ABSTRACT Entomopathogenic fungi stand out in the biological control of several agriculturally important insects. Six isolates of Metarhizium anisopliae, Cordyceps javanica, Beauveria sp. and B. bassiana were screened to control Anthonomus grandis, Euschistus heros, Oebalus poecilus, O. ypsilongriseus and Thyanta perditor, important insect pests of soybean, cotton and rice. The bioassays were conducted in a completely randomized design, with four replications (10 insects/replication). Significant differences for virulence were observed between the tested fungal species and isolates. For A. grandis, the most virulent isolate was M. anisopliae BRM 2335, followed by Beauveria BRM 14527 and BRM 67744 [82.5 to 97.5 % of mortality; average lethal time (LT50) of 5.9 to 7.8 days]. M. anisopliae BRM 2335 was also highly virulent to the four stink bug species (75 to 97.5 % of mortality; LT50 of 5.2 to 9.7 days). For the stink bugs, Beauveria sp. BRM 67744 was infectious to O. poecilus (75 % of mortality), but failed to control E. heros (16.9 % of mortality). C. javanica BRM 27666 and BRM 14526 showed average virulence to the stink bugs and A. grandis (17.5 to 57.3 % of mortality; LT50 of 6.0 to 9.7 days). M. anisopliae was consistently more virulent to the stink bugs than the other fungi. Therefore, M. anisopliae BRM 2335 was selected for further studies under screenhouse and field conditions to control A. grandis and other stink bug species, especially E. heros. insects sp B O perditor soybean rice design 10 (1 insects/replication. insectsreplication insects/replication . replication insects/replication) A M 1452 6774 82.5 825 82 5 [82. 975 97 97. mortality LT (LT50 59 9 5. 78 7 8 7. days. days days] 233 75 (7 LT5 52 2 9. days) mortality, , mortality) E 16.9 169 16 (16. mortality. C 2766 17.5 175 17 (17. 573 57 3 57. 60 6 0 6. Therefore 1 ( 145 677 82. [82 (LT5 23 16. (16 276 17. (17 14 67 [8 (LT 27 [

RESUMO Os fungos entomopatogênicos destacam-se no controle biológico de diversos insetos de importância agrícola. Seis isolados de Metarhizium anisopliae, Cordyceps javanica, Beauveria sp. e B. bassiana foram selecionados para o controle de Anthonomus grandis, Euschistus heros, Oebalus poecilus, O. ypsilongriseus e Thyanta perditor, importantes insetos-pragas da soja, algodão e arroz. Os bioensaios foram conduzidos em delineamento inteiramente casualizado, com quatro repetições (10 insetos/repetição). Foram observadas diferenças significativas, em termos de virulência, entre as espécies fúngicas e isolados testados. Para A. grandis, M. anisopliae BRM 2335 foi o isolado mais virulento, seguido por Beauveria BRM 14527 e BRM 67744 [82,5 a 97,5 % de mortalidade; tempo letal médio (TL50) de 5,9 a 7,8 dias]. M. anisopliae BRM 2335 também foi altamente virulento para as quatro espécies de percevejo (75 a 97,5 % de mortalidade; TL50 de 5,2 a 9,7 dias). Para os percevejos, Beauveria sp. BRM 67744 foi infeccioso para O. poecilus (75 % de mortalidade), mas falhou no controle de E. heros (16,9 % de mortalidade). C. javanica BRM 27666 e BRM 14526 apresentaram virulência mediana para os percevejos e A. grandis (17,5 a 57,3 % de mortalidade; TL50 de 6,0 a 9,7 dias). M. anisopliae foi consistentemente mais virulento aos percevejos do que os outros fungos. Portanto, M. anisopliae BRM 2335 foi selecionado para estudos posteriores em casa telada e campo para o controle de A. grandis e outras espécies de percevejo, principalmente E. heros. destacamse destacam se agrícola sp B O perditor insetospragas pragas soja arroz casualizado 10 (1 insetos/repetição. insetosrepetição insetos/repetição . repetição insetos/repetição) significativas testados A M 233 1452 6774 82,5 825 82 5 [82, 975 97 97, mortalidade TL (TL50 59 9 5, 78 7 8 7, dias. dias dias] 75 (7 TL5 52 2 9, dias) mortalidade, , mortalidade) E 16,9 169 16 (16, mortalidade. C 2766 17,5 175 17 (17, 573 57 3 57, 60 6 0 6, Portanto 1 ( 23 145 677 82, [82 (TL5 16, (16 276 17, (17 14 67 [8 (TL 27 [

Resumo O objetivo deste trabalho foi avaliar a dinâmica populacional do percevejo-castanho (Scaptocoris castanea) em área com algodão (Gossypium hirsutum) cultivado após plantas de cobertura. Os insetos foram contados em amostras de solo coletadas a 0-40 cm de profundidade. A incidência de insetos foi documentada em 18 espécies de cobertura, isoladas ou consorciadas, em cada estágio da planta. A distribuição das chuvas foi comparada com a flutuação populacional do inseto. Espécies de crotalária apresentam efeito supressivo sobre a população do percevejo-castanho, enquanto algumas espécies de gramíneas favorecem o seu aumento. A distribuição das chuvas influencia diretamente a população de insetos.

Abstract The objective of this work was to evaluate the population dynamics of the burrower bug (Scaptocoris castanea) in an area with cotton (Gossypium hirsutum) cultivated after cover crops. The insects were counted in soil samples collected at 0-40 cm depth. Insect incidence was documented in 18 cover crops, alone or intercropped, in each plant stage. Rainfall distribution was compared with fluctuations in the burrower bug population. Crotalaria species have a suppressive effect on the insect population, whereas some grass species favor its increase. Rainfall distribution directly influences the insect population.

ABSTRACT: The root system architecture (RSA) of plants and its functioning play a fundamental role in a number of plant growth mechanisms including water and nutrient uptake. Optimization of the RSA is important for stable and increased plant productivity under adverse conditions. Despite its great importance, studying the RSA is notoriously laborious because of the difficulty of accessing the rooting system of plants. We developed a root phenotyping platform, PhenoRoots, which allows for the non-invasive study of plant RSA. The system was built using inexpensive material and was designed to provide medium throughput. Substrate or soil-filled rhizotrons are used to grow plantlets, whose roots are directly visible through a glass plate. An experiment conducted on a panel of twenty Upland cotton (Gossypium hirsutum L.) varieties demonstrated the usefulness of the platform in assessing RSA traits. A number of traits, destructive and non-destructive, related to the RSA were measured and statistically analyzed. The non-destructive traits based on image analysis of roots were more accurate and showed high correlation with the time-consuming destructive measurements. The platform allowed for capturing the phenotypic and genetic variability found in the panel of cotton varieties, and to define three contrasting RSA patterns. PhenoRoots provides an inexpensive alternative to the medium throughput analysis of RSA traits in plants.