nickstevens agathidinae phd final

The many lineages of a unnatural grouping:The evolution of the parasitoid wasp genus Bassus

(Braconidae: Agathidinae) in Australia. Nick Stevens: Ph.D. project

Centre for Evolutionary Biology & Biodiversity, The University of Adelaide.

Supervisors: Dr N. Murphy, Prof A. Austin & Dr J. Jennings

The Agathidinae

> 1200 described species in > 50 genera worldwide.

Occur in tropical/subtropical to temperate, subarctic, & arid environments.

Monophyletic, BUT present tribal classification & many generic concepts not natural - Sharkey et al. (2006)

Generic & species diversity greater in more tropical regions

Agathidine Biology

Mostly concealed hosts:e.g. leaf curlers or stem borers.

Oviposition into ganglion of 1st or 2nd instars.

If host free living foragers then usually nocturnal.

Endoparasitoids of lepidopteran larvae

Important natural regulators of lepidopteran populations.

Numerous species used in biological control programs.

Host range Recorded lepidopteran host families:

Arctiidae Argyresthiidae Cochylidae Coleophoridae Epermeniidae Gelechiidae Geometridae Gracillariidae Lymantriidae Noctuidae Pieridae Pyralidae

Sesiidae Tortricidae Yponomeutidae.

Bassus rufipes (Nees Von Esenbeck) recorded from:

19 host species representing 15 genera & 6 families. Bassus nr unimaculata sp01 recorded from 3 native pest species:

Etiella behrii (Zeller) , Epiphyas postvittana (Walker) (Light Brown Apple Moth),Merophyas divulsana (Walker) (Lucerne Leaf Roller)

B. nr unimaculata sp01

Light brown apple moth (LBAM) larva in silken gallery

Bassus nr unimaculata sp01 searching for host LBAM

Bassus nr unimaculata sp01 ovipositing into host LBAM

Australian Fauna

Only 36 species in 9 genera described

Fauna not dealt with since Turner (1918).

Australian fauna poorly known

Initial estimates ~ 100 spp. Distinct colour pattern

- Black, Red-Orange & White (BROW complex) - putative aposematic mimicry complex

braconid lepidopterans

The BROW colour pattern

Other ichneumonoids

Bassus

Hemipterans

Dipterans

Non-BROW

Mimicry

Signal-receiver

Definition: simulation by an organism (the mimic) of signal properties of another organism (the model) that are perceived as signals of interest by a third living organism (operator/signal-receiver; eg potential predator), such that the mimic gains in fitness as a result of the signal-receiver identifying it as an example of the model (Vane-Wright 1980)

Mimic Model

MimicryMimics not always the potential prey.

Signal-receiver

Mimic Model

Mimicry Classification

ModelBatesian mimic

Batesian mimicryMullerian mimicry Strengthen signal, therefore both

model and mimic benefit;eg mimic unpalatable.

Proven or suspected mullerian mimics often referred to as co-models.

Reduce effectiveness of signal, therefore not beneficial for model; eg mimic palatable. Be selected to exist at lower densities than models.

Mullerian mimic

co-models

Mimicry Rings Evolution of similar colour patterns among sympatric species = mimicry

ring / complex. Many butterfly mimicry complexes studied & considered to consist

predominately of mullerian mimics Mutually beneficial because share burden of educating predators.

HOWEVER, not always so clear cut. Variation within species can exist; eg different toxin levels of host plant.

Toxic = unpalatable

Model

Non-toxic = palatable

Mimic

Empirical data suggests variations in unprofitability/profitability of models/mimics enhances & maintains predator education & subsequent avoidance (Skelhorn and Rowe 2005) .

“Life is like a box of chocolates …..” (Gump 1998)

BROW mimicry ring

Models

Mimics ?

If aposematic, who are the models ?

Female Wasps (arm waving conclusion) Evidence - have stings / ovipositors

- convergence of non-wasp members on wasp body form

Males: Models or mimics ?

Toxins ? Derived from plant feeding hosts ?

Generic Outline of Australian fauna Recognised This study Distribution No. spp.Agathis = Bassus spp. NA NABassus widespread ~ 150-160Biroia northern <5Braunsia northern <5Cremnops northern ~ 20-30Disophrys northern ~ 20-30Euagathis northern <5Orgiloneura syn. nov Bassus NA NAPlatyagathis syn. nov Disophrys Southwest NA

Coccygidium northern ~ 20-30Earinus northern <5Laccagathis northern <5

new records

BROW

BROW

Previous phylogenetic study: Sharkey et al. (2006)

Max. parsimony of morphology & 28S (D2 region)

62 in-group taxa; 10 Bassus spp., 1 Oz B. sp., no BROW members.

Results: - ‘n’ tribe ???????

- 4 Bassus lineages

Bassus lineage 1

Bassus lineage 2: contains Oz sp.

Bassus lineage 3

Bassus lineage 4

Aims of Ph.D. Project Investigate evolutionary relationships of

Australian Bassus- is Oz fauna monophyletic ?- has BROW strategy arisen once, twice, thrice ......

?- Bassus species complexes; can morphology

reliably define taxonomic limits ???

Revise Australian Bassus - re/describe & correctly place described spp. (24)

Develop keys (Lucid Phoenix)- Australian genera & Bassus spp.

Document ecological attributes- distribution, biology & host relationships

The agathidine files

LP3

LP4

Phylogenetic study Part 1: Putting the Australian fauna into a world context

Use morphological data matrix of Sharkey et al. (2006), but with numerous corrections & modifications

28S sequence data; genbank & this project from ‘fresh’ & pinned material

53 additional ingroup taxa (=115) 43 Bassus taxa, 28 Australian Bayesian & maximum parsimony

inference methods

T1T2

Agathidinae Phylogeny: Morphology

- Bayesian tree

- 40 parsimony informative characters

- out-group not depicted

- posterior probability 0.95

- boot-strap support values 50% below nodes

- BROW member

- convergent reductional wing venation characters

- Tribal relationships:low boot-strap Cremnoptini + Disophrini only

- 2 generic concepts well supported


- Bassus ??? Polyphyletic: 6 lineages

(albeit little or no support)



Bassus ??? - 6 lineages (albeit little or no

support)

Oz fauna ???

BROW ???

- monophyletic ?

- Multiple origins ?

- Bayesian tree - 28S (D2 region) ~ 412 bp (minus regions of ambiguous alignment)

- 297 positions informative

- out-group not depicted

- posterior probability 0.95

- boot-strap support values 50% below nodes

- BROW member

Agathidinae Phylogeny: 28S

- Cremnoptini: Cremnops other members

- Disophrini

- ‘N’ tribe


Tribal relationships

&

- Cremnoptini + Disophrini

- Earinini - Agathidini Disophrini

Cremnops

‘N’ tribe Earinini (- Earinus)

Agathidini


Bassus ??? - Polyphyletic:

6 lineages

‘N’ tribe

Earinini (- Earinus)

Agathidini


Oz fauna ???- 4 lineages

‘N’ tribe


Agathidini


Oz fauna ???

BROW ??? - at least 3 origins

- 4 lineages

‘N’ tribe


Agathidini

Agathidinae Phylogeny: Morphology & 28S

Inclusion of morphological data- no major changes- increase resolution & support basally

eg - Cremnoptini - (‘N’ tribe + (Earinini + Agathidini))

Agathidini

‘N’ tribe


Disophrini

Cremnoptini

LP3

LP4

New Morphological data matrix- 44 Characters- mouth parts- wing venation, - surface sculpturing- ovipositor

Additional genetic markers - LW (nuc markers) - higher levels - COI, 16S (mit markers) - lower

levels

Bayesian & maximum parsimony inference methods

T1T2

Phylogenetic study Part 2: Closer examination of Australian fauna

Australian fauna: Morphology

- Strict consensus tree - 32 ingroup taxa, 44 parsimony

informative characters- out-group not depicted- posterior probability 0.95- boot-strap support values 50% below

nodes- BROW member

Bassus meridionalis

B. meridionalis Hap06

Bassus rugosa

Australian fauna: All data combined (morphology, 28S, LW, CO1, & 16S)

- Bayesian - 32 ingroup taxa, 1617 characters, 9

partitions- out-group not depicted- posterior probability 0.95- boot-strap support values 50% below

nodes- BROW member

Bassus meridionalis

B. meridionalis Hap06

Bassus rugosa

Agathidini

‘N’ tribe Earinus

Disophrini

Cremnoptini Australian fauna: All data combined (morphology, 28S, LW, CO1, & 16S)

- no conflicts with inferred relationships of Part one

- LW Opsin resolved similar level to 28S

- CO1 & 16S greater resolution lower taxonomic levels and below

Conclusions

5 Tribes; 3 not defined morphologically Bassus polyphyletic with Australian representatives in all

the main lineages

BROW strategy evolved multiple times within Bassus

Many species/species complexes not able to clearly delimit morphologically

Morphology not able to resolve relationships alone BUT does enhance results in combination with molecular data

Future Research

Closer examination of species complexes (morphological & molecular)

BROW mimicry complex; aposematic ????

Further sampling, particularly NW & Central Australia

Yellabinna & Gawler Ranges Field-tripFunded by NFSA (Nature Foundation of South Australia

AcknowledgementsFunding: ABRS (Australian Biological Resources Study)

NFSA (Nature Foundation of South Australia)Australian & international insect collection staff

- in particular QM & ANICFellow lab-groupians (past & present); Danielle Carey, LachlanFarrington, Michelle Guzik, Tim Moulds, Katherine Muirhead, Cate Paull, & last but certainly not least, Claire Stephens.

THANK YOU ALL VERY MUCH

Described Bassus species in Australia Previous generic placement Bassus aalvikorum Stevens sp. nov. B. antipoda (Ashmead, 1900) comb. nov. Orgiloneura B. dimidiata (Brullé, 1846) comb. nov. Agathis B. festinata (Turner, 1918) B. fleurieuensis Stevens sp. nov. B. latibalteata (Cameron, 1906) comb. nov. Agathis B. leucogaster (Holmgren, 1868) comb. nov. Agathis B. maligna (Turner, 1918) B. martialis (Turner, 1918) B. meridionalis (Turner, 1918) B. minima (Turner, 1918) B. minor (Szépligeti, 1905) B. pedunculatus (Szépligeti, 1905) B. ruficeps (Szépligeti, 1905) B. rufipes (Nees von Esenbeck, 1814) B. rufithorax (Turner, 1918) B. rufobrunnea (Turner, 1918) B. rugosa (Turner, 1918) B. tenuissima (Turner, 1918) syn. nov. B. ruficeps B. tigris Stevens sp. nov. B. tricolor (Szépligeti, 1905) B. unimaculata (Turner, 1918) B. xanthopsis (Turner, 1918)

nickstevens agathidinae phd final

Documents