Stored-Product Insects: Biology (Continued) Slide 31: The slide set is a continuation of lecture 8. In this set, you will be introduced to the biology of additional stored-product insects.

Cigarette Beetle, Lasioderma serricorne Stout, oval, 2-2.5 mm long Light brown in color Elytra smooth, without striae, but with short hairs 11-segmented antennae (4-10th are serrate) When disturbed adult head is concealed under pronotum Slide 32: The cigarette beetle is not a pest of whole cereal grains, but is found associated with feed materials, packaged food, and pharmaceuticals. See notes in the slide for details.

Cocoa, tobacco, tobacco products and processed food, oil seeds Holes in produce, and pupal cells in infested material 4-6 instars Adults live for 2-6 weeks 20-37.5oC, temperature limits (25-120 days from egg-to-adult). 25% RH low end Mycetomes, yeast-like structures in hindgut Adults are active fliers Female lays 110 eggs Slide 33: See notes in the slide.

Drug Store Beetle, Stegobium paniceum Last 3 antennal segments are large and appear as loosely segmented Striae on elytra Less common in tropics Chocolate, confectionary, biscuits, herbs, spices, pharmaceuticals. 15-34oC at RH > 35% Adults live for 13-65 days Female lays 75 eggs Slide 34: This species feeds on materials similar to that of the cigarette beetle. Both cigarette beetle and drug store beetle can penetrate packaged materials. See notes in the slide.

Slide 35: Color picture of cigarette beetle (left) and drug store beetle (right). Below, cigarette beetle is on the left (e) and drug store beetle on the right (f).

Sawtoothed and Merchant Grain Beetles, Oryzaephilus spp. Sawtoothed grain beetle, O. surinamensis. Merchant grain beetle, O. mercator. Foods: Stored grain, cereal products, dried fruit, oilseeds, and processed oilseeds. O. mercator - household pest of processed cereals, especially those of high oil content. Slide 36: These two closely related species have similar biologies. However, sawtoothed grain beetle is also found in stored grain, but not the merchant grain beetle. Both species do welkl on foods of high protein and oil content.

Slide 37: Picture of the sawtoothed grain beetle Slide 37: Picture of the sawtoothed grain beetle. Both species have the pointed teeth like projections on the pronotum.

Slide 38: The temple behind the eye is a key characteritic separating both the species. You have seen this character in the laboratory.

O. surinamensis does not develop on foods without carbohydrates. Unable to attack sound grain, but attacks grain with small lesions in pericarp. Feeds on germ Cannot complete development on endosperm alone. Can feed on eggs and dead adults of storage moths. Slide 39: See notes in the slide.

Both species have similar life histories. Eggs laid singly or in small clusters. In coarse foods, eggs are deposited in crevices; in finely ground material they are laid loosely. Instars, 3-4 (> in mercator than surinamensis). Temperature limits: 20 – 38oC. Optimum range = 30-35oC for surinamensis and 30-32.5oC for mercator. Low RH prevents development of only mercator. Rate of development increases with humidity For example, for both species: At 30oC, 74% RH-- 19 days (egg-to-adult). At 12% RH,-- 24 days. Mortality > 30% at RH below 33%. Slide 40: See notes in the slide.

Fecundity highest at 54% RH (surinamensis) and 74% RH (mercator). Oviposition, 1 week after eclosion. Max. 2nd and 3rd week after emergence. Rate of egg laying high for 10 weeks. 260-280 eggs/female (both species). RH affects length of oviposition period and no. eggs laid. At 12% RH, 52 eggs are laid. Life span of mated females: 4 – 19 weeks (12% RH and 74% RH). Adults and larvae are somewhat tolerant to cold. Slide 41: See notes in the slide.

Flour Beetles, Trobolium spp. 9 species. castaneum, confusum, madens, audax, destructor, anaphe, thusa, brevicorne, and parallelum. T. castaneum – warmer climates. T. confusum – cooler climates. Become established in heated facilities. T. castaneum – grain and grain products. T. confusum – flour. Peas, beans, cacao, cottonseed, nuts, dried fruit, vegetables, drugs, milk, chocolate, peanuts (only T. castaneum). Milled products are favored diets. Slide 42: These beetles prefer floury materials, and are commonly found in grain as well as in food processing facilities.

Slide 43: Picture of the red flour beetle.

T. castaneum and T. confusum Differences Between T. castaneum and T. confusum Slide 44: Differences between the red and confused flour beetle.

Both species: eggs are laid singly. Tacky. Instars: 7-8. E-to-A development: see handout for T. castaneum. Slide 45: See notes in the slide.

Minimum: 20-22.5oC. Maximum: 37.5-40oC. Optimum = 32-35oC. Minimum, Optimum, Maximum temps. For development: 2.5oC lower for T. confusum compared with T. castaneum. Minimum: 20-22.5oC. Maximum: 37.5-40oC. Optimum = 32-35oC. Development < 1 month at 30oC. Progeny production varies with diet. Can feed on eggs and dead adults of the Indianmeal moth. Egg laying period: At 27oC, 148 (castaneum) to 235 days (confusum). No. eggs laid: 119-539 eggs/female (low to high temps). Average life span = 1-2 years. Slide 46: See notes in the slide.

Both species can breed on seed-borne fungi Both species can breed on seed-borne fungi. Can feed on 24 species of fungi. Oviposited on 16 species. Completed development on 7-8 species. Rate of self multiplication: 1.29 at 22.5oC to 2.71 at 35oC for T. castaneum at 70% RH. T. confusum rate of increase is slightly lower than that of T. castaneum. Slide 47: See notes in the slide.

Cadelle, Tenebroides mauritanicus Family: Trogositidae. Adults are 5-11 mm long Larvae and adults feed on many nuts, seeds, grains and grain products. Can eat adults of R. dominica, S. oryzae, and O. surinamensis. Larval development: 69 days on corn and wheat. Eggs laid in batches (10-60). Incubation: 15-17 days at 22C. Instars, 7-8. Larvae overwinter. Mature larvae burrow into soft wood and create a chamber for pupating. Can bore into hard woods. With overwintering: E-to-A = 271-410 days. Slide 48: This is a seriosu pest in oriental regions, and an occasional and not so devasttaing pest here in the US. See notes in the slide.

Slide 49: Picture of adult and larvae, and information on development throughout the year. A slow developing insect, usually found in grain and grain products that are going out of condition, or produced in facilities made of wood.

Lay eggs throughout adult life (mean fecundity = 910 eggs total). Adults live for a year. Lay eggs throughout adult life (mean fecundity = 910 eggs total). 2-3 generations per year. Slide 50: See notes in the slide.

Dermestids Family: Dermestidae. 700 species. 3 categories: breed only on animal protein (Dermestes spp.) breed on plant and animal materials (Attagenus spp., Trogoderma spp.) breed on cereals and cereal products (Trogoderma spp.). Trogoderma granarium (Khapra beetle). Serious pest of stored grain. Eradicated from US (CA, AZ, NM). Slide 51: These insects can feed on a variety of products of both and animal origin. They are also associated with bird nests. See notes in the slide.

Short antennae with 10-11 segments Larvae hairy; some hairs detachable Oval in shape Colored hairs on body Short antennae with 10-11 segments Larvae hairy; some hairs detachable Slide 52: See notes in the slide. Picture of dermestids showing hairy bodies, that produce a characteristic pattern useful in species identification.

Slide 53:

Larvae unable to penetrate intact seeds. Larvae feed on germ and endosperm. On wheat, eat only the germ. Eggs laid singly. Instars, 4-5. Optimum temp. 35C. Maximum = 40C. Develop at 23-73% RH. Adults are short-lived. They do not feed. One mating – 25-46 eggs/female. Starvation: retrogressive molting. Temperature, food, population density, and genetic makeup – influences diapause.

Stored-Product Moths Adult wings covered with scales Coiled mouth parts Larvae – caterpillars, 3 pairs of true lesgs on thorax and 5 pairs of false prolegs on abdominal segments 3-6 2 families: Pyralidae – Indianmeal moth, almond moth Gelechidae – Angoumois grain moth

Angoumois grain moth, Sitotroga cerealella Hind wings sharply pointed, and have long fringes Fore wings have a dark spot distally Adults live for 5-10 days Female lays 200 eggs Dev. 16-35C and 50-90% RH Adults are strong fliers

Indianmeal Moth, Plodia interpunctella Forewings, basal 1/3rd cream colored; distal 2/3rd copper colored Feeds on germ, endosperm of kernels Webbing 400 eggs/female Larvae undergo diapause Wandering stage 20-36C; RH 20-90%.

Almond moth, Cadra cautella Fore wings grayish brown with a distinct pattern Hind wings have broadly rounded tips 300 eggs/female 15-36C, 20-90% RH Mandibular secretions: female egg-laying. Also acts as dispersal pheromone. Moth activity Both species: pop. Increase 50X/lunar month

Storage Moths: Temperature vs Egg-to-adult development Source: Subramanyam and Hagstrum (1992)