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

Eggs and nymphs of Triatoma dimidiata were described using both light and scanning electron microscopy. The egg body and operculum have an exochorion formed by irregular juxtaposed polygonal cells; these cells are without sculpture and the majority of them are hexagonal in shape. The five instars of T. dimidiatacan be distinguished from each other by characteristics of the pre, meso and metanotum. The number of setiferous tubercles increases progressively among instars. The sulcus stridulatorium of 1st instar nymphs is amorphous, showing median parallel grooves; from the 2nd instar on the sulcus is, progressively, elongate, deep and posteriorly pointed with stretched parallel grooves. All instars have a trichobothrium on the apical 1/3 of segment II of the antenna. The opening of the Brindley's gland is on the mesopleura. Fifth instar nymphs have an apical ctenidium on the ventral surface of the fore tibia. Dorsal glabrous patches are found on the lateral 1/3 of abdomen. Bright oval patches are found on the ventral median line of the abdomen, from segment IV-VI; 1st instar nymphs lack these patches. Abdominal dorsal plates are present from the 1st-5th instars; the 1st instar also contains a rectangular plate in segment IX. From the 2nd instar on, variably-shaped plates are present on segments VII to IX. Morphometric data were also obtained and proved to be useful for distinguishing T. dimidiata instars.

Morfologia comparada dos ovos e ninfas de Triatoma vandae Carcavallo, Jurberg, Rocha, Galvão, Noireau & Lent, 2002 e Triatoma williami Galvão, Souza & Lima, 1965 (Hemiptera, Reduviidae, Triatominae) / Comparative morphology of eggs and nymphs of Triatoma vandae Carcavallo, Jurberg, Rocha, Galvão, Noireau & Lent, 2002 and Triatoma williami Galvão, Souza & Lima, 1965

Eggs and all nymphs of these species were studied employing light microscopy (LM) and scanning electron microscopy (SEM). The major differences observed by LM in the eggs were related to the presence and the distribution of pores on the surface of their chorion. Morphological differences among three nymphal stages (1st, 3rd, and 5th) development of each species were observed. The differential characteristics are chromatic and in the shape of connexival spots. The ultrastructure of the ventral region of the head and the IX, X, and XI abdominal segments (anal tube) of the both species were described demonstrating morphological differences that can be used for diagnosis of the species.

Aspectos morfológicos de abdômen de ninfas de 5§ estádio de seis espécies de triatominae (Hemiptera, Reduviidae) por microscopia óptica / Morphological studies of abdomen of fifth instar nymphs of six species of Triatominae (Hemiptera, Reduviidae), through optical microscopy

Descreveu-se, com o auxílio da microscopia óptica, os segmentos abdominais dorsais e ventrais de ninfas de 5§ estádio de Panstrongylus megistus, Rhodnius neglectus, Triatoma brasiliensis, T. infestans, T. matogrossensis e T. tibiamaculata. As estruturas estudadas foram: conexivo, áreas glabras, áreas brilhantes, placa quitinosa, estigmas, respiratórios e tubérculos dorsais.

Estudo morfológico de ovos e ninfas de Dipetalogaster maximus (Uhler, 1894) (Hemiptera, Reduviidae, Triatominae) / Morphological study of ovum and nymphs of Dipetalogaster maximus (Uhler, 1894) (Hemiptera, Reduviidae, Triatominae)

A fim de proporcionar novos parâmetros a serem usados na Taxonomia dos Triatomíneos, vetores da Doença de Chagas e ampliar os conhecimentos a respeito desta espécie, realizou-se um estudo da estrutura de ovos e da morfologia externa dos cinco estádios ninfais, através de microscopia óptica e eletrônica de varredura. Os ovos mostram em microscopia óptica (M.O.), a superfície do exocório do corpo e opérculo formada por áreas poligonais, mais nítidas quando observadas em microscopia eletrônica de varredura (MEV). Os 5 estádios ninfais apresentam no ápice do 3§ segmento do rostro 1+1 estruturas alongadas, que se exteriorizam; anida no 2§ segmento tarsal, um adensado apical de cerdas longas e delicadas, de coloraçäo dourada (Lent and Wygodzinsky, 1979)