Stored-Product Insects: Stored-Product Insects: BiologyBiology

(Continued) (Continued)

Cigarette Beetle, Cigarette Beetle, Lasioderma Lasioderma serricorneserricorne

Stout, oval, 2-2.5 mm longStout, oval, 2-2.5 mm long Light brown in colorLight brown in color Elytra smooth, without striae, but Elytra smooth, without striae, but

with short hairswith short hairs 11-segmented antennae (4-1011-segmented antennae (4-10thth

are serrate)are serrate) When disturbed adult head is When disturbed adult head is

concealed under pronotumconcealed under pronotum

Cocoa, tobacco, tobacco products and Cocoa, tobacco, tobacco products and processed food, oil seedsprocessed food, oil seeds

Holes in produce, and pupal cells in Holes in produce, and pupal cells in infested materialinfested material

4-6 instars4-6 instars Adults live for 2-6 weeksAdults live for 2-6 weeks 20-37.5oC, temperature limits (25-120 20-37.5oC, temperature limits (25-120

days from egg-to-adult). 25% RH low days from egg-to-adult). 25% RH low endend

Mycetomes, yeast-like structures in Mycetomes, yeast-like structures in hindguthindgut

Adults are active fliersAdults are active fliers Female lays 110 eggsFemale lays 110 eggs

Drug Store Beetle, Drug Store Beetle, Stegobium paniceumStegobium paniceum

Last 3 antennal segments are large and Last 3 antennal segments are large and appear as loosely segmentedappear as loosely segmented

Striae on elytraStriae on elytra Less common in tropicsLess common in tropics Chocolate, confectionary, biscuits, Chocolate, confectionary, biscuits,

herbs, spices, pharmaceuticals.herbs, spices, pharmaceuticals. 15-3415-34ooC at RH > 35%C at RH > 35% Adults live for 13-65 daysAdults live for 13-65 days Female lays 75 eggsFemale lays 75 eggs

Sawtoothed and Merchant Grain Sawtoothed and Merchant Grain Beetles, Beetles, Oryzaephilus Oryzaephilus spp.spp.

Sawtoothed grain beetle, Sawtoothed grain beetle, O. surinamensisO. surinamensis.. Merchant grain beetle, Merchant grain beetle, O. mercatorO. mercator..

Foods:Foods: Stored grain, cereal products, dried fruit, oilseeds, and Stored grain, cereal products, dried fruit, oilseeds, and

processed oilseeds.processed oilseeds. O. mercatorO. mercator - household pest of processed cereals, - household pest of processed cereals,

especially those of high oil content.especially those of high oil content.

O. surinamensisO. surinamensis does not develop on foods does not develop on foods without carbohydrates.without carbohydrates.

Unable to attack sound grain, but attacks Unable to attack sound grain, but attacks grain with small lesions in pericarp.grain with small lesions in pericarp.

Feeds on germ Feeds on germ Cannot complete development on endosperm Cannot complete development on endosperm

alone.alone. Can feed on eggs and dead adults of storage Can feed on eggs and dead adults of storage

moths.moths.

Both species have similar life histories.Both species have similar life histories.Eggs laid singly or in small clusters.Eggs laid singly or in small clusters.

In coarse foods, eggs are deposited in crevices; in In coarse foods, eggs are deposited in crevices; in finely ground material they are laid loosely.finely ground material they are laid loosely.

Instars, 3-4 (> in Instars, 3-4 (> in mercatormercator than than surinamensissurinamensis).).Temperature limits: 20 – 38Temperature limits: 20 – 38ooC.C.Optimum range = 30-35Optimum range = 30-35ooC for C for surinamensissurinamensis and 30- and 30-32.532.5ooC for C for mercatormercator..Low RH prevents development of only Low RH prevents development of only mercatormercator..Rate of development increases with humidityRate of development increases with humidity

For example, for both species:For example, for both species:At 30At 30ooC, 74% RH-- 19 days (egg-to-adult). At 12% RH,-- 24 C, 74% RH-- 19 days (egg-to-adult). At 12% RH,-- 24 days. Mortality > 30% at RH below 33%.days. Mortality > 30% at RH below 33%.

Fecundity highest at 54% RH (Fecundity highest at 54% RH (surinamensissurinamensis) ) and 74% RH (and 74% RH (mercatormercator).).

Oviposition, 1 week after eclosion. Max. 2Oviposition, 1 week after eclosion. Max. 2ndnd and 3and 3rdrd week after emergence. Rate of egg week after emergence. Rate of egg laying high for 10 weeks. laying high for 10 weeks.

260-280 eggs/female (both species). RH 260-280 eggs/female (both species). RH affects length of oviposition period and no. affects length of oviposition period and no. eggs laid. At 12% RH, 52 eggs are laid.eggs laid. At 12% RH, 52 eggs are laid.

Life span of mated femalesLife span of mated females:: 4 – 19 weeks 4 – 19 weeks (12% RH and 74% RH).(12% RH and 74% RH).

Adults and larvae are somewhat tolerant to Adults and larvae are somewhat tolerant to cold. cold.

Flour Beetles, Flour Beetles, Trobolium Trobolium spp.spp. 9 species.9 species. castaneum, confusum, madens, audax, destructor, castaneum, confusum, madens, audax, destructor,

anaphe, thusa, brevicorne, anaphe, thusa, brevicorne, andand parallelum parallelum.. T. castaneumT. castaneum – warmer climates. – warmer climates. T. confusumT. confusum – cooler climates. – cooler climates. Become established in heated facilities.Become established in heated facilities. T. castaneumT. castaneum – grain and grain products. – grain and grain products. TT. confusum. confusum – flour. – flour. Peas, beans, cacao, cottonseed, nuts, dried fruit, Peas, beans, cacao, cottonseed, nuts, dried fruit,

vegetables, drugs, milk, chocolate, peanuts (only vegetables, drugs, milk, chocolate, peanuts (only T. T. castaneumcastaneum).).

Milled products are favored diets.Milled products are favored diets.

Differences Between Differences Between T. castaneumT. castaneum and and T. T.

confusumconfusum

Both species:Both species: eggs are laid singly. Tacky. eggs are laid singly. Tacky.

Instars: 7-8.Instars: 7-8.

E-to-A development: see handout for E-to-A development: see handout for T. T. castaneumcastaneum. .

Minimum, Optimum, Maximum temps. For Minimum, Optimum, Maximum temps. For development: 2.5development: 2.5ooC lower for C lower for T. confusumT. confusum compared with compared with T. castaneumT. castaneum..

Minimum: 20-22.5Minimum: 20-22.5ooC. Maximum: 37.5-40C. Maximum: 37.5-40ooC. C. Optimum = 32-35Optimum = 32-35ooC.C.

Development < 1 month at 30Development < 1 month at 30ooC. C. Progeny production varies with diet.Progeny production varies with diet. Can feed on eggs and dead adults of the Can feed on eggs and dead adults of the

Indianmeal moth.Indianmeal moth. Egg laying period: At 27Egg laying period: At 27ooC, 148 (C, 148 (castaneumcastaneum) )

to 235 days (to 235 days (confusumconfusum). ). No. eggs laid: 119-539 eggs/female (low to No. eggs laid: 119-539 eggs/female (low to

high temps).high temps). Average life span = 1-2 years.Average life span = 1-2 years.

Both species can breed on seed-borne fungi. Can Both species can breed on seed-borne fungi. Can feed on 24 species of fungi. Oviposited on 16 species. feed on 24 species of fungi. Oviposited on 16 species. Completed development on 7-8 species. Completed development on 7-8 species.

Rate of self multiplication: 1.29 at 22.5Rate of self multiplication: 1.29 at 22.5ooC to 2.71 at C to 2.71 at 3535ooC for C for T. castaneumT. castaneum at 70% RH. at 70% RH.

T. confusumT. confusum rate of increase is slightly lower than rate of increase is slightly lower than that of that of T. castaneumT. castaneum..

Cadelle, Cadelle, Tenebroides mauritanicusTenebroides mauritanicus

Family: Trogositidae.Family: Trogositidae. Adults are 5-11 mm longAdults are 5-11 mm long Larvae and adults feed on many nuts, seeds, Larvae and adults feed on many nuts, seeds,

grains and grain products.grains and grain products. Can eat adults of Can eat adults of R. dominica, S. oryzae, and O. R. dominica, S. oryzae, and O.

surinamensissurinamensis.. Larval development: 69 days on corn and wheat.Larval development: 69 days on corn and wheat. Eggs laid in batches (10-60). Incubation: 15-17 Eggs laid in batches (10-60). Incubation: 15-17

days at 22C.days at 22C. Instars, 7-8. Larvae overwinter.Instars, 7-8. Larvae overwinter. Mature larvae burrow into soft wood and create a Mature larvae burrow into soft wood and create a

chamber for pupating.chamber for pupating. Can bore into hard woods.Can bore into hard woods. With overwintering: E-to-A = 271-410 days.With overwintering: E-to-A = 271-410 days.

Adults live for a year.Adults live for a year. Lay eggs throughout adult life (mean Lay eggs throughout adult life (mean

fecundity = 910 eggs total).fecundity = 910 eggs total). 2-3 generations per year.2-3 generations per year.

DermestidsDermestids

Family: Dermestidae.Family: Dermestidae. 700 species.700 species. 3 categories: 3 categories:

breed only on animal protein (Dermestes spp.)breed only on animal protein (Dermestes spp.) breed on plant and animal materials breed on plant and animal materials

(Attagenus spp., Trogoderma spp.)(Attagenus spp., Trogoderma spp.) breed on cereals and cereal products breed on cereals and cereal products

(Trogoderma spp.).(Trogoderma spp.). Trogoderma granariumTrogoderma granarium (Khapra beetle). (Khapra beetle). Serious pest of stored grain.Serious pest of stored grain. Eradicated from US (CA, AZ, NM).Eradicated from US (CA, AZ, NM).

Oval in shapeOval in shape Colored hairs on bodyColored hairs on body Short antennae with 10-11 Short antennae with 10-11

segmentssegments Larvae hairy; some hairs Larvae hairy; some hairs

detachabledetachable

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

genetic makeup – influences diapause.genetic makeup – influences diapause.

Stored-Product MothsStored-Product Moths

Adult wings covered with scalesAdult wings covered with scales Coiled mouth partsCoiled mouth parts Larvae – caterpillars, 3 pairs of true Larvae – caterpillars, 3 pairs of true

lesgs on thorax and 5 pairs of false lesgs on thorax and 5 pairs of false prolegs on abdominal segments 3-6prolegs on abdominal segments 3-6

2 families:2 families: Pyralidae – Indianmeal moth, almond mothPyralidae – Indianmeal moth, almond moth Gelechidae – Angoumois grain mothGelechidae – Angoumois grain moth

Angoumois grain moth, Angoumois grain moth, Sitotroga cerealellaSitotroga cerealella

Hind wings sharply pointed, and Hind wings sharply pointed, and have long fringeshave long fringes

Fore wings have a dark spot distallyFore wings have a dark spot distally Adults live for 5-10 daysAdults live for 5-10 days Female lays 200 eggsFemale lays 200 eggs Dev. 16-35C and 50-90% RHDev. 16-35C and 50-90% RH Adults are strong fliersAdults are strong fliers

Indianmeal Moth, Indianmeal Moth, Plodia Plodia interpunctellainterpunctella

Forewings, basal 1/3Forewings, basal 1/3rdrd cream colored; cream colored; distal 2/3distal 2/3rdrd copper colored copper colored

Feeds on germ, endosperm of kernelsFeeds on germ, endosperm of kernels WebbingWebbing 400 eggs/female400 eggs/female Larvae undergo diapauseLarvae undergo diapause Wandering stageWandering stage 20-36C; RH 20-90%. 20-36C; RH 20-90%.

Almond moth, Almond moth, Cadra cautellaCadra cautella

Fore wings grayish brown with a distinct Fore wings grayish brown with a distinct patternpattern

Hind wings have broadly rounded tipsHind wings have broadly rounded tips 300 eggs/female300 eggs/female 15-36C, 20-90% RH15-36C, 20-90% RH Mandibular secretions: female egg-laying. Mandibular secretions: female egg-laying.

Also acts as dispersal pheromone.Also acts as dispersal pheromone. Moth activityMoth activity Both species: pop. Increase 50X/lunar Both species: pop. Increase 50X/lunar

monthmonth

Storage Moths: Temperature vs Storage Moths: Temperature vs Egg-to-adult developmentEgg-to-adult development

Source: Subramanyam and Hagstrum (1992)