Response of the apple aphid Aphis citricola van der Goot adults to treatment with several classes of insecticides varied from most toxic (esfenvalerate with LC50 0.89 ppm [AI]) to least toxic (monocrotophos with LC50 385.51 ppm [AI]). Esfenvalerate, which was most toxic to A. citricola, was also most toxic to the aphidophagus coccinellid Harmonia axyridis Pallas. The response of the aphid Myzus I1wlisllctus Matsumura adult to different insecticides varied from highly susceptible (deltamethrin with LC50 0.01 ppm [AI]) to highly tolerant (fenpropathrin with LC50 6.95 ppm [AI]). Esfenvalerate, which was 3rd in the order of toxicityto M. malisucttls, was the most toxiccompound to H. axyridis. Alphamethrin,which showed the lowest selectivityratio, was also much safer to the predator than to the pest. Based on their selectivity ratios, alphamethrin appeared tDbe the most promising candidate fDrIlse in integrated pest management prDgramswhere H. axyridis is the majDrnatural enemy.

:Three lepidopteran insect pests of the legume pod borer, Maruca vitrata (Lepidoptera: Pyralidae), the soybean pod worm, Matsumuraeses phaseoli (Lepidoptera: Tortricidae) and an Ostrinia spp. (Lepidoptera: Pyralidae) attacking adzuki bean, Vigna angularis, were confirmed as the major insect pests during the reproductive developmental stage of adzuki bean, and M. vitrata existed dominantly. Almost all plants in the adzuki bean field were injured by at least one of the three species, and 15~60% of reproductive organs were injured. Unbloomed inflorescence occurred continuously through the reproductive stage of adzuki bean. While the flower was many at the early stage and its number soon decreased, the pod was few at the early stage, but its number increased soon and maintained at a constant level. The results suggested that the adzuki bean injured by insect pests compensate the flower loss by developing new inflorescence, but the compensation do not cause the development of new pods. While M. vitrata and M. phaseoli were observed in flowers, pods and stem mainly during the first half of reproductive stage of adzuki bean, Ostrinia spp. was observed only in pods and stem during the second half. In addition, while all instars of larvae of M. vitrata were observed, larvae between the third and fifth instars for M. pahseoli and Ostrinia spp. were observed. KEY WORDS

: The toxicity of herbicides widely used in apple orchards to the twospotted spider mite (T etranychus urticae) was evaluated in laboratory and Ðeld studies. In a laboratory study with susceptible T . urticae, glufosinate-ammonium was highly e †ective against larvae, protonymphs and adults, but non-toxic to eggs. Its efficacy was much greater than that of the commonly used acaricide azocyclotin. The immatures died within 24 h after treatment, suggesting that the nymphicidal action may be attributable to a direct e †ect rather than an inhibitory action of chitin synthesis. Glufosinate-ammonium showed a positive temperature coefficient of toxicity against T . urticae adults at six temperatures from 10 to 32¡C, being more toxic at higher temperatures. Very low levels of resistance to the herbicide were observed in the seven Ðeld-collected T . urticae populations resistant to various acaricides. Treatment with glufosinate-ammonium did not cause a repellent response from either adults or immature stages of T . urticae. Paraquat dichloride and glyphosate were ine †ective against all stages of T . urticae. In a Ðeld study of a population of T . urticae, glufosinate-ammonium when sprayed to weeds caused signiÐcant decrease in T . urticae population densities in apple trees for nine weeks after treatment, as compared with the control. Thereafter, a single application of standard acaricides to apple foliage greatly reduced population densities, although there was no di †erence in the densities between the glufosinate-ammonium-treated and control plots. Based upon laboratory and Ðeld data, two single treatments with glufosinate-ammonium to weeds in May and a selective acaricide to apple trees in July may be used to prevent damage by T . urticae.