Final Exam (after midterm) Flashcards
Order Dermaptera
Earwigs Chewing mouthparts Cerci forceps (female & nymphs = straight; males = curved) Long filiform antennae Tegmina (forewings short & leathery); hind wings membranous & folded beneath forewings (sometimes absent) Nocturnal Omnivorous Some have scent glands on abdomen
What are dermaptera forceps used for?
Grooming Courtship Defense Manipulation of prey Mating Folding hind wings under tegmina
Parental care of Dermaptera
Adults overwinter in same nest
Females lay eggs at end of winter/early spring and male is removed from nest
Female guards eggs. Removes fungi on eggs by licking
Female provides food to young nymphs in early instar
Female dies before mid summer
Order Plecoptera
Stoneflies
Live near freshwater habitats (nymphs are aquatic)
Mouthparts often reduced/non-functional in adults
Dull coloration mostly (dark)
Dorso-ventrally flattened
Four membranous wings held flat over body (mostly non-functional and reduced)
Long cerci and long antennae
Small (<1.5cm)
Some emerge during winter months
Use repeated abdominal drumming for attracting mates
Plecoptera nymphs
Flattened body often with bright colors Long antennae and long cerci (pair) Aquatic Gills are tufts of filaments on thorax and first two abdominal segments Detritus feeders/predaceous Takes 1-3 years for development Leave water for final molt
Order Embioptera
Web spinners
Mostly tropical and subtropical (few species in southern US)
Live in silken tunnels
1.5-2.0 cm
Chewing mouthparts
Live gregariously (females show parental care behavior)
Embioptera body
Silk glands located on first tarsomere of forelegs
Elongated body with short legs (hind femora enlarged for reversal movements)
Wings on males (soft and flexible able to fold over head during reversal)
Embioptera food
Eat dead plant material, bark, mosses, and lichens
Silk galleries are expanded as new food source is needed
Embioptera silk
Produced by males, females, and nymphs
Ejected from specialized setae located on first tarsomere of forelegs
Used in nest production
Order Zoraptera
Zorapterans (also called angel insects)
Similar in appearance to termites/psocids
Live gregariously (not social insects)
Live in cellulose-rich environment but don’t feed on wood
Feed on fungus and small arthropods
Two forms: apterous (w/out wings) or alate (w/ wings)
Zoraptera (apterous)
Wingless
Unpigmented and eyeless
Dominates
As population grows, alate form appears in individuals for dispersion
Zoraptera (alate form)
Winged
Pgemented with compound eyes
Winged individuals can disperse to new nesting sites
They shed their wings after dispersing
Order Psocoptera
Psocids, barklice, booklice Most occur outside Less than 6mm Large head with swollen clypeus Chewing mouthparts Long antennae; no cerci
Psocoptera (barklice)
four membranous wings
Found outside
Feed on algae, lichens, fungi, organic debris
Some species live in the nest of birds and mammals
Some live on feathers and fur
Psocoptera (booklice)
Wingless
Found in building or warehouses (damp coniditions)
Feed on stored products, wallpaper paste, book bindings, microscopic mold
Order Phthiraptera
Lice
Parasitic
Have morphological adaptations for parasitic life (small size(.5-6mm), wingless, dorsoventrally flattened, compound eyes reduced/absent, short antennae, short legs with long claws)
Variable mouthparts (mandibulate or haustellate)
Phthiraptera parasite
Spend all development stages on host
Only parasitic hemimetabolous insect
Host specific
Phthiraptera (chewing lice)
Most of the species
Broad head, mandibulate mouthparts
Associated with birds and some mammals (not humans)
Feed on feathers, hairs, skin, oily secretion, blood
“Dust baths” are to get rid of lice
No important disease transmitter
Phthiraptera (sucking lice)
Smallest group of lice Small head, conical Sucking mouthparts Associated with mammals only (includes humans) Feeds on blood Some can transmit diseases Body lice, head lice, or pubic lice
Phthiraptera (sucking lice: body lice)
Pediculus humanus humanus
Historically responsible for deadly diseases (including epidemic typhus)
Associated with crowded, unsanitary environments (found on dirty clothes/bedding)
Phthiraptera (sucking lice: head lice)
Pediculus humanus capitis Smaller than body lice (but otherwise identical) Live on scalps Not vectors of diseases Not associated with poor hygiene Don't hop/fly (crawl rapidly on hairs) Transmission via head to head contact
Phthiraptera (sucking lice: body lice eggs)
Called nits
Glued to host hairs (firmly attached and difficult to remove)
Females lay 5-10 eggs per day
Eggs with developing embryo usually yellow-brown
Empty egg shells are paler
Phthiraptera (sucking lice: pubic lice)
Phthirus pubis
Also called crab lice
Mostly associated with pubic hair but also found on armpit hairs or facial hairs
Order Hemiptera
Sucking mouthparts (form of long proboscis (rostrum))
- Allo them to bypass many plant defensive mechanisms (such as wax, thorns, spines, setae) and pesticides
Feed on liquid food only (exception: ?)
Mostly phytophagous, some predaceous, blood feeders, or detritus feeders
Largest order of hemimetabolous insects
Three suborders:
- Heteroptera
- Sternorrhyncha
- Auchenorrhyncha
Suborder Heteroptera general
True bugs (Order Hemiptera)
Hemelytra forewings (basal part is leathery (corium); apical part is membranous)
Membranous hindwings
When at rest, wings held flat over body & overlapping
Divided into: terrestrial, semi-aquatic, aquatic
Corium
leathery basal part of hemelytra forewings
Suborder Heteroptera feeding
Piercing-sucking mouthparts (rostrum) arising from front of head
Various feeding habits (phytophagous, predaceous, blood-feeders, sometimes detritus feeders)
Suborder Heteroptera defense mechanisms
Scent glands - Repellent odor - Alarm pheromone Biting Cryptic shapes/colors Mimicry (mostly ant) Aggregation
Terrestrial Heteroptera
Plant feeders: - Miridae (plant bugs) - Lygaeidae (seed bugs) - Blissidae (chinch bugs) - Coreidae (leaf-footed bugs) - Pentatomidae (stink bugs) Predators: - Pentatomidae (stink bugs) - Reduviidae (assassin bugs) Blood-feeders: - Reduviidae (assassin bugs) - Cimicidae (bed bugs)
Semi-aquatic Heteroptera
Found on water surface
Predators:
- Gerridae (water striders)
Aquatic Heteroptera characteristics
Live in freshwater
Obtain O2 via morphological adaptations such as breathing tube (siphon): one-two spiracles (modified open traceal system)
or
via trapping O2 on hydrophobic (hydrofuge) hairs: oxygen comes in direct contact with spiracles called physical gills (open tracheal system)
- Gills can be temporary (replenished at surface) or permanent (O2 continuously extracted from water)
Have distinct leg adaptations for aquatic life (not forelegs)
- oarlike and fringed
Short concealed antennae
Aquatic Heteroptera
Predators: - Belostomatidae (giant water bugs) - Nepidae (water scorpions) - Notonectidae (back swimmers) Detritus feeders: - Corixidae (water boatmen)
Family Miridae
Suborder Heteroptera Plant bugs Largest family of Heteroptera Distinctive hemelytra with cuneus & one/two closed cells Important pests of cultivated plants
Cuneus
Triangular apical piece of corium
Pests of Miridae
Lygus lineolaris (tarnished plant bug)
- Feed on 300 different plants
- Responsible for strawberry or other fruit deformities (catfacing)
Family Lygaeidae
Suborder Heteroptera
Seed bugs
Small family
Feed on milkweed plants
Bright red and black coloration of milkweed bugs
- Used to advertise their bad taste and toxicity
Important Lygaeidae bugs
Small milkweed bugs
Large milkweed bugs
Family Blissidae
Suborder Heteroptera Chinch bugs Small (about 4mm) Adults have black and white wings Nymphs have bright red abdomen Major lawn pest Prefers hot, dry, and sunny environments Common species of CA: hairy chinch bugs
Blissidae as pests
A major lawn pest found in great numbers
Feed on sap of grass stems
Affected lawn turns yellow
Family Coreidae
Suborder Heteroptera
Leaf-footed bugs
Have narrow head
Hind tibia expanded and leaflike (sometimes only males; sometimes small enlargement)
Diverse in tropics
Well developed scent glands
Includes some of largest terrestrial Heteroptera (up to 4cm)
Species of Coreidae
Squash bug: serious pest of Cucurbitaceae (squash, pumpkin, etc.)
- Common in CA
Leptoglossus occidentalis (Western conifer seed bug): Feed on various conifer trees; adults spend winter in sheltered places
- Native to western U.S; migrated to Europe
Family Pentatomidae (phytophagous)
Suborder Heteroptera
Stink bugs
Distinct shape: large pronotum
Brightly colored
Five segmented antennae
Produces bad odor (often leaves a bad taste on berries)
Nymphs and adults have different coloration
Eggs often barrel-shaped & can be covered in spines on top
Sometimes responsible for fruit damages and deformities (catfacing)
Species of Pentatomidae phytophagous bugs
Halyomorpha halys (brown marmorated stink bug)
- New pest in N.A.; accidentally introduced from Asia
- Highly polyphagous
- Hibernate in homes
Family Pentatomidae (predaceous)
Suborder Heteroptera
One subfamily of stink bug
First segment of proboscis short and slightly enlarged
Generalist predators
Family Reduviidae (predaceous)
Suborder Heteroptera
Assassin bugs
Base of head constricted and necklike
Rostrum stout and fits into groove on prosternum
- Acts as stridulatory organ when scraped against prosternal groove (for mate attraction/courtship)
Main group of predatory Heteroptera
Can inflict painful bite
Generalist predators (can take down large prey)
Eggs often in batches and glued to plants
- Sometimes males guard the eggs
Some species carry dead insect bodies on back for camouflage
Some females use resin on underside of abdomen to coat eggs and help grasp prey
Household species of Reduviidae
Reduvius personatus (masked hunter)
Black and found in houses
Feed on other insects (predaceous)
Single eggs laid in the dust, cracks, and corners
Nymphs cover themselves with dust particles
Body covered with short hairs connected to glands
- Glands produce sticky substance
Subfamily Phymatinae
Family Reduviidae Ambush bugs Predaceous Bright black and yellow (cryptic coloration) Spiny thorax Commonly found on goldenrod flowers Short, stout raptorial forelegs (elongated coxae) Huge swollen femora
Family Reduviidae (blood feeders)
Few species feed on blood (called kissing bugs)
Bites are painless
Bite during the night
Can be vectors of Chaga’s disease
Chaga’s disease
When feeding, bugs leave excrement on skin
It becomes infected when feces of Reduviidae are:
- scratched into open wound
- brought into the mouth
- rubbed into the eyes
Family Cimicidae
Suborder Heteroptera
Bed bugs
Small (about 5mm)
Flattened, oval, wingless
Reddish adults
Translucent white nymphs
Feed on blood of mammals (mainly bats) and birds
Only one N.A. species feeds on human blood
Nocturnal
Don’t transmit diseases, but bites cause irritation
Transported in luggage from hotels or used furniture
Haemocoelic insemination (traumatic)
Family Gerridae
Suborder Heteroptera
Water striders
Found on water surface (standing or flowing water)
Mid- and hind-legs are natatorial (long)
- can’t walk on land or leaves (get trapped easily)
Forelegs used to grab small insects on surface of water (short)
Use surface tension with water repellent feet
Dark-colored, elongated, winged or wingless, big eyes
All freshwater but one genus
Attach eggs to plants or stone
After mating, male guards female by riding on her back
Family Gerridae water repellence
Hydrophobic (hydrofuge) hairs
Legs covered with microscopic bristles that trap air (form air bubbles between leg and water surface)
Body covered with same bristles (if pushed underwater, air bubbles allow them to rapidly come back up)
Family Gerridae communication
Use ripples in water to detect prey and communicate
Ripples produced by leg movements
Males use it to attract females, stimulate oviposition, and warn other other males away
Detect via sensitive chordotonal sensillae located inside tarsal segments
Famiy Gerridae marine water striders
Called ocean skaters Five species of genus Halobates Only truly marine species (semi-aquatic) Lay eggs on any floating objects available Wingless
Family Belostomatidae
Suborder Heteroptera
Giant water bugs (other common names = electric light bug or toe biter)
Largest bugs of the order (up to 10cm)
Forelegs raptorial
Mid- and hindlegs broad, flattened, and fringed
Stout and strong proboscis (rostrum)
- May inflict painful bite
Live in ponds and lakes
Breath via siphon at tip of abdomen
Feed on other insects, snails, and small fish
Thoracic scent glands give characteristic flavor
Reproduction of Belostomatidae
Genus Lethocerus lay eggs above water
- Males stay until hatching, watering them regularly to avoid desiccation
- Eggs are marked with chemicals from scent glands
Genus Belostoma glue eggs on back of a male
- Up to 100 eggs
- male carries until hatching (male triples in weight by hatching)
Family Nepidae
Suborder Heteroptera
Water scorpions
Two forms: similar to either giant water bug or walkingstick
Sedentary (wait among vegetation for passing prey)
Can stay submerged in water if respiratory siphon connects to outside
Forelegs = raptorial
Mid- and hindlegs have little adaptations for swimming
Family Notonectidae
Suborder Heteroptera
Backswimmers
Small (up to 2cm)
Body with convex dorsal surface and flat underside
Hind legs long, oarlike and fringed; angled toward the head
Forelegs shorter and used to grasp prey
Always swim upside down
Found in ponds and lakes
Well developed rostrum (can inflict painful bite)
Voracious predators: insects, tadpoles, small fish
Temporary physical gills (can last a few hours)
Family Corixidae
Suborder Heteroptera Water boatmen Most common aquatic bugs Mostly found in ponds and lakes Body broad Large eyes Hind legs are oarlike and fringed Forelegs short with scoop-shaped and fringed tarsi Broad and short rostrum Feed mostly on algae, detritus, and small organisms (scoop with fringed foretarsi) Don't bite Temporary physical gills (can last a few hours)
Sternorrhyncha Homopterans
Aphids
Scale insects
Mealy bugs
Auchenorrhyncha Homopterans
Cicadas
Hoppers
Homopterans
Contains Sternorrhyncha and Auchenorrhyncha suborders
Uniform winged hemiptera
Most have four wings (some are wingless; male scale insects have only forewings)
- Forewings with uniform texture (membranous or slightly thickened)
- Hindwings membranous
When at rest, wings are generally held roof-like over body
Piercing-sucking mouthparts (rostrum) arising from lower back margin of head (opisthognathous)
Terrestrial and phytophagous (feed on plant sap)
Produce honeydew (sugar-rich sticky substance secreted by insects feeding on plant sap)
Suborder Sternorrhyncha characteristics
Proboscis (rostrum) is extremely opisthognathous
- Arises between the coxae of the forelegs
Sedentary lifestyle (some spend entire life on one spot on a plant)
Often gregarious
Winged or wingless
Some with reduced legs and antennae
Defensive mechanisms of Suborder Sternorrhyncha
Some live concealed in wax secretions or under external shells
Some have defensive fluid
Rapid growth via parthenogenetic reproduction and viviparity
Built strong association with ants
Family Aphididae
Suborder Sternorrhyncha
Aphids
Small, soft-bodied and pear-shaped
Winged or wingless
Variety of colors
Have cornicles that secrete sticky defensive fluid and serves as alarm pheromones
Suck on plant sap from stems and leaves (some species on plant roots)
- Needs lots of sap for required nutrients
Excess sap excreted as honeydew from anus
Important pests of agricultural crops, forests, and orchard trees
- Important vectors of viral plant diseases (honeydew provides place for black sooty mold to grow)
- Cause wilting, stunted/abnormal growth, leaf curling
Cornicles
Tubelike structures projecting on posterior end of abdomen
Life cycle of Family Aphididae
Complex life cycle
Mix of asexual and sexual reproduction
Oviparity and viviparity
Production of winged and wingless individuals
Ant-aphid mutualism
Ants protect aphids in exchange for honeydew
- Aphids have many predators and parasitoids (ladybugs, lacewings, parasitoid wasps) that keep their populations under control
Ants carry aphids around
- Ex. Ants will story Corn Root Aphid eggs in their nest for the winter until they are transported to roots of weeds -> corn roots in the spring and summer
Ants “milk” aphids (gently stroke them with their antennae to get droplets of honeydew)
Superfamily Coccoidea (scale insects)
Homopterans (Sternorrhyncha)
Live under waxy or scalelike covering (soft or hard)
Wax produced from epidermal glands
Dramatic sexual dimorphisms in some
Life cycle of superfamily Coccoidea (scale insects)
First instar nymphs = legs and are active (called crawlers)
- This is the dispersal stage
After first molt = start secreting a covering; some loose their legs
Females grow, mate, produce offspring, and die without leaving covering
Males have extra “pupa-like” instars so they develop into winged adults
Sexual dimorphism of superfamily Coccoidea (scale insects)
Adult females = no wings, no antennae, no eyes, no legs, waxy covering, sessile, mostly larger (about 1-5mm)
Adult males = one pair of wings (hind wings reduced to haltere-like processes), long tail-like projection, long antennae, eyes present, don’t feed, short lived, rarely see (less than 2mm)
Superfamily Coccoidea (mealybugs)
Homopterans (Sternorrhyncha)
One family: Pseudococcidae
Similar characteristics to scale insects except:
- Waxy covering a white powdery secretion
- Females have well developed legs
Similar life cycle as scale insects
Economic importance of Superfamily Coccoidea
Suck plant fluid
Important ornamental and agricultural pests
Protective covering makes them resistant to insecticides (chemicals are best)
Many secrete honeydew (causes sooty mold)
Cochineal red dye extracted from scale insects (good for humans)
Family Dactylopiidae
Cochineal insects (scale insect family)
Produce carminic acid: deters predators)
Can be extracted to make carmine dye
Used for food coloring and cosmetics
Suborder Auchenorrhyncha
Homopterans
Opisthognathous (not as extreme as Sternorrhyncha)
Large pronotum and large clypeus
Active lifestyle (many can jump and fly between plants)
Live gregariously or individually
Family Cicadidae
Suborder Auchenorrhyncha Large size (largest Homopteran) Clear wings held roof-like over body Adults live for about 1 month Feed on plant sap Males produce species-specific sound with tymbals (located on each side of abdomen) by rapidly vibrating them through muscle contractions and resonating through large tracheal air sacs - Sound for attracting females, courtship, communication, defense - Tympana is also present on abdomen
Life cycle of Family Cicadidae
Adult females insert eggs in twigs of tree and shrubs
Young hatch and burrow underground (feed on sap in roots of trees)
- Have fossorial legs for burrowing
Long life cycles (4-17 years in nymphal stage)
Exuviae of last instar are common on tree trunks or vegetation
N.A. species of Cicadidae
Genus Magicicada = periodical cicada
Genus Neotibicen = dog day cicada or annual cicada
Genus Magicicada
Periodical cicada (7 species, all in eastern U.S)
Smaller than annual cicadas
Reddish eyes and reddish wing veins
Appear in late May and early June
All young of multiple species with same life-cycle become adults in same year
- Result in mass emergence of cicadas
Life cycle = 13 (southern) or 17 years (northern)
- 17-year cicadas have 12 broods
- Brood X (ten) is the largest of the 17-year broods (has a wide distribution)
Brood
All periodical cicadas of the same life cycle type that emerge in a given year
Genus Neotibicen
Dog day or annual cicadas
Have multiple-year life cycles that are not synchronized
Usually blackish with greenish markings
Appear in July and August
Adults can be found in same location every year
Do not occur in huge numbers (like periodical cicadas do)
Family Cicadellidae
Leafhoppers
Auchenorrhyncha
Large family
Small hopping insects
Often colorful
Feed mostly on leaves (host specific but occur on all type of plants)
Ecominically important pest species: cause white spots on leaves by feeding and are plant pathogen vectors
Family membracidae
Auchenorrhyncha
Treehoppers
Small hopping insects easily recognized by large pronotum that covers head and extends over much of the back
Produce honeydew and often protected by ants
Eggs of Membracidae
Little economic importance: most damage caused by egg laying
Eggs are a target for various predators and parasitoid wasps
Females of some species guard eggs
Nymphs are found in large aggregations
- Have an extensible anal tube used to deposit honeydew away from their body
Common species in N.A.: Buffalo treehopper
- Lays eggs in twigs of various trees
Family Cercopidae
Auchenorrhyncha Froghoppers Small hopping insect Similar to leafhopper in appearance, but often sit "froglike" with head elevated Usually brownish or grey Attack grasses and herbaceous plants
Nymphs of Cercopidae
Often called spittlebugs
Nymphal stages cover themselves with frothy or spittle-like mass
One mass = one spittlebug
Yellowish-green
The mass protects nymphs from predation, parasitism, and desiccation
Spittle is produced from fluid emitted from anus (composed of excess plant sap)
- Air bubble are introduced into spittle through special air canal located on ventral surface of abdomen
Order Thysanoptera
Thrips
Small (less than 2mm)
Narrow and fringed wings
Sing. and plur. spelled the same way (thrips)
Sucking mouthparts
Feeding habits extremely variable but most feed on plant tissues
- Often feed on flower heads
Important pests of Thysanoptera
Western flower thrips Found worldwide Important vector of plant viruses -Ex. tomato spotted wilt virus Also greenhouse pest
Pterygote orders with holometabolous development?
Raphidioptera Megaloptera Neuroptera Mecoptera Strepsiptera Siphonaptera Coleoptera Trichoptera Lepidoptera Hymenoptera Diptera
Order Raphidioptera
Snakeflies
Small order (found in temperate regions of western N.A., Asia, & Europe)
Commonly found on trees
- Most lay eggs in crevices of bark where larvae develop
Predators
Order Megaloptera (dobsonfly)
Large insects
Adults found close to water
Nocturnal
Attracted to lights at night
Adults don’t live very long (rarely feed)
Male dobsonflies have large mandibles while females don’t
- Long mandibles used in sexual competition and courtship
Species of Dobsonflies
Corydalus cornutus (Eastern Dobsonfly) Reaching 7cm in body length (over 12cm with mandibles and wings)
Megaloptera (fishflies)
Similar to dobsonflies but: - smaller (about 4-5cm) - short mandibles - Pectinate or serrate antennae Some have black wings
Larval stage of Megaloptera
Aquatic
Live under stones in rivers and streams or in lakes
strong mandibles (bite can be painful)
Predaceous on other aquatic organisms
Lateral tactile filament located on most abdominal segments
Attach to stones using anal hooks or prolegs on tip of abdomen
Breathing:
- Have tufts of abdominal gills that are present latero-ventrally
- Have spiracles that allow them to breath out of water as well
Leave water to pupate on soil nearby (pupa can move)
Hellgrammites
Megaloptera larvae used as bait by fishermen
Order Neuroptera
Chrysopidae (lacewings), mantispidae (mantispids), and myrmeleontidae (antlions)
Four membranous wings with many veins
Larvae having “sucking jaws” adapted for piercing and sucking
Larvae are terrestrial
Adults have chewing mouthparts
Family Chrysopidae
Order Neuroptera
Green lacewings
Adults have chewing mouthparts
Some are predaceous (eat soft-bodied insects) while some eat nectar
Adults are nocturnal
Females lay eggs on tiny silken stalks that they produce with an accessory gland
- Stalks protect them from predators
Transparent wings, golden/copper eyes, bright green body
Long filiform antennae
Larvae of Chrysopidae
Sometimes called aphidlions
Larvae have long mandibles used to puncture their prey and suck out liquefied content
Feed on soft-bodied insects (mostly aphids)
Some camouflage themselves by attaching dead bodies of prey/other debris to spines on backs
Family Mantispidae
Order Neuroptera Mantispids Look like small mantids with clear wings More diverse in the tropics Many are good mimics of wasps larvae are predaceous on spider eggs
Family Myrmeleontidae
Order Neuroptera Antlions Adults similar to damselflies but: - nocturnal - have clubbed antennae Larvae have long jaws and are predaceous Some lie in sand pits to wait for prey (such as ants)
Order Mecoptera
Scorpionflies and hangingflies
Most have an elongated face with chewing mouthparts at the tip
Four membranous wings with spots/bands
Various feeding habits (mostly feed on living or dead insects)
Order Mecoptera (scorpionflies)
Adults and larvae feed on dead insects
Give nuptial gifts (males give dead insects (most successful) or salivary secretions)
Small (about 10-15mm)
Called “scorpion” because males genitalia are enlarged and recurved
Species of scorpionflies
Snow scorpionflies Small (4mm) Dark and wingless Occur in snow during mild winter days Feed on moss
Order Mecoptera (hangingflies)
Adults and larvae are predaceous
Legs modified for hanging and catching prey (catch with hind tarsi)
- Fifth tarsal segment folded against the fourth
Give nuptial gifts (males offer prey insects)
Order Strepistera
Twisted wing parasites
Internal parasites of various insects
Extreme sexual dimorphism
Females have cephalothorax region protruding from host to attract males with sex pheromone
- Insemination via haemoceolic insemination (traumatic)
Sexual dimorphism of Strepsiptera
Females = maggotlike: wingless, no eyes, no antennae, no legs, head and thorax fused (forms cephalothorax). Spends entire life inside host (except first instar) Males = big raspberry-like eyes, antler-like antennae (branched = flabellate), large hind wings, front wings reduced to haltere-like structures. Are free-living
Life cycle of Strepsiptera
Vivaporous
Give birth to over 1000 larvae that escape through her body (female dies after)
First instar larvae (called triangulin): have legs and eyes
- They leave the host to attach to new host
- Burrows into new host and molts to legless larva
Larva absorbs nutrients by filtering the host’s haemolymph
After several molts, larva pushes small opening between host’s abdominal sclerites to pupate
- Male leaves after pupation while female stays (only females cephalothorax region is protruding)
Order Siphonaptera
Fleas
Ectoparasites
Eggs, larvae, and pupae develop freely in nest or habitat of host
Small (2-7mm)
Wingless
Laterally flattened with long jumping hind legs
Piercing-sucking mouthparts
Adults feed on blood of mammals or a few birds
Blood is needed for egg development
Some are host-specific but others may accept different hosts if needed
About 3/4 of flea species are parasites of rodents
A few species are vectors of diseases (bubonic plague)
Species of Siphonaptera
Cat fleas
Accept different hosts if needed
Most common parasites of cats and dogs
Serve as an intermediate host for a tapeworm commonly found in dogs and cats
Bubonic plague
Killed 25% of population of western Europe in 1300s
Bacteria multiply in flea until they block the gut completely
- Flea transmits plague to humans by regurgitation of bacteria at the time of biting
Symptoms = enlarged lymph nodes
Order Coleoptera
Beetles
Largest order of insects (found everywhere)
Represents ~40% of known species
Vary from >1mm-15cm
Some are flightless
Larvae are variable in color/shape
- Most have 3 pairs of legs on thorax but some are legless
Various feeding habits: predaceous, phytophagous, or saphrophagous
Characteristics of Coleoptera
Elytra: thickened pair of forewings
- Meet at midline and cover the membranous hind wings
Hind wings are longer and folded under forewings
Flightless have fused or greatly reduced elytra
Adults and larvae have chewing mouthparts
- Exception (Dytiscidae & Gyrinidae larvae = sucking jaws)
