The preference for feeding in 5 soybean varieties of two species of leaf beetles, D. speciosa (Germar) and C. arcuata (Oliv.) (Coleoptera, Chrysomelidae) was tested at Campinas, State of São Paulo, Brazil, under greenhouse conditions, in a free choice type of experiment. Two Brazilian commercial soybean varieties Santa Rosa and Paraná, were compared with the PI 227 687, PI 229 358 and PI 171 451. The PI 227.687 was less preferred for feeding by D. speciosa than the commercial varieties and the other two PIs were intermediate. The C. arcuata leaf beetle showed a significant preference for young leaves of the variety Santa Rosa over the young leaves of PI 227.687, but in general there was no conspicuous feeding preference for the commercial varieties as much as there was for D. speciosa.

O número de vezes que o percevejo-verde Nezara viridula (L., 1758) (Hemiptera: Pentatomidae) se alimentou em cinco diferentes genótipos de soja foi estimado através das bainhas do estilete que permaneceram no local onde ele se alimentou. Foram feitas estimativas a olho nu, através de lupa sem corante e através de lupa após tratamento das vagens com corante de fucsina ácida, como foi proposto por BOWLING. A olho nu, notaram-se distintamente os locais das picadas nos cultivares Paraná e Hill e muito poucas picadas nas linhagens IAC 73/228 e IAC 77/656. A primeira geração do cruzamento entre 'Paraná' e IAC 73/228 apresentou comportamento intermediário, quando observada sem corante. Após tratarem-se as vagens com corante, ficou reduzida a diferenciação entre as linhagens IAO e os cultivares Hill e Paraná, enquanto a geração F1 deixou de ser intermediária e igualou-se aos cultivares suscetíveis. Os resultados sugerem a presença de um grau alto de tolerância à alimentação de percevejo nas linhagens IAC 73/228 e IAC 77/656.

The number of stylet sheaths of Nezara viridula (L., 1758) (Hemiptera: Pentatomidae) in 5 soybean (Glycine max (L.) Merrill) varieties was estimated under greenhouse conditions, at Campinas, State of São Paulo, Brazil. When estimated with naked eyes, the number of stylet sheaths was low in the varieties IAC 73/228 and IAC 77/656, high in the commercial varieties 'Hill' and 'Paraná' and intermediate in the F1 generation between Paraná and IAC 73/228. When estimated under the stereo microscope after staining the pods with acid fucsin, the number of stylet sheaths was high in the commercial varieties 'Hill', 'Paraná' and the F1. It was intermediate in IAC 73/228 and IAC 77/656. It seems from these results that a moderate degree of non preference for feeding might be present in the varieties IAC 73/228 and IAC 77/656, but further research is needed to support or to reject the existence of this moderate degree of non preference. The varieties IAC 73/228 and IAC 77/656 showed low stylet sheath counts when the pods were not stained and higher counts after staining. This suggests that they have high tolerance to the feeding activity of the green stink bug, not showing much reaction to its feeding activity. It is easier to notice the feeding punctures of the green stink bug on the pods of susceptible varieties than on resistant varieties. The variety IAC 73/228 has been previously shown to suffer low damage caused by green stink bug under field conditions. Both IAC 73/228 and IAC 77/656 are descendents of crosses involving the PI 274454 with the susceptible commercial variety 'Hill'. The Pi 274454 is probably a good source of resistance to the green stink bug. It is a vigorous, procumbent, late maturing variety from the Japanese island of Okinawa.

Os cultivares de soja 'paraná', 'viçoja' e 'santa-rosa', a linhagem IAC 73-223 e as introduções PI 171451 e PI 229358 foram testados em condições de campo para avaliar a resistência a percevejos. Ocorreram nesse campo experimental apenas as espécies de percevejos pentatomídios Nezara viridula L. e Piezodorus guildinii Westw. em iguais proporções. A linhagem IAC 73-228 teve a menor porcentagem de grãos danificados (48,1%) na metade superior da planta e as introduções PI 171451 (71,1%) e PI 229358 (79,1%) apresentaram porcentagem intermediária de grãos danificados. O cultivar 'paraná' foi o mais danificado, com 96,87%. Houve correlação significativa entre porcentagem de dano e porcentagem de plantas com retenção foliar (hastes verdes) por ocasião da colheita. Houve correlação positiva entre tamanho dos grãos e dano dos percevejos. O dano foi maior na parte superior das plantas que na inferior.

The soybean cultivars Paraná. Viçoja and Santa Rosa, the line IAC 73-228 and the introductions PI 171451 and PI 229358,e were tsted in Campinas, State of São Paulo, Brazil, in relation to the stink bugs Nezara viridula L. and Piezodorus guildinii Westw. The line IAC 73-228 had the least percentage of damaged seed (48,l%) in the superior half of the plant, whereas Paraná had the highest (96,8%). The introductions PI-171451 (71,1%) and PI 229358 (79,1%) had intermediate degrees of damaged seeds. This difference in damaged seeds could be due to actual resistance to the stink bugs, to resistance to Nematospora coryli transmitted by these insects or due to host evasion. It has been observed by DAUGHERTY et al. (1964) and LINK & COSTA (1974), that varieties with shorter period from flowering to harvest are less damaged by stink bugs and this would be a case of pseudo resistance called host evasion according to PAINTER (1951). There was a high positive correlation between percentage of seeds damaged and green stems at harvest. This feature could be used for field selection against these insects. There was positive significant correlation between damage and seed size. The seed size may be linked in some way to susceptibility to stink bugs. The damage was higher in the superior half of the plants than in the inferior.

A queda dos frutos é um problema grave em caquizeiro. Na variedade Fuyu, uma das mais cultivadas no Estado de São Paulo, a queda chega a 70%. Frutos antes da queda, examinados com binocular de 25 aumentos, mostram entre o cálice e o fruto populações grandes de ácaro eriofiidio Aceria diospyri K. Pulverizações com Sevin (Carbaryl) 85 PM (2 g/l) foram altamente eficientes para o controle dêsse eriofiidio, e o pegamento dos frutos tratados aumentou de 16,1% eni 1967/68, 9,8% em 1968/69 e 25,3% em 1969/70.

Early fall of persimmon (Diospyrus kaki L.) fruits, of the Fuyu variety, is an important problem in São Paulo State and seems to be partially related to a heavy infestation of the mite Aceria diospyri K. (Acarina: Eriophyidae) which lives under the fruit buttons. The rôle of the mite in the fruit fall was investigated through its control using Sevin 85 PM. Three spraying with monthly interval, beginning after petal fall, at the dosage of 2g/l, produced an absolute control of the mites and increased the fruit setting of the Fuyu variety by 16%, 10% and 25% in the 1967/68, 1968/69 and 1969/70 crop season, respectively.