Table 1

Natural and laboratory hybridization between species of Heliconius (see Additional File 1 for specimen details)

Genus

Species 1

Species 2

Geographic relationship

No. of natural hybrids

Backcrossing in lab or field

Laboratory hybrids

Molecular evidence

Assortative mating

F₁ female sterility

Eueides

lybia

vibilia

sympatric

1

-

-

-

(+)

?

isabella

vibilia

sympatric

4

-

-

-

(+)

?

isabella

procula

sympatric

1

-

-

-

(+)

?

pavana

vibilia

sympatric

1

-

-

-

(+)

?

Heliconius (melpomene-cydno-silvaniform group)

numata

melpomene

sympatric

4

-

-

-

(+)

?

ismenius

cydno

sympatric

-

+

+

-

+

+

hecale

melpomene

sympatric

2

-

+

-

+

?

hecale

elevatus

sympatric

3

+

-

-

(+)

?

hecale

atthis

sympatric

-

+

+

-

+

+

ethilla

melpomene

sympatric

4

+

-

-

+

?

ethilla

numata

sympatric

2

-

-

-

(+)

?

ethilla

besckei

sympatric

6

+

-

-

(+)

?

melpomene

cydno

sympatric

68

+

+

+

+

+

melpomene

heurippa

sympatric

1

+

+

+

+

+

melpomene

pachinus

sympatric

-

+

+

+

+

+

cydno

pachinus

parapatric

3

+

+

+

+

-

cydno

heurippa

parapatric

-

+

+

+

+

-

Heliconius (erato-sara-sapho group)

himera

erato

parapatric

57

+

+

+

+

-

erato

charithonia

sympatric

1

-

-

-

+

?

charithonia

peruvianus

parapatric

1

+

-

+

(+)

?

hecalesia

hortense

sympatric

1

-

-

-

(+)

?

hecalesia

clysonymus

sympatric

1

-

-

-

(+)

?

Total

161

Mallet et al. BMC Evolutionary Biology 2007 7:28   doi:10.1186/1471-2148-7-28