scholarly journals Differentiation of Five Species of Megachile (Hymenoptera: Megachilidae), based on Wing Shape

2016 ◽  
Vol 60 (2) ◽  
pp. 41-50 ◽  
Author(s):  
Shahram Falamarzi ◽  
Behzad Habibpour ◽  
Mohammad S. Mossadegh ◽  
Alireza Monfared

Abstract In the present work we used landmark-based geometric morphometrics to compare the wing shapes of five species of Megachile (belonging to three subgenera) to confirm whether this technique may be used reliably for differentiation of this group. Analyses of wing shape by the use of principal component analysis (PCA), and canonical variate analysis (CVA) led to a clear differentiation among species. We found a close phenotypic similarity in wing shape between M. albisecta (belonging to the subgenus Creightonella) and M. picicornis (belonging to the subgenus Eutricharaea). According to the results of UPGMA, a higher degree of divergence between M. farinosa (belonging to the subgenus Pseudomegachile) and species belonging to other subgenera, was detected. The results of a cross-validation test indicated that geometric morphometrics is an effective technique to use for distinguishing between Megachile species. The reliability rate of this technique was between 85.71-100%. Using only two submarginal cell landmarks for generating shape variables, the cross-validation test correctly assigned individuals to their respective species, with a 92.85-100% reliability rate. Significant differences in wing size were obtained among the analysed species.

2019 ◽  
Vol 35 (6) ◽  
Author(s):  
Daniel Vieira de Morais ◽  
Lorena Andrade Nunes ◽  
Vandira Pereira da Mata ◽  
Maria Angélica Pereira de Carvalho Costa ◽  
Geni da Silva Sodré ◽  
...  

Leaves are plant structures that express important traits of the environment where they live. Leaf description has allowed identification of plant species as well as investigation of abiotic factors effects on their development, such as gases, light, temperature, and herbivory. This study described populations of Dalbergia ecastaphyllum through leaf geometric morphometrics in Brazil. We evaluated 200 leaves from four populations. The principal component analysis (PCA) showed that the first four principal components were responsible for 97.81% of variation. The non-parametric multivariate analysis of variance (NPMANOVA) indicated significant difference between samples (p = 0.0001). The Mentel test showed no correlation between geographical distances and shape. The canonical variate analysis (CVA) indicated that the first two variables were responsible for 96.77 % of total variation, while the cross-validation test showed an average of 83.33%. D. ecastaphyllum leaves are elliptical and ovate.


Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 84
Author(s):  
Ming Wang ◽  
Lixiang Wang ◽  
Ningning Fu ◽  
Chenglong Gao ◽  
Tegen Ao ◽  
...  

Sirex noctilio F. (Hymenoptera: Siricidae) is an invasive woodwasp from Europe and North Africa. Globalization has led to an expanding global presence in pine forests. S. noctilio has been previously introduced outside of its native range and now co-occurs in trees with native S. nitobei Matsumura (first discovered in 2016). Damage to Pinus sylvestris var. mongolica Litv in northeast China can be attributed to two types of woodwasp. To distinguish the two species by the traditional taxonomic morphology, we mainly differentiate the color of the male’s abdomen and the female’s leg. There remains intraspecific variation like leg color in the delimitation of related genera or sibling species of Sirex woodwasps. In this study, we used landmark-based geometric morphometrics including principal component analysis, canonical variate analysis, thin-plate splines, and cluster analysis to analyze and compare the wings, ovipositors, and cornus of two woodwasps to ascertain whether this approach is reliable for taxonomic studies of this group. The results showed significant differences in forewing venation and the shapes of pits in the middle of ovipositors among the two species, whereas little difference in hindwings and cornus was observed. This study assists in clarifying the taxonomic uncertainties of Siricidae and lays a foundation for further studies of the interspecific relationships of the genus Sirex.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 763
Author(s):  
Federica Raspa ◽  
Angela Roggero ◽  
Claudia Palestrini ◽  
Martina Marten Canavesio ◽  
Domenico Bergero ◽  
...  

The effects of specific feeding positions upon the horse’s shape variations of the back and neck postures as well as the variations of the mandibular angle have never been objectively studied. For this reason, geometric morphometrics was applied. Six horses, aged 14 ± 8 years (mean ± standard deviation, SD), were video-recorded while using three different feeding positions: on the ground—control position (CP); neck held 15 ± 3° below withers height with low hay net position (LP); neck held 15 ± 3° above withers height with high hay net position (HP). Data were analyzed using principal component analysis (PCA), multivariate analysis of variance (MANOVA), and partial least squares (PLS). A mixed model procedure was applied to evaluate differences in the magnitude of the mandibular angle. Whilst differences between individual horses were confirmed by canonical variate analysis (CVA), PCA analysis showed that a characteristic feeding position could also be identified on a group level. During the HP hay net position, the back and neck postures as well the mandibular angle were different compared to those exhibited by horses feeding from CP. In LP hay net position, the back posture more closely resembled those exhibited while feeding from CP; however, no similarity between LP and CP was found for neck posture and mandibular angle. Since only a few degrees of variation of the feeding position can influence back and neck postures, this aspect should be further investigated. The right compromise between horse welfare, horse safety, and management practices need to be further explored and long-term effects should be investigated.


2014 ◽  
Vol 58 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Leonidas Charistos ◽  
Fani Hatjina ◽  
Maria Bouga ◽  
Mica Mladenovic ◽  
Anastasios D. Maistros

Abstract Honey bees collected from 32 different localities in Greece were studied based on the geometric morphometrics approach using the coordinates of 19 landmarks located at wing vein intersections. Procrustes analysis, principal component analysis, and Canonical variate analysis (CVA) detected population variability among the studied samples. According to the Principal component analysis (PCA ) of pooled data from each locality, the most differentiated populations were the populations from the Aegean island localities Astypalaia, Chios, and Kythira. However, the populations with the most distant according to the canonical variate analysis performed on all measurements were the populations from Heraklion and Chania (both from Crete island). These results can be used as a starting point for the use of geometric morphometrics in the discrimination of honey bee populations in Greece and the establishment of conservation areas for local honey bee populations.


2016 ◽  
Vol 4 (16) ◽  
pp. 1
Author(s):  
Mariya A. Chursina ◽  
Oleg P. Negrobov

A study of 186 specimens of Poecilobothrus regalis was conducted in order to examine intraspecific variability of wing shape. The wing shape variation was analyzed using geometric morphometrics analyses. Significant differences in the structure of wing were found both between sexes and between populations. Differences between sexes were observed in the structure of the medium portion of wing. The first extracted canonical variate of geographic variation showed a moderately linear association with latitude and average temperature of February and March. The second canonical variate was correlated with longitude and values of average wind flow velocity. Allometric relationships were weak both between populations and sexes.


2018 ◽  
Author(s):  
Πέτρος Μαρτσικάλης

Για την επίτευξη της ιχνηλασιμότητας των πληθυσμών ιριδίζουσας πέστροφας Oncorhynchus mykiss (Walbaum, 1792) στην Ελλάδα υιοθετήθηκε μια διαθεματική προσέγγιση, η οποία ως αλληλένδετους πυλώνες της περιελάμβανε α) την πληθυσμιακή γενετική μελέτη στο μιτοχονδριακό DNA των ιχθύων, β) την ταυτοποίηση και ποσοτικοποίηση των ελεύθερων αμινοξέων στο μυϊκό ιστό των ιχθύων και γ) τη γεωμετρική μορφομετρία του σώματος των ιχθύων, εκφράζοντας ένα αντιπροσωπευτικό δείγμα των εντατικών εκτροφών της ελληνικής επικράτειας. Η ιριδίζουσα πέστροφα αποτελεί μη γηγενές είδος των ευρωπαϊκών εσωτερικών υδάτων. Εξαιτίας όμως του γεγονότος ότι παρουσιάζει αξιοσημείωτα πλεονεκτήματα, όπως είναι η ταχεία αύξηση και η προσαρμοστικότητά της σε ποικίλα ενδιαιτήματα υπό διαφορετικές συνθήκες, εξελίχθηκε σε κυρίαρχο εντατικά εκτρεφόμενο είδος στα εσωτερικά ύδατα της Ελλάδας. Παρά τη σημαντική οικονομική σημασία της, υφίσταται παντελής έλλειψη πληθυσμιακών γενετικών μελετών αναφορικά με την προέλευση των αθρόων εισαγωγών γόνου που έλαβαν χώρα τις προηγούμενες δεκαετίες στον κλάδο της ελληνικής πεστροφοκαλλιέργειας. Για τη διενέργεια της πληθυσμιακής γενετικής μελέτης πραγματοποιήθηκε πέψη τμημάτων του μιτοχονδριακού DNA (mtDNA) που ενισχύθηκαν με την αλυσιδωτή αντίδραση πολυμεράσης (Polymerase Chain Reaction-PCR) με τη χρήση περιοριστικών ενζύμων (Restriction Fragment Length Polymorphism-RFLP). Τα τμήματα-στόχοι του mtDNA που πολλαπλασιάστηκαν με την τεχνική της PCR ήταν ολόκληρη η περιοχή του βρόχου εκτόπισης, τα tRNA γονίδια της προλίνης και της θρεονίνης, το κυτόχρωμα β, τα γονίδια ND-5 και ND-6 και τμήμα των γονιδίων ATPάση VI και κυτόχρωμα c οξειδάσης 3 (COIII) περιλαμβάνοντας περισσότερα από 5.500 ζεύγη βάσεων DNA από τα περίπου 16.600 ζεύγη βάσεων που απαρτίζουν το συνολικό mtDNA της ιριδίζουσας πέστροφας. Η ανάλυση της πληθυσμιακής δομής αποκάλυψε ότι οι απλότυποι διακρίνονται σε δύο κεντρικούς κλάδους. Η συνύπαρξη απλότυπων και από τους δύο κλάδους σε όλους τους πληθυσμούς ενδέχεται να υποδηλώνει την ύπαρξη κοινής γονιδιακής δεξαμενής. Επίσης, η συνολική γενετική ποικιλότητα οφειλόταν σε σημαντικό βαθμό στην ύπαρξη ποικιλότητας ενδοπληθυσμιακά παρά στην ύπαρξη ποικιλότητας ανάμεσα στους πληθυσμούς. Το ποσοστό γενετικής ποικιλότητας ανάμεσα στους πληθυσμούς σε σύγκριση με τη συνολική παρατηρούμενη ποικιλότητα αντανακλά την πανμιξία δύο αρχικών πληθυσμών (γενεών), υπογραμμίζοντας την ύπαρξη μια κοινής δεξαμενής γονιδίων σε όλες τις εντατικές εκτροφές ιριδίζουσας πέστροφας στην Ελλάδα. Αυτό το γεγονός ενισχύεται και από το δίκτυο απλότυπων που δημιουργήθηκε και αποκάλυψε την ύπαρξη δύο αρχικών κλάδων σε όλο το φάσμα των εντατικών εκτροφών. Παράλληλα, η ταυτοποίηση και ποσοτικοποίηση των ελεύθερων αμινοξέων στο μυϊκό ιστό των ιχθύων διενεργήθηκε με τη χρήση Αντίστροφης Φάσης - Υγρής Χρωματογραφίας Υψηλής Απόδοσης (Reversed Phase – High Performance Liquid Chromatography, RP-HPLC). Τα εξεταζόμενα δείγματα παρουσίασαν διαφορετικά προφίλ ελεύθερων αμινοξέων ανάλογα με τη γεωγραφική τους προέλευση. Η Ανάλυση Κύριων Συνιστωσών (Principal Component Analysis – PCA) αποκάλυψε τον σαφή διαχωρισμό των πληθυσμών μεταξύ ανατολικής και δυτικής Ελλάδας, ο οποίος ενδέχεται να οφείλεται στην ύπαρξη διακυμάνσεων στις κλιματικές συνθήκες που επικρατούν και επηρεάζουν καταλυτικά τους αβιοτικούς παράγοντες κάθε εντατικής εκτροφής. Η γεωμετρική μορφομετρία του σώματος των ιχθύων κατέδειξε την ύπαρξη σημαντικών διαφορών μεταξύ των πληθυσμών διαφορετικής προέλευσης. Η Ανάλυση Κανονικών Μεταβλητών (Canonical Variate Analysis – CVA) διέκρινε τους πληθυσμούς σε δύο ομάδες παρουσιάζοντας σε πολύ μεγάλο βαθμό ομοιότητες με τη διενεργηθείσα πληθυσμιακή γενετική μελέτη. Η διεξαγωγή των Γενικών Γραμμικών Μοντέλων (General Linear Models – GLM) δεν επέδειξε συσχέτιση των απλότυπων και της διατροφής με το σχήμα του σώματος των ιχθύων. Εντούτοις, το σχήμα του σώματος των ιχθύων παρουσίασε σημαντική συσχέτιση με τη γεωγραφική προέλευση, τη θερμοκρασία νερού, τις γεωλογικο-χημικο-κλιματικές ζώνες, την ιστιδίνη και την αργινίνη. Επομένως, η παρατηρούμενη μορφολογική διαφοροποίηση δύναται να οφείλεται στις διαφορές των αβιοτικών παραγόντων που υφίστανται μεταξύ αυτών των ζωνών όντας το αποτέλεσμα του φαινομένου της φαινοτυπικής πλαστικότητας.Συμπερασματικά, οι αβιοτικοί παράγοντες και οι συνθήκες εκτροφής διαδραματίζουν τον κυρίαρχο ρόλο σε σύγκριση με την προέλευση του γόνου. Η παρούσα διαθεματική προσέγγιση αποτελεί ένα πολύτιμο και χρήσιμο εργαλείο στην αποτελεσματική ιχνηλασιμότητα των εντατικά εκτρεφόμενων πληθυσμών ιριδίζουσας πέστροφας, έχοντας καθοριστική συνεισφορά και προάγοντας την έρευνα σε τομείς, όπως η περιβαλλοντική ανάλυση κινδύνων για την αξιολόγηση ενδεχόμενων οικολογικών επιπτώσεων που στοχεύουν στην επίτευξη της αειφορικής διαχείρισης των ιχθυοκαλλιεργειών.


2017 ◽  
Vol 66 (1) ◽  
pp. 75-86
Author(s):  
Marek Semelbauer

Abstract The females of the European species Homoneura consobrina, H. patelliformis and H. thalhammeri are not easy to discern. A possible method of identifying females is to apply geometric morphometrics to the wing shape, when we expect females of certain species to have wing shape more similar to conspecific males, than to other species. For this purpose, 94 specimens of the three species were collected mainly by means of Malaise trap in western and central Slovakia and Montenegro. The combination of morphological and distribution data allowed for the females to be divided into three groups. In next step, wings of both males and females were digitized, aligned by Generalized Procrustes Analysis and analyzed via multivariate methods (principal component analysis, multivariate analysis of variance, linear discriminant analysis). Results of the analysis clearly suggest that females with large and convex 8th sternite belong to H. patelliformis, while females with reduced 8th sternite belong to either H. thalhammeri or H. consobrina.


2009 ◽  
Vol 78 (3) ◽  
pp. 129-140 ◽  
Author(s):  
Lj. Francuski ◽  
A. Vujić ◽  
A. Kovačević ◽  
J. Ludoški ◽  
V. Milankov

The present study investigates phenotypic differentiation patterns among four species of the Cheilosia variabilis group (Diptera, Syrphidae) using a landmark-based geometric morphometric approach. Herein, wing geometric morphometrics established species boundaries that confirm C. melanopa and C. redi stat. nov. as evolutionarily independent entities or separate species within the previously described C. melanopa species. Seventeen samples of C. lasiopa, C. variabilis, C. melanopa and C. redi from 11 localities on the Balkan Peninsula were analysed. Based on wing shape and size, both species boundaries and intraspecific divergent units were delineated indicating the possible presence of evolutionarily independent units within the analysed taxa. Significant differences in wing size were obtained among the analysed species and canonical variate analysis showed that wing shape was sufficiently different to allow the correct classification of 99.7% and 100% individuals of males and females, respectively. Considerable wing size variation was detected among males and females of conspecific populations of C. melanopa and males of C. variabilis. Contrary to partial discrimination based on the male wing shape among conspecific populations of C. redi and C. variabilis, clear separation of conspecific populations of C. melanopa (for both sexes) and females of C. redi and C. variabilis was observed. The UPGMA cluster analysis based on squared Mahalanobis distances revealed a close similarity between C. melanopa and C. redi, whereas C. lasiopa was the most divergent species. Results presented in this study utilize wing shape and size as new taxonomic characters in delimitating the closely related species and populations of the Cheilosia variabilis group.


Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 274
Author(s):  
Carolina Vilaseca ◽  
Marco A. Méndez ◽  
Carlos F. Pinto ◽  
Hugo A. Benítez

The morphological variations of four populations of geographically isolated Triatoma infestans located in the area of inter-Andean valleys and Chaco of Chuquisaca, Bolivia, were evaluated. Fifty-three females and sixty-one males were collected in the peri-domicile and analyzed with geometric morphometrics tools to study the patterns of the head and wing shape variation. The principal component analysis and canonical variate analysis revealed morphological variations between the populations studied, which were then confirmed by the permutation test of the differences between populations using Mahalanobis and Procustes distances. The multivariate regression analysis shows that the centroid size influences the shape of the heads and wings. T. infestans of the inter-Andean valleys are longer in the head and wings compared to the population of the Chaco. We propose that the geometric shape variation may be explained by geographical changes in climatic conditions, peri-domiciliar habitats, food source quality, and the use of insecticides.


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