ABSTRACT
Species of the subtribe Oedionychina not only have a highly uniform diploid number of 2n = 22 (20+X+y) but have the karyotypic peculiarity of possessing extremely large sex chromosomes. We analyzed Paranaita opima embryos and gonadal cells to determine their diploid number, chromosomal morphology, type of sex determination system, constitutive heterochromatin pattern and which chromosomes bear nucleolus organizer regions (NORs). The diploid number of P. opima was 2n = 22 (20+XY/XX) with all chromosomes being metacentric. Chromosome pair 6 showed an interstitial secondary constriction on the short arm. The C-banding technique revealed centromeric constitutive heterochromatin in all chromosomes, which, in pair 6, extended up to the secondary constriction of the short arm, additional C-bands also being present on the Y chromosome. Silver nitrate nucleolar organizer region (Ag-NOR) staining showed NORs on the secondary constriction of pair 6. Fluorochrome analysis with chromomycin A3 (CMA3), 4'-6-diamidino-2-phenylindole (DAPI) and the distamycin A (DA) counterstain showed that the short arm of chromosome pair 6 exhibited a GC-rich block extending from the proximal to the median region, including part of the secondary constriction. The same techniques also showed AT-rich blocks at the centromeric region of all chromosomes and at the terminal region of the short arm of pair 6. The basic karyotype characteristics and C band pattern of P. opima are similar to those described for other species in the subtribe Oedionychina. The pattern of autosomal NORs observed in P. opima corresponds to that registered in the majority of the Chrysomelidae species.
Subject(s)
Animals , Coleoptera/genetics , Heterochromatin , Nucleolus Organizer Region , Coleoptera/embryology , Cytogenetic Analysis , Chromosomes/genetics , Fluorescent Dyes , KaryotypingABSTRACT
Este trabalho teve como objetivo avaliar a influência do pó e do extrato aquoso de Chenopodium ambrosioides L. sobre o comportamento e a sobrevivência do gorgulho-do-milho, Sitophilus zeamais Mots. As plantas de C. ambrosioides foram cultivadas na área experimental do Departamento de Entomologia, Fitopatologia e Zoologia Agrícola da ESALQ/USP. Foram obtidos pós de folhas, ramos, frutos e da planta inteira (com frutos), quando a planta estava no estágio de frutificação. Os insetos utilizados nos ensaios foram obtidos de criação mantida em grãos de trigo. Foi avaliado o efeito do pó das diferentes estruturas vegetais e da planta inteira (com frutos) sobre o comportamento (atratividade e/ou repelência) e atividade inseticida nos adultos. Foi avaliado também o potencial inseticida do extrato aquoso das diferentes estruturas e da planta inteira (com frutos) sobre as fases imatura e adulta de S. zeamais. Os resultados obtidos foram: a) pós de frutos, ramos e folhas de C. ambrosioides não apresentaram repelência para adultos de S. zeamais; b) os pós de frutos e da planta inteira (com frutos) apresentaram atividade inseticida sobre adultos de S. zeamais; c) os extratos aquosos dessas estruturas vegetais não afetaram a sobrevivência e a emergência de adultos de S. zeamais.
This work deals with the influence of the powder and aqueous extracts of Chenopodium ambrosioides L. on behaviour and survival of the maize weevil, Sitophilus zeamais Mots. The powders tested were obtained from leaves, branches, fruits and the whole plant (with fruits), when the plant was in the fructification period. The insects were obtained from a population reared on wheat grains. The effect of the powders from the different vegetal structures and from the whole plant (with fruits) was evaluated concerning the insect behavior (attractiveness and/or repellence) and insecticide activity on the adult phase. The insecticide activity of the aqueous extract from the different structures and from the whole plant (with fruits) was evaluated on immature and adult S. zeamais. The results were as follows: a) powders from fruits, branches and leaves of C. ambrosioides were not repellent to S. zeamais adults; b) powders from fruits and whole plant (with fruits) presented insecticide activity against S. zeamais adults; c) the aqueous extracts from these structures did not affect survival and adult emergence in S. zeamais.
Subject(s)
Coleoptera/anatomy & histology , Coleoptera/growth & development , Coleoptera/embryology , WeevilsABSTRACT
The testes of Palembus dermestoides are formed by six follicles coated and interconnected by a peritoneal sheath. Long, cylindrical and slightly twisted spermatophores were observed. Spermiogenesis followed the usual sequence for insects. During spermiogenesis, the nucleus was transferred to the cell periphery and the mitochondria were grouped at the posterior pole of the cell. Two mitochondrial derivatives and two paracrystalline electrondense bodies were present close to the axoneme. The mitochondrial derivatives were surrounded by a single row of microtubules in immature spermatozoa. The axoneme had the typical 9+9+2 microtubular pattern of insects.