RESUMO
Sesame, an oilseed plant with multiple applications, is susceptible to infestations by the stink bug Nezara viridula (Linnaeus, 1758) (Hemiptera: Pentatomidae). This pest suctions the seeds of this plant and injects toxins into them. Possible sources of resistance on sesame cultivars are important to manage this bug. The objective of this study was to evaluate the biological aspects of N. viridula fed on three sesame cultivars aiming to select possible resistance sources for integrated pest management (IPM) programs of this stinkbug. The experimental design used randomized blocks with three treatments and four replications, each with newly emerged N. viridula nymphs fed with sesame capsules of the cultivars BRS Anahí (T1), BRS Morena (T2) and BRS Seda (T3). Two to three green sesame capsules were supplied every two days per group of ten N. viridula nymphs as one replication until the beginning of the adult stage. Adults of this stinkbug were fed in the same manner as its nymphs but with mature sesame capsules until the end of the observations. Survival during each of the five instars and of the nymph stage of N. viridula with green sesame capsules was similar between cultivars, but the duration of the nymph stage was shorter with green capsules of the BRS Morena than with those of the BRS Anahí. The oviposition period, number of egg masses and eggs per female, and the percentage of nymphs hatched were higher with mature capsules of the sesame cultivar BRS Anahí and lower with the others. Nymphs did not hatch from eggs deposited by females fed mature seed capsules of the sesame cultivar BRS Morena, which may indicate a source of resistance against this stinkbug in this cultivar. The worldwide importance of N. viridula to sesame cultivation makes these results useful for breeding programs of this plant aiming to develop genotypes resistant to this bug. In addition, the BRS Morena is a cultivar already commercially available and can be recommended in places where there is a history of incidence of N. viridula, aiming to manage the populations of this pest.
RESUMO
O crescimento da produção avícola provocado pela alta demanda do mercado acarreta um aumento da criação de aves em confinamento, o que resulta em um aumento da densidade das aves dentro do galpão. Em função disso, há um incremento da umidade da cama aviária, proveniente tanto das excretas das aves, como da água dos bebedouros, que favorece o crescimento de populações do coleóptero Alphitobius diaperinus, popularmente conhecido como cascudinho. O contato direto do inseto com a cama das aves, assim como a alimentação a partir de aves moribundas e mortas, faz do A. diaperinus um veiculador de diversos patógenos, sendo destacados bactérias, protozoários e vírus que causam imunossupressão nas aves. Além da relação com os patógenos, os cascudinhos podem provocar danos nas instalações avícolas, pois, na fase larval, escavam túneis no material isolante para empuparem e destroem a proteção de poliuretano usada para isolamento térmico dos galpões em países de clima frio, a qual precisa ser trocada a cada dois ou três anos. Outro fator prejudicial às aves é a substituição da ração balanceada por larvas e adultos do coleóptero, uma vez que afeta o ganho de peso, principalmente, das mais jovens. Frente ao exposto, a presença do cascudinho em instalações avícolas torna-se um problema, tanto sanitário, como financeiro. O controle do A. diaperinus é considerado difícil, e inseticidas químicos são comumente utilizados em aviários, mas apresentam desvantagens, pois deixam resíduos na carcaça, bem como no meio ambiente. A presença de alta quantidade de matéria orgânica nos aviários provoca a diminuição da efetividade dos inseticidas químicos. Vários estudos vêm sendo desenvolvidos na busca de alternativas, como, por exemplo, nematoides e fungos entomapatogênicos, mas até o momento não são produzidos em escala comercial. Outra linha de pesquisa é a utilização de terra diatomácea, um pó-inerte que não deixa resíduos na carne de frango e no ambiente.
The growth in poultry production because of the high market's demand causes an increase in the confinement raising, which increases the density of birds in poultry houses. As a result of this function, there is moisture increase in broiler litter, both from the excreta and drinkers, which favors the growth of the coleopterons Alphitobius diaperinus, popularly known as darkling beetle. The direct contact of the insects with the broiler litter as well as their feeding from dead and sick broilers make the A. diaperinus a vehicle for various pathogens, especially bacteria, protozoa and viruses. Besides the relationship with the pathogens, the darkling beetle can cause damage to poultry house, because at the larva stage they tent to burrow in to the insulating material and destroying the protection of polyurethane used for thermal insulation of poultry houses in countries with cold climate, which have to be changed every two or three years. Another harming factor to the broilers is the replacement of theirs balanced diet for larvae and adults of coleopterons, which affect the weight gain, mainly within younger individuals. Due to this factor, the presence of darkling beetle in poultry installations becomes a health as well as financial problem. The control of A. diaperinus is regarded as difficult and the use of chemical insecticides is common in poultry raising, even though it has disadvantages because it leaves residue in the carcass and in the environment. The presence of high amount of organic matter in poultry causes the decrease of the effectiveness of chemical insecticides. Several studies have been developed in research for alternatives, such as nematodes, fungi entomopathogenics, but they are not yet available commercially. Another line of research is the use of diatomaceous earth, an inert and non toxic powder which leaves no residues in chicken meat or in the environment.
