Metaphase Karyotypes of Fruit Flies of Thailand. IV. Evidence for Six New Species of the Bactrocera dorsalis Complex.

Abstract

Summary Wild samples of larvae of 6 new fruit fly species belonging to the Bactrocera dorsalis complex have been temporarily designated as species I, J, K, L, M and N, based on cytological evidence. The flies are also morphologically distinguishable as adults. The larvae of these species seem to specifically infest fruits of different host plants. Cytological examination of larvae of these new species has revealed distinct patterns of metaphase karyotypes on the basis of different amounts and distribution of constitutive heterochromatin in sex chromosomes and autosomes. Thus the mitotic karyotype of species I is somewhat similar to that of B. dorsalis and is classified into Group 1. On the other hand, species L, M and N exhibit mitotic karyotypes of Group 4 showing specific patterns of heterochromatin in the centromeric regions of the X chromosome. Species J and K show a general feature of the mitotic karyotype of Group 3, which exhibits distinctive patterns of heterochromatin in sex chromosomes. These findings support the important role of constitutive heterochromatin in karyotypic evolution of these members of the B. dorsalis complex. Such a gross difference in heterochromatin is also a useful tool in cytotaxonomic study of closely related species of the fruit flies of Thailand.

Analysis of Mitotic and Polytene Chromosomes and Photographic Polytene Chromosome Maps inBactrocera cucurbitae(Diptera: Tephritidae)

“…In addition, they show a different degree of chromatid separation, a situation that is in agreement with their heterochromatic nature. The heterogametic karyotype (XY) was ascribed to the male that is consistent with all tephritid species analyzed so far, C. capitata (Bedo 1986;Zacharopoulou, 1987Zacharopoulou, , 1990, Bactrocera oleae (Gmelin) (Mavragani-Tsipidou et al 1992), Bactrocera tryoni (Froggatt) (Zhao et al 1998), B. cucurbitae (Bhatnagar et al 1980, Singh and Gupta 1984, Shahjahan and Yesmin 2002, Bactrocera dorsalis (Hendel) (Baimai et al 1995(Baimai et al , 1999(Baimai et al , 2000, Rhagoletis cerasi L. (Kounatidis et al 2008) as well as several Anastrepha species (Selivon and Perondini 1997, Cevallos and Nation 2004, Selivon et al 2005, Cáceres et al 2009, Garcia-Martinez et al 2009). Male heterogamety in B. cucurbitae also is sup- Fig.…”

Cytogenetic and symbiont analysis of five members of the B. dorsalis complex (Diptera, Tephritidae): no evidence of chromosomal or symbiont-based speciation events

“…Six laboratory colonies, representing Bactrocera dorsalis s.s. (two colonies), Bactrocera papayae , Bactrocera philippinensis , Bactrocera invadens and Bactrocera carambolae , were examined (Table 1) and all exhibited the form A mitotic karyotype. This was quite a surprise, since it is not in agreement with previous studies, where a distinct karyotype with a quite large X chromosome, carrying an ‘elongated’ arm with a secondary constriction, was described for Bactrocera carambolae from Thailand (Baimai et al 1999). In addition, polytene chromosomes did not reveal any fixed CRs among these five taxa that could be used as diagnostic markers (Augustinos et al 2014b).…”

“…In Tephritids, there is a number of studies presenting and discussing mitotic karyotypes, especially for Bactrocera (Hunwattanakul and Baimai 1994, Baimai et al 1995, 1999, 2000, Baimai 1998, 2000), Anastrepha (Cevallos and Nation 2004, Selivon et al 2005, Goday et al 2006, Selivon et al 2007) and Rhagoletis species (Bush and Boller 1977). However, useful polytene chromosome maps, so far available for five genera, represent only 11 species: one of Anastrepha ( Anastrepha ludens ) (Garcia-Martinez et al 2009), one of Ceratitis ( Ceratitis capitata ) (Zacharopoulou 1990), one of Dacus ( Dacus ciliatus ) (Drosopoulou et al 2011b) and three of Rhagoletis , namely Rhagoletis cerasi (Kounatidis et al 2008), Rhagoletis cingulata (Drosopoulou et al 2011a) and Rhagoletis completa (Drosopoulou et al 2010).…”

Mitotic and polytene chromosomes analysis of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

“…Detectable differences in the amount and distribution of heterochromatin have been observed in diverse eukaryotic genera, including Dipteran genera such as Drosophila, Anopheles and Bactrocera. The differences in the amount of pericentromeric heterochromatin of mitotic chromosomes among two Bactrocera species complexes, B. dorsalis and B. tau (Walker), have been used as genetic markers for the identification of cryptic species (Hunwattanakul and Baimai 1994;Baimai 1998;Baimai et al 1995Baimai et al , 1999aBaimai et al , b, 2000.…”

“…At the cytological level, mitotic chromosome differences have helped to distinguish entities within the B. dorsalis complex, including B. dorsalis s.s. (Hunwattanakul and Baimai 1994;Baimai 1998;Baimai et al 1995Baimai et al , 1999aBaimai et al , b, 2000. Several autosomal recessive mutations were described for B. dorsalis s.s., belonging to five linkage groups [reviewed in McCombs and Saul (1992)].…”