entomology exam 2

orthopteroid orders

• plecoptera (stoneflies)

• phasmida (stick bugs)

• orthoptera (grasshoppers, locusts, crickets, katydids)

• dermaptera (earwigs)

• isoptera (termites)

• blattodea (roaches)

• mantodea (mantids)

-primitive mouthparts

-complex wing venation

-pleated hindwings usually larger than leathery forewings

-male genitalia is external

-cerci present

-many malphigian tubules

-hemimetabolous

-trochanter is separated from epimeron by suture or membrane

hemipteroid orders

• psocoptera/psocodea (lice)

• mallophaga (chewing/biting lice)

• anoplura (sucking lice)

• thysanoptera (thrips)

• hemiptera (bugs, leafhoppers)

• homoptera (true bugs)

-mandibulate mouthparts; haustelate = adapted for sucking

-lacinia is slender; labial palps absent

-enlarged clypeus associated with cybarial pump

-cerci lacking

-fewer malphigian tubules

-fusion of ventral ganglia

-if hindwing present → no large anal lobe

• arachneae

• class: arachnida

• most abundant arachnids → over 40,000 described species

• all spiders produce silk extruded by the spinnerets on the end of the abdomen

  • use it to trap insects in webs but there are many spiders that hunt freely

  • silk can aid in climbing, form smooth walls for burrows, build egg sacs, wrap prey, temporarily hold sperm, or even fly

• only about 200 species have bites that can pose health problems to humans

  • larger species’ bites may be painful but will not produce lasting health problems

• spiders are found all over the world (including the arctic) w/ some extreme species living underwater in silken domes that they supply with air or on the tops of the highest mountains

families:

• theraphosidae (tarantulas)

• salticidae (jumping spiders)

• araneidae (orb weavers)

• lycosidae (wolf spiders)

dangerous spiders:

• Atrax robustus (Australian funnel web spider)

• Loxosceles reclusa (brown recluse)

• Lactodectus mactans (black widow)

• Cheiralanthium mildei (yellow sac spider)

*brown recluse + black widow are only two medically significant spiders in N. America

• ephemeroptera

• mayflies “for a day”

characters:

• small-medium bodied

• soft cuticle

• nymphs have chewing mouthparts; adults are vestigial

• compound eyes + 3 ocelli

• setaceous antennae

• forewings are triangular and hindwings are smaller; held over the body at rest

• long filamentous cerci

• 3-5 segmented tarsi

-nymphs are aquatic

-most are general collecter-gatherers; some are filterers or scrapers; some are predators

-live in lotic (flowing) or lentic (still) water

-many body shapes (burrowers, sprawlers, climbers, swimmers, etc)

-important immediate consumers (fish food, water quality indicators, some nuisance emergences)

-external gills, especially along abdomen

odonata

• dragonflies & damselflies

characters:

• medium-large; elongate

• chewing mouthparts

• nymphs have prehensile labium

• antennae are short and bristle-like

• wings have complex venation, nodus, and stigma

• males:

  • gonopore on 9th segment

  • complex penis on 2nd segment

  • cerci on 1st segment

-adults mate in flight → male uses secondary genitalia

-nymphs and adults are predaceous

-oviposition may take place w/ the pair still in tandem

-adults are long lived

-nymphs can use jet propulsion for predator avoidance

anisoptera: dragonflies (suborder of odonata)

• eyes meet on head

• wings are held flat at rest; hindwings are larger

• strong fliers

• no sexual dimorphism

• nymphs have internal gills → do jet propulsion

zygoptera: damselflies (suborder of odonata)

• eyes are separated

• wings are held over body at rest; forewing & hindwing are similarly sized

• weak fliers

• sexual dimorphism present

• nymphs have 3 external gills

• plecoptera “pleated wings”

• stoneflies

characters:

• small-medium; soft bodied

• nymphs have chewing mouthparts; adults are vestigial

• compound eyes & 3 ocelli

• antennae are long & tapered

• wings are membranous and folded at rest; complex venation

• 3 segmented tarsi

• hemimetabolous

*minor order

-can be detritivores or carnivors

-nymphs are aquatic and look like adults

-good indicator species (intolerant of organic and thermal pollution)

-mate near water

-lotic: live in actively moving water

-lentic: living in calm water

-sprawlers & clingers

• many are hyporheic (live in the region beneath and alongside a stream bed where there is mixing of shallow groundwater and surface water)

-fish food, predators of fish eggs and fry

-external gills

-campodeiform (elongated, flattended, and active)

• dermaptera

• earwigs

characters:

• small-medium; narrow & elongated

• chewing mouthparts

• moniliform antennae

• wings are short, have truncate leathery tegmina; hindwings are semicircular & fan-like (folding wings)

• cerci function in prey capture, defense, & mating

• nocturnal; live in damp environments; omnivorous

• females provide parental care

orthoptera

• “straight wings”

• grasshoppers, crickets, katydids, locusts

characters:

• minute-large

• chewing mouthparts; hypognathous + opistognathous

• compound eyes, 0-3 ocelli

• filiform antennae

• forewings are narrower and hardened at the base; hindwings are folded/pleated

• saltatorial (jumping) legs; enlarged hind femora on 3-4 tarsi

• external male genitalia

• cerci present

• many malphigian tubules

• hemimetabolous (nymphs resemble adults)

• trochanter is separated from epimeron by suture/membrane

caelifera: grasshoppers (suborder of orthoptera)

• short filiform antennae

• short ovipositor

• tympana on 1st segment

• stridulate by hindleg + wing

ensifera: crickets, katydids (suborder of orthoptera)

• long antennae (>30 segments)

• 3-4 tarsi

• long ovipositor

• tympana on base of leg

• stridulate by wing rubbing (file + scraper)

• phasmatodea “phantom”

• stick bugs/walking sticks

characters:

• hind femora not enlarged → do not jump

• wings are variable; in many leaf life forms, at least hindwing is well developed; wings may also be greatly reduced or absent

• no stridulatory organs or tympana

• cerci is short (1 segment)

• ovipositor is short and concealed

• tarsi 5-5-5 (sometimes 3-3-3)

• plant feeders

• eggs resemble seeds and adults resemble plant stem

• move slowly so as not to attract predators

• some squirt noxious chemicals at predators

-3000 species in the world (predominantly tropical; only ~30 species north of Mexico)

-usually on trees or shrubs

-can be knocked from vegetation to collect (easier than looking for one bc very well camoflaged)

-eggs are dropped on the ground; often don’t hatch until 2nd following spring; some species are more abundant in alternate years

mimicry in 2 forms: leaf like, stick like

• grylloblattodea

• ice crawlers

• one family from western North America and Eastern Asia

• very common in the past → loss of alpine habitat from climate change means that ranges of some species are rapidly contracting

• lifespan of five years in some species

• feed on dead arthropods and organic material from surface of ice and snow during snow melt

• mantophasmatodea

• heelwalkers & gladiators

• predators like a cross between a mantid and a walking stick

• new order discovered in the 21st century

• found originally in amber and then museum specimens from Namibia and Tanzania → found living specimens in Namibia collected from Karoo

• communicate through substrate vibrations from drumming the abdomen

• may mate uninterruptedly for 3 days

• eat molted skin

• predaceous

• mantodea

• mantids/praying mantids

characters:

• elongate, cylindrical torso

• elongated prothorax

• mandibulate; hypognathous

• compound eyes & 3 ocelli

• filiform antennae

• wings present in males; forewing leathery, hindwing membranous

• single typmanum on metasternum

• raptorial front legs

• cerci and males styli on 9th abdomenal segment; females make ootheca (egg sac)

• triangular head

• young eat each other as soon as sac hatches (survival of the fittest)

• blattodea/blatteria

• cockroaches

characters:

• exopterygote (external wing development)

• dorsoventrally flattened

• small-large

• highly darkened (melaninized)

• mandibulate mouthparts

• compound eyes & 2 ocelli

• filiform antennae

• forewings leathery; hindwings membranous

• enlarged anal area

• cursorial legs (large coxa)

• styli on 9th segment in males

• female ovipositor is reduced on 7th segment on abdomen

• thorax is compressible

• shield-like pronotum nearly covers head

• mostly tropical & omnivorous

• oviparous (egg-laying); ovoviparous (eggs hatch within the body); vivaparous (gives birth)

• gradual metamorphosis (hemimetabolous)

• female lays ootheca (occasionally)

*roach infestation is not related to socioeconomic status or cleanliness

• German cockroach Blatella germanica

• small; can barely fly

• most troublesome domestic pests (eats meats, starches, sugars, fatty foods - as well as some household items such as soap, glue, and toothpaste)

• in famine conditions → turn cannibalistic and chew at each others legs and wings

*infestation is a major reason for asthma in inner city children (from cockroach frass)

• American cockroach Periplaneta americana

• largest species of common cockroach and often a pest

• produces odorous secretions that can alter the flavor of food

• can pick up Salmonella bacteria on their legs and later deposit them on foods → cause food infections or poisoning

• house dust containing frass or body parts can trigger allergic reactions and asthma

• common in basements, crawl spaces, cracks, and crevices of porches, foundations, and walkways

• in areas outside the tropics: live in basements and sewers, may move outdoors into yards in warmer weather

• brown banded cockroach Supella longipalpa

• eats anything that is organic

• found in homes and apartments (less common in restaurants)

• avoids daylight → not often found during the day

• Oriental cockroach Blatta orientalis

• large

• may infest homes in summer but are primarily outdoor species

• look like palmetto bugs

• odiferous (smelly; like many roaches)

• isoptera “equal wings”; sometimes grouped with blattodea

• termites

characters:

• minute to large

• chewing mouthparts

• compound eyes in winged forms

• apterous forms may be lacking 0-2 ocelli

• filiform or moniliform antennae

• 4-6 tarsi

• fontanelle on dorsum of head = frontal gland pore/hole

• have kings and queens

• only one species in northeast USA: Reticulitermes flavipes

• very important ecologically; eat all the dead/rotting wood

-2000 species worldwide (~40 species in North America)

-polymorphic with distinct castes

• social living with limited # of reproductives

• many sterile & wingless workers & soldiers

-wings (if present) are long, flat over body, about equal size and shape, may also be shed

-short cerci

-termites desiccate easily → live in mounds or underground

-adults shedding wings = autolyzed wings

-some queens lay 2000-3000 eggs/day for as long as 15-50 years

• =54,750,000 eggs from one female

-termites convert 6-7 tons/year/hectare of plant matter = 50% of fall

-castes:

• worker

• mandibulate soldier

• nasute soldier

• winged reproductive

• primary king

• primary queen

• secondary queen → daughter of primary queen; mates with king when the queen ages or dies

-tropholaxis (feed each other)

• use this behavior as a control method

termites gain entry by:

• timbers in direct contact with soil

• openings in stone foundations

• cracks in concrete foundations

• expansion joints in concrete floors

• earthen tubes (and tunnels) over foundations

• hidden cracks and crevices in masonry, can be inside cinder blocks in basements

• steps are a common location for entry

• old stumps are a source of infestation (whenever a tree is cut down, the remaining wood is attractive)

methods for termite control:

**must call a reputable professional company (homeowner cannot do this themselves)

• drill into cinderblocks, sidewalks, patios

• set up trench drench and chemical barrier

• bait stations (rely on tropholaxis) placed all around the house

• contain treated wood

psocodea/psocoptera

• lice

characters:

• exopterygotes

• soft bodied

• swollen clypeus

• chewing mandibles

• maxilla with lacinia as a slender rod → scrapes food

• prothorax is collarlike; meso and metathorax are subequal

• filiform antennae

• no cerci

• walking legs → cannot jump

• feed on algae, fungus, lichens

• scavengers feed on stored products like books (book lice)

• gregarious on bracket fungus

• many are parthenogenic - may be controlled by endosymbionts

• phthiraptera/mallophaga: chewing lice (suborder of psocodea)

• chewing lice

• feed on feathers, skin detritus, sometimes blood

• all orders of birds and mammals are parasitized (except bats and monotremes)

• irritation-emaciation in livestock and poultry

• do not paracitize people (at least not for long)

• head as wide or wider than prothorax

• dorsoventrally flattened

• filiform or capitate antennae loose from head (3-5 segments)

• apterous

• legs (1-2 segments)

• no cerci

anoplura

• sucking lice

• feed on flood of host

• three sucking stylets withdrawn into head

• rostrum with teeth

• head is narrower than prothorax

• piercing-sucking mouthparts

• eyes weak or lacking

• antennae 3-5 segments

• apterous

• legs 1 segment

• no cerci

• one set of claws

• common lice of humans:

  • body lice

  • head lice

  • crab lice

• crab lice Pthirus pubis

• “papillon de amour”

• not just found on groin area → can be found on rest of body (not as common)

• possible indication of abuse when found on children

• don’t transmit disease

• able to live off of host for at least 24 hours in bedding

• head lice Pediculus humanus capitus

• not known to transmit disease but bacterial infection from scratching can occur from any lice infestation

• infestation is not related to cleanliness of the person or their environment

• head lice are mainly spread by direct contact with the hair of an infested person

• greater prevalence among female children

• some correlation between homelessness, hygiene, and health as far as contracting them

• body lice Pediculus humanus humanus

• eggs attached to clothing

• disease carried:

  • relapsing fever

  • epidermic typhus

  • trench fever

*all bacterial disease: if untreated, can cause death

• only transmitted by lice

• indications that they may be able to transmit Yersenia pestis

how to control head lice:

1) prevention

• head lice are spread by infested people → pets cannot get/spread head lice

• children should not share combs, hats, or personal belongings

• frequent inspections are a must

  • search entire head, especially back of head and neck

  • part hair section by section

  • remove lice with tweezers or with lice comb

  • be careful not to spread lice to others while inspecting

2) treatment

• non-chemical treatment

  • 1) remove lice & nits

  • 2) place in soapy water or freeze

  • 3) wash all belongings in hot soapy water and dry on high heat

  • shave childs head; even a short trim can aid in detection and removal

    • last resort; don’t want to traumatize children

• chemical treatment (lice shampoo)

  • a) wash hair with household shampoo first

  • b) on completely wet hair, use lice shampoo

  • c) add warm water and leave product on head for recommended time (usually 10 min)

  • d) rinse thoroughly with warm water while removing any dead lice/nits

  • e) retreatment may be necessary in 7-10 days to kill hatching eggs

3) treatment of other items

• bag all other items/wash laundry as previously described

4) post treatment inspection

• individuals inspected up to 10 days following treatment

*classrooms should not be treated

• lice live entire lifecycle on human body → will die within 24 hrs after falling off host

• treatment of classrooms with insecticidal sprays is unnecessary and potentially hazardous

• thysanoptera

• thrips

characters:

• very minute to small (1-3mm)

• eggs are laid in plant tissue

• ½ of species feed on fungi

• ½ of species are primarily phytophagous

  • suck out contents of single cells

• some plant feeders are damaging → often found in flowers and damage is often mistaken for something else (looks like wrinkled leaves)

• problem pest in greenhouses

• only insects with assymetrical mouthparts

• egg, larval, prepupal, adults

  • argument for hemimetabolous or holometabolous → consensus is hemi but more like mix → missing link?

• feathery wings

• subsocial behavior such as parental care; some species are gregarious

*western flower thrips act as vectors of viruses that damage plants (Frankliniella occidentalis)

hemiptera

• bugs; leaf hoppers

characters:

• minute to large

• piercing/sucking mouthparts

• degenerate palpi

• labial sheath arises from front of head

• eyes are well developed

• ocelli: 2 or more

• 4-5 segmented antennae

• hemelytra (basal half of wing is sclerotized while the rest of the wing is membranous)

• scutellum on mesothorax

-many families w/ nymphs and adults aquatic/semiaquatic

-mostly active swimmers (nektonic)

-neustonic in lentic or slow lotic situations (like some water striders on open ocean)

-voracious predators: piercing/sucking mouthparts; one family feeds on algae (Corixidae)

-control nuisance insects, feed on fish, human & pet food, fish food (corixids)

-breathe atmospheric oxygen at water surface

-triangular scutellum

• bed bugs; family cimicidae; order hemiptera

signs:

• red spots on mattress or box springs

• ammonia smell

• bites on appendages

prevention:

• don’t put suitcase on bed

• close suitcase when not in use

• look behind headboard

• use UV light to examine rugs, drapes, bed, etc

• stay at moderately price hotels/motels

• don’t pick up used furniture along the road

*can survive 5 months without a blood meal

*reproduce using traumatic insemination

*insect repellents don’t work well - depends on how hungry they are

*reason why new mattresses are wrapped in plastic

***becoming more common due to international travel and resistance to pesticides

homoptera

• uniform, winged

characters:

• minute to large

• piercing sucking mouthparts; degenerate palpi labial sheath positioning

• eyes present

• ocelli: 2-3

• antennae are filiform to setaceous

• 1-3 segmented tarsi

• cerci lacking

• exclusively terrestrial

suborders:

• auchenorruncha

  • antennae are short and bristlelike; arise from posterior of head

  • active

    • cicadas, leaf hoppers, spittle bugs, spotted lantern fly

• sternorryncha

  • proboscis arises from between front coxa

  • antennae are long and filiform

  • sedentery

    • aphids, whiteflies, scale insects

neuroptera

• lace wings, ant lions

• “nerve winged”

holometabolous - endopterygotes

• egg → larva → pupa → adult

  • can live in totally different habitats; broader selection pressure

characters:

• simple biting mouthparts

• long, multisegmented antennae

• large compound eyes; no ocelli

• hindwing is approximately = to forewing, many veins + cells

• 5mm-120mm

• no or poor wing coupling; crude flyers

• predaceous

larvae:

• distinctive larval sucking mouthparts

• pupation in silken cocoon

• predaceous

• campodeiform

• lace wings; family chrysopidae; order neuroptera

• wings are similar shape

• larvae have mandibulate sucking mouthparts

• hindwing non folding anal region

• larvae are terrestrial

• eggs on stalks

• larvae predatory, some with debris on backs

• adults predatory or feeding on pollen (or rarely honeydew)

*green lacewings are beneficial

megaloptera

• neuroptera

• dobsonflies, alderflies, fishflies

• most primitive endopterygote

• aquatic larvae with prognathous mouthparts (predaceous)

• decticious pupa

• hindwing is broader than forewing

• thorax is 3 subequal segments

• metathoracic wings are pleated anal region folded over at rest

rhaphidioptera

• neuroptera

• snakeflies and mantidflies

• elongate prothorax legs attached to end of prothorax

• terrestrial larvae

• adults have strong mandibles, maxillae, and labium

• large compound eyes

• wings are similar; forewing has pterstigma

• long ovipositor

• strikes prey in snakelike fashion because of shape of headcapsule and prothorax

• woodlands larvae under loose bark, leaf litter

• 2 yr lifecycle

• only US species is found in the west

• myrmeleontidae; order neuroptera

• antlions

• damselfly-like with long, clubbed antennae

• feeble flying, attracted to lights

• wings often spotted

• larvae are doodlebugs; long, sicklelike mandibles, fast forward and back; some surface feed, others lay in wait or in pittfalls

• strepsiptera

• twisted wing parasites

• paracitize 7 other orders of insects

• females are larviform

• young are produced in the body of the female

• larvae exit onto flowers to wait for a host, then enzymatically soften the host cuticle

• females release pheromones to attract the males and males mate via brood canal; males live 5 hours and have vestigial mouthparts

• most are observed in paper wasps

coleoptera

• “leather winged” (elytra)

• beetles

• most diverse animals on earth; occupy every conceivable habitat, including water (largest order, 25% of all described animal species)

• cam be beneficial or pests

characters:

• endopterygote; holometabolous

• minute to large; highly sclerotized

• larvae can be campodeiform, eruciform (caterpillar), scarabeiform, vermiform

• pupae exarate; appendages are not glued to the body

• prognathous and hypognathous mouthparts

• compound eyes; ocelli lacking; some larvae have lateral ocelli

• legs can be cursorial, natatorial, saltitorial, or fossorial

• wings: forewing highly sclerotized, hindwing membranous

• pronotum single conspicuous sclerite

-400,000+ species

-mostly terrestrial herbivores, some predatory, some parasitic

-seed predation, leaf miners, leaf borers, stem borers, subcortical, leaf litter, fungivores, dung, carrion

-rare nectar feeders

aquatics:

• larvae and/or adults of many groups are aquatic

• many must surface to breathe as larvae and adults; some pierce plants for air; some have plastrons = array of hairs or bumps used to trap air next to the body of some aquatic insects where it forms a gill; many larvae have gills

• many lentic, lotic, or both

• many trophic roles (predators, algae feeders, omnivores, herbivores on vascular plants)

• carabidae (family); suborder adephaga; order coleoptera

• ground beetle

• more than 2000 species in N. America

• many shiny, rapid moving; more likely to run than take flight

• abundant predators on ground, under stones and logs, in litter, etc

• a few are plant or seed feeding

• the first visible abdominal segment is interrupted by the hind coxae

• dystiscidae (family); suborder adephaga; order coleoptera

• predaceous diving beetle

• 475 species in Mexico

• common in ponds and streams

• smooth, oval, with flattened hind legs fringed with long hairs

• obtain air at surface of water, where they hang upside down

• long antennae, short palps, hind legs move synchronously

polyphaga

• suborder of coleoptera

• most beetles

• vary greatly

• includes:

  • hydrophilidae (water scavenger beetles), staphylinidae (rove beetles), silphidae (burying beetles/carrion beetles), lucanidae (stag beetles), scarabaeidae (June beetles, Japanese beetles, grubs - scarabs), elateridae (click beetles), psephenidae (water penny), lampyridae (lightning bugs), chrysomelidae (leaf beetles), coccinellidae (lady bugs), curculionidae (weevils), scolytidae (bark beetles), buprestidae (woodboring beetles - emerald ash borer killed all the ash trees), cerambycidae (long horned beetle), ptinidae (spider beetle)

• diptera “two winged”

• flies

characters:

• minute to large

• adopous larvae; pupa obtect, exarate, or coarctate

• mouthparts are haustellate (sucking and sponging)

• compound eyes & 3 ocelli

• antennae can be filiform, stylate, or aristate

• 1 pair of metathoracic halteres (wings)

• 5 segmented tarsi

• cerci present

aquatic diptera:

• lentic and lotic; many tightly attach to substrate (lotic) or actively mobile among detritus (lentic, lotic), some planktonic in lakes

• scrapers, collectors, shredders, predators, plant minors, parasitoids

• deep lakes, high salinity, thermal waters, marine; many in enriched water with depleted oxygen

• very important plant and insect food, many economically or medically important groups

• tracheal gills, surface breathers, cuticular breathers, etc

-mosquitos, botflies, black flies

hymenoptera

• bees, wasps, ants, etc

• “membrane winged”

characters:

• chewing to lapping/sucking mouthparts

• vast majority are beneficial to humans

• very few “aquatic” species

  • essentially all “aquatic” species are parasitoids of aquatic larvae or the eggs of aquatic insects

• eruciform larva, exarate (antennae, legs, and wings free) pupa

• immatures are eruciform or apodous (grubs with reduced mouthparts)

  • pupa adecticious, exarate, maybe enclosed in a silkem cocoon (silk from labial glands)

*ants are the most numerous insects; probably more ants than anything else

lepidoptera

• butterflies and moths

• “scale wings”

• frenatae and jugatae wing coupling mechanism

characters:

• body covered with scales and modified hairs

• eruciform larvae; obtect pupa

• adults have coiled mouthparts, larvae have chewing mouthparts

• large compound eyes; 0-2 ocelli

• wings are large in proportion to body; forewings are larger than hindwings; few crossveins

• adults 5 tarsi; larvae 3 pairs of true legs

-a few larvae are truly aquatic

-larvae associated with aquatic and semiaquatic vegetation

-shredders, herbivores, on aquatic vascular plants or scrape algae from rocks

-some used fixed air stores (plants) or tracheal gills

butterflies:

• diurnal (during the day)

• hold wings straight up at rest

• small club on antennae

• mimetic

• enlarged humeral area of the hindwing that is widely overlapped by the forewing so the wings overlap and operate in phase

moths:

• nocturnal

• hold wings flat at rest

• pinnate or moniliform antennae

• microlepidoptera

  • small moths with a wingspan <20mm

  • not a true taxon'

  • many pests are classified within this group

• trichoptera

• have aquatic larvae

• make tube cases

• some are terrestrial

• mecoptera

• scorpion flies

• dietary habits vary; some are scavengers, some are predaceous

• males have modified genitalia on abdomen

• thought to be primitive but are closely related to fleas

• harmless

• siphonaptera

• fleas

• adults are laterally compressed

• ectoparasites of birds and primarily mammals

• some hosts have over 20 different species of flea

• oriental rat flea is the vector of bubonic plague

• there is a species of human flea although it is rare

• 16 species in north america

• locomotory behavior in adults

  • walking

  • running

  • jumping

    • important means of escape

    • way to reach hosts

  • jump using modification of flight mechanism from winged ancestors