Contribution of geometric morphometry in the control of Rhipicephalus (Boophilus) microplus (Canestrini, 1888) on the transhumance corridor between Côte d’Ivoire and Burkina Faso

Int. J. Biol. Chem. Sci. 11(6): 2630-2648, 2017

 

Amenan Claude Aimée DIAHA-KOUAME 1* , Tah Yves Nathan TIAN-BI 2 ,
Kouassi Patrick YAO 3 , Yaba Louise ACHI 4 , Marlène DUPRAZ 5 , Koffi KOUAKOU 1 et Jean-Pierre DUJARDIN 6
1
Laboratoire de Biologie de la Reproduction et d’Endocrinologie,
Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire.
2
Laboratoire de Génétique, Unité de Formation et de Recherche Biosciences,
Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire.
3
Laboratoire de Zoologie et Biologie Animale URF de Parasitologie et Ecologie Parasitaire,
Université Félix Houphouët-Boigny, Côte d’Ivoire.
4
Institut National de la Formation Professionnelle Agricole (INFPA), Ecole de Spécialisation en Elevage et de
Métiers de la Viande de Bingerville (ESEMVB), Côte d’Ivoire.
5
MIVEGEC UMR 5290 CNRS-IRD-UM, Centre IRD, 911 Avenue Agropolis,
BP 64501, 34394 Montpellier, France.
6
IRD, UMR IRD-CIRAD INTERTRYP, Campus International de Baillarguet, Montpellier, France.

 

ABSTRACT

Rhipicephalus (Boophilus) microplus is a tick characterized by its resistance to most acaricides currently used. Selection tools for control or eradication strategies to achieve sustainable results are still poorly accessible. In entomology, as well as in many other research fields involving arthropod studies, the study of shape variation has proven useful for species identification and population characterization. Thus, in our study,
we studied the morphological diversity of R. (B.) microplus using two methods of morphometry: classical morphometry (MC) and geometric morphometry (MG) on ticks collected in ten farms from two axes of the Ivoiro-Burkinabé transhumance corridor. The analysis of the results showed a morphological heterogeneity according to the  geographical position of the populations studied on the two axes. Both methods showed
similar results but the geometric morphometry presented itself as an interesting approach because it allows to visualize the differences of form between groups or between individuals. We have thus shown to what extent these two approaches can help to understand the epidemiology, the structure and the mobility of tick populations at a lower cost and consequently, to contribute to the improvement and the sustainability of the regional control activities.

 

The modern morphometric approach to identify eggs of Triatominae

Soledad Santillán-Guayasamín 1 , Anita G. Villacís 1 , Mario J. Grijalva 1,2* and Jean-Pierre Dujardin 1,3

1

Center for Research on Health in Latin America (CISeAL), School of
Biological Sciences, Pontifical Catholic University of Ecuador, Av. 12 de
Octubre 1076 y Roca, Quito, Ecuador

2

Infectious and Tropical Disease Institute, Department of Biomedical
Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens,
OH 45701, USA

3

IRD, UMR 177 IRD-CIRAD INTERTRYP, Campus international de Baillarguet, Montpellier, France.

 

Parasites & Vectors (2017) 10:55
DOI 10.1186/s13071-017-1982-2

 

Abstract
Background: Egg morphometrics in the Triatominae has proved to be informative for distinguishing tribes or genera, and has been based generally on traditional morphometrics. However, more resolution is required, allowing species or even population recognition, because the presence of eggs in the domicile could be related to the species ability to colonize human dwellings, suggesting its importance as a vector.
Results: We explored the resolution of modern morphometric methods to distinguish not only tribes and genera, but also species or geographic populations in some important Triatominae. Four species were considered, representing two tribes and three genera: Panstrongylus chinai and P. howardi, Triatoma carrioni and Rhodnius ecuadoriensis. Within R. ecuadoriensis, two geographical populations of Ecuador were compared. For these comparisons, we selected the most suitable day of egg development, as well as the possible best position of the egg for data capture. The shape of the eggs in the Triatominae does not offer true anatomical landmarks as the ones used in landmark-based morphometrics, except for the egg cap, especially in eggs with an evident “neck”, such as those of the Rhodniini. To capture the operculum shape variation, we used the landmark- and semilandmark-based method. The results obtained from the metric properties of the operculum were compared with the ones provided by the simple contour of the whole egg, as analyzed by the Elliptic Fourier Analysis. Clear differences could be disclosed between the genera, between the species – among which two very close species (P. chinai and P. howardi), as well as between two allopatric, conspecific
populations. The whole egg contour (including the operculum) produced reclassification scores much more satisfactory than the ones obtained using the operculum only.
Conclusions: We propose the outline-based approach as the most convenient  characterization tool to identify unknown eggs at the species or population levels.

The wing venation patterns to identify single tsetse flies

D. Kaba a , D. Berté a , B.T.D. Ta a , J. Tellería b , P. Solano b , J.-P. Dujardin b, *
a
b
INSP/IPR Bouaké, Côte d’Ivoire
UMR 177, INTERTRYP, CIRAD-IRD, Baillarguet, France

Infection, Genetics and Evolution 47 (2017) 132–139

A B S T R A C T
This is the first study to explore the potential of various geometric morphometrics methods to help the morphological diagnostic of tsetse species, vectors of human and animal trypanosomiases in sub-Saharan Africa. We compared landmarks, semilandmarks and outlines techniques on male and female samples of species, and suggested adapted strategies according to the countries and their own Glossina fauna. We could compare up to 7 taxa belonging to the three main subgenera of the Glossina genus: Nemorhina (5 species), Glossina (1 species) and Austenina (1 species). Our sample included the major vectors of sleeping sickness:
G. palpalis palpalis, G. p. gambiensis, G. fuscipes fuscipes and G. f. quanzensis, as well as two important vectors of African animal trypanosomoses: G. tachinoides and Glossina morsitans submorsitans. The average level of correct species recognition by the wing shape was satisfactory, and slightly higher for females than for
males. The best scores of correct assignment, in both sexes, were obtained by the contour technique (96% of correct attribution in females, 92% in males), slightly higher than for semilandmarks (95% and 91%) or landmarks (94% and 89%) techniques. We made our images of wings freely available to be used as reference images (http://mome-clic.com), and we describe the conditions and the analytical steps to be followed to identify unknown specimens using external reference images. Under adequate conditions, such use of reference images obtained from a free access server could help species identification of new samples anywhere in Africa.

The Diachasmimorpha longicaudata complex in Thailand discriminated by its wing venation

Sangvorn Kitthawee1 and Jean-Pierre Dujardin2

1 Department of Biology, Faculty of Science, Mahidol
University, Rama VI Rd., Bangkok 10400, Thailand
2 UMR17 IRD-CIRAD INTERTRYP TA A 17/G Campus
International de Baillarguet, 34398 Montpellier Cedex 5,
France

Zoomorphology
DOI 10.1007/s00435-016-0307-x

 

Abstract

It has been proven that Diachasmimorpha longicaudata consists of three sibling species (A, B, and BB) exhibiting strong shape differences as based on their
wing venation geometry. We used these differences to classify specimens collected from different parts of Thailand.
Thus, 414 adult D. longicaudata (206 males and 208 females) were collected from 10 provinces in Thailand, mounted under transparent tape in the field and submitted to individual morphometric identification. To perform such identification, the shape of the right wing of each individual was compared to the average shape of wings from old laboratory colonies corresponding to each species and assigned to the closest one. Since this process made the identification depending on the choice of the reference
groups, we performed several tests modifying the reference groups. The modifications applied to the reference groups were the mounting technique, the sex, and the number of generations spent in the laboratory. Although liable to modify the size, and to some extent the shape, of the wings used as a reference, these various effects could not impair the classification. Thus, for species recognition within the D. longicaudata complex, the individual morphometric identification appears as a reliable technique, not or poorly influenced by the mounting technique, by the sex or by our laboratory conditions. According to this classification, and as previously observed in Thailand, species A was the most abundant and widely distributed one (eight provinces),
followed by the B species found in six provinces. The less abundant BB species was more frequent in the southern part of the country.