Termos para indexação: Ipomoea batatas, melhoramento, resistência. SCREENING OF SWEET POTATO CLONES RESISTANT TO SOIL INSECTSABSTRACT -A research was carried out with the objective of selecting commercial clones for weather conditions of the Triângulo Mineiro, Minas Gerais State, Brazil. Sixty of the clones evaluated were obtained by polycross and given by the Universidade Federal de Lavras, three were from the farmers of the municipalities of Araguari, Uberlândia and Machado, located in Minas Gerais State, and nine clones were used as standards (Brazlândia Branca, Brazlândia Rosada, Surpresa, Rio Doce, Morena Roxa, Coquinho, Arroba, Pira 1 and Clone 042). The experiment was installed in a spacing of 1.10 x 0.45 m, using a randomized block design, with 72 treatments, four replicates and 16 plants per plot. Among the evaluated clones, 32.8% showed high or moderate resistance to soil insects. The clone with the highest yield was the clone number 95041, which produced 28,048.96 kg/ha. The others, 95009, 95010, 95014, 95020, 95033, 95042 and 95057 were highly resistant to soil insects.

The effect of benzoilfenylureas on the reproduction of Spodoptera littoralis (Boisd.) was studied. Third instar larvae were treated with either lufenuron or flufenoxuron by ingestion and contact (DL60 rate). The surviving larvae were observed until the adult stage. Adult males and females were mated in different combinations between treated and untreated individuals. The following variables were studied: average number of spermatophore, female fecundity and percentage of ecloded larvae (egg viability). A small change in spermatophore number (ca. 1 to 1.5) was noted specially in the combinations where males were obtained from treated larvae. The percentage of fecundity of females and hatched larvae decreased (ca. 45% and 30%) when both sexes were obtained from larvae treated with lufenuron and flufenoxuron.

RESUMEN -Ha sido evaluado el efecto de benzoilfenylureia sobre la capacidad copuladora de machos de Spodoptera littoralis (Boisd.) (Lepdoptera: Noctuidae). Dos grupos de larvas de 3 o estadio fueron tratados con el flufenoxuron, uno por ingestión y el otro por contacto, con una concentración del producto igual a la DL60. Cuando hubo la emergencia de los adultos, 10 machos por tratamiento fueron individualizados en cilindros de papel de filtro y puestos a copular con hembras vírgenes, que eron sustituídas diariamente, hasta la muerte de las mismas. Las hembras que fueron ofrecidas a los machos, al morir, eron dissecadas para verificar se estaban o no copuladas, a través de la observación de la presencia de espermatóforos en la bursa copulatrix. Fue observado que los machos de S. littoralis provenientes de larvas tratadas con el flufenoxuron, no tuvieron su capacidad copuladora alterada. La metodología fue considerada adecuada para evaluar la atividad copuladora y el número de copulaciones realizadas por el macho de esta especie.Términos para índice: lucha química, gusano del algodón, fertilidad. FLUFENOXURON EFFECTS ON COPULATING CAPACITY OF SPODOPTERA LITTORALIS (BOISD.) (LEPIDOPTERA: NOCTUIDAE) MALESABSTRACT -The effect of benzoilphenylureas was studied on the copulating capacity of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) males. Two groups of third instar larvae were treated with flufenoxuron, one by ingestion and another by contact with an DL60 rate. After emergence of the adults, ten males of the each treatment were put individualy in a filter paper cylinder, from the first night until death, in the presence of a virgin female that shift daily. After the female death they were desiccated in order to see the presence or not of the spermatophore in the bursa copulatrix. It was observed that the S. littoralis males that proceeded from the flufenoxuron treated larvae did not change their copulating capacity. The metodology was considerate efficient to evaluate the copulate capacity of this specie males. Monitoramento e Avaliação de Impacto Ambiental (CNPMA), Rod. SP 340, km 127,5, Caixa Postal 69, C E P 1 3 8 2 0 -0 0 0 J a g u a r i ú n a , S P . E -m a i l :