A taxonomic review of the genus Lagria Fabricius is presented. Two species are identified: Lagria nigricollis Hope and a new record, Lagria rufipennis Marseul. A key, description, habitus photographs of adults, and illustrations of diagnostic characteristics are provided.
Seventy two species of armored scale have been recorded from the Korean peninsula since late 1920s. Nine of these species were obtained from greenhouses. Of these 9 armored scale species, 7 species are considered to have failed to colonize fields or greenhouses and 2 species, which were collected from pineapple plants, Tillandsia plants and cactus trees in greenhouses, were never taken from the exterior environment.
A study was conducted to find out plant flora, the occurrence of insect pests and natural enemies in the fallow paddy fields of Jeonnam and Jeonbuk provinces from 2004 to 2005. They were identified as 124 plant species in 32 families, 58 insect pest species in 30 families and 11 natural enemy species in 9 families. Plant species belonging to Poaceae and Asteraceae were founded as 28 and 18 species, respectively, and dominated significantly among plants growing in the fallow paddy fields. In insect pests, Conocephalus chinensis, Nysius plebejus, Cletus punctiger, Eysarcoris aeneus, Nephotettix cincticeps, Laodelphax striatellus and Tipula sp. occurred significantly in the fallow paddy fields. Among them, occurrences of N. cincticeps and L. striatellus were low from May to June, and that of L. striatellus was high in August and September. In insect natural enemies, Coenagrion sp., Harmonia axyridis, Propylea japonica and Eristalis tenax occurred significantly in the fallow paddy fields.
Adoxophyes spp. (Lepidoptera: Tortricidae) are economically important pests of fruit trees in Asia and Europe. The geographical distribution of three Adoxophyes species, A. orana, A. honmai and A. paraorana, in Korea was surveyed using species-specific sex pheromone traps for males in 2006 and 2007. The distribution of A. orana was restricted in the midwestern area, while A. honmai was found mainly in the southern area. In contrast to these two species, A. paraorana was widely distributed. Moreover, A. paraorana coexisted with A. orana in the midwestern area, and with A. honmai in the southern area. The seasonal fluctuation of male catches was monitored with pheromone traps in 2008. In the central regions, males of A. orana and A. paraorana were captured from May to September, with peak numbers in late May, middle July, and late August. A. honmai males were trapped from late April to late September, with peak catches in middle May, late June, early August, and early September in Naju.
For the comparing of mortality of the resistance and susceptible population of Myzus persicae, etofenprox was treated in the recommended concentration of 200ppm. Mortalities of resistance population were 16.7 and 36.7%, and susceptible population were 86.7 and 86.7% after 24 and 48 hours treatment, respectively. For the detect of cross resistance to other pyrethroids, 6 pyrethroids were examined. Mortalities of susceptible and resistance populations were 90 and 31% to deltamethrin, 92 and 23% to lambda cyhalothrin, 81 and 14% to cypermethrin, 70 and 20% to α-cypermethrin, 29 and 28% to fenpropathrin, 84 and 29% to fenvalerate, respectively. It was showed that resistance populations were generally resistive to other pyrethroids. On the other hands, for recognized ecological characteristic of M. persicae susceptible and resistance populations life table was tested on the pepper leaves in the petri dish and on the plant in the pot. This results were showed that intrinsic rate of increase (r<SUB>m</SUB>), net reproduction number (R₀) and generation time in day (T<SUB>c</SUB>) were significantly different between two population in both tested. However, life span and reproduction period were slightly different between them. Otherwise, feeding behaviors were tested using EPG technique with non- and treated etofenprox. First potential drop time of susceptible and resistance population was 73.5 and 257.9 sec with non-treated and 93.3 and 1076.2 sec after treated, respectively. Electrical probing signals were 8.2 and 48.8 times with susceptible and resistance individuals after treated etofenprox, respectively. It was supposed that the resistance is more probings than susceptible population. After treated, total feeding time have more 6,728.9 sec on resistance than 965.5 sec on susceptible population. So, total non penetration time of susceptible population was 3,000 sec longer than resistance population.
Nymphal development, adult longevity, and oviposition of six different species of stink bugs were compared on seeds of a soybean cultivar, Taekwangkong, and two mung bean cultivars, Kyungseonnogdu and Jangannogdu in the insect rearing room (28±2℃, 16L:8D). Nymphs of six species of stink bugs normally developed on Taekwangkong seed. While nymphs of Riptortus clavatus, Halyomorpha halys, and Dolycoris baccarum developed on seeds of Kyungseonnogdu and Jangannogdu normally, all nymphs of Plautia stali, Piezodorus hybneri and Nezara antennata died after 4th instars on Kyungseonnogdu and after 3rd instars on Jangannogdu. Each instar period tended to be increased as nymphal stages were progressed. Nymphal period was shortest on Taekwangkong seed, followed by Kyungseonnogdu and Jangannogdu, irrelevant to stink bugs species. Emergence rate, adult longevity, and preoviposition period of 6 stink bugs were different depending on the reared seeds. Of 6 different species examined, Riptortus clavatus, Halyomorpha halys, and Dolycoris baccarum which fed on Jangannodu did not emerge, Plautia stali, Piezodorus hybneri, and Nezara antennata which fed on Jangannodu did not oviposit.
Woolly apple aphid, Eriosoma lanigerum, overwintered as adult or nymph stage on rootstocks, and crown- and root sucker in the soil. In an unsprayed apple orchard, the number of E. lanigerum colony started to increase from mid-April, showed the 1st peak between late June and early July, thereafter decreased followed by the 2nd peak in late July, and then again peaked in late September as the size in the 1st peak. In this orchard, the number of E. lanigerum colonies per tree did not exceed 3.5 colonies during the peak occurrence period, and was maintained around 2 colonies throughout seasons. In all seasons, parasitism of Aphelinus mali on E. lanigerum was much lower on root colonies than on aerial colonies that located on shoots and tree trunks above the ground. The parasitism of E. lanigerum was high in most orchards examined, showing parasitism of > 70% in maximum in most cases. In the laboratory bioassay for the mortality effects of several insecticides on E. lanigerum, fenitrothion, dichlorphos, machine oil, methidathion, thiacloprid, and imidacloprid showed 97.8, 96.8, 95.4, 91.5, 26.7, and 7.8% morality, respectively. Also, the adult emergence rates from A. mali mummies were 51.2, 72.6, 14.2, 3.5, 72.2, and 85.4% in the treatment of the above insecticides, respectively. Insecticides belong to neonicotinoid, which are newly developed to control aphids, showed low mortality against E. lanigerum. Fenitrothion and dichlorphos were effective on E. lanigerum control and had a low toxic to A. mali. Consequently, the insecticides should be useful in integrated pest management system for E. lanigerum in apple orchards.
Biological Characteristic of Obolodiplosis robiniae and insecticidal activity of some insecticides against larvae of O. robiniae were investigated. Egg was in oval shape, and its color was light orange and became red when close to hatch. Length of the major axis and the minor axis of egg was 0.4 ㎜ and 0.1 ㎜, respectively. Larval color was milky and size was 2.6 ㎜. Pupa was deep brown and its size was about 3.2 ㎜. Wing and abdomen of adult was black and reddish, respectively. Size of female adult was about 3.3 ㎜, and larger than male adult. Number of eggs in the ovary was 192.3±50.7. First emergence was from late April to late May, and second from late May to late June. Third emergence was from late June to late July. Newly emerged adult escaped from soil, and second and third emerged adult escaped directly from gall of Robinia pseudoacacia leaf. Egg parasitoid was identified as Platygaster robiniae and parasite rate was 51.6%. Among test insecticides, imidacloprid 10% WP and thiacoprid 10% FL showed very strong insecticidal activity against larvae of O. robiniae at 48h later after treatment.
Effect of four nematicidal herbal extracts (Daphne genkwa, Eugenia caryophyllata, Quisqualis indica and Zingiber officinale) and 3 acricidal herbal extracts (Pharbitis nil, Xanthium strumarium, and Desmodium caudatum) on entomopathobenic nematodes [Steinernema carpocapsae Pocheon strain (ScP) and Heterorhabditis sp. Gyeongsan strain (HG)], silkworm (Bombyx mori), and ground beetles (Synuchus sp.) were investigated in the laboratory and field. D. genkwa was highly toxic to ScP and HG (100% mortality) at the concentration of 5,000 ppm in X-plate. All the infective juveniles of HG were dead after 3 days by E. caryophyllata and Q. indica. The mortality of ScP and HG was below 10% by D. genkwa, D. caudatum, E. caryophyllata, Q. indica and Z. officinale at the concentration of 1,000 ppm two days after treatment while mortality of HG was 62.8% by D. genkwa at the concentration of 1,000 ppm in X-plate. However, 1,000 ppm had not effect on nematode survival and pathogenicity of ScP in sand column. On the contrary, E. caryophyllata had effect on pathogenicity of HG. Mean number of dead Galleria mellonella larva of HG was 0.5 in E. caryophyllata treatment. Q. indica did not effect silkworm reared on mulberry leaves at the treatment of 1,000 ppm in 10 days after treatment. However, there were 20.0 and 100% mortalities in the treatment of D. genkwa 3 and 10 days after treatment, respectively. The weight of silkworm was low in D. genkwa and did not pupate. The weight of pupa and cocoon were not different in E. caryophyllata, P. nil, Q. indica, X. strumarium and Z. officinale. D. genkwa, E. caryophyllata, P. nil, Q. indica and Z. officinale had no effect on ground beetles, Synuchus sp. in forest soil.
This study was conducted on the biological control effects of the natural enemy, Amblyseius cucumeris , against Polyphagotarsonemus latus. The broad mite moved to a new habitat after the carrying capacity of the preferred habitat on the upper leaf has been reached. Population dynamics between predator, Amblyseius cucumeris, and prey, P. latus, were quite well synchronized since the predator followed the movement of the prey. In predation test by Amblyseius cucumeris on P. latus, A. cucumeris fed on 8.8, 15.2, 27.0 and 30.3 individuals/day under the temperatures of 15, 20, 25, and 30℃, respectively. The A. cucumeris larva, protonymph, deutonymph, adult male, and adult female fed on 0.5, 1.6, 5.2, 3.8, and 27 individuals of adult P. latus per day, respectively, under 25℃ condition. The functional response curve of adult P. latus to the densities of A. cucumeris showed Holling’s Type Ⅱ curve. The consumption of prey by A. cucumeris increased with the prey density increase, but the consumption rate decreased. The critical ratio of predator vs. prey effectively to suppress (98% over) the population of P. latus by releasing A. cucumeris was 1:40 on red pepper.
By releasing predatory mite, Amblyseius swirskii Athias-Henriot, with 25 individuals per cucumber plant in a commercial greenhouse (1,600 ㎡), the population of western flower thrips, Frankliniella occidentalis (Pergande), was kept under the economic threshold level. The initial thrips population of 18.3 individuals per leaf decreased to 2.1 individuals per leaf after four weeks, while the number of A. swirskii reached to 16.6 individuals per leaf. It was also observed that at a point where the thrips occurred in high density of about 34.3 individuals per leaf, A. swirskii population built up on the lower part of cucumber plant first, but as time passed the predatory mites moved upward to the top of the plant and aggregated.
We have investigated some biological characteristics, such as survival rate and fecundity, of Orius laevigatus and Phytoseiulus persimilis, which have been stored at 6, 8, 10, 12±1℃, RH 70±10%, in dark condition. Overall, an appropriate temperature for cold storage was 10℃ for O. laevigatus and 8℃ for P. persimilis. 70% of adult O. laevigatus could survive for 36 days at 10℃. The O. laevigatus stored at 10℃ for 10~50 days laid 37.1～120.5 eggs. Since fresh (no storage) O. laevigatus laid 224.5 eggs, comparative fecundity of stored adults was 16.5~53.7% of normal fecundity. P. persimilis stored at 8℃ for 7~42 days with (food eggs of Tetranychus urticae) laid 11.9～18.9 eggs. Since fresh P. persimilis laid 26.4 eggs, comparative fecundity of stored adults was 45.1~71.6% of normal fecundity.
A commercial egg parasitoid, Trichogramma sp. Nabis101, was released into agricultural cultivating areas in Korea due to its wide host spectrum against insect pests. Moreover, an application technique has been recently developed to enhance its control efficacy by mixture treatment with a microbial control agent. Despite its expansion of commercial availability, any genetic identification on this commercial strain was not determined. Also, to meet inconsistent demands from consumers, the live parasitoids need to be stored without significant loss of their survival and parasitic activity. This study determined nucleotide sequence of internal transcribed spacer (ITS) of the wasp species. The identified ITS sequences indicate that this wasp species is most similar to T. brasiliensis. Optimal storage condition of this wasp required young parasitized stage at 10℃. Under these conditions, survival, sex ratio, longevity, and parasitic behavior were not much impaired for 5 weeks.
This study was conducted to investigate the total phenol contents, antioxidative activities and antibacterial activities of twenty species of entomopathogenic fungi. The total phenol content was highest in Aspergillus flavus (553.0±52.15 ㎍/g) and A. parasiticus (529.9±60.10 ㎍/g). On the other hand those in other strains were within the range of 26.6～121.9 ㎍/g. The antioxdative activity was shown in the most of strains and the highest DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical scavenging activity was observed in A. flavus (90.9±2.90%) and A. parasiticus (77.9±4.13%). This result indicated that the antioxidative activities were very correlated with the total phenol contents. The antibacterial activitiy was found in the every tested pathogenic bacteria. Especially, the antibacterial activity was strongest against Listeria monocytogenes and Escherchia coli.
Two entomopathogenic bacteria, Xenorhabdus nematophila and Photorhabdus temperata subsp. temperata, are known to be potent against the diamondback moth, Plutella xylostella, when the bacteria are injected into the hemocoel. This study investigated any pathogenic effect of their culture broth on P. xylostella by oral administration. Only culture broth of both bacterial species did not give enough pathogenic effects by the oral administration. However, when the culture broth was orally treated together with Bacillus thuringiensis (Bt), both cell-free culture broth significantly enhanced Bt pathogenicity against the 3rd instar larvae of P. xylostella. The culture broth was then fractionated into hexane, ethyl acetate, and aqueous extracts. Most synergistic effect on Bt pathogenicity was found in ethyl acetate extracts of both bacterial species. Thin layer chromatography of these extracts clearly showed that ethyl acetate extracts of both bacterial culture broths possessed metabolites that were different to those of hexane and aqueous extracts. These results suggest that the both entomopathogenic bacteria produce and secrete different factors to give significant synergistic effect on Bt pathogenicity.
About 50,000 hives of Bombus terrestris are used for pollination of tomato and other economical crops (fruit vegetables and fruit trees) in Korea. Therefore this study was conducted to find out the effective use of B. terrestris and its economic effect in the major beefsteak-tomato cultivation areas from February to August in 2008. The pollinating activities, rate of bite-mark and lifespan of B. terrestris"s hive according to all beefsteak-tomato varieties (Super Momotaro, Zeus42, Mascara and Super Sunroad, 500 ㎡, 9,600～12,000plants) were apparent by regular supplement of pollen (5～6g/3 days) to the hive of B. terrestris. Especially, Super Momotaro and Super Sunroad variety were most distinctive in the effects by regular pollen supplement.