Studies on bionomics of the bean bugs occurring in mountain areas, with particular reference to that of Halyomorpha picus and to the insecticidal tests in laboratory and field

Abstract

Bean bugs are well known as a harmful insect from an agricultural view point. Recently one of the bugs Halyomorpha picus, however, has been found to give a bad influence upon persons living in mountain areas of Tohoku districts in Japan, because of the adult invasion into house under their densely populated condition owing to their hibernation habit in autumn and of the nasty smell resulting from their odor gland fluid on that occasion. During late June to late November 1963, prior to the insecticidal experiments in laboratory and field, survey of H. picus including other common bean bugs occurring on mountain plants had been carried out and these observations led to the following results : 1) H. picus was found living on mountain plants such as malberry, paper malberry, valley deutzia, raspberry and paulownia, etc. Egg masses, each larval stage and adults were collected on these plants during from latter part of June to August. 2) Besides H. picus, some other bean bugs Menida violacea, Plautia stali, Carbula humerigera, Eusarcoris parvus, Elasmucha putoni and Acanthosoma forficula, were also collected on the above-indicated plants and some others. 3) Adults of H. picus capable of oviposition were attracted by light traps in hot summer, in which a large number of them were collected from basin water applied directly under the lamp. They, however, were hardly collected from there in autumn. 4) It was noticed from the rearing in our laboratory that an adult female of H. picus usually laid 28 milky white-colored eggs at a time in the form of an egg mass and further successive few time ovipositions were seen at intervals of about 7 days. 5) About 40 days were necessary to finish their development from eggs through 5 larval stages to adults in hot summer, and at least 2 months being required during late summer to autumn. 6) Various insecticides used were all effective upon the adult H. picus, one of which Sumithion showed a most excellent insecticidal activity. 7) DDVP (0.3% kerosene solution) and Sumithion (1.5% powder) were practically used in the field control and the satisfactory results being obtained.