137 research outputs found
Phylogeography of Scarabaeus (Pachysoma) Macleay (Scarabaeidae: Scarabaeinae)
Scarabaeus (Pachysoma) consists of 13 flightless dung beetle species endemic to the arid west coast of southern Africa. Scarabaeus (Pachysoma) are unique in their feeding and foraging habits, in that they randomly search for dry dung/detritus which, when found, is dragged forwards, and buried in a pre-constructed holding chamber, as opposed to the convention of rolling it backwards. This action is repeated to provision the chamber after which the nest is expanded to below the moisture line to allow the stored food to re-hydrate. Poor vagility, taxonomic contention - seen in Scarabaeus taxonomy - and conservation concern, made Scarabaeus (Pachysoma) an ideal group of beetles to study both the phylogenetics and potential influences that anthropogenic and environmental changes have had on structuring the species and populations thereof. Both molecular and morphological data were used as individual datasets and combined in a total evidence approach. Biogeographic inferences were made based on recent detailed Namib biogeography and the ages of the species were estimated using the molecular clock method. A phylogeographic study was done on three of the species of Scarabaeus (Pachysoma) – S. (P.) hippocrates, S. (P.) gariepinus and S. (P.) denticollis - that had previously shown south-north morphological clinal variation. Lastly, an attempt was made to isolate microsatellite loci for Scarabaeus, in the hope of characterising genetic diversity within and between populations of the same species. Scarabaeus (Pachysoma) was found to be monophyletic within Scarabaeus and was therefore classified as a derived subgenus thereof. Morphologically Scarabaeus (Pachysoma) was shown to have 13 species while at a molecular level strong resolution for 11 of the 13 was obtained. S. (P.) hippocrates and S. (P.) glentoni formed a species complex the hippocrates/glentoni complex. The combined phylogenetic tree showed good overall support for all 13 species. Both the morphological and molecular data partition phylogenies show congruence with the combined phylogeny, lending support for combining datasets. Scarabaeus (Pachysoma) appears to have arisen 2.9 million years ago. The formation of advective fog is a consistent water source for Desert dwelling organisms and appears to be associated with Scarabaeus (Pachysoma) radiation into inhospitable areas. Analysis of gene flow revealed large amounts of south-north movement, lending support for movement of psammophilous taxa with their substratum, the barchan dune. Population demographics of the three species, S. (P.) hippocrates, S. (P.) gariepinus and S. (P.) denticollis, chosen for this study differed greatly except in areas of geographic similarity. Major rivers appear to have acted as gene barriers, allowing for distinct genetic entities to be identified within the three species. Phylogeographic partitioning was supported by an AMOVA analysis. All three species were shown to have undergone historical population expansion dating back to the Pleistocene era. Nested Clade Analysis indicated that allopatric speciation; isolation by distance and continuous range expansion could be the factors having affected overall population structure. Recent events show that human induced factors, environmental barriers and reduced vagility have influenced the species population structure. Four potentially polymorphic loci were isolated for Scarabaeus using the FIASCO protocol. Identification of at least one additional locus is needed in order to obtain statistical significance for future studies directed at uncovering recent population dynamics.Thesis (PhD (Entomology))--University of Pretoria, 2007.Zoology and Entomologyunrestricte
Phylogeny of the African ball-rolling dung beetle genus Epirinus Reiche (Coleoptera : Scarabaeidae : Scarabaeinae)
Recent phylogenetic analyses have pointed to the dung beetle genus Epirinus as the
putative African ancestral roller group. Consequently, we tested the roller status of species in the
genus with observational studies and constructed a molecular phylogeny based on partial
sequences of two mitochondrial and two nuclear genes for 16 of 29 species. Tested species were
confirmed to be dung rollers. Monophyly of the genus was confirmed, lending support to the
synonymy of the wingless genus Endroedyantus with Epirinus. Moreover, the phylogenetic
hypothesis was found to have a similar topology with a previously published one based on
morphological data. A combined molecular/morphology analysis showed congruence between
the molecular and morphological datasets. The loss of flight in some species and estimated
divergence dates within Epirinus are discussed.http://www.publish.csiro.au/?nid=120ab201
A molecular phylogeny of the African Scarabaeinae (Coleoptera: Scarabaeidae)
Dung beetles of the subfamily Scarabaeinae have a worldwide distribution, with the Afrotropical region, the putative origin of the diversification
of Scarabaeinae, having the richest diversity. We use partial sequences from two ribosomal (16S, 28S) and two protein coding genes
(COI, CAD) to examine the relationships among 55 genera, representing more than half of the genera in the region. Taxa were sampled to
maximize representation of dung beetle morphological and ecological diversity in all nine tribes that occur in Africa. We estimated the divergence
times of the tribes to determine relative ages. The phylogenetic hypothesis of tribal and generic relationships was found to largely
concur with that of a recent molecular study done at a global scale, suggesting earliest diverging lineages which are quite distinct from the
ones traditionally recognized. Thus recent calls for a new classification for Scarabaeinae are supported. We suggest possible changes to the
classification, corroborate the likely African origin of the subfamily and provide support for fungus-feeding as the most likely ancestral
feeding habit in the Scarabaeinae.An NRF grant was
awarded to CHS.http://www.arthropod-systematics.deam201
Affinities of the Canthonini dung beetles of the Eastern Arc mountains
The Eastern Arc Mountains (EAM) consist of 13
separate mountain blocks running from southern Kenya
through eastern Tanzania in an arc shape. Organisms occurring
in the forests of these mountains are known for their high
levels of endemism. Some of these organisms have their
closest relatives in distant geographic regions. In this study,
molecular phylogenetic methods, based on partial sequences
of one nuclear (28S) and two mitochondrial (COI and 16S)
genes, are used to determine the relationships of three
Scarabaeinae genera (tribe Canthonini) endemic to the
EAM. Janssensantus and Tanzanolus are found to have a
sister relationship within a lineage of south-eastern African
genera, while Madaphacosoma’s closest ties are with Oriental
and Madagascan taxa Ochicanthon and Epactoides, respectively.
Divergence time estimates suggest a Miocene origin for
the ancestral lineages of the three genera with Janssensantus
and Tanzanolus separating in the Pleistocene. Our results
provide evidence for a Madagascan origin for the EAM
genera.http://link.springer.com/journal/13127hb201
Colophon larvae : descriptions and phylogenetic implications
The aim of the Colophon larval study was to enable researchers to identify the species found in the field; to use larvae as an alternative for adults in molecular studies; to comment on possible phylogenetic information that may contribute to the sub-familial placement of the genus; and to obtain habitat preference data. To achieve this, larvae of four Colophon species were examined and their main diagnostic morphological characters identified. Larvae live in a fairly homogeneous micro-habitat of moist, humus-rich soil in protected places such as under rocky overhangs and amongst the roots and tussocks of Restionaceae. Colophon larvae show small inter-specific differences and larval characters contributed little equivocal information from which phylogenetic support for family placement could be deduced. Apparendy, as with many scarabaeoid groups (Trogidae, Scarabaeidae), larval morphology may not have diversified much from the basal ground-plan and it remains for other (adult) phylogenetically significant morphological characters or DNA to provide more clarity on Colophons subfamilial placement.http://booksandjournals.brillonline.com/content/journals/1876312xhb201
On Afromantispa and Mantispa (Insecta, Neuroptera, Mantispidae) : elucidating generic boundaries
Werner Strümpher is thanked for his valuable and critical comments on the manuscript.
We would also like to extend our gratitude to Johan Saayman for his enthusiasm
and willingness to help with the photography, as well as Morgan Trimble for some of the photos used in this publication. Mervyn Mansell is thanked for his willingness to
discuss and for his meaningful advice. We are also grateful for all the staff of SANC,
MRAC and ZMB who helped with the curation and lending of specimens.The genus Afromantispa Snyman & Ohl, 2012 was recently synonymised with Mantispa Illiger, 1798 by
Monserrat (2014). Here morphological evidence is presented in support of restoring the genus Afromantispa
stat. rev. to its previous status as a valid and morphologically distinct genus. Twelve new combinations
(comb. n.) are proposed as species of Afromantispa including three new synonyms.The National Research Foundationhttp://zookeys.pensoft.net/am201
A remarkable teratological case for Eucymatodera parva Schenkling, 1908 (Cleridae : Tillinae) from Namibia
Teratology can be defined as the study of the
causes producing abnormalities, malformations or
defects of the physical development (Ujházy et al.
2012). Teratological examples have been described
in almost all animal groups, including insects
(Ferrer et al. 2014). The importance of reporting
teratological events in insects has been discussed
by Glasgow (1925), Cockayne (1937) and Savini &
Furth (2004). Glasgow (1925) stated that insect
malformations should be documented to make
these cases available to investigators who may
have a special interest in such events. Cockayne
(1937) mentioned that, even if the observed
teratologies do not represent something novel,
it seems desirable to publish these descriptions
accompanied by plates illustrating the
nature of the abnormality. Savini&Furth (2004) in
their discussion of malformations in Coleoptera,
stressed the importance of recording insect abnormalities,
indicating that, in some cases, these
abnormalities offer valuable information about
the influence of environmental conditions during
insect development.http://www.journals.co.za/content/journal/entohttp://www.entsocsa.co.za/Publications.htm2020-03-01am2018Zoology and Entomolog
Phylogeny and historical biogeography of silky lacewings (Neuroptera: Psychopsidae)
Psychopsidae (silky winged lacewings) are a small family of Neuroptera characterized by broad hirsute wings that impart a physical resemblance to moths. The fossil record includes many psychopsid-like taxa from the Late Triassic to Early Oligocene from all major continents. Extant species have a disjunct, tripartite distribution comprising Afrotropical, Southeast Asian and Australian regions that is significant to historical biogeography. Two subfamilies are currently recognized: Zygophlebiinae in the Afrotropics, and Psychopsinae in Australia and Southeast Asia. This study explores phylogeny and historical biogeography of Psychopsidae, using data from biogeography, comparative morphology and molecular sequences (16S, 18S, CAD, COI). Our results show that: (i) the morphological phylogeny is incongruent with molecular data; (ii) Afrotropical Silveira Navás represent a separate lineage that warrants placement in its own subfamily; (iii) the family originated in Pangea; and (iv) the present genus level distribution resulted from two vicariance events associated with Gondwanan fragmentation.The National Research Foundation (NRF), the Research and Development funding body at the University of Pretoria and the JRS Biodiversity Foundation, U.S.A.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-31132019-01-30hj2018Zoology and Entomolog
On Afromantispa and Mantispa (Insecta, Neuroptera, Mantispidae) : elucidating generic boundaries
The genus Afromantispa Snyman & Ohl, 2012 was recently synonymised with Mantispa Illiger, 1798 by
Monserrat (2014). Here morphological evidence is presented in support of restoring the genus Afromantispa
stat. rev. to its previous status as a valid and morphologically distinct genus. Twelve new combinations
(comb. n.) are proposed as species of Afromantispa including three new synonyms.Werner Strümpher is thanked for his valuable and critical comments on the manuscript.
We would also like to extend our gratitude to Johan Saayman for his enthusiasm
and willingness to help with the photography, as well as Morgan Trimble for some of the photos used in this publication. Mervyn Mansell is thanked for his willingness to
discuss and for his meaningful advice. We are also grateful for all the staff of SANC,
MRAC and ZMB who helped with the curation and lending of specimens.The National Research Foundationhttp://zookeys.pensoft.net/am201
Genetic evidence for spatial structuring in a continuous African elephant (Loxodonta africana) population
Earlier studies on savannah elephants (Loxodonta
africana) investigated the genetic structure of
fragmented or isolated populations. Contrastingly, this
study aimed to determine if there was genetic evidence for
spatial structuring in a continuous elephant population in
the Kavango-Zambezi Transfrontier Conservation Area
(KAZA-TFCA). We sequenced one mtDNA gene region
for 88 individuals and genotyped 100 individuals for ten
nuclear microsatellite loci. Bayesian Clustering Algorithms
in Geneland identified groups of genetically similar individuals.
An analysis of molecular variance determined if
these groups (sub-populations) were significantly differentiated.
We identified geographic areas with high genetic
divergence (genetic barriers) between samples using a GIS
landscape genetic toolbox. There were three significantly
differentiated mtDNA sub-populations (Fst = 0.787) and
two nDNA sub-populations that were not significantly differentiated (Fst = -0.02; Rst = -0.045), implying
obstructed mtDNA, but high nDNA gene flow across the
study region. The KAZA-TFCA population has a genetic
diversity (mtDNA pairwise number of differences
(p) = 2.59; nDNA mean alleles/locus and He = 7.5, 0.71)
higher than other southern African populations, and interpopulation
movements may be responsible for maintaining
this genetic diversity. We discount anthropogenic and
geographic barriers as the primary drivers of genetic
structuring in the KAZA-TFCA population and suggest
that future studies should consider the influence of intrinsic
factors (resource dependencies and social variables that
limit movement) when investigating the genetic structure
of elephant populations. We recommend continued support
for conservation initiatives that aim at maintaining and
restoring connectivity between populations, which in so
doing may ensure inter-population gene flow and uphold
the current genetic state of the KAZA-TFCA population.International Fund for Animal Welfare and the Conservation Foundation (Zambia).http://link.springer.com/journal/105922016-07-01hb201
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