• Korean journal of applied entomology
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• v.24 no.1 s.62
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• pp.11-14
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• 1985

Some experiments were conducted to evaluate the aphidivorous activity of coccinellid beetle, Harmania axyridis Pallas. Experiments were carried out using with laboratory reared beetles and two aphid species(Aphis gossypii and Myzus persicae). Factors referred in the study of aphidivorous activity were the age of beetle, aphid species, temperatreu and illumination time. The aphidivorous activity was greatly different in relation to aphid species, developmental stages of the beetle, and the temperature. The 3rd and 4th instar larvae consumed more aphids than the 1st and 2nd instar larvae. Though the beetles consumed more number of cotton aphid, total weight of aphids consumed the more or less the same. Aphidivorous activity of the 1st to 4th instar larvae increased with a rise in temperature and adult activity was relativel high at $20^{\circ}C$ and low at $15^{\circ}C\;and\;30^{\circ}C$. The aphidivorous activity of the beetles was not influenced by the illumination period under the conditions given in this experiments, however, seem to require further study.

• Korean Journal of Agricultural Science
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• v.24 no.1
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• pp.21-28
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• 1997

For the investigation of occurrence of insect pests and their natural enemies, total number of 353 controlled agricultural farms were visited and surveyed. In the 73% of total controlled agricultural farms, 52 species insect pests were occurred. Among these pests, the western flower thrip (Frankliniella occidentalis), the two spotted spider mite (Tetranychus urticae), the greenhouse whitefly (Trialeurodes vaporariorum), the cotton aphid (Aphis gossypii) and the green peach aphid (Myzus persicae) were mainly occurred. On the other hand, small numbers of natural enemies were sustained in 40 controlled agricultural farms, which was 11% and 17% of visited farms and pest occurred farms, respectively. For the most part of collected natural enemies, there were included in Braconid, Coccinellid and Anthocorid, as 63, 20 and 8% of them, respectively.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.210-217
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• 2006

The study was carried out to select the effective adjuvant as a photostabilizer for acetamiprid 5% SL(soluble concentrate) and to find its optimum content by using chemical and biological methods. Adjuvants used for the study were KS1 and KS2. Photodegradation test, insecticidal efficacies and residual analysis for the study were investigated. Although photodegradation rate of acetamiprid SL was decreased by addition of KS1 and KS2, the difference between KS1 and KS2 was not significant. As KS2 showed better efficacies against the cotton aphid (Aphis gossypii) and higher amount of residue on pepper than KS1, KS2 was selected as a photostabilizer for acetamiprid SL. Acetamipid SL with KS2 showed lower photodegradation rate, better efficacies against the cotton aphid (Aphis gossypii) and higher amount of residue on pepper as content of KS2 in acetamiprid SL was decreased. Therefore, it was concluded that the optimum content of KS2 was 0.1%. These results have demonstrated that the selected adjuvant could be used to enhance insecticidal activity and reduce spay dose of insecticide by protecting its photodegradation.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.397-403
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• 2012

This study compared the Aphelinus varipes and Aphelinus asychis in terms of how they parasitized the cotton aphid, Aphis gossypii and green peach aphid, Myzus persicae. Host-feeding, parasitism, emergence, the proportion of females and development time were all studied at 15, 20, 25 and $30^{\circ}C$ in controlled climate cabinets. When A. gossypii were provided for the two aphid parasitoids, the number of aphids killed by host-feeding for A. varipes (5.4 and 9.7 aphids) at $15^{\circ}C$ and $25^{\circ}C$ was higher than those for A. asychis (2.0 and 2.9 aphids). At $15^{\circ}C$ and $30^{\circ}C$, the parasitized A. gossypii were higher in A. varipes (11.1 and 21 aphids) than in A. asychis (7 and 12.3 aphids). The emergence rate was also significantly different between A. varipes (83.3%) and A. asychis (69.4%). The proportion of females was higher for A. asychis (75.2 and 73.9%) than for A. varipes (19.5 and 48.6%) at $15^{\circ}C$ and $30^{\circ}C$, respectively. No significant differences were found in development time between the two parasitoids. When M. persicae were provided for the two parasitoid species, the host-feeding number and the emergence rate of two parasitoids were not different at all four temperatures. The M. persicae were more highly parasitized by A. varipes (12.1 and 17.1 aphids) than by A. asychis (6.1, 10 aphids) at 20 and $25^{\circ}C$. The proportion of females for A. varipes (65.3 and 90.0%) was higher than that for A. asychis (34.4 and 78.8%) at $15^{\circ}C$ and $25^{\circ}C$. The development time from oviposition to the adult emergence of A. varipes (19.9 d) was significantly longer than that of A. asychis (16.5 d) at $20^{\circ}C$. Development times decreased with increasing temperature for both in two parasitoid species.

• Korean journal of applied entomology
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• v.39 no.4
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• pp.251-258
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• 2000

These studies were conducted to investigate the prey consumption and suppression of cotton aphid and green peach aphid by Chrysopa pallens Ramber as a predator. The 3$^{rd}$ instar of C. pallets fed on 29.8, 77.9, 133.6, and 155.7 individuals of apterous Aphis goussypii Glover a day at 17,22, 27, and 32$^{\circ}C$, respectively. A preovipositing female fed on 73.1 individuals, ovipositing female on 86.6 individuals, and adult male on 69.7 individuals of apterous Myzus persicae (Sulzer) a day at the 27$^{\circ}C$. The functional response curve of the larvae and adults of C. pallens to the densities of A. gossypii indicated Helling’s Type II: the consumption of prey by the C. pallens increased with the prey density but the consumption rate decreased. The attack rate of 3rd instar of C. pallens was the highest among the 2nd instar, 3$^{rd}$ instar, adult male and adult female, and handling time was the shortest. The critical ratio of the predator vs. the prey to effectively suppress the population of A. gossypii by releasing C. pallets eggs was 1 : 4 on red pepper and egg plant, and 1 : 3 on cucumber. Release of second larval stave of C. pallens at the ratio of 1 : 30 of the predator vs. the prey controlled satisfactorily A. gossypii on red pepper, and 1 : 20 on cucumber and tomato. The three-times introduction of the eggs of C. pallens was as effective as four applications of insecticides from mid-June to late September.r.

• Korean journal of applied entomology
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• v.50 no.1
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• pp.79-82
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• 2011

Biological control of Aphis gossypii by natural enemies was carried out in watermelon from April to June. Aphidius colemani was released 3 times at rate of $2/m^2$ to control A. gossypii(April 24, May 8, and May 22 in 2007). In A. colemani-released plots, A. gossypii showed low population density of < 0.6 per leaf with the highest parasitism of 57.2%, and 2.0~10.6% in the percentage of leaves with aphids. In control, the population of A. gossypii kept on increasing from early May and reached 653.2/leaf on may 29.

• Korean journal of applied entomology
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• v.38 no.1
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• pp.29-33
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• 1999

Orius strgicollis Poppius is an endemic natural enemy of thrips recently found. To estimatethe optimum temperature for rearing in laboratory, development and oviposition of 0. strigicollis wasstudied at 15, 20, 25 and 30$^{\circ}$C with a 16L : 8D photoperiod and 60-80% RH. Cotton aphid, Aphisgossipyii, was supplied as prey. Total number of eggs laid per female ranged from 39.1 to 68.5 with thehighest at 25$^{\circ}$C. Adult longevity decreased as temperature increased, and the reverse was true for eggsurvivorship. Survivorship of larvae was 26.7,43.3, 76.7 and 46.7% at 15, 20, 25 and 30$^{\circ}$C, respectively.Duration of eggs and larvae at tested temperatures ranged from 3.4 days to 18.9 days and from 9.4 days to45.6 days, respectively. A linear regression model could describe development of the predator as afunction of temperature (R2=0.949-0.997). The lower developmental threshold temperatures for egg,larvae, and total immature stage were estimated to be 12.4, 11.4, and 11.6"C, respectively.6"C, respectively.vely.

• Korean journal of applied entomology
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• v.39 no.2
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• pp.59-71
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• 2000

The Asian ladybird, Harmonia axyridis, might be distinguished in biological control agents for the several aphid species in the greenhouses as well as in the fields. Therefore, feeding behavior and predacious capability characteristics were observed. When ladybirds are searching for aphids as their preys, they use the maxillary palpus as contact reception. Otherwise, most of aphids escape from walking or chewing ladybird to other place (mainly move to near-by leaf, or fall down to the under-leaf or ground) instead of plant sucking. Consumed time of ladybirds for searching and feeding prey were significantly different and dependent on their development stage. The ladybird adults ate about 120 green peach aphids and 257 cotton aphids per day. The 3rd instar of ladybirds ate 2,420 and 2,750 eggs of greenhouse whitefly on the cucumber and tomato leaf, respectively, as well. However, ladybird instars taken greenhouse whitefly eggs could not continuously develope to adult, on the other hand, ladybirds taken aphids were normal condition.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.35-41
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• 2003

Anthocorid bugs (Orius spp.) are known as polyphagous predators preying on thrips, aphids, mites, eggs of small insects and whiteflies. This study was conducted to investigate the nym-phal development, survival rate, longevity of Orius sauteri adult and oviposition, when nymphs of western flower thrips (Frankliniella occidentalis) and cotton aphid (Aphis gossypii), and eggs of two-spotted spider mite (Tetranychus uritcae) were fed as diets. Nymphal development of female/male O. sauferi fed with F. occidentalis, A. gossypii and T urticae took 12.2/12.8, 13.0/l3.2, and 17.9/17.8 days at 27$^{\circ}C$, respectively, Survival rates during nymphal development were 96.4, 78.4, 73.8%, longevity of female/male adults were 55.9/51.0, 30.2/30.8, and 25.8/25.1 days, and daily oviposition were 5.6, 4.1, and 1.9 eggs, respectively. Oviposition of O. sauteri fed with F. occidentalis usually began 3-4 days after emergence at 27$^{\circ}C$, and reached at its peak of 7-8 eggs female day 20-40 days after emergence.

• Korean journal of applied entomology
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• v.48 no.1
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• pp.87-94
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• 2009

KNI3126 which is the eco-friendly material made by plant extracts - neem and matrine - have been evaluated for efficacies against 6 main pests and toxicity on natural enemies. Insecticidal efficacies of KNI3126 against plant hopper were above 95% at 5 days after treatment (DAT), whereas pesticidal effects against the cotton aphid were above 95% at 3 DAT and slightly decreased at 5 DAT. Insecticidal efficacy against the palm thrips resulted in lower control value as 68.1% than that of chemical insecticides. KNI3126 showed more than 95% control value against diamond back moth, suggesting that it could suppress the population of pest hard to control as eco-friendly material. Mortalities against two-spotted spider mite were about 80% at 1 DAT and over 90% at 5 DAT, respectively. For evaluation of the toxicity on natural enemies, effect against predatory natural enemy was classified as moderate selective toxicity based on the criterion of International Organization of Bio-Control (IOBC), whereas against parasitic natural enemies was found to be relatively safe. Repellent effect was weak against plant hopper, but strong against two-spotted spider mite. In the toxicity test for safety, KNI3126 was classified as the lowest level at acute oral, acute dermal and fish toxicity test and did not induce the irritancy at skin irritation test and eye irritation test.