INSECT GALLERY

Beetles

General:

Beetles represent the insect order with the most species – they are found nearly everywhere on the planet. The outward appearance of beetles is generally familiar, characterized in general by a hard and solid body surface. Ancient cultures revered some beetles as holy, and even today some species are thought to bring good luck. Although many beetle species are beneficial, others are plant pests and still others stored product and material pests.

Biology:

Beetles develop in several stages. The larvae emerge from the eggs, then pupate after a number of moultings. Following pupation, the adult beetle then emerges from the pupa. Most beetle species can fly.

Damage:

The beetle relevant in this context can be classified as either stored product pests or material pests. The stored product (or storage) pests include the species that infest food, non-edible foodstuffs or feeds. They not only cause feeding damage, but also represent serious problems for hygienic reasons due to contamination of foods. Material pests often infest valuable products such as furs, carpets, woollens, books, etc. A number of species are also dangerous wood pests. Both the larva and adult forms of many beetle species can cause considerable damage.

Moths

General:

The insects generally known as “moths” belong to the same order as the butterflies (Lepidoptera) and are sometimes classified as microlepidopterans or simply “moths”. Moths include classic stored product pests that live in foodstuff stores. Private households (kitchen, pantry) are also often affected. Some species (e.g. the common clothes moth) are also problematical material pests. In contrast to butterflies, moths are relatively small and their colouration tends to be subdued. They are most active during the night and twilight hours.

Biology:

The development cycle of moths includes the stages egg, larva, pupa and adult (or imago). The larva, in most cases a worm-like caterpillar, begins feeding after it emerges from the eggs. After a series of moultings, they reach a certain size and pupate, in which stage the development of the adult animal takes place. The adult moths normally do not feed. They are responsible for reproduction and, after pairing, lay eggs near or on the stored foodstuffs. The duration of development from egg to adult moth depends on the species, temperature and nutrient substrate and can take several weeks to several months.

Damage:

The actual damage is cause by the larval stage, i.e. the caterpillars. They feed on stored products, produce cocoons and contaminate the foodstuffs with them and their droppings. Material pest moth larvae cause damage by eating holes in, for example, textiles.

Categories: ,

<strong>Angoumois Grain Moth (<em>Sitotroga cerealella</em>)</strong><br><br>
<strong>Biology:</strong>  The Angoumois grain moth has a wingspan of up to 18 mm. The wings are stretched, pointed and feature long fringes at the posterior edge. The forewings have a dull clayey yellow colour with black dots. The larvae grow to 7 mm, are at first yellow-red and later turn white. They live inside cereal grains and are therefore hard to find. The caterpillars hollow out the entire grain and pupate inside.<br><br>
<strong>Damage:</strong>  This hollowing out of the grains causes the most damage. All grain types are affected, in particular wheat and maize, but also rice, millet, legumes, sweet chestnuts and cocoa beans. The odour and taste of the infested products are severely affected.
<strong>Common Bean Weevil (<em>Acanthoscelides obtectus</em>)</strong><br><br>
<strong>Biology: </strong> The pear-shaped common bean weevil grows to a length of up to 5 mm. It is brownish, with light grey lengthwise spots on the wings and green-yellow hairs on the upper side. The adult beetles fly well. The larvae bore into legume seeds (beans, peas, etc.) and pupate there. This beetle species is highly thermophilic.<br><br>
<strong>Damage: </strong> Besides beans, various legumes (peas, lentils, vetches, etc.) are infested by the common bean weevil. Damage results from hollowing out of seeds, inside of which the larvae, pupae and young weevils are found. The seeds show circular exit holes when the beetles have left them.
<strong>Cadelle</strong><br><br>
<strong>Appearance:</strong> The slim, flat, 6-11 mm long beetle is brown to black, ventral side, antennae and legs are red-brown. A particular feature is the waisting between wing covers and neck shield, whose front outer corners extend towards the head. The dirty-white larva, 15-18 mm long, has a black head, behind this a black shield, two black hooks at the end of the body and long body hairs. The yellowish-white pupa is 7-10 mm long.
 <br><br>
<strong>Life History:</strong> The female deposits some 500-1,000 eggs in clusters in the grain or grain products over the course of several months. The entire development period is about 1 year in temperate zones, and up to 3 generations per year in the tropics. In mills, the larvae are mainly found in clumps of Mediterranean flour moth webs, but also in cracks in timber. Before pupation, the larvae bore into wood or make a bed of flour and other materials. The larvae hibernate before pupation. The adults are long lived, often more than a year. 
  <br><br>
<strong>Distribution:</strong> World-wide.
  <br><br>
<strong>Damage:</strong> Is a serious pest in the tropics. The cadelle is found in mills, silos and warehouses, on grain, mill products, feeds, groundnut seeds, etc. Irregular borings are found in kernels; germs are preferred. The cadelle gnaws through the bolting cloths in mills, and through its tunneling may weaken timber sections in mill equipment and storage bins.
<strong>Warehouse (Cocoa) Moth</strong>
   <br><br>
<strong>Appearance:</strong> The moth has a wing expanse of 14-17 mm; when at rest, the wings folded to a roof over the body, it is 8-11 mm long. The grey to brown-grey forewings have wavy transverse bands with dark borders. The caterpillars are whitish, yellowish or reddish (depending on nutrition) with brown head and neck shields. They grow to a length of 10-15 mm.
   <br><br>
<strong>Life History:</strong> The female deposits about 100 eggs, singly or in small clusters. The caterpillars cover the infested goods with webbing. Pupation occurs in a cocoon. The development period depends on warmth and nutrition. Depending on the season, complete development takes 2-6 months. Mass reproduction only in temperate climates, here also in outside locations. 
    <br><br>
<strong>Distribution:</strong> Practically all temperate-zone countries. 
  <br><br>
<strong>Damage:</strong> The caterpillars live on dry vegetable materials such as grain, nuts, cocoa beans, chocolate goods, tobacco, herbs, dried fruits, mainly in such places as warehouses, chocolate factories, drugstores.
<strong>Cigarette Beetle (<em>Lasioderma serricorne</em>)</strong><br><br>
<strong>Biology</strong>:  These oval, brown-red beetles are 2 to 4 mm long. The head is characteristically hidden beneath the neck plate. The adult beetles do not feed, but the yellow-white, larvae, up to 4 mm long and covered with dense hair, cause feeding damage in stored plant products. They can also develop and reproduce on tobacco and tobacco products due to digestive symbionts that help them degrade and detoxify nicotine.
<br><br>
<strong>Damage</strong>:  The damage is cause primarily by larval feeding. Affected products include tobacco and tobacco products, as well as herbal drugs, dried fruit, cocoa, spices, etc.
<strong>Cacao Moth (<em>Ephestia elutella</em>)</strong><br><br>
<strong>Biology:</strong>  The cacao moth inhabits Europe and extensive parts of North America. The adult has a wingspan of 16-20 mm. Its grey to brown-grey forewings are characterized by wavelike cross-patterns with dark edges. The habitus is largely the same as for the Indian meal moth. The cacao moth also occurs, however, in outdoor areas.
<br><br>
<strong>Damage:</strong>  Not only the habitus, but the preferred food of the cacao moth is very similar to that of the Indian meal moth, resulting in similar damage. The many names given to this moth (cacao moth, hay moth, tobacco moth) reflect the wide range of its diet, including grain products, nuts, sweets (a major pest in the sweets industry), as well as cocoa beans, tobacco and even hay and straw.
<strong>Coffee Bean Weevil</strong>
 <br><br>
<strong>Appearance:</strong> This compact beetle is 1.5-4 mm long, dark brown with light brown spots and long antennae. The footless, slim larva is curved and hairy and grows to a length of 5-6 mm.
 <br><br>
<strong>Life History:</strong> The beetle flies to fields and lays its eggs on damaged cobs. Larvae bore into coffee beans in which they pupate. 
 <br><br> 
<strong>Distribution:</strong> Is found in coastal countries of the tropics and subtropics. 
  <br><br>
<strong>Damage: </strong>Mainly to corn, cocoa, coffee beans, dried fruits, nutmegs, ginger, etc., in tropical stores. Is transported to the temperate zones in cocoa and coffee beans but generally does not survive there.
<strong>Confused Flour Beetle</strong>
 <br><br>
<strong>Appearance:</strong> A slim beetle of 3-4 mm length, of uniform red-brown to black color.
 <br><br>
<strong>Life History:</strong> The eggs, which are laid loosely on the stored product, are not readily discernible; the female deposits eggs for a period which can exceed 1 year, 350400 eggs on average. The total development period is 7-12 weeks, depending on temperature; the larvae pupate loosely in the infested goods. Sensitive to cold; high humidity favors development. The beetles seldom fly, and can live more than 3 years.
  <br><br>
<strong>Distribution:</strong> All parts of the world; in cooler climates, restricted to warm storages. 
  <br><br>
<strong>Damage:</strong> Beetles and larvae feed on a very wide variety of dry vegetable substances, for example, milled cereal products, groundnuts, cocoa beans, legumes, spices, dried fruits, tapioca, oilseed cake, etc. A frequent mill pest; badly infested flour has a sharp odor and turns brown; its baking properties are damaged. This pest can also attach undamaged wheat kernels.
<strong>Drugstore Beetle (<em>Stegobium paniceum)</em></strong><br><br>
<strong>Biology:</strong>  The rust-red to brown drugstore beetle grows to a length of 2 to 4 mm. Its wing cases are covered with fine hairs and strips of dots. The head is covered by the neck plate. This beetle flies well, but does not feed in the adult stage. The white larvae live in the nutrient substrate, where they build cocoons in which they moult and pupate. The drugstore beetle is among the commonest pests in households, pharmacies and drugstores.<br><br>
<strong>Damage:</strong>  The damage results from larval feeding. Affected products are contaminated and their appearance is ruined by the feeding and emergence holes. The larvae are not very particular and are found in baked goods, pasta, grain and grain products, herbal drugs, cocoa and many other products as well as in leather, bookbinding, etc. They also bite through packaging materials such as paper, cardboard, etc.
<strong>Flour Mite (<em>Acarus siro</em>)</strong><br><br>
<strong>Biology: </strong> Flour mites are very small animals, usually less than 0.5 mm long, with 6 legs in the larval form and 8 legs in the adult stage. They are arachnids, i.e. relatives of spiders. 
The development of the flour mite is normally from egg to larvae, followed by various nymph stages and then the adult form. However, durable forms are often produced that can survive very long periods of unfavorable conditions. Mass reproduction usually follows when conditions become favorable.<br><br>
<strong>Damage: </strong> Flour mites infest mainly products made from cereal grains, pasta and baked goods. Infested products are coated with a light-coloured dust. They spoil and often taste bitter. 
Foodstuffs infested with flour mites may cause severe allergic reactions, asthma attacks and other pathological symptoms.
<strong>Ground Nut Borer</strong> <br><br>
<strong>Appearance:</strong> These dark reddish-brown pests have smudgy black spots on the wing covers and is 3-7 mm long.
  <br><br>
<strong>Life History:</strong> It is found in the tropics on whole and shelled groundnuts, both in the field and in store. Pupation occurs outside the seed and also outside the shell, in a thin cocoon. 
   <br><br>
<strong>Distribution:</strong> All tropical countries.
 <br><br> 
<strong>Damage: </strong>To groundnuts, pods of tamarinds and other types of acacia found in the tropics. Is carried into the temperate zones with groundnuts, but does not become established.
<strong>Indian Meal Moth (<em>Plodia interpunctella</em>)</strong><br><br>
<strong>Biology: </strong> The Indian meal moth has developed into the most frequently occurring moth in industry, commercial trade and human habitations. The adults have a wingspan of 20 mm. The part of the forewing next to the body is yellow-grey, the wingtip red-brown to copper red. One females lays 200 to 400 eggs. The larvae grow to a length of 16 mm and vary in color depending on what they feed on between whitish, greenish and reddish.<br><br>
<strong>Damage:</strong>  Despite its name, the Indian meal moth eats all kinds of foodstuffs; the name “meal moth” reflects this. These animals are found, for instance, on dried fruit, nuts, chocolate, grain, spices, etc. The larvae eat the germ out of the grains; holes are eaten in foodstuffs. The foodstuffs are heavily contaminated by cocoon spinning and fecal crumbs.
<strong>Khapra Beetle (<em>Trogoderma granarium</em>)</strong><br><br>
<strong>Biology: </strong> The Khapra beetle has an oval form and grows to a length of up to 3 mm, whereby the males are somewhat smaller than the females. The beetles are dark brown, covered with fine hairs and have pale yellow and reddish brown bands across the wing cases. The typically hairy larvae are yellow-brown and can be up to 5 mm long. A group of setae emerge from the posterior end of the larva. The animals are highly thermophilic, but they can also lapse into a state of rest or torpor (diapause) to survive unfavorable conditions in the long run. The adult beetles do not feed, but the larvae have a very broad nutritional spectrum and live on all kinds of plant and animal products.<br><br>
<strong>Damage:</strong>  This beetle species is originally from India, has now been inadvertently imported into many countries and is one of the most dangerous quarantine pests of all. Damage to stored goods results from larval feeding. Their broad nutritional spectrum includes, among other things, cereal grains, grain
<strong>Larder Beetle (<em>Dermestes lardarius</em>)</strong><br><br>
<strong>Biology:  </strong>The larder beetle grows to a maximum length of 9 mm. The wing cases are basically black, but show a yellow-brown coloring on their front halves as well as three black spots on each side. The larvae are up to 15 mm long, are more slender towards the posterior end and are thickly covered with hairs. The pupae are found for instance in wood, mortar and wall bricks. The beetle can fly. In addition to human habitations, leather and fur stores, meat processing operations, warehouses etc. it is also found outdoors, especially on cadavers and in birds' nests. Other larder beetle species, such as the uniformly brown to black-colored hide beetle (Dermestes maculatus), are similar in habitus and damage to the larder beetle.
<br><br>
<strong>Damage: </strong> The larvae of the larder beetle ruin foodstuffs such as bacon, ham, sausage, cheese, nuts, dried fruit, etc. by feeding and with their feces. They also destroy hides, leather and woolen textiles by scraping and eating holes in them.
<strong>Lesser Grain Borer (<em>Rhizopertha dominica</em>)</strong><br><br>
<strong>Biology:</strong>  The neck plate of this approx. 3 mm long, dark brown to black beetle is drawn up over the head like a hood. The feelers, ending in a tripartite club, are visible. The females lay their eggs on cereal grains. Both larvae and beetle feed on grain, leaving irregular holes of differing size. Older larvae bore into the grains and pupate there. This beetle species is best adapted to warmer temperatures and was accidentally introduced here.<br><br>
<strong>Damage: </strong> The lesser grain borer causes damage by feeding on grain, grain products, baked goods, legumes, herbal drugs, etc. The nutrient substrate emits a honey-like odour when infested. These beetles can also damage packaging materials by boring into them.
<strong>Mealworm Beetle (<em>Tenebrio molitor</em>)</strong><br><br>
<strong>Biology: </strong> The gleaming black-brown mealworm beetle is among the largest stored product pests with a body length of 13 to 18 mm. It occurs in bakeries, storehouses and flour mills, but also in human habitations, pigeon lofts and outdoors, especially in birds’ nests. The larvae grow to a length of 28 mm, are yellow-brown and are the “mealworms” used as feed for fish, reptiles and birds. Both larvae and beetles feed on flour and other grain products as well as many other products derived from animals and plants.<br><br>
<strong>Damage:</strong>  Larvae and beetles cause feeding damage and contamination damage to the affected products. The larvae also occasionally bore holes in rotten wood. With its long life cycle, this species does not generally tend to mass outbreaks, so that thorough cleaning and elimination of food residues should be sufficient to prevent a serious infestation.
<strong>Mediterranean Flour Moth (<em>Ephestia kuehniella</em>)</strong><br><br>
<strong>Biology: </strong> The Mediterranean flour moth is coloured very like the cacao moth, but is somewhat larger (wingspan 20-25 mm). The caterpillars reach a length of 20 mm. The habitus of the Mediterranean flour moth is also generally similar to that of the Indian meal moth and cacao moth.<br><br>
<strong>Damage: </strong> The Mediterranean flour moth is the principle pest of flour mills and large-scale bakery operations. Its geographical distributions is practically the same as that of the cacao and Indian meal moths. This species also shows a similarly flexible range of feeding tastes. Besides flour, the products infested include coarse meal, semolina, noodles, bran, oat flakes, rice, dry baked goods, beans and cereal grains, etc. In milling operations, the cocoons may be so numerous as to clog conveyor and sieving equipment.
<strong>Saw-toothed Grain Beetle (<em>Oryzaephilus surinamensis</em>)</strong><br><br>
<strong>Biology:</strong>  This very lively, slender, flattened beetle is up to 3 mm long and is colored grey-brown to rusty brown. The neck plate has two flat broad lengthwise grooves and six sharp points on each side. These beetles feed on cereal grains, flour products, pasta, baked goods, dried fruit, nuts, etc. The females lay the eggs on these nutrient substrates. Following larval development, the grubs pupate either unattached or in a cocoon comprising pieces of the nutrient substrate glued together. In warm grain stores massive proliferations can develop rapidly.<br><br>
<strong>Damage:</strong>  After the grain weevil, the saw-toothed grain beetle is the most important grain pest, causing extensive damage to the food industry. This is a feared pest because of its small size and extraordinary mobility, enabling it to get into everything, so that the insects are often transported inside food packaging. They are feared in the grain storage industry for their rapid and massive reproductive capacity. Damage is cause by feeding on the foodstuff substrates and resulting loss of quality due to heating and raised humidity followed by proliferation of mold fungi.