Flávia Rabelo Barbosa

Controle do caruncho-do-feijoeiro Zabrotes subfasciatus com óleos vegetais, munha, materiais inertes e malathion

(3) Resumo – Na busca de alternativas ao controle quimico do caruncho Zabrotes subfasciatus (Coleoptera:Bruchidae), avaliou-se, em feijoeiro (Phaseolus vulgaris L.), o efeito de tres genotipos, cv. Carioca e duas linhagens contendo a proteina arcelina (Arc1 e Arc3), e da adicao nos graos armazenados de oleo de soja (Glycine max Merrill); oleo de nim (Azadirachta indica A. Juss.), munha (residuo de trilha da colheita), calcario dolomitico e terra de formigueiro, comparativamente aos graos nao tratados e ao controle quimico com malathion 500 CE. O experimento foi realizado no laboratorio da Embrapa-Centro Nacional de Pesquisa de Arroz e Feijao, localizado no Municipio de Santo Antonio de Goias, GO, em condicoes nao controladas. Na linhagem Arc1, constatou-se maior protecao aos danos do caruncho, observando-se reducao do numero de ovos e de adultos emergidos e da porcentagem de sementes danificadas em relacao a Arc3 e a cv. Carioca. Quando os graos foram tratados com malathion, oleo de nim e oleo de soja, observou-se menor numero de ovos e de adultos emergidos e reducao de danos, e nao houve diferenca na porcentagem de sementes danificadas entre o malathion e o oleo de nim. A mistura das sementes com terra de formigueiro conferiu baixa protecao ao caruncho, enquanto os tratamentos com munha e calcario dolomitico nao apresentaram eficiencia na reducao da progenie e dos danos de Z. subfasciatus. Termos para indexacao: Phaseolus vulgaris, controle de pragas, resistencia aos pesticidas. Control of the Mexican bean weevil Zabrotes subfasciatus with vegetable oils, trashing residues, inert materials and malathion

Efeito da proteína arcelina na biologia de Zabrotes subfasciatus (Boheman 1833), em feijoeiro

Arcelin is a seed protein found in wild beans (Phaseolus vulgaris) which gives resistance to Mexican bean weevil, Zabrotes subfasciatus (Boheman 1833) (Coleoptera: Bruchidae). Studies were carried out with the objective of estimating the effect of four alleles of protein arcelin (Arc1, Arc2, Arc3 and Arc4) on the biology of Z. subfasciatus. The experiment was carried out in laboratory at Embrapa- Centro Nacional de Pesquisa de Arroz e Feijao, in Santo AntUnio de GoiAEs, GO, Brazil, under non controlled conditions. The highest levels of antibiosis to Z. subfasciatus were observed in Arc1, with reduction in the number of eggs, number of emerged adults, adults longevity. In the line Arc2 only reduction in the number of emerged adults was observed. The lines Arc3 and Arc4 showed low efficiency on the reduction of progeny of Z. subfasciatus and effects in the longevity and egg-adult cycle were not detected. Insect sexual ratio was not altered by the presence of Arc1, Arc2, Arc3 and Arc4 in the seeds.

Nível de dano, plantas invasoras hospedeiras, inimigos naturais e controle do psilídeo da goiabeira (Triozoida sp.) no submédio São Francisco

This study was conducted to increment the integrated management of Triozoida sp. (Hemiptera, Psylliidae) in guava plants at the Sao Francisco River Valley. The damage level, weed hosts, selectivity and effect of the thiamethoxam 10GR and 250WG in the control of psylliidae were evaluated. The experiment was carried out in an irrigated area, at Petrolina, Pernambuco, in a randomized block design with four replications. Treatments consisted of: 1) thiamethoxam 10GR applied on soil; 2) thiamethoxam 250WG sprayed weekly; 3) thiamethoxam 10GR applied on soil + thiamethoxam 250WG sprayed weekly; 4; 5; 6) thiamethoxam 250WG sprayed when 10, 20 and 30% of infested branches were reached, respectively; 7; 8; 9) thiamethoxam 10GR applied on soil + thiamethoxam 250WG sprayed when 10, 20 and 30% of infested branches were reached, respectively; and 10) control (no insecticide). The percentage of infested branches in the control treatment differed significantly from the treatments 2 (2.8%), 3 (4.3%), 4 (19.7%), 7 (13.4%), 8 (14.5%) and 9 (15.0%). When thiamethoxam was used, the population reduction of natural enemies ranged from 12.5 to 39.6%, corresponding, in the selective scale, to grades (1 = non offensive (< 25%), 2 = not very toxic (25-50%). Number and weight of fruits were similar in all the treatments. Fifty one weed species and no host of Triozoida sp. were found.

Estabilidade da resistência a Zabrotes subfasciatus conferida pela proteína arcelina, em feijoeiro

RESUMO - A arcelina e uma proteina encontrada em feijoes silvestres e confere resistencia ao carunchodo-feijao, Zabrotes subfasciatus (Boh., 1833) (Coleoptera: Bruchidae). Comparativamente as cultivares suscetiveis Porrillo 70 e Goiano Precoce, estudou-se a estabilidade da resistencia, conferida por dois alelos da proteina arcelina, nas linhagens do feijoeiro Arc1 e Arc4, apos a criacao do inseto por quatro geracoes sucessivas no mesmo genotipo. O experimento foi conduzido no Laboratorio da EmbrapaCentro Nacional de Pesquisa de Arroz e Feijao (CNPAF), no municipio de Santo Antonio de Goias, GO, em condicoes nao-controladas, utilizando-se delineamento experimental inteiramente ao acaso. Observaram-se, nas linhagens portadoras de arcelina, reducao do numero de ovos e de adultos emergidos, reducao do peso dos insetos, e prolongamento do periodo ovo-adulto. Na linhagem Arc1, a resistencia ao Z. subfasciatus foi mais expressiva. Nessa linhagem, os parâmetros numero de ovos, numero de adultos emergidos, periodo ovo-adulto, razao sexual e peso de machos nao foram alterados, porem observou-se aumento progressivo de peso das femeas nas geracoes. Na linhagem Arc4, houve reducao do periodo ovoadulto, embora o numero de ovos e de adultos emergidos, razao sexual e peso de machos e femeas nao tenham sido alterados. Termos para indexacao: Phaseolus vulgaris, resistencia a insetos, biologia de insetos, caruncho, armazenagem. STABILITY OF THE RESISTANCE TO ZABROTES SUBFASCIATUS CONFERRED BY PROTEIN ARCELIN IN COMMON BEANS PLANTS

Ocorrência de afídeos causando danos em mangueira (Mangifera indica L.), no Vale do São Francisco

A high infestation of aphids was observed at private orchards of mango (Mangifera indica L.) in the Brazilian northeast, with significant damage to young leaves, buds and inflorescences of the plants. Three aphid species were identified from collected samples: Aphis craccivora, Aphis gossypii and Toxoptera aurantii. In Brazil, this is the first record of A. craccivora and A. gossypii as pest on this fruit crop. Voucher specimens are deposited at the Entomology Laboratory of the Embrapa Semi-arido Research Center.

EFEITO DO CONTROLE CULTURAL E QUÍMICO SOBRE O ÁCARO DA NECROSE DO COQUEIRO, EM COCO-ANÃO IRRIGADO

One of the most harmful pests of coconut tree crop is the mite Aceria guerreronis. This pest damage the coconut fruits in the first development stage, causing partial or total losses in fruit production. The objective of this work was to evaluate the effect of chemical products and crop management in the control of A. guerreronis, aiming to use them in a management program for this pest. The research was carried out in Petrolina-PE from August to December, 1999. A complete randomized block design, with four treatments and four replications, was used. Each replication consisted of two plants of green dwarf coconut tree variety. Treatments were: A ¾ Cleaned plants without chemical control; B ¾ Cleaned plants with chemical control; C ¾ Plants not cleaned and with chemical control; D ¾ Plants not cleaned and without chemical control. All fruits damaged by mite were taken out from plants in the treatments with cleaned plants for three times. Fenpyroxymate, tetradifon and adhesive, at the levels 200ml, 300ml and 15ml for 100 l water, respectively, were mixed and applied for three times. Results showed that the individual uses of chemical products and crop management had efficiency of 26-87% and 64-89%, respectively, on mite control. However, the association of these two control managements showed a synergic effect on mite control with efficiency of 87-96%.