ABSTRACT
The high consumption rate of vegetables stimulates the cultivation and increases the demand regarding the adequacy of the production processes. The attack of the pest Plutella xylostella causes high losses by reducing product quality, typifying a phytosanitary problem. This study aimed to verify the bioactivity of aqueous extracts of leaves of Jacaranda decurrens and Jacaranda mimosifolia at concentrations of 5, 10, and 15% on the insect. The choice test was carried out at the laboratory to determine the food effect of plant extracts and evaluate changes in the life cycle of insects exposed to active compounds through the analysis of biological parameters. Plant extracts of J. decurrens and J. mimosifolia presented with phagodeterrent classification in the choice experiments. The three J. decurrens extract concentrations promoted a prolongation of larval and pupal duration, while the duration of individuals treated with J. mimosifolia at 10% was significantly reduced. Occurred reduction in larval survival of individuals treated with aqueous extracts of J. decurrens and J. mimosifolia. Eggs from treatments with aqueous extract of J. decurrens and J. mimosifolia had reduced survival. Pupal survival of individuals treated with extract at 15% showed a significant reduction compared to the treatments at 5% and 10%. Pupae from the treatment with aqueous extract of Jacaranda mimosifolia showed a reduction in biomass in the treatment at 15% differing from the control e 5%. Thus, the aqueous extracts of the species J. decurrens and J. mimosifolia show insecticidal potential in the tests performed on P. xylostella.
Subject(s)
Bignoniaceae , Lepidoptera , Humans , Animals , Pupa , Larva , Plant Extracts/pharmacologyABSTRACT
Plants produce a wide variety of bioactive compounds with insecticidal properties, such as secondary metabolites capable of interfering with the nutrition and reproduction of pest species such as Plutella xylostella. Thus, the objective of this study was to evaluate the effects of aqueous and ethanolic extracts of Ludwigia spp. (Onagraceae) on the feeding and oviposition of P. xylostella. Choice bioassays were performed using aqueous and ethanolic extracts. The aqueous extract of L. tomentosa resulted in an approximately 81% reduction in larval feeding compared to that in the control, with an antifeedant index (AI) of 52%. The aqueous and ethanolic extract of L. nervosa acted by stimulating larval feeding. The oviposition was significantly reduced in the kale leaves treated with aqueous and ethanolic extracts of Ludwigia spp. The aqueous extracts promoted an average 90% reduction in oviposition when compared to that in the control, and an oviposition deterrent index (ODI) above 61% was classified as an oviposition deterrent. In addition, ethanolic extracts affected 81% of oviposition, with an ODI above 41%. Bioassays should be performed to clarify the use of aqueous and ethanolic extracts of L. nervosa as they acted as phagostimulants in the feeding tests and as deterrents in the oviposition tests. The phenolic compounds-flavonoids, condensed tannins, and alkaloids-were more abundant in L. nervosa, L. tomentosa, L. sericea, and L. longifolia. The extracts of L. longifolia and L. tomentosa showed the best results, interfering with the host choice for feeding and oviposition in P. xylostella and representing an alternative for the control of diamondback moths.
ABSTRACT
This study aimed to describe the diversity of fish parasites in the Amambai River, in theMato Grosso do Sul State, and generate information to facilitate studies of the biotic integrity of the region.During the period of September 2015 and July 2015, 48 specimens of 11 species of fish were analyzed forparasites. A total of 56.25% of the fish sampled from the Amambai River were infected with one or moremetazoan species. A total of 21,514 parasite specimens belonging to 24 different species we found; theywere distributed among six groups: Acanthocephala (Neoechinorhynchida), Cestoda (Proteocephalidea),Crustacea (Ergasilidae), Digenea (Cladorchiidae, Dadaytrema), Monogenea (Dactylogyridae) and Nematoda(Atractidae, Cucullanidae, Camallanidae, Rhabdochonidae). Of these, a monogenean, Mymarothecium sp.and four nematodes Cucullanus sp.; Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas, andPereira, 1928; Rabdochona acuminate (Molin, 1860); and Rondonia rondoni Travassos, 1920 were recordedfor the first time on new hosts. This is the first work to gather information about the parasite fauna of fishfrom Amambai River in the Mato Grosso do Sul State, and provides records that contribute new reports ofthe occurrence of parasites in new locations.
Este estudo teve por objetivo descrever a diversidade dos parasitos de peixes do rio Amambai,Estado do Mato Grosso do Sul, a fim de gerar informações que possam servir como subsídios para estudosde integridade biótica da região. Entre o período de setembro de 2014 e julho de 2015 foram coletados eanalisados 48 espécimes de peixes, pertencentes a 11 espécies. No rio Amambai, no período estudado, umtotal de 56,25% dos peixes estavam parasitados por pelo menos uma espécie de metazoário. Foramencontrados 21.514 espécimes de parasitos pertencentes a 24 espécies diferentes, distribuídos em seisgrupos: Acanthocephala (Neoechinorhynchida), Cestoda (Proteocephalidea), Crustacea (Ergasilidae),Digenea (Cladorchiidae, Dadaytrema), Monogenea (Dactylogyridae) e Nematoda (Atractidae, Cucullanidae,Camallanidae, Rhabdochonidae). Destes, um Monogenea, Mymarothecium sp. e quatro Nematoda Cucullanus sp.; Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas, and Pereira, 1928; Rabdochonaacuminate (Molin, 1860); e Rondonia rondoni Travassos, 1920 foram registrados pela primeira vez em novoshospedeiros. Este é o primeiro trabalho que reúne informações sobre a fauna parasitária de peixesprovenientes do rio Amambai, no Estado do Mato Grosso do Sul, onde os registros ampliam a lista denovos relatos de ocorrência de parasitos em novas localidades.
