Double-origin of swarm founding in the genus Ropalidia ?
(Insecta: Hymenoptera: Polistinae)
Fuki Saito-­‐Morooka, Rissho Univ. JAPAN (currently Ibaraki Univ.)
Subfamily PolisBnae (ca. 900 spp.) have the two way of starBng a new colony. Independent-­‐founding Swarm founders in PolisBnae
Partly Solitary phase
P047
DistribuBon map of swarm founding groups in PolisBnae Neotropical swarm founders
・ Foundress(es) are able to found a new colony. Colony founding by inseminated female(s) (= foundress)
Colony grows
Swarm-­‐founding (A_er Jeanne, 1991)
Polybioides
Neotropical swarm founders
Trail pheromones
Colony founding by workers + queen(s)
•  Chemical communicaBon is necessary. •  Queens are unable to found a new colony without aid of workers.
Nest construcBon by workers
OviposiBon by queen(s)
Swarm founding Ropalidia
•  DistribuBon areas of swarm founders are restricted in Tropics. •  Swarm founders have larger biomass than independent founders in Tropical regions.
•  Swarm founding is evolved several Bmes in the subfamily PolisBnae. Ropalidia is the unique example of having both mode of founding colony in a genus.
・　The genus Ropalidia is a large group in the DistribuBon map of the genus Ropalidia
PolisBnae, and consists of about 200 species. Some species are known as swarm founder; more than 15, but exact number is sBll unknown. ・　Swarm founding species have not been recorded from Sulawesi and Moluccas. → Swarm founding Ropalidia shows ・PhylogeneBc relaBonships among swarm-­‐founding species of genus Ropalidia with disjuncBve distribuBon ・The origin and distribuBon of swarm-­‐founding Ropalidia with reference to the historical geography of SE Asia, New Guinea and Australia disjuncBve distribuBon pa^ern.
R. romandi (Australia)
OUTGROUPS
guttatipennis
gracilenta
proletaria
plebeiana
socialistica
australis
macliventris
nigra
latetergum
romandi
kurandae
festina
rufocollaris
mathematica
artifex
socialis
stigma
marginata
laticincta
taiwana
malayana
rufoplagiata
rufoixys
latebalteata
turneri
cyathiformis
impetuosa
fasciata
variegata
dichroma
ornaticeps
flavopicta
opifex
copiaria
vietnama
Dist. area of swarm founding species
granulata
L = 3719　(obtained single tree) Support values for each clade lower than 80% were not shown. Results • 
Analysis for mitochondrial gene sequences shows monophyly of Australian and New Guinean swarming species. (support value 81% for MP tree, 84% for ML tree) • 
Asian swarm founding species are showed as a paraphyleBc group. They form a clade with other independent founding species, such as Ropalidia pilosa and R. granulata. • 
The ML tree also showed the same topology for swarm founding species. • 
Ropalidia malayana thought to be a swarm founder, but there are no explicit report. PhylogeneBc relaBonship with other swarm founders is ambiguous in this study. pilosa
MP tree PhylogeneBc analysis using mitochondrial DNA sequences： Mitochondrial DNA; COI 1071 bp, 16S rRNA 290 bp So_ware; ‘MEGA 5.2.2’ Trees were constructed using MP & ML strategy Alignment; Muscle algorithm SubsBtuBon model for ML; GTR+G+I (model was selected as the best fit model by MEGA 5.2.2) Support value; bootstrap 1000 repeats Ancestral States ReconstrucBon : Parsimony reconstrucBon using so_ware ‘Mesquite’
PhylogeneBc relaBonships of swarm founding species distributed in SE Asian or New Guinea + Australia
Borneo Myanmmer〜Sumatra Sulawesi Malay Peninsula, Sumatra Vietnam Jawa Malay Peninsula, Borneo Hong Kong〜Sumatra
India〜Malay Peninsula
Outgroups : Parapolybia varia, Pa. indica & Belonogaster juncea
sumatrae
swarm
opulenta
independent
*R. malayana seems swarm founder, but there are no explicit report. As shown above, in swarm founders, new colony is founded by a large number of workers accompanied by a smaller number of queens. Workers construct a new nest and forage food, and queens were engaged exclusively in oviposiBon. Then colony rapidly grows. The swarm founding is said to associate highly social systems among colony members, such as chemical communicaBon. ・　Swarm founding have been thought more derived system than independent founding. ・　Swarm founders are limited the dispersal of across the water. Australia + New Guinea fes=na kurandae romandi latetergum nigra maculiventris australis socialis=ca
SE Asia opulenta sumatrae vietnama copiaria opifex flavopicta orna=ceps
Ropalidia spp. : 15 swarm founding species 23 independent founding species 1 unknown (Ropalidia malayana)
Character: founding
EvoluBon of swarm founding in Ropalidia Parsimony reconstruction
(■ swarm [Steps:
□ independent) (Unordered)
5]
New Guinea Australia Australia Australia New Guinea New Guinea New Guinea Australia
Swarm founding is evolved several independent
Bmes in the genus Ropalidia! swarm
Evolution of swarm founding
These results may suggest Gondowana origin of swarm-­‐founding Ropalidia. But, phylogeneBc relaBonships of swam-­‐founding species do not show a nested pa^ern and well reflect current distribuBonal pa^ern of the wasps. And swarm founders are limited the dispersal of across the water. CONCLUTION: It is possible that swarm founding evolved more than once in the genus Ropalidia! In this study, support values on clade of the genus Ropalidia are low! ・　SelecBon of genes? or needs improvement of alignments? ・　Poor taxon sampling? I have to consider Ropalidia montana (not included in this study). This species is also swarm founders and restricted in south India. And my analysis included over 40 species of Ropalidia, but African independent founding species and New Guinean species are lacking. These include primiBve species. Very li^le is yet known about the biology of the Old World genus Ropalidia. More samples and biological informaBon are needed for the further study.