Ent302 Lecture Exam 2

Apterygota reproductive strategies

1. indirect insemination

a) with spermatophore produced
2. often associated with complex courtship

a) spermatophore may be deposited on thread (accessory glands)

b) male may maneuver female over spermatophore

Apterygota metamorphosis

1. ametabolous
2. mature female must mate subsequent to each ecdysis

a) spermatheca (ectodermal) - cuticular lining (and contents) lost at ecdysis

Apterygota misc. primitive features

1. vestigial, paired appendages sometimes present (=abdominal styli)
2. elongate caudal cerci plus a median caudal filament
3. primitively wingless

Apterygota significant advanced (= pterygote-like) features

1. ectognathous mouthparts
2. antennal musculature (scape + pedicel with intrinsic muscles)
3. epimorphosis
4. meroblastic cleavage

Order Archeognatha habitat

1. most common in dry chaparral, dry woodlands

a) usually with eversible vesicles near abdominal styli of abdominal segments 1-7 (for water uptake and regulation)

b) some apparently able to subsist largely/solely upon metabolic water (water produced from oxidation of carbs, fats, and proteins)

Order Archeognatha feeding habits

1. phytophagous - on lichens, algae
2. saprophagous

Order Archeognatha adaptations

active, extremely fast (cursorial legs); able to jump (hence, jumping bristletails)

Order Thysanura habitats

diverse

* free-living - humid, moist microhabitats (silverfish); hot, arid areas (firebrat)
* nest associates - mammals, ants (=myrmecophiles)

Order Thysanura feeding habits

omnivorous - molds, fungi, detritus, starchy materials

Order Thysanura adaptations

active (free living species); cursorial legs

Subclass: Pterygota; “primitively winged” “paleopterous” orders

* Order Ephemeroptera and Order Odonata
* No wing flexion
* Hemimetabolous
* Setaceous antennae
* Membranous wings, typically with supernumerary venation

Order Ephemeroptera “primitive” features

1. development and musculature of paired, bilateral abdominal tracheal gills - suggestive of podite ancestry
2. subimago - suggests “indeterminate” type of ametaboloys development seen in apterygote orders
3. paired gonopores - exit body posterior to 7th abdominal ventrite

Order Ephemeroptera notable features

1. naiads (=wigglers) aquatic; often long-lived (hemimetabolous = numerous instars)
2. body form and gill anatomy highly correlated with microhabitat parameters

a) slow (lentic) vs fast (lotic) water

b) active vs burrowing habits
3. subimago (=dun) and adult (=imago, spinner) often have synchronous emergences and mating swarms
4. naiads important “basal” element of many aquatic food chains
5. mass emergences can be nuisance

Order Ephemeroptera feeding habits

1. naiads mostly phytophagous, saprophagous (a few are predaceous)
2. adults non-feeding

a) have vestigial (=incompletely formed) mouthparts

b) mesentron highly modified for flight (=air sack)

Order Ephemeroptera adaptations

adults typically exhibit obvious gender dimorphism (eyes and prothoracic legs of males usually much larger/longer than those of females)

Order Odonata “primitive features”

1. flight mechanism almost entirely via direct flight muscles
2. modified indirect insemination - male transfers spermatophore from gonopore to accessory copulatory organ; female responsible for completion of sperm transfer

Order Odonata notable features

1. oviposition/naiad microhabitat correlation

a) oviposition endophytic (most Zygoptera, few Anisoptera): correlated with slender naiads on submerged vegetation
2. oviposition ectophytic (most Anisoptera, few Zygoptera): correlated with broadly flattened naiads on substrate (often hidden in bottom detritus)
3. migration

Order Odonata feeding habits

1. naiads and adults voracious predators

a) significant natural control agents (mosquitoes)

Order Odonata mating strategies

1. male transfers spermatophore from gonopore to accessory copulatory organ
2. male approaches female, grasps her with legs
3. male then changes hold by grasping female with cerci

a) by her head → Anisoptera

b) by her prothorax → Zygoptera
4. female then bends her abdomen around to bring her gonopore to the accessory copulatory organ of the male (=flying in tandem)

Infraclass Neoptera

1. Accounts for \~90% of insect species
2. insects are enabled to (for the first time) flex wings to fold them down over the abdomen

a) pleural muscle inserts on 3rd axillary sclerite
3. divided into 3 putatively monophyletic clades

a) Clade Polyneoptera

b) Clade Paraneoptera

c) Clade Holometabola

Clade Polyneoptera

A. external development of wings from pad like structures


1. similar to “paleopterous” insects in this regard
2. immature stage referred to as nymph \n a. exception: Plecoptera (= stoneflies) →\[hemimetabolous: naiads\]

B. Polyneoptera presently divided into three well supported superordinal clades as well as 2-3 ordinal lineages of uncertain placement:


1. Superorder – Plecopterida \n a. Order – Plecoptera \n b. Order – Embiodea \n c. Order – Zoraptera
2. Order - Dermaptera
3. Order - Grylloblattodea
4. Order- Mantophasmatodea
5. Superoder - Orthopterida

a. Order - Phasmatodea

b. Order - Orthoptera
6. Superorder - Dictyoptera

a. Order - Blattpdea (+ Isoptera)

b. Order - Mantodea

Order Plecoptera development

hemimetabolous (=aquatic naiads)


1. important to aquatic food chain (naiads)
2. particularly lotic (fast flowing streams)
3. most species with high oxygen requirements

a. among the 1st species to drop out in polluted (ie oxygen depleted) water

Order Plecoptera feeding habits

1. naiads mostly phytophagous (some predaceous)
2. adults short lived, commonly don’t feed (some observed feeding on algae, lichens, etc - probably rare)

Order Plecoptera habitat

1. naiads aquatic (especially quality streams - good as indicator species due to dissolved oxygen tolerance limits)
2. adults usually on foliage, etc - near habitat of naiadal stages (some also attracted to lights)

Order Plecoptera naiad adaptations

1. tracheal gills (when present) often tuft like, associated with thoracic sterna (near bases of coxae and sometimes caudal end of abdomen)
2. gas exchange also commonly through integuement directly (some species lack gills, entirely)

Order Plecoptera classification

1. many primitive features (mouthparts, antennae, prothoracic pleuron, supernumerary wing venation, etc)
2. most primitive prothoracic pleuron of all Pterygota (not divided into episternum and epimeron): structure strongly suggestive of subcoxal sclerite of primitively wingless insects (eg Thysanura)

Order Embiodea diversity

small order - most diverse in tropics


1. notably lacking from most islands (females apterous)
2. fewer than a dozen species recorded from southern US

Order Embiodea feeding habits

1. (female) fungal spores, lichens, mosses, bark, etc
2. males apparently non feeding as adults

a. well developed mandibles (males) used to grasp head of female during precopulatory and copulatoru behavioral sequences

Order Embiodea habitat

usually found gregariously in silken galleries within crevices of logs, rocks, etc

Order Embiodea adaptations

1. silk produced in swollen first tarsomere (=basitarsus) of prothoracic legs
2. rapid backward running facilitated by well developed, sensitive cerci and highly developed tibial depressor muscle (origin in swollen metathoracic femur)
3. wings (males) with poorly developed venation

a. unique among winged insects in being able to flex wings at any point

b. rigidity enhanced by pumping hemolymph into special blood cavity formed from enlarged radial blood vein to facilitate flight

Order Embiodea lifestyle

1. Eggs and early instar nymphs tended by mother
2. gender dimorphic - males (alate) → dispersice form (outcrossing, gene pool maintenance)
3. Males short lived, often consumed by female after mating
4. some species with both sexes apterous
5. some species are thelytokous (only females → parthenogenetically)

Order Zoraptera diversity

2nd smallest order (39 extant species)


1. 2 species in US (SW states)

Order Zoraptera feeding habits

(poorly observed) gut content analyses suggest fungal spores and perhaps minute invertebrates are ingested

Order Zoraptera habitat

1. Decaying vegetative materials
2. commonly found in association with termites (wood) - nature of association unknown (perhaps none)
3. often found gregariously, but appear to lack subsocial or social organization

Order Zoraptera polymorphic species

1. development of wings, compound eyes, ocelli
2. may be response to overexploitation of resources

Order Dermaptera feeding habits

1. generally omnivorous (some predaceous)
2. several of these are nest associates of mammals (bats and rodents)

a. these have several anatomical features suggestive of parasites
* strongly flattened body
* strongly reduced eyes, wings
* unspecialized cerci

b. no evidence yet that they are parasites

Order Dermaptera reproductives strategies

1. some viviparous (mammal associates)
2. males of some species with paired gonopores

order Dermaptera primitive subsociality

1. females brood over eggs, care for early instar nymphs
2. overlap of generations - important prerequisite for evolution of eusociality

Order Dermaptera habits

well adapted to life in crevices, flower buds, etc (tight places)


1. elytra (=mesothoracic wings) protect flight (metathoracic) wings
2. metathoracic wings have developed intricate folding pattern (associated with their highly modified anatomy); ear-like

Order Dermaptera highly derived forceps-like cerci

1. defense
2. manipulation of food (short elytra allow for great degree of abdominal flexibility)
3. assist with folding and unfolding of metathoracic wings
4. courtship and precopulatory behavior (often gender dimorphic)

Order Dermaptera classification

diverged early from Polyneoptera, perhaps most closely related to Grylloblattodea

Order Notoptera “Grylloblattodea” diversity

smallest order of insects


1. only 33 species known, all 1 family
2. W North America (15 species)
3. Siberia, Japan, Korea, China (18 species)

Order Notoptera “Grylloblattodea” habitat

1. rarely encountered
2. apparently nocturnally active
3. cold, moist mountainous areas

a. often crawling over rocks, snow fields

b. tolerate narrow range of temperatures within a few degrees of freezing

Order Notoptera “Grylloblattodea” feeding habits

poorly studied- may be predaceous, but probably omnivorous, opportunisits

Order Notoptera “Grylloblattodea” life cycle

1. long lived; thought to be 5-8+ years
2. adaptation to harsh environment - may be relatively inactive - burrowed down in rocky talus for periods when temperatures fo much above freezing

Order Notoptera “Grylloblattodea” classification

1. Many features of Orthoptera (=Gryllo-); several more suggestive of Dictyoptera (=-blattodea)
2. possible relationship to Dermaptera and Phasmatodea, but especially close relationship with Mantophasmatodea
3. highly disjunct geographical distribution together with comparative anatomy suggests they reflect a relictual evolutionary lineage that diverged early in the polyneopteran phylogeny

Order Notoptera “Mantophasmatodea” diversity

1. only 19 extant species
2. southern Africa endemic

Order Notoptera “Mantophasmatodea” habitat

1. rarely encountered
2. apparently nocturnally active
3. hot, dry deserts and mountainous areas

Order Notoptera “Mantophasmatodea” feeding habits

presumably all are nocturnally active predators

Order Notoptera “Mantophasmatodea” classification

1. recently described as a new order
2. putatively closely related to Grylloblattodea
3. perhaps same lineage as Grylloblattodea (proposed to be Notoptera)

Order Phasmatodea diversity

mostly tropical - particularly Old World tropics

Order Phasmatodea feeding habits

1. phytophagous
2. some species with cyclical population density structure (predator prey equation)
3. infrequently of some economic significance as defoliators of oaks, Eucalyptus

Order Phasmatodea adaptations

related to predator avoidance


1. often more active nocturnally; may remain virtually motionless all day
2. crypsis: cryptic camouflage (stick and leaf-like)
3. some species able to alter color to match background

a. regulate distribution of pigment in epidermis

b. under endocrine control
4. some with well developed chemical defense mechanisms

a. fluids exit body from thoracic glands
5. limb autonomy (weakness in leg - breaks off easily at trochanter/femur joint)

Order Phasmatodea reproductive strategy

parthenogenesis known in some species

Order Orthoptera diversity

the dominant order of Polyneoptera

Order Orthoptera feeding habits

mostly phytophagous species

Order Orthoptera predator avoidance

1. often cryptic → tend to mimic vegetation they feed upon
2. saltatorial metathoracic legs

a. direct predator avoidance

b. facilitate flight: jump to clear vegetation → flight

Order Orthoptera sound

profoundly significant in this group


1. behaviorally (communication)
2. evolutionarily (reproductive isolating mechanism)
3. most sound production (=singing) done by males; both genders have tympana

a. calling behavior to attract females
4. aggressive behavior (male approaching another male - often highly territorial)

Family Acrididae diversity

largest family of Orthoptera (10,000+ species)

Family Acrididae habitat

primarily terrestrial (geophilic)

Family Acrididae habits

most activity is diurnal (primarily visual and auditory behavioral cues)


1. large compound eyes
2. tympana

a. chordotonal organ attached to thin cuticular “membrane'“

b. located bilaterally on the 1st abdominal segment
3. sound production by stridulation

a. snap metathoracic wings together while in flight

b. mesothoracic wings and metathoracic femora
4. legs and antennae relatively short - enhances rapid, efficient movements (predator avoidance)

Family Tettigoniidae and Family Gryllidae adaptations

most activity is nocturnal (primarily tactile and auditory behavioral cues)


1. tympana - located proximally on prothoracic tibiae
2. sound production also by stridulation - vibrate overlapping areas of mesothoracic wings
3. legs and antennae very elongate - to enhance tactile feedback (dark)

Family Tettigonidae habitat

mostly arboreal (usually on shrubs, bushes, etc)

Family Gryllidae habitat

1. mostly geophilic (crickets, field crickets, etc)
2. some arboral (tree crickets)
3. some myrmecophilous

Order Blattodea diversity

most diverse in tropics - many colorful, diurnally active species (some arboreal)


1. only \~1% are the cosmopolitan associates of human dwellings (these are largely nocturnally active)

Order Blattodea feeding habits

1. mostly omnivorous

a. usually salivate on food and lap up material

b. something in one end → something out the other - potential for mechanical transmission of diseases

Order Blattodea habits

most are solitaru or “loosely” gregarious


1. except Cryptocercidae (wood roaches)

a. subsocial in rotting wood

b. sister group to termites (Isoptera)
2. except Isoptera (termites)

a. eusocial in wood, soil, social structures, etc

Order Blattodea reproductive strategies

1. stereotyped precopulatory behavior (like most insects)
2. often involve sex (=releaser) pheromones
3. “tail to tail” copulation
4. ootheca produced by females

a. structure usually species specific

b. generally 20-30 developing embryos in two, parallel rows
5. secondarily lost in most termites

Order Blattodea classification

1. ordinal sister group to Mantodea
2. both orders possess highly derived ootheca

Clade Isoptera diversity

most diverse in tropics; many construct characterisitc colonial structures (“mounds”)

Clade Isoptera feeding habits

1. largely phytophagous or saprophagous on wood and cellulose-rich materials
2. some are mycophagous (cultivate fungi on decaying plant matter)
3. economically significant (postive and negative) in all areas where they occur

a. destruction of cellulose (mostly wood and wood products)

b. in tropics, they (together with ants) are the ecological counterparts of what earthworms are in temperate regions

Clade Isoptera habits

highly developed social structure (=eusocial)


1. social polymorphism - morphologically distinct types; related to specialization (=polymorphic)

a. primary reproductives (males = kings, females = queens)

b. supplementary reproductives (males and females)

c. workers (males and females)

d. soldiers (males and females)

Clade Isoptera primary reproductives

1. reproductively mature
2. adults with 2 pairs of wings (=alate)

a. break off along weakened lines near base after nuptial flight
3. relatively more heavily sclerotized (more exposed to external environment) and more darkly pigmented than other morphs
4. female of some species becomes physogastric
5. eyes (compound and ocelli) usually present

Clade Isoptera supplementary reproductives

1. reproductively mature
2. lack wings

a. secondary reproductives have wing pads

b. tertiary reproductives lack wing pads
3. sclerotization/pigmentation and eyes reduced

Clade Isoptera workers

1. sterile
2. apterous
3. soft bodied, usually eyeless
4. may be set morph (unable to differentiate to become reproductives, etc). or, false workers (=pseudergates =nymphal reproductives)

a. in some species, these may be produced by retrogressive molting

Clade Isoptera soldiers

1. sterile
2. apterous
3. soft bodied (except head), lack eyes
4. 2 basic defensive strategies

a. typical “meat heads” - enlarged cranium/mandibles

b. nasute “nozzle heads” - some tropical species

c. in some species, both strategies are combined

Clade Isoptera social polymorphism determination

1. extrinsic (=nest environment) factors

a. most significant

b. eggs and 1st instar nymphs equipotent

c. a blend of 3 major factors
* pheromones - especially primer pheromones from primary reproductives
* nutritional control - amound and type of food given to nymphs
* sensory control - amount and type of tactile and olfactory stimuli
2. intrinsic (=genetic basis)

a. apparently some control in certain species

Clade Isoptera formation of new colonies

1. swarming
2. budding

Order Mantodea feeding habits

1. predaceous (sometimes even cannibalistic)
2. not good backyard biological control agents
3. generalists - size is major consideration
4. rely greatly upon camouflage strategy

a. often blend in with foliage, flowers, bark, etc
5. associated specializations

a. well developed compound eyes

b. head with externally great range of motion

c. raptorial prothoracic legs

d. cryptic structure and coloration of body

Order Mantodea mating behavior

1. courtship (“sneak attack”)
2. spermatophore
3. females of some species may sometimes attack and partially consume male during or immediately following copulation

a. possible adaptive significance - inhibitory center in brain of male

Order Mantodea oviposition

1. frothy mass - secretion from accessory glands of female
2. dries to papery texture
3. deposited on twigs, etc

Order Mantodea classification

1. sometimes with roaches and termites as the single order Dictyoptera
2. or, as separate order, but still closely related to Blattodea and Isoptera

Clade Paraneoptera wings

external development of wings from pad-like structures


1. similar to Polyneoptera in this regard
2. immature stages likewise referred to as nymphs

Clade Paraneoptera divided into 3 ordinal clades

1. Order Psocodea
2. Order Thysanoptera
3. Order Hemiptera

Order Psocodea feeding habits

omnivorous (starchy materials), fungal spores, molds, etc. OR ectoparasites of birds and mammals

Order Psocodea reproductive strategies

1. parthenogenesis fairly common (thelytoky and amphitoky)
2. viviparity established for some species
3. copulation in free-living species usually with precopulatory “dance” (male); spermatophore produced

Order Psocodea adaptations

1. sitophore-pestle

a. between oral cavity and esophagous

b. sitophore = modified base of hypopharynx

c. crushing function (\~mortar pestle) hypothesized, no longer standard interpretation

d. external manifestation: swollen frontoclypeal region (increases surface area of cranium for attachment of muscles to operate “pestle”)
2. silk production (at least some species)

a. labial silk glands - modified salivary glands

b. produces “webbing” used as shelter

Order Psocodea economic significance

1. some minor damage to stored products (book bindings, insect collections, etc)

Order Psocodea - Lice habits

ectoparasites of birds and mammals


1. ecoparasitic trends

a. secondarily wingless

b. compound eyes reduced or lacking, ocelli lacking

c. antennae reduced (often concealed)

d. body flattened (dorsoventrally in lice); often with setae and spines projecting backwardly; body very tough, leathery

e. tarsi often modified to grasp hairs, feathers of host
2. most exhibit great host specificity

a. in terms of host species utilized

b. in terms of particular region of host’s body preferred (microhabitat selection)
3. Medical significance: heavy infestations downgrade host, leading to drop in production (wool, dairy, poultry, etc)

Order Psocodea - Lice - Suborder Amblycera

chewing lice, in part


1. mostly associated with birds (and 2 common species on Guinea pigs)
2. feeding habits: feathers, hair, scales, exudates from sebaceous glands

Order Psocodea - Lice - Ischnocera

(chewing lice, in part)


1. one group associated with birds, another with placental mammals (not humans)
2. feeding habits: feathers, hair, scales, exudates from sebaceous glands

Order Psocodea - Lice - Suborder Anoplura

sucking lice


1. mammalian hosts (including humans)
2. feeding habits: blood
3. Serve as vectors of disease

a. 3 major human diseases spread by human body louse
* epidemic typhus: rickettsial pathogen (small, non-motile bacteria); high mortality; Napolean’s defeat
* trench fever: rickettsia, WWI
* relapsing fever: spirochete (motile bacteria, spiral shape), WWI, WWII
4. Pathogens multiply in gut of vector - pass in feces: mechanical transmission

a. fecal material inhaled

b. feces or lice crushed and introduced into skin, eyes by scratching

Order Psocodea - Lice - Classification

1. closely related to Psocoptera (especially evident in Amblycera)

a. similar structure of mouthparts (maxillary lacinia)

b. similar sitophore-like apparatus
2. once viewed as two orders: Mallophaga (=chewing) + Anoplura (=sucking) lice
3. Recent studies suggest lice are a clade related to the common booklice
4. Suggests one ancestral lineage with 4 suborders (the 3 + Rhynchopthirina) OR a polyphyletic evolutionary grade with 2 independent ancestors within Psocodea

Order Hemiptera suborders

1. Sternorrhyncha
2. Auchenorrhyncha
3. Heteroptera

Order Hemiptera diversity

1. largest order of Paraneoptera clade
2. Orthoptera (Polyneoptera) is the second largest order seen thus far

Order Hemiptera mouthparts modifications

1. sucking mouthparts preadapted to feeding on plant phloem
2. radiation of Hemiptera coincides with that of vascular plants
3. majority of Hemiptera are phytophagous (on phloem)
4. became well adapted to this “niche” prior to radiation of the large, holometabolous orders (out-competed Holometabola for this microhabitat)

Order Hemiptera adaptations

1. proventriculus, rectum reduced (reduced need for crushing food and water conservation)
2. extraoral digestion

a. salivary secretions with numerous proteolytic (digestive) enzymes

b. predators often with paralytic enzymes

c. some groups feeding on blood of mammals are significant in biological transmission of pathogens
3. Many with mesentron subdivided into distinct regions (Ventriculus I, II, III, etc.) - selective absorption of nutrients
4. Many Sternorrhyncha and Auchenorrhyncha with filter chamber
5. Many phytophagous Hemiptera produce honeydew

a. mutualistic behavior (eg with ants)

Suborder Heteroptera segmentation of beak

1. beak = labium (protective sheath surrounding stylets)
2. generally, correlated with trophic

a. long, 4 segmented beak → phytophagous

b. short, 3 segmented beak → predaceous

Family Corixidae habitat

generally aquatic (but, active fliers - often abundant around lights at night)

Family Corixidae abundance

1. extremely abundant in certain habitats
2. adults have been utilized as food for humans
3. eggs harvested from surfaces of aquatic plants are dried, ground into flour