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Home , Acari, Arachnid, Cercopidae, Chelicerata, Cicadidae, Cucujiformia

Phylum Arthropoda Phylum Arthropoda

Most “successful” lineage on Earth greatest biomass (>750 kg per person) numbers of numbers of individuals number of ecological niches

Phylum Arthropoda Trilobitomorpha Trilobita Subphylum Class Merostomata Class Pycnogonida Class Arachnida Subphylum Class Crustacea Class

Class From: Briggs & Fortey (2005) Wonderful strife: Systematics, stem groups, and the phylogenetic signal of the radiation. Paleobiology supplement to Vol 31(2): 94-112

ARTHROPODA Why so successful? 1. -allowed invasion of land & flight

2. & limbs -allowed incredible limb modifications

3. Short span & high fecundity -allows higher rates of

1 Subphylum Chelicerata Subphylum Chelicerata Apomorphies

• No antennae (lost) • • Two tagmata – Prosoma & (no distinct head)

Subphylum Chelicerata Subphylum Chelicerata

Chelicerae Chelicerae first two modified for chelate (pinching) feeding, clawed - not mandibles or venomous fangs or piercing stylets (for sucking body or plant juices)

Sun

Subphylum Chelicerata

Pedipalps - 2nd pair of appendages modified for sensory perception communication catching prey conveying ()

2 Subphylum Chelicerata

Pedipalps

Subphylum Chelicerata Subphylum Chelicerata

12 appendages Three classes 1 pair of chelicerae • Merostomata 1 pair of pedipalps – relic, 4 species left 4 pair of /swimming legs • Pycnogonida (3 pair in immature & ) (1st pair sensory in many groups = 3 pair for walking) – marine “sea spiders”, 1,000 spp. Most species are predators • Arachnida Most are liquid feeders (don’t chew) – spiders, , etc. 70,000 Gnathobases - grind prior to ingestion spp.

Subphylum Chelicerata Subclass

Class Merostomata Horseshoe crabs not crabs (not ) Xiphosura - Horseshoe crabs closest extant relatives of • 4 species left (3 genera: NA, se Asia, Malaysia) & – “living ” “evolutionary relic” “ ” • all marine, shallow (but oviposit on shoreline) • only chelicerates with compound • primitive ! simple!

3 Class Arachnida

4 Class Arachnida Class Arachnida

• primarily terrestrial (marine origin) Among the earliest on land – few mites & spiders secondarily aquatic – Tracks 460-500 mya ? (some mites parasitize marine animals & – Most activity from the (410- some live in deep ocean trenches) 360 mya) – Fossil mites, scorpions, spiders • ~ 93,000 species – 1 m long aquatic /amphibious scorpions

• Most are spiders (37,000 spp) & mites (45,200 spp)

Class Arachnida

• Respiration via 2-4 pairs of book and / or rudimentary tracheae - open via spiracles

• Tracheae not homologous with those of other terrestrial (& not as efficient = lower metabolic rates) • Usually “sit & wait” predators

Class Arachnida Class Arachnida Pumping

Species with tracheae rely less on for ( do not use blood for gas exchange)

Book

5 Class Arachnida ~93,000 species Orders No. described spp. 1. Aranae ~37,000 2. ~45,200 (~500,000 new?) 3. () Solpugida 1,065 4. Uropygi 101 5. 126 6. ~4,500 7. Pseudoscopriones 3,100 8. Scorpiones 1,260 9. 195 10. Rincinulei 53 11. 80 Data from: Coddington, J. A. & Colwell, R. K. 2001. , pp. We will focus on those indicated in bold 199-219 in Encyclopedia of vol. 1 Academic Press.

Ricinulei Class Arachnida

Order Araneae - 7th largest order • Spiders – , glands – Chelicerae modified into fangs - tubes – A few species dangerous to • Black widow, brown recluse, hobo(?) • Most “bites” are not – All predators, (on insects)

SEM of Spider spinnerete & silk

Gasteracantha sp.

Silk - used for:

prey capture safety lines sacks aerial dispersal lines air bags for diving

One of the strongest & 5 times stronger than steel of toughest natural fibers same weight & more elastic Crab spider: known than nylon

6 Jumping spiders Salticidae .

Orb-weavers Araneidae: Gasteracantha sp.

Courtship dances by jumping spiders (Salticidae) Class Arachnida by Dr. W. Maddison (UBC) Order Acari • Mites & – Hyperdiverse – ~ 1 million undescribed species – rival & in species # – Many parasitic – & predators

7 Class Arachnida

Order Acari • Prosoma & opisthosoma ~ fused • Ticks - vector pathogens, e.g. • (Spirochaete ) • Some plant pests • “Chiggers” & mange • Some aquatic spp.

Class Arachnida

Order Acari • folliculorum -the eyebrow -harmless, usually -cosmopolitan - < 0.4 mm

Ixodidae: komodoense

8 Class Arachnida opilo L.

Order Opiliones – “Daddy long-legs,” “Harvestmen” – No venom – 4,500 spp – fused – only – Have penis – Can eat solids

Class Arachnida

Order Pseudoscorpiones – ~ 3,100 species – Predaceous, in leaf litter & crevices – Often phoretic on flying insects – 7mm or less, usually 5 or less – Pedipalps large, pincerlike, no – glands in pedipalps

9 Class Arachnida

Order Scorpiones – Terrestrial, largest bodied – Large, chelate pedipalps – 1,260 species – Poison gland in tail – Aquatic 425 mya – Terrestrial 400 mya – Nocturnal

Phylum Arthropoda Subphylum Mandibulata Good with curry!

10 Phylum Arthropoda Subphylum Mandibulata

Subphylum Trilobitomorpha ! Concept of Snodgrass 1930-1950s Class Trilobita ! Three classes Subphylum Chelicerata ! Class Merostomata ! • Myriapoda Class Pycnogonida ! – , , ~13,000 spp Class Arachnida ! • Crustacea Subphylum Mandibulata – shrimps, lobsters, etc. 45,000 spp. Class Myriapoda Class Crustacea • Hexapoda Class Hexapoda – insects, 1,000,000+ spp.

Subphylum Mandibulata Subphylum Mandibulata Crustacea + Myriapoda + Insecta

Apomorphy • Mandibles ( jaws) –Shared development & genetics

Crustacea Hexapoda () Hexapoda () Mandibles - developed from limbs

11 Class Myriapoda

Class Myriapoda Class Myriapoda Centipedes & Millipedes Centipedes - Chilopoda

• 2,800 species (8,000 total?) Largely homonomous body

• Terrestrial (some marine?) Direct development (no larvae) • Unwaxed & un-closable spiracles = moist , nocturnal • Genital opening posterior <1 - 30 cm

Class Myriapoda Geophilomorpha

Centipedes - Chilopoda Centipedes

• Predators Common

Defensively • Poison fangs (1st limbs on trunk) produce HCN gas

No. body • One pair of legs per segments not body segment constant even in a species

12 Scolopendromorpha Scutigeromorpha

Dorsal spiracles!

Class Myriapoda Class Myriapoda Millipedes - Diplopoda Millipedes - Diplopoda

• 7,000 species (80,000 total?) • No venom

• Terrestrial • Trunk of diplosegments (2 segments fused) = 2 pair of legs per segment • , herbivores • Many with calcium hardened cuticle (tough! • Genital opening anterior But also rare in acidic habitats)

13 Hexapods Phylum Arthropoda Subphylum Trilobitomorpha ! Class Trilobita ! Subphylum Chelicerata ! Class Merostomata ! Class Pycnogonida ! Class Arachnida ! Subphylum Mandibulata ! Class Crustacea ! Class Myriapoda ! Class Hexapoda

Tagmosis & limb loss CLASS HEXAPODA in the Insecta Characteristics From hypothetical worm-like & myriapod- • 6 walking legs (each of up to 6 segments) like ancestors • 3 tagmata

Note loss of limbs on • Cuticle tanned with sclerotin (a lightweight ) Note incorporation of limbs as mouthparts • Abdomen originally of 11 segments

CLASS HEXAPODA Reconstruction of

Fossil History praecursor Among the oldest No marine fossil hexapods? (Crustaceans?) terrestrial animals

Devonian (400 mya) Oldest fossil hexapods ~ 400 mya (Devonian)

order Collembola - of Scotland Rhyniella praecursor

14 richness In fossil record

Order Collembola - Labandeira & Sepkoski 1993

Fossil record Phylogeny of the Hexapoda Collembola & Archeognatha

Earliest Hexapods

Fig. 8.1 Fig. 7.2

Phylogeny of Hexapoda

Insecta

Fig. 7.3 © Dave Walter

15 Ectognathy! Subclass & Order • No antennae, wings, or eyes see. p.230-231 – (pseudoculus)

• Entognathous mouth – (mouthparts inside cavity)

• 400-600 species, 8 families ~ 48 species in

© Dave Walter

Subclass & Order Protura Subclass & Order Protura • Small (0.6-1.5 mm) • Inhabit soil, decaying vegetation, and rotting see. p.230-231 wood • Prolegs modified for sensory • Associated with (thought to purposes feed on mycorrhizal fungi)

• Tracheal system reduced • Rare in collections, no? specialist • Anamorphosis - autapomorphic. in North America Immature has few segments & more are added posteriorly during • Rarely seen alive - collected with development Berlese funnels (as are Diplurans)

Functionally a Subclass & Order Collembola • Abdomen reduced to 6 or fewer segments – Tracheal system reduced / absent

• Entognathous mouth ( & no palps) – (mouthparts inside cavity)

• 6,000-9,000 species, 700 in North America • Many undescribed spp.

© Dave Walter

16 Subclass & Order Collembola Subclass & Order Collembola • Abdominal seg 1 has collophore • Ubiquity similar to Acari & nematodes – Used for many purposes, incl. osmoregulation – but not as many species

• Furca - “spring tail” a forked jumping organ • Ubiquitous & abundant (100,000+ / m3 of surface soil & most common on , -20m in fresh & marine habitats, • Small 2-3 mm, up to 12mm Coenaletidae species live in shells with terrestrial hermit crabs!) • With postantennal sensory • Found in all habitats that contain metazoans organs (possible – coldest to hottest (48°C volcanic vents) homologs of – treetops to deepest 2nd antennae) – some species can survive desiccation (anhydrobiosis, completely dry without death) • Molting continues for life (52 molts is the record) • Feed on decaying vegetation, fungi, etc. – some species can survive without (more likely to survive nuclear war than !)

Life in the undergrowth - Collembola - globular

First 4 abdominal segments fused

Arthropleona Life in the undergrowth - Collembola - mating (Spermatophore placed on substrate) - elongate

Which do you think is more derived?

17 Archeognatha

© Alex Wild

Palaeodictyoptera Dominant insects of the (50% of species)

Beaked herbivores (83% of leaf showed evidence of herbivory)

“Paleoptera” End Permian extinction of & superorder (multiple closely related paleopteran orders)

Fig. 7.2 Prothoracic paranotal lobes

18 Order - Dragon & Damselflies Order Odonata - Dragon & Damselflies

• 5,500 species, mostly tropical, predacious • Two suborders hold 99% of species • Nymphs with extensible pre-hensile labial mask • : Anisoptera modified for grasping prey – Wings to side, larvae with rectal • Male copulatory organs on segments 2&3 but • Damselflies: Zygoptera on segment 9 – Wings vertical, larvae with 3 caudal lamellae (gills) copulate in unique ‘wheel position’ • 360° vision - aerial hunters

Phylogeny of the Phylogeny of the Hexapoda Hexapoda

Neoptera - 90% of Hexapoda

Polyneoptera - - Hemipteroids (Holometabola)

Fig. 7.2 Fig. 7.2

19 20 - Acrididae

21 Katydids - - Tettigonia chinensis

Phylogeny of the Phylogeny of the Hexapoda Hexapoda

Neoptera

Polyneoptera - Orthopteroids etc Paraneoptera - Hemipteroids Endopterygota (Holometabola)

Fig. 7.2 Fig. 7.2

Order Phthiraptera - lice • Dorsoventrally flattened

• ~ 5,000 species (we have 2 species)

• Eyes absent or reduced

22 Phylogeny of head/body

Deep (old) split within the louse phylogeny

1.18 million ago

How is this possible if modern Homo sapiens is less than 0.2 million years old?

H. neanderthalensis [0.6 mya] H. erectus [1.8 mya]

Phylogeny of human head/ Order

• Bugs, hoppers, , , scale Mapped onto phylogeny insects, , etc. of Homo • Largest non-endopterygote order (~90,000 spp) H. neanderthalensis is • Mandibles and maxillae modified too recent as piercing stylets • Lack palps Deep split is consistent • In beak-like labium with split between = rostrum or proboscis H. erectus and our lineage • Wings coupled in flight - fore & hind act as one wing

Box 11.8 one possible scenario

23 Order Hemiptera

Fig. 7.5

“Homoptera” - “” “Homoptera” - Cicadas, spittlebugs, plant-, leaf-, & psyllids, whiteflies, aphids, scale insects - with tymbal acoustic system

Cicadidae

Cicadellidae

Coccoidea - coccids, scales, mealy bugs

Gerromorpha: :

24 lectularius Swallow bugs

Cimicomorpha Assassin bugs Plant bugs Lace bugs Minute Pirate bugs Bed bugs

Carabidae Cerambycidae Chrysomelidae Fig. 7.2

25 Fig. 7.2

26 Order Siphonaptera -

• 2,500 species, apterous, laterally compressed • Ectoparasites of birds & ~ 74% use as hosts • No compound eyes, (ocelli or none) • Piercing & sucking mouthparts • DNA & new morphological data suggest fleas evolved from within the (sister to snow fleas - Boreidae)

Order Trichoptera -

• Aquatic larvae with hook-bearing prolegs at end of abdomen • Larvae make cases, or are free-living • Sister order to the - Very well supported

27 Order Trichoptera - caddisflies Aquatic Hexapods - 30,000 species (370 marine)

• Wings with hairs, rarely scales Major contributors Minor contributors • Collembola • ~11,000 species with -like adults • Odonata • • Diverse feeding habits - predators, detritivores, • Ephemeroptera • adults often do not feed • • • Lepidoptera • Hemiptera • • • Coleoptera • Diptera • Trichoptera

Order Lepidoptera - Order Lepidoptera - moths • “Microlepidoptera” - 40% of species • Antennae typically filiform or plumose – small (moths) or knobbed / clubed () – Lots of leaf miners • Butterflies are modified, diurnal moths • Macrolepidoptera - 60% of species – Larger bodied – With tympanal organs in some lineages (Many are • “moths” paraphyletic with respect to tuned to detect bat sonar) butterflies

• ~160,000 species (14,500 species)

Butterflies - 82 Alaskan species, Ken Philip

28 Silk moths - Order Hymenoptera - , , 1,500 species • Flight driven by forewings - hindwings coupled to forewings with small hooks (hamuli)

• ~100,000 species (36,000 in NA - more than Coleoptera; outnumber global Coleoptera due to many tiny wasps; estimated that 60-96% of the order is undescribed)

• Many species beneficial to humans - pollinators & (biocontrol)

• Haplodiploidy - females diploid, males haploid

Order Hymenoptera - ants, wasps, bees Order Hymenoptera - ants, wasps, bees Traditionally, two suborders: Four basic life patterns: – “Symphyta” (wood wasps & ) • 3 segmented 1. the primarily phytophagous “Symphyta” • Larvae caterpillar-like & phytophagous

– (ants, bees & wasps) 2. the parasitic or gall-making Apocrita • Propodeum (abdominal segment 1) joined to thorax = remainder of abdomen is the gaster (or ) 3. the non-social Apocrita whose larvae are • One with ovipositor modified into sting fed prey or captured by the mother

4. the social Apocrita

29 Prolegs continuous to posterior Lepidoptera larvae not so - have a ‘gap’

30 31