Conservation of Hawaiian Drosophila using phylogenetic,

ecological and population genetic data.

Patrick M. O’Grady

University of California, Berkeley

Dr. Karl Magnacca

Richard Lapoint

Breeding ecology of the endemic Hawaiian Drosophilidae (Magnacca, Foote and O’Grady, Pacific Science)

Population genetics of a recently divergent group of Hawaiian Drosophila (Lapoint and O’Grady, P12)

– Estimating population genetic parameters (ancestral population size, migration rates, etc)

Outline

Phylogeny

Population Genetics

– Placement of the Hawaiian Drosophila & Scaptomyza– Time scale for drosophilid evolution– Ages of major Hawaiian lineages– Ecological associations

Introduction – Hawaiian Drosophila

Hawaiian Drosophila- 1,000 endemics

- diverse behavior & morphology

- single colonist?

- biogeography

- ancient: 25 mya

D.hanaulae

D.ingens

D.cyrtolomaD.melanocephala

D.obscuripes

D.neoperkinsi

D.oahuensis

D.nigribasis

D.neopicta

D.substenopteraD.hemipeza

D.silvestris

D.heteroneura

D.differens

D.planitibiaD.picticornis

D.setosifrons

D.primaeva

D.adunca

K

H

M

Mo

H

H

O

O

O

O

MN

Mo

EM

WM

WM

EM

EM

Habitat degradation (alien species, development, natural disaster, fire)

Pest control (insecticides, non-target effects)

Predation from alien arthropods (ants, wasps)

Competition (introduced Drosophila, Stratiomyidae, Neriidae)

Hawaiian Drosophilaand the genusScaptomyza

99

The Hawaiian Drosophilidae (genus Scaptomyza plus the Hawaiian Drosophila) form a clade. This is indicative of a single ancestral colonization event.

What group issister to the Hawaiian Drosophila?

How many colonizations of Hawaii?

51525354555

Colonization ofHawaii - 25my

multiple calibration points (fossils,biogeography)

How old are theendemic HawaiianDrosophilidae?

15my

16my

9my

21my

61

100

100

99

Species group relationships in Hawaiian Drosophila lineage agree with previous work.

100

antopocerus/modified tarsus

picture wing/nudidrosophila

modified mouthpart

haleakalae

Scaptomyza

99

10my

Phylogeny and Diversification Times

antopocerus/modified tarsus

picture wing/nudidrosophila

modified mouthpart

haleakalae

Scaptomyza

Araliaceae

Campanulaceae

Hawaiian Drosophilidae use ~40% (34/87) of native flowering plant families as larval substrates

Ecology

53

7

6

19

0 0

28 18

6 20

Araliaceae and Campanulaceae are used by nearly all major lineages

Loss of host plants via rarity or extinction

Endangered Hawaiian Drosophilidae

D. aglaia D. differens D. hemipeza D. heteroneura D. montgomeryi D. mulli D. musaphilia

D. neoclavisetae

D. obatai D. ochrobasis D. substenoptera

D. tarphytricha

picture wingconspicuousextensively studied

D. aglaia D. differens D. hemipeza D. heteroneura D. montgomeryi D. mulli D. musaphilia

D. neoclavisetae

D. obatai D. ochrobasis D. substenoptera

D. tarphytricha

– Taxonomy not well understood.– Difficult to work with (little known

of their ecology, not culturable in the laboratory, polytene chromosomes are not amenable to study).

– Historical distribution and abundance data not available.

Other groups?

Loss of host plants via rarity or extinction

D. aglaia D. differens D. hemipeza D. heteroneura D. montgomeryi D. mulli D. musaphilia

D. neoclavisetae

D. obatai D. ochrobasis D. substenoptera

D. tarphytricha

Endangered Hawaiian Drosophilidae

Drastic reduction in numbers of populations and population sizes.

once considered extinct; single population recently discovered

collected five times since 1975

collected frequently from 1967 -- 1975; not seen since 1986 historically known from 7 localities; only 1 population remainsextinct in part of historical range (Ko’olau Mountains)

known only from single, highly restricted localitiesknown only from single, highly restricted localities

Population Genetics

Population genetic techniques to estimate effective population size, Ne, of a given population

Drosophila neutralis

1,447,500

How large is a population? Is it small enough to be considered for conservation action? When should a very small population be considered inviable?

Laupohoehoe

Hawaii

Kau

Olaa

Stainback

670,414

1,442,708

2,605,417Ne ~ 6,000,000

Population Genetics

Population genetic techniques to estimate effective population size, Ne, of a given population

Rates of migration/gene flow

Coalescent theory to estimate ancestral population sizes

How large is a population? Is it small enough to be considered for conservation action? When should a very small population be considered inviable?

Does a species have a small population because it has (1) always been found in low numbers (rarity), (2) recently undergone a population decline (3) is the result of a founder event

Can we assess connectivity between proposed conservation management units?

D. neutralis

D. neutralis

D. dasycnemia

Ecological data is important when considering which taxa to target for conservation action. All taxa using a rare or endangered host plant may be at risk of population declines.

Conclusions

Knowledge of phylogeny, as well as the phylogenetic distribution of host plant use, can yield an appreciation for how many lineages (percentage of the total diversity) will be impacted by a decline in a given host plant.

Population genetic measures can be useful in the monitoring and evaluation of conservation decisions.

Population genetic techniques should be used before conservation management decisions are made to determine whether a population is truly in decline, and whether it is a viable candidate in which to invest limited resources.

Integration of Data

phylogeny

ecology

population structure

Fungi (1)

Araliaceae (4)

Nyctaginaceae (3)

Campanulaceae (3)

Monocots (3) Sapindaceae (2)

Myrtaceae (1)

Other

LeavesBarkStemsSap FluxFungiEquivocal