the cynipoid genus paramblynotus - American Museum of Natural ...

ABSTRACT
The genus Paramblynotus is the most species-rich genus of the so-called macrocynipoids, the
large cynipoid parasitoids of wood-boring and cone-boring insect larvae. The species range in
size from some of the largest to the smallest macrocynipoids, comparable in size to
microcynipoids. Paramblynotus members occur on all continents except Europe and Australia,
with most species being tropical or subtropical. The biology is poorly known but a few
observations indicate that the species are parasitoids of beetle larvae. In this monographic
revision of the genus, we present a species-level cladistic analysis based on qualitative and
quantitative features of the external morphology.
For analysis of quantitative features, we present for the first time a novel coding method, the
method of Finite Mixture Coding (FMC) based on k-means clustering, or FMCK. The new
method is similar to the FMC method proposed by previous authors in that they both generate
codes (character states) for phylogenetic analysis as the direct output of a statistical procedure,
thus avoiding the subdivision of quantitative data into discrete states on the basis of arbitrary
criteria as with other coding methods. Through incorporating finite mixture analysis and
likelihood estimation as used in FMC and k-mean cluster analysis for a priori statistical
modeling of component distributions, FMCK is advantageous over FMC in that it can be
implemented using readily available statistic programs with k-mean cluster analysis, such as
STATISTICA, MINITAB or SYSTAT, available on both PC and Macintosh platforms. We
were able to identify 8 quantitative characters among 23 as useful for cladistic analysis by using
the new coding method. In total, our character matrix has 132 coded characters.
The phylogenetic analysis indicates that species of the previously recognized genus Decellea
form a monophyletic group deeply nested within Paramblynotus. Decellea is therefore
synonymized with Paramblynotus, which is separated into seven monophyletic species groups:
the virginianus, scaber, yangambicolus, nigricornis, apeosus, ruficollis, andpunctulatus groups.
Based on the phylogeny, we reconstruct the historical biogeography of the liopterid subfamily
Mayrellinae, consisting of the genera Paramblynotus and Kiefferiella, using dispersal-vicariance
analysis in combination with palaeoenvironmental data. The results suggest that the subfamily
originated in the Northern Hemisphere and then expanded its distribution early by way of the
Bering area. The divergence between Paramblynotus and Kiefferiella was apparently associated
with the formation of the Rocky Mountains about 50 million years ago. An early
Paramblynotus lineage dispersed to Africa from the eastern Palearctic by way of Arabia, and
it subsequently diversified along with montane forests in Africa. The relatively high diversity of
Paramblynotus in Southeast Asia is considered to be partly caused by the frequent sea level
changes since late Oligocene (29 Ma), which drastically changed the land configuration of this
area.
We end this paper with a taxonomic revision of the genus Paramblynotus, with a total of 92
species treated, including 72 described as new and 20 previously known, of which 18 are
redescribed. Keys to the species groups as defined in this paper and to all known species of each
species group are provided. For all species, the available information on their biology and
distribution are summarized.
INTRODUCTION
The genus Paramblynotus Cameron, 1908
is one of three currently recognized genera in
the liopterid subfamily Mayrellinae. It is by
far the most speciose genus of the family,
including 20 described and many undescribed
species (Ronquist, 1995a). Members of the
genus are distributed in all major biogeographical
regions except the western Palearctic
and Australia, with the greatest diversity
being found in the eastern Palearctic and
Oriental regions (Ronquist, 1995a). According
to Ronquist (1995a), the closest relative
of Paramblynotus is the small genus Decellea
Benoit, 1956, consisting of two species, one of
which is undescribed. The distribution of
Decellea is limited to Africa. The third genus
of Mayrellinae is Kiefferiella Ashmead, 1903,
which is endemic to southwestern North