Occurrence of Euscepes postfasciatus (Coleoptera: Curculionidae) in Ipomoea batatas in Diamantina, Minas Gerais, Brazil

Abstract One complementary or alternative control measure to chemical insecticide is interplanting of plants that affect insect behavior. While few successes are known based on interplanting of different varieties of the same crop, such intra-crop interplanting may be effective against insects that feed on a limited range of plants and have persistent preference to one cultivar. Here, we report three field trials that examined the efficacy of intra-crop interplanting of sweet potato varieties, Ipomoea batatas (L.) Lamarck (Solanales: Convolvulaceae), on an oligophagous weevil, Euscepes postfasciatus (Fairmaire) (Coleoptera: Curculionidae), planting a preferred variety, Beni-masari, together with a less preferred one, Kyushu 166. In the first experiment, Beni-masari was planted as a border around Kyushu 166 and this arrangement decreased tuber damage in the main crop (Kyushu 166), although damage reduction was not statistically significant from monoculture plantings of Kyushu 166. In the second experiment, both varieties were planted in plots spaced 3 m apart to test the attractiveness of Beni-masari to weevils from Kyushu 166. No attractive effects of Beni-masari were observed. In the third experiment, the two varieties were planted in separate plots that were contiguous to each other, and in this experiment Beni-masari preferentially attracted weevils away from Kyushu 166 within 3 m distance, and tuber damage in Kyushu 166 within that zone was reduced owing to the attractiveness of Beni-masari. We discuss the potential of the intra-crop interplanting in pest management.

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Estimation of the population density of the sweetpotato weevils on the Mariana Islands

Journal of Entomological and Acarological Research ◽

10.4081/jear.2012.e4 ◽

2012 ◽

Vol 44 (1) ◽

pp. 4 ◽

Cited By ~ 7

Author(s):

Gadi V.P. Reddy ◽

James McConnel ◽

Aleandro E. Badilles

Keyword(s):

Population Density ◽

Ipomoea Batatas ◽

Pacific Islanders ◽

Mariana Islands ◽

Wet Season ◽

Significant Relationships ◽

Absolute Measure ◽

Euscepes Postfasciatus ◽

Major Pest ◽

Pest Density

The sweetpotato Ipomoea batatas L. (Convolvulaceae) has been one of the most important foods for Pacific islanders for centuries. However, the yield levels have been declining in the recent past due to the presence of sweetpotato weevils Cylas formicarius (Fabricius) (Coleoptera, Brentidae), Euscepes postfasciatus (Fairmaire) and Daealus tuberosus (Zimmer man) (Coleoptera, Curculionidae). Therefore, urgent management or eradication methods are sought in the Mariana Islands (Guam, Rota, Saipan, and Tinian). However, the management or eradication of these weevil pests requires accurate assessments of the target pest density. Currently, no advice is provided to growers on the best method for sampling sweetpotato for weevil pests, although pheromone-based traps or chemicals are being used. This study defines the results of field counts designed to adjust relative sampling techniques for three sweetpotato weevil pests by inspecting plants visually and at random in the field with an absolute measure of population density. Significant relationships were detected between the relative four sampling sites between the three weevil pests. In the dry and wet season, 90% and 35.5%, respectively, of population density of C. formicarius was noticed in Rota. This density of the population levels of this species is significantly lower in Saipan, Guam and Tinian. No incidence of E. postfasciatus and D. tuberosus was observed on Guam. However, E. postfasciatus is identified as the second most destructive pest in Rota, Tinian and Saipan in both the dry and wet seasons. Likewise, D. tuberosus is the third major pest as the recorded population density ranged from 12.5% to 2.5%. Also, it is evident from the sampling study that the population densities of all three weevils are significantly higher in the dry season than the wet season.

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Aspectos biológicos de Tetranychus ludeni Zacher, 1913 (Acari: Tetranychidae) alimentados com folhas de batata-doce pulverizadas com o 2,4-D

Arquivos do Instituto Biológico ◽

10.1590/1808-1657000822015 ◽

2018 ◽

Vol 84 (0) ◽

Author(s):

Ludmila Aglai da Silva ◽

Marcus Alvarenga Soares ◽

Luciana Monteiro Aguiar ◽

Caroline Conrado Ferreira ◽

Estela Rosana Durães Vieira ◽

...

Keyword(s):

Ipomoea Batatas ◽

Minas Gerais ◽

Tetranychus Ludeni

RESUMO: Batata-doce [Ipomoea batatas (L.) Lam.] apresenta grande versatilidade de usos no Brasil. Com a ampliação das áreas de cultivo, essa espécie estará sujeita à contaminação por herbicidas. Eventualmente, organismos não alvos podem ser expostos aos resíduos. O objetivo deste trabalho foi avaliar aspectos biológicos do ácaro Tetranychus ludeni alimentado com folhas de batata-doce pulverizadas com diferentes doses do herbicida 2,4-D. O experimento foi conduzido no Laboratório de Controle Biológico da Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), em Diamantina, Minas Gerais. Foram utilizadas 175 fêmeas de T. ludeni e 6 doses de 2,4-D, em g.ha-1 (8,06; 20,15; 40,30; 80,60; 201,50; e 806,00), mais o tratamento-controle com água destilada. Adotou-se delineamento inteiramente casualizado, com sete tratamentos e cinco repetições, contendo cinco fêmeas de T. ludeni em cada repetição. Foram avaliados a mortalidade inicial do ácaro em 24 h, o número de ovos, as ninfas e a longevidade das fêmeas. Os dados foram submetidos à análise de variância, sendo as médias significativas analisadas pelo teste de Duncan. Observou-se que doses maiores desse herbicida podem aumentar a mortalidade e reduzir a longevidade das fêmeas de T. ludeni.

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