators and augers in mills, and its larvae gnaw through sieves. Warehouse enemies.
Wheat and rice weevils, as well as the Surinamese mealworm and the Moorish beetle are representatives of the order Coleoptera (beetles), damaging granaries, bakeries, mills, and candy and pasta warehouses. Warehouse beetles enter and infect the interior of the stored grain layer, and when the grain warms up, they migrate in the direction of the higher temperature. The larvae gnaw through the interior of the grain. Weevils attack only whole grains and to prevent their activity it is necessary for the grain to be ground (feed). They transmit Escherichia coli, as well as aflatoxin through the mold Aspergillus flavus.
The wheat and rice weevils occur together and contaminate grain feeds, making them unsuitable and dangerous for animal food. The Surinamese mealworm multiplies in broken grains and grains already damaged by proboscis and moth larvae. The adult Moorish beetle feeds on grain, flour, pasta, gnaws at mill screens and cardboard packaging, and its larva gnaws at the inside of the husked rice.
Harm
Storage pests cause enormous losses to the country’s economy, due to their high fertility, rapid reproduction and the lack of any compensatory mechanisms for damaged food and materials. Therefore, there is no Threshold of Economic Harm for them.
The damage caused by pests to stored grain is no less than that caused by pests in the field, but in stored products they most often remain hidden, at least at the beginning of their harmful activity, while the density is relatively low.
The appetite of some storage pests is impressive:
– an adult grain weevil eats about 1 g of grain during its life (the beetle weighs less than 1 milligram);
– a rat eats 22 kg of grain every year;
– a house sparrow pecks 12 – 13 g of grain per day.
Storage pests contaminate products and materials with::
– eggs (chorions);
– larvae, pupae and their body shells;
– excrement and corpses of dead adults.
Storage pests also cause indirect damage. They cause self-heating of the bulk grain during their active activity. In the foci of self-heating, the temperature rises to 42°C, with a grain humidity of 15%. During self-heating, the surface of the grain layer becomes moist and a crust forms. This phenomenon is best observed in autumn, when the surface of the bulk grain cools faster. Water vapor moves from the place of self-heating to the cool surface layer, where it causes mold and seed germination to a depth of 15-20 cm. Sometimes self-heating is of even higher value and can lead to self-ignition.
The rice weevil
The rice weevil (Sitophilus) (Sitophilus oruzae) is very common in our country. It is small (2-3 mm long) and yellowish-red to dark brown in color. It has real wings and flies in the field, where it attacks the grains of cereal plants in the field, before they are harvested. The rice weevil is of higher density compared to other storage pests. It prefers soft wheat varieties, but it also develops well in other cereal crops. Unlike the wheat weevil, two larvae can develop in one grain. It is a more thermophilic species and is more sensitive to the effects of low temperatures, which can be used successfully in the fight against it.
The rice weevil (Sitophilus) (Sitophilus oruzae) is very common in our country. It is small (2-3 mm long) and yellowish-red to dark brown in color. It has real wings and flies in the field, where it attacks the grains of cereal plants in the field, before they are harvested. The rice weevil is of higher density compared to other storage pests. It prefers soft wheat varieties, but it also develops well in other cereal crops. Unlike the wheat weevil, two larvae can develop in one grain. It is a more thermophilic species and is more sensitive to the effects of low temperatures, which can be used successfully in the fight against it.The grain weevil
The grain weevil (Calandra granaria) (Calandra granaria) is a small beetle (3-4 mm long), with an oval-elongated body, slightly convex on the dorsal side, with a dark brown to black color. The head is elongated into a long proboscis. It has no real wings and cannot fly. It moves mainly by crawling. The larva has a short, fleshy body, with an arcuately curved back and an almost flat belly. It is whitish in color, up to 3 mm long. The pupa is white.
The grain weevil is a very dangerous enemy of stored grains. It damages wheat, rye, barley, corn, rice and others, as well as the products of their processing – flour, bran, semolina and dough products – macaroni, vermicelli, bread, etc. It multiplies strongly in damp, unventilated rooms. There are 3-4 generations during the year. It overwinters in all stages of development, but mainly as a beetle. The damage is caused by the beetles and larvae. They gnaw at the grains and feed on them. The larvae completely eat away the inside of the grains. The females lay their eggs singly in the hollowed-out pits, the openings of which they then close. The hatched larvae feed in the grains and pupate in them.
The grain weevil (Calandra granaria) (Calandra granaria) is a small beetle (3-4 mm long), with an oval-elongated body, slightly convex on the dorsal side, with a dark brown to black color. The head is elongated into a long proboscis. It has no real wings and cannot fly. It moves mainly by crawling. The larva has a short, fleshy body, with an arcuately curved back and an almost flat belly. It is whitish in color, up to 3 mm long. The pupa is white.The grain weevil is a very dangerous enemy of stored grains. It damages wheat, rye, barley, corn, rice and others, as well as the products of their processing – flour, bran, semolina and dough products – macaroni, vermicelli, bread, etc. It multiplies strongly in damp, unventilated rooms. There are 3-4 generations during the year. It overwinters in all stages of development, but mainly as a beetle. The damage is caused by the beetles and larvae. They gnaw at the grains and feed on them. The larvae completely eat away the inside of the grains. The females lay their eggs singly in the hollowed-out pits, the openings of which they then close. The hatched larvae feed in the grains and pupate in them.Bean grain borer
The bean grain borer (Acanthoscelides obtectus) is widespread. In addition to beans, it attacks peas, broad beans, lentils, fava beans, etc. The larva that develops in the beans and damages them is harmful. Damaged beans are unfit for consumption and sowing. The bean grain borer attacks beans, both in the field and in storage. It overwinters in bean grains and develops one generation in field conditions and 3-4 in storage. It lays its eggs by gnawing holes in the grains. The hatched larvae gnaw into the grains and remain there until the end of their development, and more larvae can develop in one grain. Fully developed beetles gnaw round holes in the seed coat, through which they exit.
The bean grain borer (Acanthoscelides obtectus) is widespread. In addition to beans, it attacks peas, broad beans, lentils, fava beans, etc. The larva that develops in the beans and damages them is harmful. Damaged beans are unfit for consumption and sowing. The bean grain borer attacks beans, both in the field and in storage. It overwinters in bean grains and develops one generation in field conditions and 3-4 in storage. It lays its eggs by gnawing holes in the grains. The hatched larvae gnaw into the grains and remain there until the end of their development, and more larvae can develop in one grain. Fully developed beetles gnaw round holes in the seed coat, through which they exit.German cockroach
The German cockroach (Blattella germanica) is one of the most common species of cockroaches. Their harmful significance lies in the fact that, crawling on food products, they sometimes contaminate them with various disease-causing viruses and bacteria (causes of dysentery, salmonellosis, hepatitis A, plague, cholera, typhoid fever, and others). They often cause allergic reactions in some people. The German cockroach can be found anywhere in the building, but prefers warm and humid places. Any crack or crevice located near a source of food or water is a potential refuge, where the German cockroach spends about 75% of its life. Adult specimens reach a size of 13 – 15 mm. They are light brown to yellowish in color. They live on average from 100 days to one year. Females lay 30-40 eggs in an ootheca – a brown capsule measuring up to 8x3x2 mm, which they carry on average between 14-35 days. The female German cockroach lays 4-9 capsules in her lifetime.
The German cockroach (Blattella germanica) is one of the most common species of cockroaches. Their harmful significance lies in the fact that, crawling on food products, they sometimes contaminate them with various disease-causing viruses and bacteria (causes of dysentery, salmonellosis, hepatitis A, plague, cholera, typhoid fever, and others). They often cause allergic reactions in some people. The German cockroach can be found anywhere in the building, but prefers warm and humid places. Any crack or crevice located near a source of food or water is a potential refuge, where the German cockroach spends about 75% of its life. Adult specimens reach a size of 13 – 15 mm. They are light brown to yellowish in color. They live on average from 100 days to one year. Females lay 30-40 eggs in an ootheca – a brown capsule measuring up to 8x3x2 mm, which they carry on average between 14-35 days. The female German cockroach lays 4-9 capsules in her lifetime.Shiny beetle
Shiny beetle (Carpophilus hemipterus). Adults reach a size of 1.8 – 2.1 mm. When food supplies are exhausted, the beetles migrate to other places.
Shiny beetle (Carpophilus hemipterus). Adults reach a size of 1.8 – 2.1 mm. When food supplies are exhausted, the beetles migrate to other places.Grain moth
Grain moth (Sitotroga cerealella Oliv) wis widespread throughout the country. It attacks grains of barley, corn, wheat, rye and to a lesser extent oats, rice, sorghum and some other crops. It is mainly harmful in warehouses and in farmyards where grain is stored outdoors, but it can also attack grain crops in the field. The body length of the butterfly reaches 9 mm, and the wingspan reaches 19 mm. The color of the butterfly is straw yellow, almost merging with the grain. Adult caterpillars reach a length of 7-8 mm.
Grain moth (Sitotroga cerealella Oliv) wis widespread throughout the country. It attacks grains of barley, corn, wheat, rye and to a lesser extent oats, rice, sorghum and some other crops. It is mainly harmful in warehouses and in farmyards where grain is stored outdoors, but it can also attack grain crops in the field. The body length of the butterfly reaches 9 mm, and the wingspan reaches 19 mm. The color of the butterfly is straw yellow, almost merging with the grain. Adult caterpillars reach a length of 7-8 mm.The female butterfly lays up to 150 eggs during her life, sticking them on the grains. The hatched caterpillar gnaws through the shell of the grain where the egg is stuck, and bites into the endosperm. There it develops until pupation, having previously gnawed a round cover glued with a cobweb in the shell, through which it later imagines the butterfly. One caterpillar develops in each grain. Sometimes up to three caterpillars are observed in corn grains. The duration of development of one generation under favorable conditions (25 – 26 оC) lasts 25 – 35 days. In the southern parts of the country, 2 generations can develop.
Bedbugs
Bedbugs (Cimex hemipterus) are flat-bodied blood-sucking insects with stunted wings, reaching up to 8 mm in size. They live in human dwellings, hiding during the day in cracks in plaster, wallpaper, wooden objects, folds of beds and mattresses. Bedbugs attack humans, animals and birds at night. With their proboscis they pierce the skin and begin bloodsucking, which lasts about 15 minutes, they can swallow up to 7 ml. of blood at one meal. They feed every 1-2 days. They can survive without food for up to half a year, and at low temperatures up to 4 years.
Bedbugs (Cimex hemipterus) are flat-bodied blood-sucking insects with stunted wings, reaching up to 8 mm in size. They live in human dwellings, hiding during the day in cracks in plaster, wallpaper, wooden objects, folds of beds and mattresses. Bedbugs attack humans, animals and birds at night. With their proboscis they pierce the skin and begin bloodsucking, which lasts about 15 minutes, they can swallow up to 7 ml. of blood at one meal. They feed every 1-2 days. They can survive without food for up to half a year, and at low temperatures up to 4 years.Temperature is an important factor for their survival, since a temperature of 13-15°C is necessary for the normal course of hatching, the development of the nymph and the life of the adult individual. The female bedbug lays about 5 to 12 eggs per day /about 250 eggs by the end of her life/ at a temperature of 12 to 37 degrees. The eggs are about 1mm in size. At first they are white, but then they turn yellow. They are usually collected in piles and attached to dry places in the cracks where adult bedbugs hide. The development of the embryos depends on the temperature. Below 10 degrees their development stops, at a temperature of 14-18 degrees they hatch in 15-29 days, at a temperature of 37 degrees they hatch in 4-7 days. Under very good conditions their development can be completed in 28 days, but when the temperature is lower it is extended to 2-3 months.
Flat grain beetle
The flat grain beetle (Cryptolestes testaceus) reaches sizes up to 2.5 mm. The body is rusty in color, densely covered with hairs. The beetles have wings and fly well. The beetles live up to six months, they can survive without food for 2.5 months. The female lays several dozen eggs. After a few days, larvae hatch from the eggs. The development of one generation lasts from 70 to 100 days. During the year, 3 to 5 generations can develop.
They do not tolerate low humidity. They develop best at 20-23 °C and in an environment with high air humidity. Their development stops at a temperature of 12-14 °C.
The flat grain beetle (Cryptolestes testaceus) reaches sizes up to 2.5 mm. The body is rusty in color, densely covered with hairs. The beetles have wings and fly well. The beetles live up to six months, they can survive without food for 2.5 months. The female lays several dozen eggs. After a few days, larvae hatch from the eggs. The development of one generation lasts from 70 to 100 days. During the year, 3 to 5 generations can develop.
They do not tolerate low humidity. They develop best at 20-23 °C and in an environment with high air humidity. Their development stops at a temperature of 12-14 °C.
Mosquitoes
Mosquitoes, (Culicidae) are a family of small dipterous insects. The mouthparts of mosquitoes are adapted for piercing and subsequent sucking. There are about forty species of mosquitoes in Bulgaria. The eggs and larvae of mosquitoes are entirely aquatic. Male mosquitoes feed on plant juices, while females prefer the blood of mammals, birds and, most importantly, humans.
Mosquitoes, (Culicidae) are a family of small dipterous insects. The mouthparts of mosquitoes are adapted for piercing and subsequent sucking. There are about forty species of mosquitoes in Bulgaria. The eggs and larvae of mosquitoes are entirely aquatic. Male mosquitoes feed on plant juices, while females prefer the blood of mammals, birds and, most importantly, humans.Mosquitoes (especially females) are carriers of a variety of pathogens that can infect people whose blood the infected mosquitoes have drunk. Only female mosquitoes suck blood. When the female feeds on blood, a batch of eggs is laid. With its keen sense of smell, the mosquito finds the suitable host and flies to it at a distance of 2-3 km. The amount of blood taken in with each bloodsucking exceeds the weight of the insect. The life cycle of mosquitoes includes the egg, larva, pupa and adult phases – a complete cycle. The first three phases live in an aquatic environment, and the imago (adult) – in an air one. They live in slow-flowing and stagnant waters. In our country, the first egg laying occurs in early May. A worm-like larva hatches from them, which breathes atmospheric air. One female lays about 300-350 eggs in her entire life. Their life span lasts from 3 to 6 months. Male mosquitoes fertilize the females and die.
House mouse
The house mouse (Mus musculus) has a body length of 15-19 cm, half of which is the tail. They are active in twilight and at night, they do not like light. Territorial animals, usually a dominant male lives together in his territory with several females and younger specimens. It settles near its food sources. They feed mainly on plant food, but can also be omnivorous. They almost do not need water. Pregnancy lasts about 19-21 days and gives birth to 7-13 young. It can give birth 5-10 times a year.
The house mouse (Mus musculus) has a body length of 15-19 cm, half of which is the tail. They are active in twilight and at night, they do not like light. Territorial animals, usually a dominant male lives together in his territory with several females and younger specimens. It settles near its food sources. They feed mainly on plant food, but can also be omnivorous. They almost do not need water. Pregnancy lasts about 19-21 days and gives birth to 7-13 young. It can give birth 5-10 times a year.Gray flour moth
The gray flour moth (Ephestia kuehniella) develops 3-4 generations per year in unheated warehouses, and in heated premises it can develop year-round and have up to 8-10 generations. It overwinters as a caterpillar, in a silk cocoon and limitedly as a pupa (in unheated warehouses). Usually in the second half of April – the first half of May, the caterpillars pupate. The pupal stage lasts 5-7 days.
The imagined butterflies are sexually mature and shortly after imagining they copulate. They are active at night, and during the day they hide in dark places. One female lays 200-300 eggs, singly or in small clusters. The eggs are laid in cracks in the walls, on the floor, sacks, food and other places. At a temperature of 13-150C, the egg stage lasts 12-21 days, and at 22-240C – 6-10 days.The hatched caterpillars crawl to the stored products and begin to feed by gnawing them. They secrete abundant silk threads, with which they bind the food products in the form of large balls (globes), reaching from half to several kilograms. With these balls they can clog the sieves and elevators in the mills and large warehouses. The caterpillars have extremely strong jaws and are able to gnaw through the thin sieves in the mills, which may require their replacement and stopping the work process. The duration of their development depends mainly on the temperature. When it is favorable, it ends in 17-20 days. The food host is also important.
The fed caterpillars leave the feeding areas and go into cracks in the floor and walls, in the attics, or to other hiding places, where they spin a silk cocoon and pupate in it.
The gray flour moth (Ephestia kuehniella) develops 3-4 generations per year in unheated warehouses, and in heated premises it can develop year-round and have up to 8-10 generations. It overwinters as a caterpillar, in a silk cocoon and limitedly as a pupa (in unheated warehouses). Usually in the second half of April – the first half of May, the caterpillars pupate. The pupal stage lasts 5-7 days.
The imagined butterflies are sexually mature and shortly after imagining they copulate. They are active at night, and during the day they hide in dark places. One female lays 200-300 eggs, singly or in small clusters. The eggs are laid in cracks in the walls, on the floor, sacks, food and other places. At a temperature of 13-150C, the egg stage lasts 12-21 days, and at 22-240C – 6-10 days.The hatched caterpillars crawl to the stored products and begin to feed by gnawing them. They secrete abundant silk threads, with which they bind the food products in the form of large balls (globes), reaching from half to several kilograms. With these balls they can clog the sieves and elevators in the mills and large warehouses. The caterpillars have extremely strong jaws and are able to gnaw through the thin sieves in the mills, which may require their replacement and stopping the work process. The duration of their development depends mainly on the temperature. When it is favorable, it ends in 17-20 days. The food host is also important.
The fed caterpillars leave the feeding areas and go into cracks in the floor and walls, in the attics, or to other hiding places, where they spin a silk cocoon and pupate in it.
Tobacco beetle
The tobacco beetle (Lasioderma serricorne) develops 3 generations per year and overwinters as larvae of different ages in the damaged areas. Younger larvae usually die in winter or early spring, as they are sensitive to low temperatures. In heated warehouses, the tobacco beetle develops year-round. When the temperature rises above 10-120C, the immature larvae fully develop and pupate in a special chamber, in the folded parts of cigarette and cigar boxes, inside the damaged tobacco, along the main vein of raw tobacco leaves and in other protected places..
The tobacco beetle (Lasioderma serricorne) develops 3 generations per year and overwinters as larvae of different ages in the damaged areas. Younger larvae usually die in winter or early spring, as they are sensitive to low temperatures. In heated warehouses, the tobacco beetle develops year-round. When the temperature rises above 10-120C, the immature larvae fully develop and pupate in a special chamber, in the folded parts of cigarette and cigar boxes, inside the damaged tobacco, along the main vein of raw tobacco leaves and in other protected places..
Surinamese flour beetle
The Surinamese flour beetle (Oryzaephilus surinamensis) is a small beetle with a body length of about 2–2.5 mm. The female lays up to 400 eggs on cereals and grains, flour (hence its name), dried fruits and spices. The larvae develop rapidly, especially in damp places (with a relative humidity of more than 14%), feeding on stored products. They pupate in cracks and crevices. The larvae complete their development in 4–6 weeks, depending on the air temperature. Adults sometimes live for a long time, up to 3 years.
The Surinamese flour beetle (Oryzaephilus surinamensis) is a small beetle with a body length of about 2–2.5 mm. The female lays up to 400 eggs on cereals and grains, flour (hence its name), dried fruits and spices. The larvae develop rapidly, especially in damp places (with a relative humidity of more than 14%), feeding on stored products. They pupate in cracks and crevices. The larvae complete their development in 4–6 weeks, depending on the air temperature. Adults sometimes live for a long time, up to 3 years.
American cockroaches
American cockroaches, (Periplaneta americana) reach a length of 34-53 mm. They are reddish brown in color, with a pale brown to yellowish band around the edge of their pronotal shield. Both male and female American cockroaches have wings, but their flight is very poorly developed. They inhabit a wide variety of environments, and can live in very dry climates, as long as they have access to water. They prefer temperatures of 29 degrees and cannot tolerate cold temperatures.
American cockroaches, (Periplaneta americana) reach a length of 34-53 mm. They are reddish brown in color, with a pale brown to yellowish band around the edge of their pronotal shield. Both male and female American cockroaches have wings, but their flight is very poorly developed. They inhabit a wide variety of environments, and can live in very dry climates, as long as they have access to water. They prefer temperatures of 29 degrees and cannot tolerate cold temperatures.
Gray rat
The gray rat (Rattus norvegicus), also known as the barn rat, has a relatively long body up to 25 cm. The tail is slightly shorter or equal to the body length of 22–25 cm. They give birth 2-4 times a year, 6-10 to 17 young.
Newborns are blind and see after two weeks. The mother nurses for one month. After 3–4 months, they reach sexual maturity. They live up to 3 years. They feed on both plant and animal food.
The gray rat (Rattus norvegicus), also known as the barn rat, has a relatively long body up to 25 cm. The tail is slightly shorter or equal to the body length of 22–25 cm. They give birth 2-4 times a year, 6-10 to 17 young.
Newborns are blind and see after two weeks. The mother nurses for one month. After 3–4 months, they reach sexual maturity. They live up to 3 years. They feed on both plant and animal food.
Grain beetle
The grain beetle (Rhyzopertha dominica) is a primary enemy of cereals and seeds. It destroys almost completely the grains, leaving only part of the husks. The larvae destroy about 30% of the endosperm of the grain. In one day, the beetles destroy an amount of grain that is approximately equal to their mass. With a large population of grain beetles, the grain acquires a characteristic musty honey smell.
The grain beetle (Rhyzopertha dominica) is a primary enemy of cereals and seeds. It destroys almost completely the grains, leaving only part of the husks. The larvae destroy about 30% of the endosperm of the grain. In one day, the beetles destroy an amount of grain that is approximately equal to their mass. With a large population of grain beetles, the grain acquires a characteristic musty honey smell.
Ticks
Ticks (Ixodoidea) are a superfamily of small arachnids of the subclass Acari. They are ectadartisiophorasites that feed by sucking blood from mammals, birds, and in some cases reptiles and amphibians. They are an important vector for the spread of many infectious diseases. The true parasite is the female tick. After fertilization, it digs small tunnels /galleries/ in the uppermost layer of the skin, in which it lays 24 eggs measuring 0.10-0.16 mm. By the third to seventh day, they turn into larvae, and by the 17th day – into nymphs, which are already capable of transmitting the infection. Blood-sucking ticks inhabit grassy-shrubby and forest areas and prefer high humidity.
Ticks (Ixodoidea) are a superfamily of small arachnids of the subclass Acari. They are ectadartisiophorasites that feed by sucking blood from mammals, birds, and in some cases reptiles and amphibians. They are an important vector for the spread of many infectious diseases. The true parasite is the female tick. After fertilization, it digs small tunnels /galleries/ in the uppermost layer of the skin, in which it lays 24 eggs measuring 0.10-0.16 mm. By the third to seventh day, they turn into larvae, and by the 17th day – into nymphs, which are already capable of transmitting the infection. Blood-sucking ticks inhabit grassy-shrubby and forest areas and prefer high humidity.
Rusty flour beetle
The rusty flour beetle (Tribolium confusum) has an elongated body up to 3.5 mm long, with a shiny rusty-red color. It has well-developed wings and flies well, especially at night.
The optimal temperature for the development of the rusty-red flour beetle is about 30°C. At this temperature, the female can lay an average of 300-400 eggs and a maximum of 1000. The species can also develop at a grain humidity of 11-12%. Under optimal conditions, the life cycle from egg to adult takes about 32-35 days and can develop from 6 to 8 generations per year. Adults live up to two years.
The rusty flour beetle (Tribolium confusum) has an elongated body up to 3.5 mm long, with a shiny rusty-red color. It has well-developed wings and flies well, especially at night.
The optimal temperature for the development of the rusty-red flour beetle is about 30°C. At this temperature, the female can lay an average of 300-400 eggs and a maximum of 1000. The species can also develop at a grain humidity of 11-12%. Under optimal conditions, the life cycle from egg to adult takes about 32-35 days and can develop from 6 to 8 generations per year. Adults live up to two years.
Trogoderma
Trogoderma (Trogoderma granarium) is one of the most dangerous species attacking grain products. It damages the seeds of wheat, barley, corn, rice, peanuts, cotton, legumes and others. Among the damaged products there is a large amount of larval cuticles. The fastest development occurs at 30 – 35 C, and the lower threshold is 8 C. At low temperature and low humidity, the larvae hide in cracks and fall into diapause and withstand hunger for up to 4 years.
Trogoderma (Trogoderma granarium) is one of the most dangerous species attacking grain products. It damages the seeds of wheat, barley, corn, rice, peanuts, cotton, legumes and others. Among the damaged products there is a large amount of larval cuticles. The fastest development occurs at 30 – 35 C, and the lower threshold is 8 C. At low temperature and low humidity, the larvae hide in cracks and fall into diapause and withstand hunger for up to 4 years.