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.

Influência da temperatura e umidade na biologia de Rhodnius neglectus Lent, 1954 em laboratório (Hemiptera, Reduviidae,Triatominae) / Influence of the temperature and humidity on the biology of Rhodnius neglectus Lent, 1954, in laboratory conditions (Hemiptera, Reduviidae, Triatominae)

O objetivo do presente trabalho foi observar o desenvolvimento de R. neglectus em diferentes condições de temperatura e umidade. Três grupos foram formados:33/40 (33+/- 1ºC e 40% +/-5% UR), 33/70 (33+/- 1ºC e 70% +/-5% UR), e 28/70 (28+/- 1ºC e 70% +/-5% UR). Todos os grupos foram observados diariamente para avaliação do período de incubação dos ovos, período de desenvolvimento dos estádios ninfais, percentual de mortalidade por estádio, número de repastos realizados, e período de desenvolvimento da eclosão a muda imaginal. O desenvolvimento embrionário apresentou diferenças significativas em todos os tratamentos, o grupo 33/40 apresentou o menor período de incubação. O menor número de repastos foi observado no grupo 33/40 exceto para o primeiro estádio (grupo 28/70). O período de desenvolvimento ninfal foi significativamente reduzido no grupo 33/40; entretanto, o percentual de mortalidade deste grupo foi alto, e os insetos não conseguiram realizar a muda imaginal.

The objective of the present paper was to study the development of R. neglectus in the laboratory under different conditions of temperature and humidity. Three groups were prepared: 33/40 (33+/- 1 degree C and 40% +/-5% UR), 33/70 (33+/- 1 degree C and 70% +/-5% UR), and 28/70 (28+/- 1 degree C and 70% +/-5% UR). All these groups were observed daily to evaluate the eggs' incubation period, the development period of each instar nymph, the mortality rate of each stage, the frequency of feeding and the hatching - adult ecdysis period. The embryonic development showed significant differences between the treatment given, the group 33/40 presented the lowest incubation period. The lowest bloodmeals number was observed in the group 33/40 except for the first instar (group 28/70). The period of nymphal development was significantly reduced in the group 33/40, however, the mortality was high and the specimens did not reach the adult phase.

Alterations in the morphology of the external genitalia of Panstrongylus megistus (Burm., 1835), caused by treatment with a juvenile hormone analogue (Hemiptera, Reduviidae, Triatominae).

Sao dsecritas as alteracoes observadas na genitalia externa de adultoides e ninfas extranumenarias de sexto estadio de Panstrongylus megistus, produzidas pela acao do analogo do hormonio juvenil N-(2,5-diclorofenil)-3,7-dimentil-2,6-octadienilamina. Na maioria dos machos observou-se parametros atrofiados e falo mal constituido. Estas alteracoes de um modo geral, eram mais pronunciadas quanto maior fosse o grau de juvenilizacao dos insetos analizados. Nas femeas o conjunto das placas genitais apresentou-se sempre completo porem com alteracoes principalmente nos gonocoxitos do oitavo e nono segmento, como tambem nas gonapofises do nono segmento