Three species: Anorthoa angustipennis (Matsumura), Harutaeographa stenoptera (Staudinger), and Cerastis pallescens (Butler), are recorded for the first time from China, and Nikara castanea (Moore) is newly added to the fauna of Northeast China. The image of adult, genitalic characteristics, and the distributions are given as necessary.
This study was conducted to investigate the seasonal occurrence of chestnut weevil, Curculio sikkimensis. The chestnuts infected by the weevils were collected from Gongju, Buyeo, and Cheongyang in Chungnam Province, Republic of Korea. Investigation was focus on the escape period of chestnut weevil larvae from the fruits, invading time and vertical distribution in soil, survival rates of larvae during overwintering, emergence period, emergence rate, and sex ratio and longevity of adults. For precocious species, larvae escaped the chestnut from the mid-September to the early-October, middle species and slow species, were escaped from the late-September to the mid-October and from the early-October to the mid-November. After escaping from the chestnut fruits all of the larvae burrowed into the soil within 35 minutes. Overwintering larvae inhabited in the range of 0~48 ㎝ from the soil surface and highly distributed in the range of 18~36 ㎝. The 74.1% of wintering chamber were distributed within 18~36 ㎝ from the surface. Survival rates observed were 38.0% in 1st year, 16.0% in 2nd years, and 2% in 3rd years, respectively. Seasonal occurrence period of C. sikkimensis was from the early-Aug. to early-Oct. and the optimal occurrence period was the early and mid-Sept. Emergence rate decreased to 8.4% in 1st year, 3.6% in 2nd years, and 0.8% in 3rd years, respectively. Sex ratio was showed in the range of 0.51-0.55. It is female biased ratio. Longevity of adults was 9.9 days for female and 8.9 days for male.
This survey was conducted from 1992 to 2005 in the major apple producing districts in southern part of South Korea including 4~8 cities, to know the occurrence and damage level of two major pests, Carposina sasakii and Grapholita molesta that attack apple fruit. The fruit damage by G. molesta during the harvest period ranged from 0.02 to 1.64%. A tendency of higher damage of G. molesta was observed after 1997 compared with the previous years. The other hand, the fruit damage by C. sasakii was 0.02 to 1.30%, and the damage level was very low with fruit damage of ＜ 0.3% except 1998. The orchard infested with G. molesta was 13 to 71%, while 12 to 57% with C. sasakii. The rates of orchards where fruit damage by G. molesta was found were higher than those by C. sasakii after 1997. The tendency of fruit damage rates in the orchard where the most fruit damage was found was same with the trend of orchard rates infested with the pests. The maximum damage rate by G. molesta was 20.0% in 2005, while 4.5% by C. sasakii in 1998. The damaged shoot rates by the first generation G. molesta was 0.1~8.1%, and it had a positive correlation with the rates of fruit damage during the harvest period. Consequently, it is concluded that G. molesta is dominant species compared with C. sasakii in commercial apple orchards recently.
The biology of indian meal moth and maize weevil on the trehalose gene introduced rice (var "Nakdong") (T-Nakdong) was compared to that on the rice without gene introduction (Nakdong) at 28±1.0℃. Development of the both two insects was significantly delayed, on T-Nakdong, the developmental periods of female moth (±SE) and weevil were 38.46±0.42 and 36.38±0.28 days, respectively. Whereas those on Nakdong were 36.38±0.28 and 34.33±0.18, respectively. Net reproduction rate of Indian meal moth on T-Nakdong (3.0±0.14) was significantly lower than that on Nakdong (9.25±0.13), due to the lower emergence rate (21.08±0.04% vs 48.30±0.06%). The life table statistics of maize weevil on T-Nakdong was estimated to be similar to those on Nakdong. The delayed development of T-Nakdong suggested that the factor for development of the insects could be changed by the introduction of trehalose gene into the rice variety.
The ㎝bryonic and postembryonic developments of Nezara antennata Scott were observed in 5 different rearing cages such as A (Cylindrical, ø 10 ㎝ × 4 ㎝), B (Cylindrical, ø 14.5 ㎝ × 2.8 ㎝), C (Rectangle, 6.5 L × 6.5 ㎝W × 10 ㎝H), D (Cylindrical, ø 9 ㎝ in bottom & ø 11.5 ㎝ in upper × 10.8 ㎝) and E (Cylindrical, ø 15 ㎝ × 7.5 ㎝) containing soybean and peanut seeds as food, and sponge soaked with water under laboratory condition of 24℃ and 15L : 9D. Hatchability ranged from 93 to 97%. Nymphal duration was shortest of 6 days in the 1st instar and longest of 10 days in the 5th instar. The nymphal duration was 38 to 39 days observed in the rearing cages. Emergence rate was in the range from 53 to 62% with highest in A and B cages. Adult longevity was 65 to 75 days for male, and 67 to 74 days for female, and was longest in the B cage. Total number of eggs laid by female adult was in the range from 51 to 56 without significant difference in the rearing cages, and was the most in the B cage. Accordingly, the reproductive rate of N. antennata for 1 generation was within 25 to 33 times, and was highest in the B rearing cage. Therefore, it could be concluded that B cage is most suitable for stable rearing of N. antennata under laboratory condition.
Oriental fruit moth, Grapholita molesta, is a serious pest on apples. To control this pest in an environmentally friendly method, mating disruption strategy using sex pheromone has been developed. Area-wide application of mating disruption has been needed to be effective, with little understanding on how much size of apple cultivating area should be treated in one time application of the mating disruption technique. On this matter, we needed to determine a minimal mating active zone of G. molesta that should be applied with mating disrupters to be effective. Molecular markers to discriminate a specific population should be developed to trace population migration for reproductive behaviors. Here we developed two effective molecular markers using random amplified polymorphic DNA (RAPD) technique. Different field populations of G. molesta, based on locations and seasons, were analyzed with these markers. In a specific location, G. molesta populations varied in genetic composition with different seasons. Different local populations showed differential variation according to their relative distances among apple orchards. In overall, genetic variation among different populations became lessen with progression of seasons.
For the development of friendly environmental control of the beet armyworm, Spodoptera exigua that is too hard to control in the field, 25 insecticides were chosen from 58 registered to the beet armyworm, and bioassayed. There are 12 insecticides with neurotoxical activities, 10 with insect growth regulators and 3 Bacillus thuringiensis products. Among 12 insecticides with neurotoxical activities, mortality of S. exigua was 100% with emamectin benzoate (EC) and indoxacarb (WP) within 3 and 5 days after application, respectively. Otherwise, WG and SC of indoxacarb, Indoxacarb + etofenprox (WP) and pyridalyl (EW) were showed up to 91%. Methoxyfenozide + spinosad (SC) was better than any other insect growth regulator as 100% mortality within 3 days after application. And methoxyfenozide (WP), tebufenozide (WP) and methoxyfenozide (SC) were 92% by 5 days. However, 3 kinds of B. thuringiensis products were showed under 35% mortality within 5 days from first spray.
This study demonstrates a variability in efficacy of mating disruption against the oriental fruit moth, Grapholita molesta, populations infesting apples cultivated in differential environmental conditions. Throughout the growing seasons, trap catches of G. molesta male moths and damaged leaf and fruit were examined to evaluate the efficacy of a commercialized mating disruptor. Treatment of the mating disruptor significantly reduced the trap catches of male moth in treated plot, compared to those of the untreated plot. This reduced trap catches were significantly correlated with leaf and fruit damage. Moreover, the highest host damage occurred in June just after the highest overwintering adult peaks in both plots. The treatment of mating disruptors in Chungsong effectively disrupted the overwintering population in April and May, resulting in no noticeable host damage during the following growing seasons. However, there was a marked difference in host damage between two plots, especially in late seasons. Variation in the efficacy of mating disruption technology in terms of host damage appeared to be related with nearby pheromone-untreated orchards, which may result in the immigration of gravid females.
Insecticidal activity of 20 plant species against adults of Myzus persicae, female adults of Tetranychus urticae, and 2<SUP>nd</SUP> or 3<SUP>rd</SUP> instar larvae of Plutella xylostella was evaluated in this study. Thirteen plant extracts showed over 80% acaricidal activity to T. urticae at the concentration of 1%, while Capsicum annuum (hot-pepper seed), Inula helenium, and Acorus calamus revealed 82.8-86.2% acaricidal activities at 0.5%. Insecticidal activities of the plant extracts to M. persicae and P. xylostella were relatively low compare to the mite. Among the plant extracts, C. anuum and Brassica juncea revealed 48.6% and 42.9% respectively insecticidal activities to the aphid at the concentration of 0.5%. Extracts of C. anuum and Jeffersonia dubia provided 55% and 50% insecticidal activity against P. xylostella at 1%. And, the highest antifeeding activity of the insect was observed in the J. dubia extract as 79.4%. Results indicated that some plant extracts including hot pepper seed could be used as potential botanical pesticides for organic farming.
Methanol extracts of 35 plant species in 20 families were tested for their insecticidal activities and repellent effects against Nilaparvata lugens female adult by topical application and spray methods. The insecticidal activities and repellent effects of various plant species and parts were different. The methanol extracts from stem of Garcinia xanthochymus, Senecio scandens and Phytolacca americana, seedcoat of Ginkgo biloba, and leaf + stem of Ailanthus altissima and Catalpa ovata showed potent insecticidal activities against N. lugens. Specially, the G. biloba extract exhibited higher than 90% mortality against N. lugens at a concentration of 4,000 ppm. Repellent effects of plant extracts obtained from whole plant of Daucus carota, fruit of Semecarpus anacardium, leaf + stem of C. ovata and Wisteria sinensis were active, and potent. Also, the plant extracts that are potent in insecticidal activity not necessarily have high repellent activity showing no significant corelation between the two activities.
Many kinds of environment friendly agricultural materials (EFAMs) were used for the plant protection, furthermore they support the growth of crops in the greenhouses and the kindly environment friendly farming. Natural enemies might be used for control of insect pest with EFAMs at the same space and time. For testing the toxicity of EFAMs against to natural enemies, 10 EFAMs were selected and tested in small greenhouses and farm"s fields. In case of Harmonia axyridis larva, there was no predacious activity against cotton aphids in the block with EFAMMo L, EFAMPE D, EFAMME G and EFAMAE A, otherwise, aphid population was rapidly decreased in the control block without EFAMs. Both of Trialeurodes vaporariorum and Encarsia formosa population were slightly decreased in the block with EFAMs. There were significantly decreased in the block with IEFAM C, FEFAM D, EFAMSM Band EFAMPE D compared with control area. Especially, there was significantly maintained a very low population, both T. vaporariorum and E. formosa in the block with EFAMMo C. The parasitized ratio of Aphidius colemani is also very low in the block with EFAMs compared with control area. In the block with IEFAM C, FEFAM D, EFAMPE D and EFAMMo L, there were significantly different with control area in the number of mummies. Otherwise, in case of Diglyphus isaea and Liriomyza trifolii, there was no significantly different between blocks with and without EFAMs. In the block with EFAMMo C, Tetranychus urticae and Phytoseiulus persimilis populations were significantly maintained a very low level. However, the population of T. urticae was increased, but P. persimilis was decreased in the block with EFAMMo L.
Bacillus thuringiensis with selected high toxicities against tobacco cutworm, Spodoptera litura were isolated from domestic soils. When being observed under a phase-contrast microscope, the insecticidal crystal proteins were showed a bipyramidal crystal types. New CAB 109 isolate was identified to B. thuringiensis subsp. aizawai in the H serotype. As a results of insecticidal activities between CAB 109 isolate and 3 existing ready-made products against 3rd larva of S. litura, CAB 109 isolate showed 100% mortality with spore concentration (1.3×10⁷ cfu/㎖). It was a very high insecticidal activity compared with a existing ready-made B. t. products. LD₅₀ values of CAB 109 isolate was 9.78×10⁵, 6.87×10⁶ and 1.83×10⁷ cfu/㎖ spore concentration against 2nd, 3rd and 4th larva of S. litura, respectively. Unlike Plutella xyfostella, S. litura was slowly died after application up to 7 days. The weight of S. litura larva applied with CAB 109 isolate were 6-7 times less than controlled group. Even though it didn"t die, it did not grow into next larva. The result observed with scanning electron microscope was that CAB 109 isolate of B. t. aizawai formed a typical bipyramidal crystal protein type. Otherwise, when CAB 109 isolate was examined with SDS-PAGE and with trypsin, there was no difference between CAB 109 strain and ready-made products of B. thuringiensis.
We compared colony development and survival rate after artificial hibernation between the bumblebees, Bombus terrestris, produced from domestic and foreign companies. The number of worker and queen produced from foundation colony of three domestic and one foreign companies was 232.4-270.8 and 62.0-181.8, respectively, but there was no statistical difference. in colony development of B. terrestris queens which were terminated diapause by CO₂ narcosis at different companies, oviposition rate, colony foundation and progeny-queen production of bumblebees produced from domestic companies were superior to those from foreign company. But foreign company in the number of worker and queen was superior to domestic companies. On the other hand, survival rate and colony development of B. terrestris queens, which were terminated diapause by artificial hibernation at three domestic and two foreign companies, were no significant differences. These results indicate that oviposition, colony foundation, progeny-queen production, and survival rate after artificial hibernation showed no differences between the bumblebees produced from domestic and foreign companies.
Effects of different application of nematic ides (fosthiazate 5% G, ethoprophos 5% G, and diazinon 34% EC) for the control of Aphelenchoides fragariae in strawberry were evaluated in a greenhouse experiments. Mother strawberry (Fragaria grandiflora) cv. Yeohong were dipped in solution of nematicides (fosthiazate or ethoprophos at 2.5 g a.i./liter in 20℃ or 46℃) for 10 min. and planted in a greenhouse for dipping treatment. For the compare, mother strawberry were dipped in hot water for 10 min. without chemicals. For soil treatment, fosthiazate or ethoprophos at 3 ㎏ a.i./㏊ were mixed into soil. For foliar spray, diazinon at 3.4 g a.i./liter was sprayed at foliage until runoff. At 40, 80, and 100 days after planting, runners were harvested from each treatment and the rate of nematode infestation and the number of nematodes per plant were examined. After 100 days of planting, mother strawberry plants dipped in fosthiazate solution (2.5 g a.i./liter, 20℃) for 10 min. produced more number of healthy runners and reduced % of infected runner as much as 90% and also had fewer nematodes per runner. Fosthiazate was more effective than ethoprophos. Foliar application of diazinon was reduced A. fragariae populations only in early season. Hot water treatment and nematicide soil treatment were less effective.
Tropical fire ant, Solenopsis geminata (Fabricius) is distributed over the tropical and temperate areas. It is a polyphagous pest attacking to various plant and causes the pain to the people doing outdoor work. So it is known for a hygienic pest to human being, especially the people doing outdoor activities. It can cause severe pain to human, even with just a bite. Of particular concern is the possibility of its settlement in this country, if it invade to the farmlands and/or forests of Jeju Island and southern part in Korea. It is listed as a regulated pest in Plant Quarantine Act of Korea. This ant is usually imported through a ship and early settled in the port area where it is already distributed. Recently its distribution is rapidly spreading into Southeast Asia and southern part of China. In Korea, it was detected the one time in 1990s, but was detected the ten times from 2000 to 2006 by an imported plant quarantine process. Therefore, we would like to provide some information on the species, including morphology, distribution, host plant, damaged symptom and its general bionomics, which will be useful data for plant quarantine process and control.