Estudo morfológico comparativo de ovos e ninfas de Triatoma maculata (Erichson, 1848) e Triatoma pseudomaculata Corrêa & Espínola, 1964 (Hemiptera, Reduviidae, Triatominae)

Abstract

Utilizando a microscopia ótica (MO) e eletrônica de varredura (MEV) procurou-se fornecer dados a taxionomia através da estrutura dos ovos e morfologia das ninfas, destes vetores da doença de Chagas. Os ovos em MO apresentam a superfície exocorial do opérculo e do corpo dividida em áreas poligonais com ornamentação própria; em T. maculata o exocório do corpo tem áreas indefinidas. Em MEV o exocório dos opérculos apresenta áreas poligonais de superfície estofada com pequena sulcos irregulares e perfurações distribuídas aleatoriamente nas duas espécies. O exocório do corpo apresenta: em T. maculata áreas acolchoadas com perfurações mais numerosas nos bordos, visualizando-se a borda corial, goteira espermática, aerópilas e micrópilas; em T. pseudomaculata as áreas são planas com numerosas perfurações. Nas ninfas o sulco estridulatório e o rostro apresentam diferenças significativas. O sulco estridulatórios em MO possibilitou diferenciar ninfas de 1º, 2º e 3º estádios, os 4º e 5º estádios apresentam-se semelhantes. Em MEV a diferenciação é acentuada. O rostro em MO apresenta pilosidade característica a partir do 3º estádio. T. maculata apresenta pêlos curtos e esparsos no 1º e 2º artículos e longos e numerosos no 3º, em T. pseudo-maculata semelhantes, porém mais curtos no 3º artículo.<br>As an aid in the identification of vectors of Chagas' disease we have studied the structure of the eggs and morphology of nymphs by optical microscopy (OM) and scanning electron microscopy (SEM). The eggs as seen by OM show the exochorion of the body doesn't have defined areas. In SEM the exochorion of the cap appears as upholstered polygonal areas with small irregular grooves and perforations spread at random in both species. The exochorion of the body in T. maculata is upholstered with more numerous perforations on the edge visualizing the rim of the shell, spermatic groove, pseudomicropyles and micropyles; in T. pseudomaculata there are flat areas with numerous perforations. The nymphs show differences cencerning the stridulatory groove and rostrum. The stridulatory groove when seen by OM shows differences in nymphs of 1st, 2nd and 3rd intars, while 4th and 5th are similar; in SEM the differences are clear. In OM the rostrum shows typical pilosity to each species from 3rd instar. In T. maculata the setae are short and scattered on the 1st and 2nd segments and are long and numerous on the 3rd. In T. pseudomaculata the setae are similar but are short on the 3rd segment

Morphological study of the eggs and nymphs of Triatoma dimidiata (Latreille, 1811) observed by light and scanning electron microscopy (Hemiptera: Reduviidae: Triatominae)

“…Lizaraso (1957) concluded that populations of the same species, when provided with different laboratory and natural environments, could produce variations that affected the dimensions of the eggs without affecting the characteristics of the chorion, which remained constant. Morphometric studies of 33 Triatoma species were published (Galliard 1935b, Lizaraso 1957, Gonçalves et al 1985, Haridass 1986, Jurberg et al 1986, 1998, Jurberg & Vogel 1994, Jurberg & Campos 1995, Rosa 1995, Rocha et al 1996, Costa et al 1997, Silva et al 2000, Visciarelli et al 2004, Obara et al 2007a). According to Barata (1998), Triatoma possesses the following means: length, 2.05 ± 0.08 and diameter, 1.14 ± 0.05.…”

“…Nymphs -Forty three species of Triatoma had their nymphs described and/or some morphological aspect presented by LM and/or SEM (Espínola 1966, Galvão & Fuentes 1971, Perlowagora-Szumlewicz & Cruz 1972, Lent & Wygodzinsky 1979, Brewer et al 1981, 1983a, b, Jiménez & Fuentes 1981, Gonçalves et al 1985, Haridass 1986, Jurberg et al 1986, 1998, Brewer & Garay 1989, Rosa et al 1989, 1992a, b, 2005, Jurberg & Vogel 1994, Jurberg & Campos 1995, Rosa 1995, Rocha et al 1996, Rosa & Barata 1997, Galíndez-Girón et al 1998, Silva et al 1999a, b, 2000, Naegele et al 2003. A total of 32 species were shown through illustrations, 31 with photos in LM and 24 using SEM.…”

“…Galliard (1935b) demonstrated that there is a characteristic ornamentation on the external surface of chorion that permits the recognition of different species. The structure and ornamentation of the eggs analysed by light microscopy (LM) are useful in the identification of similar species, i.e., Triatoma maculata (Erichson, 1848) and Triatoma pseudoma-culata Corrêa & Espínola, 1964(Gonçalves et al 1985.…”

“…Lent and Wygodzinsky (1979) and Galíndez-Girón et al (1998) offered keys to identifying distinct genera based on 1st and 5th instar nymphs. Twenty two species of Triatoma had their nymphs described and/or some morphological aspects analysed in SEM (Lent & Wygodzinsky 1979, Gonçalves et al 1985, Jurberg et al 1986, 1998, Rosa et al 1989, 1992a, b, 2005, Rosa 1995, Rocha et al 1996, Rosa & Barata 1997, Galíndez-Girón et al 1998, Silva et al 1999a, b, 2000, Naegele et al 2003. In this paper, the morphological description of eggs and nymphs of T. dimidiata using both LM and SEM microscopy is shown to contribute to Triatominae systematic and phylogenetic studies.…”

Comparative study of the stridulatorium sulcus, buccula and rostrum of nymphs of Triatoma klugi Carcavallo et al, Triatoma vandae Carcavallo et al and Triatoma williami Galvão et al (Hemiptera: Reduviidae)

“…The importance of this structure was underlined by Barth in 1953 and its functionality by Galíndez-Girón et al (1998). Gonçalves et al (1985) made a comparative study of the stridulatory sulcus of T. maculata (Erichson) and T. pseudomaculata Corrêa & Espínola concluding this structure was appropriate to distinguish between both species. The stridulatory sulcus was also informative to distinguish T. guazu from T. jurbergi at both 1 st and 5 th instars (Silva 2000.…”