Arthropod Fauna of the UAE, Vol. 2, A. van Harten (Ed.): book review
- Authors: Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451625 , vital:75065 , https://hdl.handle.net/10520/EJC32810
- Description: This volume extends the UAE's catalogue of arthropods from 1400 species to 1790 species, and describes 83 new species, four new genera and even a new tribe. The chapters include about two arachnid taxa (pseudoscorpions and cunaxid mites), and cover a total of 63 families, 26 of them previously not recorded from the country. Three chapters deal with entomobryomorph springtails, earwigs and barklice, respectively, and the rest are focused on families in the 'megadiverse' orders Coleoptera, Hymenoptera, Lepidoptera and Diptera.
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- Date Issued: 2009
Data quality in thermal summation development models for forensically important blowflies
- Authors: Richards, Cameron S , Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441889 , vital:73932 , https://doi.org/10.1111/j.1365-2915.2009.00819.x
- Description: To highlight some issues regarding data quality that are significant in estimating post‐mortem intervals (PMI) from maggots, the developmental constants of thermal summation models for development of Chrysomya megacephala Fabricius (Diptera: Calliphoridae) were calculated from incidental data gathered from 12 published studies, and from data generated specifically for the purpose in a single experiment. The focused experiment involved measuring the timing of five developmental landmarks at nine constant temperatures with a sampling resolution of 6–12 h, which is characteristic of other published studies. Combining data from different studies produced inconsistent results because of statistical noise introduced by (at least) disparities in temporal precision, descriptive statistics, geographical location and rearing diets. A robust experimental design to estimate a developmental model should involve at least six constant temperatures, starting at about 7°C above the relevant developmental zero (D0) and going almost to the upper critical temperature, and a temporal sampling interval with a relative precision of about 10%, which requires sampling about every 2 h until hatching, about every 3 h until first ecdysis and about every 6 h until second ecdysis.
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- Date Issued: 2009
Development of Thanatophilus micans (Fabricius 1794)(Coleoptera: Silphidae) at constant temperatures
- Authors: Midgley, John M , Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441904 , vital:73933 , https://doi.org/10.1007/s00414-008-0280-0
- Description: Thanatophilus micans is capable of finding corpses at least as quickly as most fly species and, as the most widespread species of the Silphidae in Africa, offers a useful model for estimating post-mortem interval. Larvae were reared at ten constant temperatures from 15°C to 35°C and their length measured at 4, 8, or 12-h intervals depending on their instar. Length generally increased with increased rearing temperature, but decreased at extremely high temperatures. Note was made of the age at which individuals progressed past developmental milestones. Development took longer at lower temperatures. These results are presented as a combined isomegalen and isomorphen diagram. Developmental constants were generated for each milestone using major axis regression. Developmental threshold values did not differ significantly between milestones. Development took longer than in blow flies, but was faster than in Dermestidae. The three models presented here, therefore, cover an important time frame in estimating minimum PMI once fly larvae have matured to the point of leaving a corpse, and, therefore, provide a tool that was not previously available to forensic entomologists.
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- Date Issued: 2009
Effect of the killing method on post-mortem change in length of larvae of Thanatophilus micans (Fabricius, 1794) (Coleoptera: Silphidae) stored in 70% ethanol
- Authors: Midgley, John M , Villet, Martin H
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6857 , http://hdl.handle.net/10962/d1011140
- Description: It is recommended that insect larvae collected for forensic purposes should be killed using the same method as was used to create existing models for rate of development. Certain killing methods have been shown to be preferable because they cause less distortion of the specimens, but these are not always practicable in a particular case, and so a method of correcting for effect of killing method is required. Larvae of all instars of Thanatophilus micans (Fabricius 1794) (Coleoptera: Silphidae) were measured and then killed by immersion in ethanol, immersion in hot water or freezing. Samples were re-measured immediately after death, then stored in excess 70% ethanol and re-measured after 1 week and again after 4 weeks. The change in length was significantly different from zero in all samples (t = -9.07022, p < 0.001). An analysis of covariance showed that instar, killing method and storage time all had a significant effect on the change in length. The results showed that T. micans larvae have a great potential for change in length during storage but that the change is not predictable, as the magnitude and sign of the change are variable.
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- Date Issued: 2009
Flies in the ointment a morphological and molecular comparison of Lucilia cuprina and Lucilia sericata (Diptera: Calliphoridae) in South Africa
- Authors: Tourle, Robyn , Downie, Douglas A , Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442156 , vital:73963 , https://doi.org/10.1111/j.1365-2915.2008.00765.x
- Description: Complementary nuclear (28S rRNA) and mitochondrial (COI) genes were sequenced from blowflies that phenotypically resembled Lucilia cuprina (W.), Lucilia sericata (Meigen) or exhibited characters of both species. The aim was to test a long‐held hypothesis that these species hybridize under natural conditions in South Africa (Ullyett, 1945). Blowflies were obtained predominantly from the Cape Town metropolitan area, but reference samples were acquired for L. sericata from Pretoria. Several L. cuprina‐like flies were shown to possess a conflicting combination of nuclear and mitochondrial genes that has also been seen in Hawaiian specimens. Homoplasy, sampling of pseudogenes, hybridization and incomplete lineage sorting are discussed as possible hypotheses for the pattern and the latter is concluded to represent the most likely explanation.
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- Date Issued: 2009
Models of development for blowfly sister species Chrysomya chloropyga and Chrysomya putoria
- Authors: Richards, Cameron S , Crous, Kendall L , Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:73967 , https://doi.org/10.1111/j.1365-2915.2008.00767.x
- Description: Developmental curves for the sister species Chrysomya chloropyga (Wiedemann, 1818) and Chrysomya putoria (Wiedemann, 1830) (Diptera: Calliphoridae) were established at eight and 10 different constant temperatures, respectively, using developmental landmarks and body length as measures of age. The thermal summation constants (K) and developmental threshold (D0) were calculated for five developmental landmarks using a previously described method. Isomorphen and isomegalen diagrams were also constructed for the purpose of estimating postmortem intervals (PMIs). Chrysomya chloropyga had an average developmental threshold value (D0) of 10.91 °C (standard error [SE] = 0.94 °C, n = 5), significantly lower than that of C. putoria (13.42 °C, SE = 0.45 °C, n = 5) (paired t‐test: t = − 4.63, d.f. = 8, P 0.00). Similarly, K values for C. chloropyga were larger than those for C. putoria for all developmental events except onset of the wandering phase. These are the first data that can be used to calculate minimum PMIs and predict population growth of C. chloropyga and C. putoria in Africa; the data indicate that developmental data for one of these species cannot be used as surrogate data for the sister species.
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- Date Issued: 2009
Phylogeny, biogeography and classification of the snake superfamily Elapoidea a rapid radiation in the late Eocene
- Authors: Kelly, Christopher M R , Barker, Nigel P , Villet, Martin H , Broadley, Donald G
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442267 , vital:73971 , https://doi.org/10.1111/j.1096-0031.2008.00237.x
- Description: The snake superfamily Elapoidea presents one of the most intransigent problems in systematics of the Caenophidia. Its monophyly is undisputed and several cohesive constituent lineages have been identified (including the diverse and clinically important family Elapidae), but its basal phylogenetic structure is obscure. We investigate phylogenetic relationships and spatial and temporal history of the Elapoidea using 94 caenophidian species and approximately 2300–4300 bases of DNA sequence from one nuclear and four mitochondrial genes. Phylogenetic reconstruction was conducted in a parametric framework using complex models of sequence evolution. We employed Bayesian relaxed clocks and Penalized Likelihood with rate smoothing to date the phylogeny, in conjunction with seven fossil calibration constraints. Elapoid biogeography was investigated using maximum likelihood and maximum parsimony methods. Resolution was poor for early relationships in the Elapoidea and in Elapidae and our results imply rapid basal diversification in both clades, in the late Eocene of Africa (Elapoidea) and the mid‐Oligocene of the Oriental region (Elapidae). We identify the major elapoid and elapid lineages, present a phylogenetic classification system for the superfamily (excluding Elapidae), and combine our phylogenetic, temporal and biogeographic results to provide an account of elapoid evolution in light of current palaeontological data and palaeogeographic models.
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- Date Issued: 2009
Predicting geographic distribution of seven blowfly species (Diptera: Calliphoridae) in South Africa
- Authors: Richards, Cameron S , Williams, Kirstin A , Villet, Martin H
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6854 , http://hdl.handle.net/10962/d1011135
- Description: The predicted geographic distributions of seven forensically important blowfly species are modelled using the computer program Maxent, based on selected climatic variables for South Africa, a country with large climatic and environmental gradients. It is shown that although temperature was hypothesized to most influence the distributions of these ectotherms, moisture, and particularly humidity, was in fact usually paramount. Chrysomya albiceps (Wiedemann) and C. marginalis (Robineau-Desvoidy) had the most widespread geographic and climatic distribution, while the forest-associated C. inclinata(Walker) was the least widespread. Chrysomya putoria (Wiedemann) and C. megacephala (Fabricius) had very similar predicted distributions that were restricted mainly to Limpopo, Mpumalanga, KwaZulu-Natal and the coast of the Eastern Cape. Chrysomya chloropyga (Wiedemann) and Calliphora croceipalpis (Jaennicke) were the only species predicted to occur at high altitudes. Blowfly distributions restricted to part of the map area were predicted better than those that were more widespread in the region, presumably because species with extremely widespread distributions in a study area occupy nearly the whole range of variation of most predictor variables, leaving little variation with which themaximumentropy modelling method can discriminate between presence and absence of the organism.
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- Date Issued: 2009
Thermal ecophysiology of seven carrion‐feeding blowflies in Southern Africa
- Authors: Richards, Cameron S , Price, Benjamin W , Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442384 , vital:73980 , https://doi.org/10.1111/j.1570-7458.2009.00824.x
- Description: A variety of temperature thresholds for larvae, pupae, and adults of seven African species of carrion‐feeding blowflies (Diptera: Calliphoridae) was measured and compared to understand their basic thermal biology and the influence of temperature on their behaviour. Calliphoraácroceipalpis (Jaennicke) had consistently lower temperature thresholds than all other species tested for all larval (42.9á░C), pupal (16.6á░C), and adult (45.6á░C) stages. Larvae (50.1á░C) and adults (53.4á░C) of Chrysomyaámarginalis (Robineau‐Desvoidy) had higher upper lethal temperature thresholds than all other species and weighed more than all other species. Pupae and adults of both Chrysomyaáalbiceps (Wiedemann) and Luciliaásericata (Meigen) had similar temperature thresholds, whereas Chrysomyaáputoria (Wiedemann), Chrysomyaáchloropyga (Wiedemann), and Chrysomyaámegacephala (Fabricius) had inconsistent rank temperature thresholds between the larval, pupal, and adult stages. With a few minor exceptions, the nervous activity, muscle activity, and death thresholds in female adult flies responded at higher temperatures than conspecific male flies for all species tested. Similarly, female adult flies weighed consistently more than conspecific male flies for all species tested, except Ca.ácroceipalpis. These data suggest that there is a phylogenetic component to the thermal biology of blowflies, because Ca.ácroceipalpis belongs to a primarily Holarctic genus and shows adaptation to that climate even though it inhabits Africa. Comparisons between these temperature thresholds and the distributions of blowfly species present on three rhinoceros carcasses suggest that blowfly larvae with high upper lethal temperature thresholds (particularly C.ámarginalis) dominate in interspecific competition on the carcass by raising the temperature of the amassed maggots above the thresholds of other carrion‐feeding blowflies, through metabolically generated heat.
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- Date Issued: 2009
“The Two Cultures reunited: entomology for everyone”
- Authors: Villet, Martin H
- Date: 2009
- Language: English
- Type: Audio , text
- Identifier: vital:587 , http://hdl.handle.net/10962/d1018947
- Description: Fifty years ago C.P. Snow delivered his essay, "The Two Cultures", sparking the schism between the Humanities and the Sciences. This lecture explores cultural entomology as a means of reconciling two other cultures: academia and society, and suggests one way of addressing this alienating dilemma.
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- Date Issued: 2009