• Journal of Sericultural and Entomological Science
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• v.18 no.2
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• pp.65-78
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• 1976

The mulberry small weevil, Baris deplanata ROELOFS, has highly infested mulberry trees in Korea. As the damage caused by the mulberry small weevil in mulberry fields has been increased over the country since 1969, the authors has carried out a series of biological and controlling studies on the pest from 1971 to 1972. The results obtained are summarized as follows. 1. The adult weevil is elongate oval in shape with black in color and the probocis is long as usual in curculionidae. The size of adult female is 3.30${\pm}$0.04mm in length, 1.47${\pm}$0.04mm in width, and the length of proboscis is 1.25${\pm}$0.014mm, while adult male is 3.28${\pm}$0.06mm in length, 1.40${\pm}$0.04mm in width, and the length of proboscis is 1.30${\pm}$0.02mm. The antenna is geniculate consisting of 12 segments. The terminal sternite of the abdomen has a pointed tip in male but not in female. 2. The egg is long oval in shape, milky white in color, 0.51${\pm}$0.05mm in length and 0.32${\pm}$0.02mm in width. 3. The mature larva is cylindrical and light yellowow in color except the head of dark brown, and legless, 3.88${\pm}$0.06mm in length, 1.40${\pm}$0.02mm width, each segment bearing many wrinkless and short setae. 4. The pupa is long oval, milky white and exarate, 3.53${\pm}$0.09 in length, 1.40${\pm}$0.03mm in width. 5. Majority of the species has one generation through a year and overwinters as adult in xylem of withered branch and come out again from late April to early May in next year. But some of the female oviposit in the same year and the offsprings overwinter as larva (0.4%) or pupa (0.1%) 6. The eggs are mostly laid under the cork layer of withered branch and the number of eggs deposited by an adult female is 73.44${\pm}$8.74, the average egg-laying period is 33.88${\pm}$6.04 days. The incubation period is 11.69${\pm}$0.39 days, the larval period 45.04${\pm}$1.63 and the pupal period 11.05${\pm}$0.49 days. The period of adult's activity is 46.7${\pm}$5.90 days. 7. The larvae feed on the cambium under the bark and adults feed on the winter bud, the latent bud, the leaf stalk and the base of newly shoot. 8. An active period of adults was observed during the period of 4 months from April to July. However, the peak of adult-density occurred in the early May (in the fields of spring-prunning) and early to middle June(in the fields of summer-prunning). 9. There is a positive correlation between the density of larvae and diameter and length of the branches. 10. The pattern of distributions of the adult of mulberry small weevil is negative binomial distribution. 11. The chalcid fly was disclosed to be a natural enemy which was parasite on the larvae of mulberry small weevil and its parasitic ratio was 11.9%. 12. Phosvel D, Malix D, Salithion EC, DDVP EC, and Phosvel EC were effective for the control of adults and Satchukoto-S EC, and Salithio EC were effective for the control of larvae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.586-593
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• 1985

The rose bitterling, Rhodeus ocellatus (KNER) is commonly distributed in the fresh waters of Korea and Japan. On January 15, February 15, and March 18 in 1984, mature adults of rose bitterling were caught in the watercourse of Maeri, Kimhae, South Korea. The authors fertilized the eggs employing dry method in the laboratory on May 7, 16 and 25 in 1984. Hatched larvae were reared in small aquariums at $17{\sim}25.5^{\circ}C$ (average around $21.2^{\circ}C$). Mollusks, Anodonta woodiana in the gill chamber of which, rose bitterling lay eggs were caught in order to study natural spawning of the rose bitterling in the same watercourse. The eggs of this species are not adhesive and demersal. The size of the eggs varies from 2.54 to 2.75mm in long diameter and 1.45 to 1.65mm in short diameter. The eggs are cylindrical in form when they are extruded from ovipositor, immediately after entering water, but they acquire their distinctive form of a greatly elongated pear. Hatching took place in ca. 39 hours after fertilization. The newly hatched larvae were $2.65{\sim}2.70mm$ in total length possessing yolk sac and 13-14 myotomes. Thirteen days after hatching, the prelarvae attained 6.5 mm in total length, and the first melanophores appeared on the head, and the anterior part and sides of the yolk sac. One month after hatching, the postlarvae attained 8.5mm. in total length and emerged from the gills of the mollusks. Then the yolk sac was completely resorbed. Two months after hatching, the rose bitterling attained 14.4mm in total length, and entered the fingerling period of life. All the rays already present were the D. III, 11-12, A. III, 11-12, P. 10, V. 7. and a distinguishing, feature is the presence of a black pigment spot in the lobe of the dorsal fin.