Abstract: During an extensive taxonomic study for the identification of species of sandflies prevalent in the whole of the Balochistan Province conducted in 1996-2001, specific armatures were observed in the atria of eight sandflies species viz., Ph. papatasi, Ph. sergenti, Ph. bergeroti, Ph. salehi, Ph. alexandri, Ph. nuri, S. freetownensis var. and S. clydei. This is to the author`s knowledge the first report of armature in the atria of phlebotomine sandflies of Pakistan as previously this character was never explored in Pakistanese sandflies. The shape, size and pattern of armature were found to be specific and constant and also quite different between species. A simple method is presented to identify an unknown specimen as above cited eight species using the present morphological character of armature of genital atria. This character allows separation and may be helpful of species identification in cases where during dissection and mounting of female genitalia, spermathecae become lost. It is suggested that considering other features, this extra taxonomic character of the species may also be taken into account and considered valid while identifying the species of sandflies.
INTRODUCTION
The taxonomic significance of the armature in genital atria of Phlebotomine sandflies were first examined by Madulo-Leblond et al.[1] when they noticed that the length of the spines of the armature in the genital atrium of ♀ Phlebotomus papatasi and Ph. dubosqi were not the same. Pesson et al.[2] showed that these two species can be distinguished by this taxonomic character. Killick-Kendrick et al.[3] have shown that morphology of the genital atria of Kenyan species of Larroussius can be a distinguishing character and suggested that genital armature is more useful than the pharyngeal armature. Valenta et al.[4] proved that genital atrium is a good taxonomic character to distinguish between species of sandflies from Venezuela. Male flies can easily be identified by the morphology of the aedeagus, paramere, style and position of spines on the style whereas females some times have been considered difficult to distinguish. Previously, this character has never been examined in Pakistanese sandflies, therefore, to fill this gap, the present paper describes genital armature of the female flies, which may facilitate species identification.
MATERIALS AND METHODS
Collection of phlebotomine sandflies were made by the author from the whole of the Balochistan Province (indoors and out doors) through sticky traps and CDC light trap during 1996–2001. Flies were collected, processed, preserved, dissected and mounted according to the conventional methods especially those adopted by Johnson et al.[5], Lewis[6] and Killick-Kendrick[7]. For species identification, keys furnished by and Lewis[8-10] and Artemiev[11] were consulted. All the diagrams were drawn with the help of camera lucida and are to the given scales. Measurements are in millimeter unless otherwise indicated. Specimens are housed with the Author’s Collection of Sandflies, Department of Zoology, University of Balochistan, Quetta, Pakistan.
RESULTS AND DISCUSSION
By the light microscope, the armature of the genital atria of ♀ phlebotomine sandflies were seen to lie between the arms of the furca. The spines of the armature were found pointing towards the opening of the atrium. The length and width of bands of the spines, shape of anterior and posterior edges of band of spines, number of spines in groups and rows of spines were observed variable among species.
Morphometric measurements of genital atria and armatures of phlebotomine sandflies are given in Table 1. Within the population of ♀ Phlebotomus papatasi, the specimens from Duki showed a sharply concave anterior and posterior edges of band of spine, respectively and also spines in group of 2-3 or 2-4.
| Fig. 1: | Camera Lucida drawings of spermatheca and associated parts of ♀ Ph. papatasi from Pakistan showing: spermathecae (s), spermathecal ducts (d), furca (f), genital atrium (ga) and armature (a), (A) from Bela, (B) from Chaman, (C) from Pishin, (D) from Duki and (E) and from Uthal. (F) Ph. sergenti from Quetta, (G) from Kohlu, (H) Ph. salehi from Bela, (I) Ph. bergeroti from Turbat, (J) Ph. alexandri from Khuzdar, (K) Ph. nuri from Quetta, (L) S. freetownensis Sinton var. from Bela, (M) S. clydei from Panjgour |
This character may probably be a deviation from the normal pattern ”anterior and posterior edges of spines slightly concave and convex in line, respectively and spines in groups of 2-3” as observed in individuals of this species from Bela, Chaman, Pishin and Uthal localities.
The other species of the subgenus Phlebotomus i.e. Ph. bergeroti and Ph. salehi showed a quite different pattern of band of spine as compared with that of Ph. papatasi. In both species anterior and posterior edges of band of spine were found almost in a straight line. However, significant differences were noted in the length of genital fork and breadth of genital atrium of Ph. bergeroti (0.076, 0.06 mm) and Ph. salehi (0.084, 0.052 mm), respectively. Further, 4 rows of spines were noted in genital atrium of Ph. salehi and 3 in Ph. bergeroti.
Similarly, in between species of subgenus Paraphlebotomus, interesting differences were noted in the shape of anterior and posterior edges of band of spines and pattern of arrangement of groups of spines. The notable character observed in Ph. sergenti was that the band of genital armature did not extend from one arm of the furca to the other, but was located nearly at only one side of the furca. On the basis of characteristically sharply curved both arms of furca, Ph. alexandri can easily be differentiated from Ph. nuri.
| Table 1: | Morphometric measurements (mm) of genital atria and armature in female Phlebotomine sandflies from Pakistan |
However, S. clydei can also be identified on the basis of anterior edge of armature with a deep median indentation whereas posterior margin in a slight concave line.
Pesson et al.[2] suggested that in sandflies, the function of genital armature is presumably to assist the movement of eggs as they are laid.
ACKNOWLEDGEMENTS
The author is grateful to Professors Drs. R. Killick-Kendrick.; David, J. Bradley; R.W. Ashford; R.P. Lane and Dr. David Evans for their encouragement and valuable guidance on sandflies. My sincerest thanks are also due to respected Joanna Kapusta (BMNH), Linda Huddleston (BMNH), Dr. J.P. Dedet (France) and Dr. Farrokh Modabber (WHO) and Prof. Dr. V.N. Neronov (Russia) for providing me the literature on sandflies.