Efeito de plantas daninhas e do algodoeiro no desenvolvimento, reprodução e preferência para oviposição de Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae)

Abstract

This study investigated the effects of six weeds [Amaranthus hybridus L., Desmodium tortuosum (Sw.), Euphorbia heterophylla L., Ageratum conyzoides L., Bidens pilosa L., Ricinus communis L.] and the cotton plant Gossypium hirsutum L. CNPA Precocious 1 on Podisus nigrispinus (Dallas) life history characteristics and oviposition behavior. The study begun with P. nigrispinus eggs placed on plants and caged throughout up to female death. Egg production and selected plant for oviposition by P. nigrispinus were investigated caging mated females on weeds and cotton plants simultaneously. Nymphal development of P. nigrispinus was shorter on D. tortuosum and longer on A. hybridus. Nymphal viability was not affected by any species of plant studied. Nymphs reared on R. communis produced females weighting less compared to the other plant species. The weed A. conyzoides promoted higher female fecundity compared to those females reared on D. tortuosum, E. heterophylla and R. communis. The demographic parameters net reproductive rate (R o) and mean generation time (T) of P. nigrispinus were higher for females reared on A. conyzoides, while the intrinsic rate of population increase (r m) and finite rate of increase (λ) suggest that better performance of the predator will be yielded on B. pilosa. The weed plants A. hybridus and B. pilosa were significantly preferred by P. nigrispinus females to lay eggs. These results suggest that the weeds A. conyzoides, B. pilosa and A. hybridus can benefit the colonization and maintenance of P. nigrispinus in the cotton ecosystem by phytophagy.

Development, survival and reproduction of Podisus nigrispinus (Dallas, 1851) (Heteroptera: Pentatomidae) with salt and amino acids solutions supplementary diet

“…This seemed to be the most critic instars for the development of Pentatomidae predators which was also found for P. nigrispinus with different diets (Zanuncio et al, 1996) and Supputius cincticeps (Stal, 1860) (Heteroptera: Pentatomidae) exposed to environmental stresses . The duration of the instars of P. nigrispinus was longer with NaCl or amino acid solutions than that reported for this predator fed on different prey in the presence or absence of plants (Zamperline et al, 1992;Lemos et al, 2001Lemos et al, , 2003Evangelista Jr. et al, 2003). This showed that the development of predators could be affected by the type and quality of prey and the dietary supplement to them (Strohmeyer et al, 1998).…”

Seletividade de atrazine e nicosulfuron a Podisus nigrispinus (Heteroptera: Pentatomidae)

“…Nesse sentido, o uso de herbicidas é prática comum, em razão do menor custo e da maior eficiência de controle (Rizzardi et al, 2004). Contudo, a diversidade dessas plantas daninhas em campo pode ser um importante fator para o estabelecimento e a dinâmica de inimigos naturais de pragas, onde esses insetos usufruem dessas plantas para refúgio e sobrevivência (Evangelista Jr. et al, 2003). Os herbicidas atrazine e nicosulfuron são produtos usados atualmente em razão do baixo custo e seletividade à cultura (Rizzardi et al, 2004), sendo recomendados, respectivamente, para controle de plantas daninhas de folhas largas e gramí-neas (Brasil, 2010).…”

Impactos do controle de plantas daninhas e da aplicação de herbicidas em inimigos naturais

“…This includes pollen consumption for those with chewing mouthparts and water and minerals for sucklings (Evangelista Jr. et al, 2004). Several reports show that the quality of the host plant can improve development, fertility, size, survival and population density of non-strictly zoophagous natural enemies (Awmack e Leather 2002; Evangelista et al, 2003Evangelista et al, , 2004. Moreover, zoophytofagy allows predator insects to survive in the field in conditions of prey shortage (Coll e Guershon 2002;De Clercq 2002).…”

“…Predator Podisus nigrispinus Dallas (Hemiptera: Pentatomidae) has benefited from extra food supply provided by plants Ageratum conyzoides L., Amaranthus hybridus L. and B. pilosa. These weeds present in cotton favor colonization and maintenance of P. nigrispinus (Evangelista Jr. et al, 2003).…”

“…The weeds lower diversity can interfere in the natural enemies population establishment and dynamics (Evangelista Jr. et al 2003). Another impact on predators and parasitoids can be caused by chemicals present in herbicides.…”