O papel da planta hospedeira na história de vida do percevejo predador Brontocoris tabidus (Signoret) (Hemiptera : Pentatomidae)

Abstract

The phytophagy exhibited by predatory stinkbugs has been considered favorable for their performance although there is little information about how they use their host plants. Thus, the feeding behavior of the predatory stinkbug, Brontocoris tabidus (Signoret) (Hemiptera: Pentatomidae), related to the host plants: cotton, Gossypium hirsutum L. (Malvaceae), pig weed, Amaranthus lividus L. (Amaranthaceae) and green bean, Phaseolus vulgaris L. (Fabaceae) were studied, and the relationship between feeding period, weight gain, reproductive output and mode of feeding on cotton plant as well. Adults of the predator were allowed to choose among plants to feed, and after, they were paired and maintained on the same plants. Furthermore, nymphs and adults were reared on the same plants with and without prey. B. tabidus did not select a particular plant to feed. Likewise, feeding period and weight gain were similar among the three plants studied. The weight gain, however, was directly related with feeding period on plants. Reproductive characteristics were not related with plant selection for feeding, while the female longevity was shorter in green bean plants. Nymphal developmental periods and adult reproduction varied among plants and lower values were found on green beans. Nymphs caged exclusively on plants did not reach adult stage and lived, on average, 6,5; 5,4 e 4,5 on cotton, pigweed and green bean plants, respectively. The results on mode of feeding on plants show that B. tabidus do not damage the plant tissue. Digital images from transversal sections of main vein allowed to observe that the predator introduce the stylet several times on the same place. The main veins of the leaves are preferred site to feed, and they use different tissues such as parenchyma, phloem, xylem and mesophyll. The results indicate that B. tabidus does not select a specific plant to feed although they performed differently on each one. Furthermore, this zoophytophagous predatory stinkbug does not cause injures on the host plant.