Cuticular hydrocarbons (CHCs) are used for chemical communication among nestmates in many ant spe... more Cuticular hydrocarbons (CHCs) are used for chemical communication among nestmates in many ant species, and they may play a role in the discrimination of nestmates and non-nestmates. Using the mandible opening response (MOR) bioassay, we tested the response of the African termite raiding ant, Pachycondyla analis, to CHC extracts of nestmates and non-nestmates. The ants were able to distinguish control chemical cues, from nestmate CHCs, and from non-nestmate CHCs, and, based on a CHC recognition threshold, aggression was demonstrated toward non-nestmates. Gas chromatography (GC) and GC-mass spectrometric analyses showed that CHC components of different ant colonies had chain lengths ranging from C8 to C31, comprising mainly n-alkanes, alkenes, and methyl branched alkanes, with the n-alkanes occurring in the same proportions among all colonies. The ants were grouped successfully according to their colonies of origin by using discriminant analysis of CHCs. We demonstrate that nestmate recognition occurs in P. analis, and that some of the cues involved are evidently alkenes and methyl-branched alkanes.
Morphometric dissimilarity metrics aim
to quantify the variation between compared specimens
such ... more Morphometric dissimilarity metrics aim to quantify the variation between compared specimens such that inferences about their relatedness and alpha taxonomy can be made. Recently, the technique has developed metrics that purport to quantify shape dissimilarity between specimens—employing the use of least squares regression analysis. These metrics have been well applied by studies in the hominin fossil record with an arguably unsubstantiated backing for the technique. Originally postulated was the log10 sem metric which subsequently led to the standard error test of the null hypothesis metric. Following this, the standard deviation of logged ratios (SLR) metric arose as a pairwise dissimilarity metric that constrains the regression to a zero-intercept, that is, a significant development in the robustness of the technique. This metric was tested on extant primates in order to evaluate its effectiveness alongside the two other metrics. It was shown to be the most reliable for comparisons between specimens of primates, but was unable to discriminate between heterospecific and conspecific comparisons. Arguably, an alternative model organism with which to compare the technique is lacking. This study considers shape dissimilarity metrics with respect to a group of nonmammalian organisms (mantidflies) and tests the metrics against three lines of evidence (morphology, CO1-DNA, and geographic distribution) that can delimit the species-level taxonomy for the group. It is shown that the metrics are unable to discriminate between pairwise comparisons of closely related species, resulting in biologically erroneous groupings, and contradicting the groupings derived from morphological, CO1-DNA, and distributional comparisons. It is thus asserted that the technique is unsuitable for use in alpha taxonomy as an additional line of evidence in mantidflies. It is further supposed that morphometrics in general should be employed with caution in studies of evolutionary history as phylogeny is not the only information contained within morphometric data.
Lack of effective vaccines and therapeutics for important arboviral diseases such as Rift Valley ... more Lack of effective vaccines and therapeutics for important arboviral diseases such as Rift Valley fever (RVF) and dengue, necessitates continuous monitoring of vector populations for infections in them. Plant-based lures as surveillance tools has the potential of targeting mosquitoes of both sexes and females of varied physiological states; yet such lures are lacking for vectors of these diseases. Here, we present evidence of the effectiveness of linalool oxide (LO), a single plant-based lure previously developed for malaria vectors in trapping RVF vectors, Aedes mcintoshi and Aedes ochraceus, and dengue vector, Aedes aegypti. For RVF vectors, we used CDC traps to evaluate the performance of LO against three vertebrate-based lures: CO2 (dry ice), BioGent (BG) lure, and HONAD (a blend of aldehydes) in 2 experiments with Completely Randomized design: 1) using unlit CDC traps baited separately with LO, HONAD and BG-lure, and unlit CDC trap + CO2 and lit CDC trap as controls, 2) similar treatments but with inclusion of CO2 to all the traps. For dengue vectors, LO was evaluated against BG lure using BG sentinel traps, in a 3 × 6 Latin Square design, first as single lures and then combined with CO2 and traps baited with CO2 included as controls. Trap captures were compared between the treatments using Chi square and GLM. Low captures of RVF vectors were recorded for all lures in the absence of CO2 with no significant difference between them. When combined with CO2, LO performance in trapping these vectors was comparable to BG-lure and HONAD but it was less effective than the lit CDC trap. In the absence of CO2, LO performed comparably with the BG-lure in trapping female Ae. aegypti, but with significantly higher males recorded in traps baited with the plant-based lure. When CO2 was added, LO was significantly better than the BG-lure with a 2.8- fold increase in captures of male Ae. aegypti. These results highlight the potential of LO as a generalist plant-based lure for mosquito disease vectors, pending further assessment of possible specificity in their response profile to the different stereoisomers of this compound.
Secretions from tergal glands are part of a queen's phero... more Secretions from tergal glands are part of a queen's pheromonal control of worker reproduction in honey bees. However, in queenless honey bee colonies, workers compete to gain pheromonal, and hence reproductive dominance, over nestmates with ontogenetic changes in their glandular secretions that affect the behavioral or physiological responses of other individuals. Using gas chromatography/mass spectrometry, we investigated for the first time the age-dependent changes in tergal gland secretions of queenless workers of the clonal lineage of Apis mellifera capensis and workers of A. m. scutellata. The reproductive status of honey bee workers was determined by recording the presence of spermathecae and the level of ovarian activation. The tergal gland chemicals identified in both A. m. scutellata workers and A. m. capensis clone workers were oleic acid, n-tricosene, n-pentacosene, and n-heptacosene, with three additional compounds, palmitic acid, n-heneicosene, and n-nonacosene, in A. m. capensis clones. We report ethyl esters as new compounds from honey bee worker tergal gland profiles; these compounds increased in amount with age. All A. m. capensis clone workers dissected had spermathecae and showed ovarian activation from day 4, while ovarian activation only started on day 7 for A. m. scutellata workers that had no spermathecae. Tergal gland secretions were present in higher quantities in bees with activated, rather than inactive ovaries. This suggests that tergal gland secretions from reproductive workers could act as releaser and primer pheromones in synergy with other glandular compounds to achieve pheromonal and reproductive dominance.
This work, a sequel to Honeybees and Wax published nearly 30 years ago, starts with a brief intro... more This work, a sequel to Honeybees and Wax published nearly 30 years ago, starts with a brief introduction and discussion of nesting sites, their spaces and densities, self-organization of nest contents, and interspecific utilization of beeswax. The following chapters cover communication by vibrations and scents and wax secretion, and discuss the queen in relation to the combs. Discussions on completed nests include the significance of brood, the roles of pollen and nectar flow, and comb-building, and are followed by a triad of related chapters on the construction of cells and combs and their energetic costs. An in-depth examination of the conversion of wax scales into combs, the material properties of scale and comb waxes, and the wax gland complex are presented. The next chapters are devoted to a comprehensive analysis of the literature on the chemistry and synthesis of beeswax, and, finally, the material properties of honeybee silk are highlighted. Content Level » Research Keywords...
Because the waggle dances of honeybees contain celestial components, modifications of the dances ... more Because the waggle dances of honeybees contain celestial components, modifications of the dances occur with changing celestial moves relative to a honeybee nest. Since the direction of a particular resource is static, the dances must alter to compensate for the sun's passage. The position of the sun is seasonal between the Tropics of Cancer and Capricorn so that turns at the end of waggle runs will vary with season and latitude. The bees are confronted with a new difficulty when the sun closely approaches its zenith because only slight errors in the bees' estimation of the relative positions of the sun and zenith generate very large errors. So, the sun compass loses its usefulness when at its zenith. We review experiments and observations on both foraging and absconding in relation to the azimuth. The honeybees' solution for the paradox of the azimuth includes an azimuthal lull, preferences, and time windows.
The small hive beetle (SHB), Aethina tumida Murray, is a newly introduced coleopteran species att... more The small hive beetle (SHB), Aethina tumida Murray, is a newly introduced coleopteran species attacking honey bees (Apis mellifera L.) from mixed European stock, in North America. This species originates in sub-Saharan Africa, where it is not considered an economic pest. This is in stark contrast to the serious damage caused by this beetle in the southeastern U.S. In the present study, we determined that honey bee subspecies may be an important factor as to why the small hive beetle is not a pest in Africa, but is in the U.S. The Cape bee, Apis mellifera capensis, which has co-evolved with the SHB in South Africa, showed significantly more aggressive behavior toward adult SHB in a laboratory bioassay when compared to behavior of A. m. mellifera. The Cape bee also showed significantly more investigative contacts toward the SHB, when compared to A. m. mellifera. When given the opportunity to feed on Cape bee eggs in South Africa in a laboratory study, the SHB consumed all eggs present...
The state of knowledge on the pheromones of Asian honeybees is discussed. The queen mandibular ph... more The state of knowledge on the pheromones of Asian honeybees is discussed. The queen mandibular pheromone is known to elicit short- (retinue formation, swarm stabilisation and drone attraction) and long-term (inhibition of queen rearing) behaviours. The primer pheromones produced by the mandibular and Dufour’s glands and the releaser ones associated with alarm and aggregation are reviewed. All species appear to
Genetic considerations concern the roles and effects of genetics in Asian honeybees. Emphasis is ... more Genetic considerations concern the roles and effects of genetics in Asian honeybees. Emphasis is placed on recent developments with regard to mating frequency, the effects of multiple mating which could act directly on the queen as well as on the colony and the probability of being affected by homozygosity are considered. The effects of dominant-recessive inheritance on variation and the
The results of studies on the energetics of flight presented in this review include dimensional c... more The results of studies on the energetics of flight presented in this review include dimensional considerations of flight, scaling effects in foragers and drones, aerodynamic efficiency, low and high altitude phenotypes and fuelling flight. There are caste-specific differences within species, adaptations in relation to altitude and special requirements for absconding and migration. Workers of the Asian species of Apis comprise three design classes based on wing-loading, engine size and excess power index. The energetics of salvaging old comb wax are considered in terms of a cost analysis of wax salvage, costs for collecting the nectar to replace the wax and an energy balance trade-off, which demonstrate that recycling is a favourable adaptation, apparently unique to Apis florea.
Varroa destructor is considered the most damaging parasite affecting honeybees (Apis mellifera L.... more Varroa destructor is considered the most damaging parasite affecting honeybees (Apis mellifera L.). However, some honeybee populations such as the savannah honeybee (Apis mellifera scutellata) can survive mite infestation without treatment. It is unclear if survival is due to resistance mechanisms decreasing parasite reproduction or to tolerance mechanisms decreasing the detrimental effects of mites on the host. This study investigates both aspects by quantifying the reproductive output of V. destructor and its physiological costs at the individual host level. Costs measured were not consistently lower when compared with susceptible honeybee populations, indicating a lack of tolerance. In contrast, reproduction of V. destructor mites was distinctly lower than in susceptible populations. There was higher proportion of infertile individuals and the reproductive success of fertile mites was lower than measured to date, even in surviving populations. Our results suggest that survival of savannah honeybees is based on resistance rather than tolerance to this parasite. We identified traits that may be useful for breeding programmes aimed at increasing the survival of susceptible populations. African honeybees may have benefited from a lack of human interference, allowing natural selection to shape a population of honeybees that is more resistant to Varroa mite infestation.
ABSTRACT Because the waggle dances of honeybees contain celestial components, modifications of th... more ABSTRACT Because the waggle dances of honeybees contain celestial components, modifications of the dances occur with changing celestial moves relative to a honeybee nest. Since the direction of a particular resource is static, the dances must alter to compensate for the sun's passage. The position of the sun is seasonal between the Tropics of Cancer and Capricorn so that turns at the end of waggle runs will vary with season and latitude. The bees are confronted with a new difficulty when the sun closely approaches its zenith because only slight errors in the bees' estimation of the relative positions of the sun and zenith generate very large errors. So, the sun compass loses its usefulness when at its zenith. We review experiments and observations on both foraging and absconding in relation to the azimuth. The honeybees' solution for the paradox of the azimuth includes an azimuthal lull, preferences, and time windows.
Cuticular hydrocarbons (CHCs) are used for chemical communication among nestmates in many ant spe... more Cuticular hydrocarbons (CHCs) are used for chemical communication among nestmates in many ant species, and they may play a role in the discrimination of nestmates and non-nestmates. Using the mandible opening response (MOR) bioassay, we tested the response of the African termite raiding ant, Pachycondyla analis, to CHC extracts of nestmates and non-nestmates. The ants were able to distinguish control chemical cues, from nestmate CHCs, and from non-nestmate CHCs, and, based on a CHC recognition threshold, aggression was demonstrated toward non-nestmates. Gas chromatography (GC) and GC-mass spectrometric analyses showed that CHC components of different ant colonies had chain lengths ranging from C8 to C31, comprising mainly n-alkanes, alkenes, and methyl branched alkanes, with the n-alkanes occurring in the same proportions among all colonies. The ants were grouped successfully according to their colonies of origin by using discriminant analysis of CHCs. We demonstrate that nestmate recognition occurs in P. analis, and that some of the cues involved are evidently alkenes and methyl-branched alkanes.
Morphometric dissimilarity metrics aim
to quantify the variation between compared specimens
such ... more Morphometric dissimilarity metrics aim to quantify the variation between compared specimens such that inferences about their relatedness and alpha taxonomy can be made. Recently, the technique has developed metrics that purport to quantify shape dissimilarity between specimens—employing the use of least squares regression analysis. These metrics have been well applied by studies in the hominin fossil record with an arguably unsubstantiated backing for the technique. Originally postulated was the log10 sem metric which subsequently led to the standard error test of the null hypothesis metric. Following this, the standard deviation of logged ratios (SLR) metric arose as a pairwise dissimilarity metric that constrains the regression to a zero-intercept, that is, a significant development in the robustness of the technique. This metric was tested on extant primates in order to evaluate its effectiveness alongside the two other metrics. It was shown to be the most reliable for comparisons between specimens of primates, but was unable to discriminate between heterospecific and conspecific comparisons. Arguably, an alternative model organism with which to compare the technique is lacking. This study considers shape dissimilarity metrics with respect to a group of nonmammalian organisms (mantidflies) and tests the metrics against three lines of evidence (morphology, CO1-DNA, and geographic distribution) that can delimit the species-level taxonomy for the group. It is shown that the metrics are unable to discriminate between pairwise comparisons of closely related species, resulting in biologically erroneous groupings, and contradicting the groupings derived from morphological, CO1-DNA, and distributional comparisons. It is thus asserted that the technique is unsuitable for use in alpha taxonomy as an additional line of evidence in mantidflies. It is further supposed that morphometrics in general should be employed with caution in studies of evolutionary history as phylogeny is not the only information contained within morphometric data.
Lack of effective vaccines and therapeutics for important arboviral diseases such as Rift Valley ... more Lack of effective vaccines and therapeutics for important arboviral diseases such as Rift Valley fever (RVF) and dengue, necessitates continuous monitoring of vector populations for infections in them. Plant-based lures as surveillance tools has the potential of targeting mosquitoes of both sexes and females of varied physiological states; yet such lures are lacking for vectors of these diseases. Here, we present evidence of the effectiveness of linalool oxide (LO), a single plant-based lure previously developed for malaria vectors in trapping RVF vectors, Aedes mcintoshi and Aedes ochraceus, and dengue vector, Aedes aegypti. For RVF vectors, we used CDC traps to evaluate the performance of LO against three vertebrate-based lures: CO2 (dry ice), BioGent (BG) lure, and HONAD (a blend of aldehydes) in 2 experiments with Completely Randomized design: 1) using unlit CDC traps baited separately with LO, HONAD and BG-lure, and unlit CDC trap + CO2 and lit CDC trap as controls, 2) similar treatments but with inclusion of CO2 to all the traps. For dengue vectors, LO was evaluated against BG lure using BG sentinel traps, in a 3 × 6 Latin Square design, first as single lures and then combined with CO2 and traps baited with CO2 included as controls. Trap captures were compared between the treatments using Chi square and GLM. Low captures of RVF vectors were recorded for all lures in the absence of CO2 with no significant difference between them. When combined with CO2, LO performance in trapping these vectors was comparable to BG-lure and HONAD but it was less effective than the lit CDC trap. In the absence of CO2, LO performed comparably with the BG-lure in trapping female Ae. aegypti, but with significantly higher males recorded in traps baited with the plant-based lure. When CO2 was added, LO was significantly better than the BG-lure with a 2.8- fold increase in captures of male Ae. aegypti. These results highlight the potential of LO as a generalist plant-based lure for mosquito disease vectors, pending further assessment of possible specificity in their response profile to the different stereoisomers of this compound.
Secretions from tergal glands are part of a queen's phero... more Secretions from tergal glands are part of a queen's pheromonal control of worker reproduction in honey bees. However, in queenless honey bee colonies, workers compete to gain pheromonal, and hence reproductive dominance, over nestmates with ontogenetic changes in their glandular secretions that affect the behavioral or physiological responses of other individuals. Using gas chromatography/mass spectrometry, we investigated for the first time the age-dependent changes in tergal gland secretions of queenless workers of the clonal lineage of Apis mellifera capensis and workers of A. m. scutellata. The reproductive status of honey bee workers was determined by recording the presence of spermathecae and the level of ovarian activation. The tergal gland chemicals identified in both A. m. scutellata workers and A. m. capensis clone workers were oleic acid, n-tricosene, n-pentacosene, and n-heptacosene, with three additional compounds, palmitic acid, n-heneicosene, and n-nonacosene, in A. m. capensis clones. We report ethyl esters as new compounds from honey bee worker tergal gland profiles; these compounds increased in amount with age. All A. m. capensis clone workers dissected had spermathecae and showed ovarian activation from day 4, while ovarian activation only started on day 7 for A. m. scutellata workers that had no spermathecae. Tergal gland secretions were present in higher quantities in bees with activated, rather than inactive ovaries. This suggests that tergal gland secretions from reproductive workers could act as releaser and primer pheromones in synergy with other glandular compounds to achieve pheromonal and reproductive dominance.
This work, a sequel to Honeybees and Wax published nearly 30 years ago, starts with a brief intro... more This work, a sequel to Honeybees and Wax published nearly 30 years ago, starts with a brief introduction and discussion of nesting sites, their spaces and densities, self-organization of nest contents, and interspecific utilization of beeswax. The following chapters cover communication by vibrations and scents and wax secretion, and discuss the queen in relation to the combs. Discussions on completed nests include the significance of brood, the roles of pollen and nectar flow, and comb-building, and are followed by a triad of related chapters on the construction of cells and combs and their energetic costs. An in-depth examination of the conversion of wax scales into combs, the material properties of scale and comb waxes, and the wax gland complex are presented. The next chapters are devoted to a comprehensive analysis of the literature on the chemistry and synthesis of beeswax, and, finally, the material properties of honeybee silk are highlighted. Content Level » Research Keywords...
Because the waggle dances of honeybees contain celestial components, modifications of the dances ... more Because the waggle dances of honeybees contain celestial components, modifications of the dances occur with changing celestial moves relative to a honeybee nest. Since the direction of a particular resource is static, the dances must alter to compensate for the sun's passage. The position of the sun is seasonal between the Tropics of Cancer and Capricorn so that turns at the end of waggle runs will vary with season and latitude. The bees are confronted with a new difficulty when the sun closely approaches its zenith because only slight errors in the bees' estimation of the relative positions of the sun and zenith generate very large errors. So, the sun compass loses its usefulness when at its zenith. We review experiments and observations on both foraging and absconding in relation to the azimuth. The honeybees' solution for the paradox of the azimuth includes an azimuthal lull, preferences, and time windows.
The small hive beetle (SHB), Aethina tumida Murray, is a newly introduced coleopteran species att... more The small hive beetle (SHB), Aethina tumida Murray, is a newly introduced coleopteran species attacking honey bees (Apis mellifera L.) from mixed European stock, in North America. This species originates in sub-Saharan Africa, where it is not considered an economic pest. This is in stark contrast to the serious damage caused by this beetle in the southeastern U.S. In the present study, we determined that honey bee subspecies may be an important factor as to why the small hive beetle is not a pest in Africa, but is in the U.S. The Cape bee, Apis mellifera capensis, which has co-evolved with the SHB in South Africa, showed significantly more aggressive behavior toward adult SHB in a laboratory bioassay when compared to behavior of A. m. mellifera. The Cape bee also showed significantly more investigative contacts toward the SHB, when compared to A. m. mellifera. When given the opportunity to feed on Cape bee eggs in South Africa in a laboratory study, the SHB consumed all eggs present...
The state of knowledge on the pheromones of Asian honeybees is discussed. The queen mandibular ph... more The state of knowledge on the pheromones of Asian honeybees is discussed. The queen mandibular pheromone is known to elicit short- (retinue formation, swarm stabilisation and drone attraction) and long-term (inhibition of queen rearing) behaviours. The primer pheromones produced by the mandibular and Dufour’s glands and the releaser ones associated with alarm and aggregation are reviewed. All species appear to
Genetic considerations concern the roles and effects of genetics in Asian honeybees. Emphasis is ... more Genetic considerations concern the roles and effects of genetics in Asian honeybees. Emphasis is placed on recent developments with regard to mating frequency, the effects of multiple mating which could act directly on the queen as well as on the colony and the probability of being affected by homozygosity are considered. The effects of dominant-recessive inheritance on variation and the
The results of studies on the energetics of flight presented in this review include dimensional c... more The results of studies on the energetics of flight presented in this review include dimensional considerations of flight, scaling effects in foragers and drones, aerodynamic efficiency, low and high altitude phenotypes and fuelling flight. There are caste-specific differences within species, adaptations in relation to altitude and special requirements for absconding and migration. Workers of the Asian species of Apis comprise three design classes based on wing-loading, engine size and excess power index. The energetics of salvaging old comb wax are considered in terms of a cost analysis of wax salvage, costs for collecting the nectar to replace the wax and an energy balance trade-off, which demonstrate that recycling is a favourable adaptation, apparently unique to Apis florea.
Varroa destructor is considered the most damaging parasite affecting honeybees (Apis mellifera L.... more Varroa destructor is considered the most damaging parasite affecting honeybees (Apis mellifera L.). However, some honeybee populations such as the savannah honeybee (Apis mellifera scutellata) can survive mite infestation without treatment. It is unclear if survival is due to resistance mechanisms decreasing parasite reproduction or to tolerance mechanisms decreasing the detrimental effects of mites on the host. This study investigates both aspects by quantifying the reproductive output of V. destructor and its physiological costs at the individual host level. Costs measured were not consistently lower when compared with susceptible honeybee populations, indicating a lack of tolerance. In contrast, reproduction of V. destructor mites was distinctly lower than in susceptible populations. There was higher proportion of infertile individuals and the reproductive success of fertile mites was lower than measured to date, even in surviving populations. Our results suggest that survival of savannah honeybees is based on resistance rather than tolerance to this parasite. We identified traits that may be useful for breeding programmes aimed at increasing the survival of susceptible populations. African honeybees may have benefited from a lack of human interference, allowing natural selection to shape a population of honeybees that is more resistant to Varroa mite infestation.
ABSTRACT Because the waggle dances of honeybees contain celestial components, modifications of th... more ABSTRACT Because the waggle dances of honeybees contain celestial components, modifications of the dances occur with changing celestial moves relative to a honeybee nest. Since the direction of a particular resource is static, the dances must alter to compensate for the sun's passage. The position of the sun is seasonal between the Tropics of Cancer and Capricorn so that turns at the end of waggle runs will vary with season and latitude. The bees are confronted with a new difficulty when the sun closely approaches its zenith because only slight errors in the bees' estimation of the relative positions of the sun and zenith generate very large errors. So, the sun compass loses its usefulness when at its zenith. We review experiments and observations on both foraging and absconding in relation to the azimuth. The honeybees' solution for the paradox of the azimuth includes an azimuthal lull, preferences, and time windows.
Uploads
Papers
to quantify the variation between compared specimens
such that inferences about their relatedness and alpha
taxonomy can be made. Recently, the technique has
developed metrics that purport to quantify shape dissimilarity
between specimens—employing the use of
least squares regression analysis. These metrics have
been well applied by studies in the hominin fossil
record with an arguably unsubstantiated backing for
the technique. Originally postulated was the log10 sem
metric which subsequently led to the standard error
test of the null hypothesis metric. Following this, the
standard deviation of logged ratios (SLR) metric arose
as a pairwise dissimilarity metric that constrains the
regression to a zero-intercept, that is, a significant
development in the robustness of the technique. This
metric was tested on extant primates in order to evaluate
its effectiveness alongside the two other metrics. It
was shown to be the most reliable for comparisons
between specimens of primates, but was unable to discriminate
between heterospecific and conspecific comparisons.
Arguably, an alternative model organism with
which to compare the technique is lacking. This study
considers shape dissimilarity metrics with respect to a
group of nonmammalian organisms (mantidflies) and
tests the metrics against three lines of evidence (morphology,
CO1-DNA, and geographic distribution) that
can delimit the species-level taxonomy for the group. It
is shown that the metrics are unable to discriminate
between pairwise comparisons of closely related species,
resulting in biologically erroneous groupings, and
contradicting the groupings derived from morphological,
CO1-DNA, and distributional comparisons. It is
thus asserted that the technique is unsuitable for use
in alpha taxonomy as an additional line of evidence in
mantidflies. It is further supposed that morphometrics
in general should be employed with caution in studies
of evolutionary history as phylogeny is not the only information
contained within morphometric data.
to quantify the variation between compared specimens
such that inferences about their relatedness and alpha
taxonomy can be made. Recently, the technique has
developed metrics that purport to quantify shape dissimilarity
between specimens—employing the use of
least squares regression analysis. These metrics have
been well applied by studies in the hominin fossil
record with an arguably unsubstantiated backing for
the technique. Originally postulated was the log10 sem
metric which subsequently led to the standard error
test of the null hypothesis metric. Following this, the
standard deviation of logged ratios (SLR) metric arose
as a pairwise dissimilarity metric that constrains the
regression to a zero-intercept, that is, a significant
development in the robustness of the technique. This
metric was tested on extant primates in order to evaluate
its effectiveness alongside the two other metrics. It
was shown to be the most reliable for comparisons
between specimens of primates, but was unable to discriminate
between heterospecific and conspecific comparisons.
Arguably, an alternative model organism with
which to compare the technique is lacking. This study
considers shape dissimilarity metrics with respect to a
group of nonmammalian organisms (mantidflies) and
tests the metrics against three lines of evidence (morphology,
CO1-DNA, and geographic distribution) that
can delimit the species-level taxonomy for the group. It
is shown that the metrics are unable to discriminate
between pairwise comparisons of closely related species,
resulting in biologically erroneous groupings, and
contradicting the groupings derived from morphological,
CO1-DNA, and distributional comparisons. It is
thus asserted that the technique is unsuitable for use
in alpha taxonomy as an additional line of evidence in
mantidflies. It is further supposed that morphometrics
in general should be employed with caution in studies
of evolutionary history as phylogeny is not the only information
contained within morphometric data.