Emergence Rate of the Mexican Bean Weevil in Varieties of Beans From the Southwestern Amazon

Abstract

Common beans (Phaseolus vulgaris L.) are one of the most important protein sources worldwide. However, infestation by bruchids compromises the storage of these beans after harvest. The objective of this study was to determine the emergence rate of Zabrotes subfasciatus (Coleoptera: Chrysomelidae) in four P. vulgaris varieties (Carioca Pitoco, Enxofre, Gorgutuba Vermelho, and Rosinha) cultivated in the southwestern Amazon (State of Acre, Brazil). The grains from each variety were infested with 50 non-sexed adult Z. subfasciatus, and the insects were collected 13 days after initiating the bioassays. The adult progeny was collected from each plant variety on alternate days from the beginning to the end of the emergence period, and they were counted (number of insects/jar). The sum of emerged insects per day (SEd) was determined from the beginning of the emergence period, from which the accumulated emergence was calculated (SEa= ΣSEd, % day). There were differences in the emergence rates of Z. subfasciatus among the bean varieties, with the rates being lower in the Gorgutuba Vermelho variety. Although this bean variety had the lowest peak of adult insect emergence, the period of insect development was not of increased length in this variety compared to the other varieties. In general, the Gorgutuba Vermelho variety appears to be resistant to Z. subfasciatus.

Research Article Widespread infestation of <i>Pyemotes</i> <i>tritici</i> (Acari: Pyemotidae) in colonies of seven species of stored-product insects

“…The grain production chain requires suitable sanitary precautions owing to the occurrence of numerous pests that may cause economic damage, especially during the storage period, particularly in undeveloped countries such as Brazil (Lopes et al, 2018). Associated with this problem, several mites infest various materials, such as grains, dairy products, dried fruits, straw, and animal skin, that are produced and stored commercially; these are considered common contaminants in substrates where other arthropods also propagate (Hagstrum et al, 2013;Dhooria, 2016;Mullen and Oconnor, 2019).…”

Population Development of Bean Weevils (Coleoptera: Chrysomelidae: Bruchinae) in Landrace Varieties of Cowpeas and Common Beans

“…; Fabaceae) are legumes widely used for human consumption. They have an important social, economic, and nutritional role in countries like Brazil, where they are among the most widely consumed grains (Souza et al 2010;Oliveira et al 2013;Lopes et al 2016Lopes et al , 2018a.…”

“…Using genetically resistant varieties is an advantageous way of controlling bruchids because it maintains pests below the level of economic damage and does not require additional costs. Some studies have demonstrated the existence of cowpea genotypes resistant to C. maculatus and common bean genotypes resistant to Z. subfasciatus; the insects' reproductive development is used as a trait to characterize the source of resistance (Somta et al 2006;Cruz et al 2015;Lopes et al 2016Lopes et al , 2018a. The wide diversity of landrace beans grown by small farmers for decades in the southwestern Amazon region has been a source of resistance to bean weevils.…”