Efeito de herbicidas utilizados para a cultura do milho na reprodu??o de Podisus nigrispinus (Hemiptera: Pentatomidae)

• Main Author: Reis, Tatiane Carla
• Other Authors: Soares, Marcus Alvarenga
• Language: Portuguese
• Published: UFVJM 2016
• Online Access: http://acervo.ufvjm.edu.br/jspui/handle/1/803

Submitted by Rodrigo Martins Cruz ([e-mail]) on 2016-01-05T13:29:43Z No. of bitstreams: 2 tatiane_carla_reis.pdf: 406245 bytes, checksum: ba6fbb5543734c8101f6e3f5e1481963 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) === Approved for entry into archive by Rodrigo Martins Cruz ([e-mail]) on 2016-01-05T17:57:29Z (GMT) No. of bitstreams: 2 tatiane_carla_reis.pdf: 406245 bytes, checksum: ba6fbb5543734c8101f6e3f5e1481963 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) === Made available in DSpace on 2016-01-05T17:57:29Z (GMT). No. of bitstreams: 2 tatiane_carla_reis.pdf: 406245 bytes, checksum: ba6fbb5543734c8101f6e3f5e1481963 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2014 === Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) === O milho [Zea mays L. (Poaceae)] ? uma cultura de import?ncia mundial. Durante o crescimento e desenvolvimento dessa cultura, outras plantas podem interferir e competir por ?gua, luz e nutrientes, sendo estas consideradas daninhas e um dos principais entraves a produ??o. Por outro lado, os artr?podes ben?ficos ou pragas podem possuir uma intera??o positiva com essas plantas. Al?m dos benef?cios como fonte alternativa de alimento, essas plantas s?o capazes de melhorar o fitness dos inimigos naturais. O controle das plantas daninhas, na cultura do milho, ? mais eficiente com o uso dos herbicidas, por?m estas subst?ncias s?o capazes de interferir em rotas metab?licas n?o alvo presentes nos inimigos naturais. O objetivo deste trabalho foi verificar o efeito dos herbicidas, atrazine, nicosulfuron e mistura destes, sobre as seguintes caracter?sticas de Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae): i) o comportamento de c?pula, ii) a din?mica reprodutiva das f?meas, e iii) a morfologia e a histologia das estruturas reprodutivas das f?meas. Aos quatro dias de idade, quinze f?meas adultas de P. nigrispinus, por tratamento, receberam a dose comercial de 1,5 g L-1 atrazine; 0,3 g L-1 nicosulfuron; 1,5 g L-1 + 0,3 g L-1, atrazine + nicosulfuron. Ap?s seis horas de exposi??o, as f?meas foram transferidas para placas de Petri (10 cm), com um macho de P. nigrispinus para cada f?mea. Foi observado por 24 horas o comportamento e a dura??o de c?pula de cada casal deste predador. Ap?s o per?odo de 24 horas foi observado poss?veis altera??es no comportamento de c?pula das f?meas. Sete dias ap?s a sua emerg?ncia, tr?s f?meas de P. nigrispinus oriundas de cada tratamento foram dissecadas. Foi observado o desenvolvimento e matura??o dos ov?citos, a contagem do n?mero de ov?citos maduros e imaturos, o n?mero de ovar?olos e compara??es da histologia das estruturas reprodutivas. Para as demais f?meas foram avaliados os par?metros biol?gicos: longevidade das f?meas, per?odo de pr?-oviposi??o, per?odo de oviposi??o, per?odo de p?s-oviposi??o, n?mero de ovos por tratamento, fecundidade (n?mero total de ovos vi?veis). A dura??o dos acasalamentos, nas primeiras 24 horas, a longevidade, a morfologia e a histologia das estruturas reprodutivas, independente dos tratamentos, n?o diferiram. Por?m, f?meas de P. nigrispinus, expostas a misturas destes herbicidas, n?o apresentaram predisposi??o ? c?pula nas primeiras 24 horas, onde somente duas f?meas deste tratamento copularam. F?meas expostas aos herbicidas, atrazine, nicosulfuron e mistura, apresentaram ovar?olos com menor n?mero de ov?citos, sendo em sua maioria ov?citos imaturos. A quantidade de ov?citos encontrado em cada ovar?olo pode ser relacionada com a fertilidade da f?mea, desta forma a ovog?nese foi menor nas f?meas de P. nigrispinus tratadas com herbicidas. Assim, ? poss?vel afirmar que os herbicidas testados foram seletivos para as f?meas de P. nigrispinus, por n?o afetar sua longevidade. No entanto, ? poss?vel que a s?ntese do horm?nio juvenil tenha sido afetada, alterando as taxas reprodutivas desta esp?cie. === Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, [2014]. === ABSTRACT The corn [Zea mays L. (Poaceae)] is a crop of global importance. During the growth and development of this culture, other plants can interfere and compete for water, light and nutrients, which are considered weeds and a major constraint to production. Moreover, the beneficial arthropod pests or may have a positive interaction with such plants. In addition to the benefits as an alternative food source, these plants are able to improve the fitness of natural enemies. The control of weeds in corn, is more efficient with the use of herbicides, but these substances are capable of interfering with metabolic pathways present in non-target natural enemies. The objective of this study was to investigate the effect of herbicides atrazine, nicosulfuron and mixture thereof, on the following characteristics of Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae): i) the behavior of copulation, ii) the dynamics of reproductive females, and iii) the morphology and histology of the female reproductive structures. At four days of age, fifteen adult females of the predator by treatment received a commercial dose of 1.5 g L-1 atrazine , 0.3 g L-1 nicosulfuron , 1.5 g L-1 + 0 3 g L-1 atrazine + nicosulfuron . After six hours of exposure , the females were transferred to Petri dishes (10 cm) , with a male of the predator for each female. Was observed for 24 hours uninterrupted behavior and duration of copulation of each couple this predator. After 24 hours the possible behavior changes was observed in the mating the females. Seven days after their emergence, three females of the predator coming from each treatment were dissected. The development and maturation of oocytes, counting the number of mature and immature oocytes, the number of ovarioles and comparisons of histology of reproductive structures was observed. Female longevity, pre-oviposition, oviposition period, post-oviposition period, number of eggs per treatment, fecundity (total number of viable eggs): For other females biological parameters were evaluated. The duration of mating, the first 24 hours, longevity, morphology and histology of the reproductive structures, regardless of the treatments did not differ. However, females of the predator exposed to mixtures of these herbicides showed no predisposition to copulation in the first 24 hours, where only two females mated this treatment. Females exposed to herbicides, atrazine, and nicosulfuron mixture showed ovarioles with fewer oocytes, with the most immature oocytes. The number of oocytes in each ovariole found may be related to female fertility, thereby oogenesis was lower in females of the predator treated with herbicides. Thus, we can say that the herbicides were selective for females of the predator, not to affect their longevity. However, the synthesis of juvenile hormone may have been affected by changing the reproductive rates of the species.