• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.1
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• pp.128-134
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• 2014

Nesolynx thymus Girault (Hymenoptera: Eulophidae) is one among 20 hymenopteran parasitoids reported to attack the uzi fly, Exorista bombycis, which in turn infests the silkworm, Bombyx mori accounting a cocoon yield loss of 10-20%. A host of factors viz., age and size of host, age and size of parasitoid, availability of host, temperature and quality of host are reported to influence the reproductive efficiency of the parasitoids. In the present study an attempt was made to record the influence of foraging parasitoid density on their reproductive performance. Three day-old uzi pupae were offered to varying numbers (1 - 10) of 2 day old Nesolynx thymus adults for parasitization. The progeny production per pupa (84.44 - 132.77) increased significantly with increase in the number of foraging parasitoid adults (1 - 10) however, progeny production per female decreased. The sex ratio (M : F) (1:25.49 - 1:1.53) decreased significantly with increase in foraging parasitoid adults. The morphometric parameters except female abdomen width of first generation parasitoid showed significant negative correlation with number of foraging adults. However, correlation between the parasitoid size in first generation and their reproductive performance was nonsignificant.

• Korean journal of applied entomology
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• v.44 no.3 s.140
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• pp.237-241
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• 2005

Biological control of Indian meat moth (Plodia interpunctella ($H\"{u}bner$)) by iterative mass release of its larval parasitoid, Bracon hebetor Say, was tested in a large wheat elevator (diameter 8 m, height 41 m) containing 6,000 t of wheat. Adult parasitoids were released seven times from July 23 to September 3, 2002. The number of parasitoid adults per release time varied from 3,000 to 10,000 so that the total number released was 50,000. The moth population density in the parasitoid-released elevator was maintained at a level of ${\approx}30%$ compared to the moth population in untreated elevators.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.423-432
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• 2022

The mass-rearing system for Neodryinus typhlocybae as a biological control agent of Metcalfa pruinosa was established. Depending on the density of host nymphs and plants, the average number of cocoons produced by the parasitoids was 5-8 and 70-150 cocoons per leaf and sapling of mulberry, respectively. There is a significant difference in cocoon length between females (6.10-6.46mm) and males (4.20-4.62mm). Sex determination of cocoons before emergence will be helpful for efficiently releasing this parasitoid in fields. The parasitic rate of N. typhlocybae at the semi-field condition was on average 13-17%. The release number of this parasitoid did not affect parasitism. Nevertheless, the population growth rate of M. pruinosa was reduced by increasing the release number of N. typhlocybae. The parasitoid offspring's sex and bivoltine were influenced by the host age. On young host nymphs, the bivoltine portion of parasitoid increased. When parasitized on 4^th or 5^th nymphs, the offspring's female ratio of N. typhlocybae increased. This result may be useful for potentially controlling mass rearing production of parasitoid.

• Korean journal of applied entomology
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• v.34 no.2
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• pp.147-153
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• 1995

The occurrence of Oriental Tobacco Budworm (OTB), Helicoverpa assulta (Guenee), larvae in early and late planted tobacco fields showed tow or three distinct peaks. The parasitoid, Campoletis chlorideae Uchida, occurred for a short period with one peak following th second peak of OTB in early planted fields. However, in late planted fields, the parasitoid occurred as long as the OTB larvae were abundant. The OTB larval density was higher in late planted fields than in early planted fields. Among four varieties of tobacco, the OBT larval occurrence was relatively high on NC-744 throughout the season. However, more parasitoid cocoons were found in Burleyf-21 and NC-82. The seasonal occurrence of the larval parasitoid, C. chlorideae, assessed by an OTB larval release and recovery method, continued from late June to early September and relatively higher abundance was noticed from early July to late August. In a field cage evaluation of C. chlorideae as a biological control agent of OTB larvae, higher rate of C. chlorideae release (4 females/2$\m^2$) resulted in higher larval parasitism (86.1%) and less leaf damage (8.7%) in tobacco. The leaf damage by OTB larvae was significantly high in the untreatment plot (23.2%) and the lowest damage (1.6%) was recorded in the chemical treatment plot.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.256-260
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• 2006

This study was conducted to investigate the effect of parasititoids on the density-fluctuation of the pine needle gall midge, Thecodiplosis japonensis. The density of T. japonensis and its parasitoids was observed by emergence trap in pine forest in Namsung-dong, Keumho-eup, Youngcheon-shi, Kyeongsangbuk-do, Korea, from 1986 to 2005. After 1987, density fluctuations of adults pine needle gall midge and its parasitoids showed similar trends and density of parasitoids was dependent on density of host population. Sex ratio of the pine needle gall midge, T. japonensis, was female-biased and had some variations in according to years. These trends were similar to those of parasitoid populations and sex ratio of Inostemma seoulis was more female-biased than that of I. matsutama. T. japonensis adults emerged in the field from May 16 to July 27 and the peak of emergence was between late May and early June. The adults of Inostemma matsutama emerged from May 16 to June 11 (peak between late May and early June), whereas those of Inostemma seoulis emerged from June 9 to July 27 (peak: late June).

• Korean journal of applied entomology
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• v.40 no.4
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• pp.301-307
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• 2001

The pine needle gall midge (PNGM), Thecodiplosis japonensis Uchida et Inouye, is a serious pest in pine forests in Korea. Since the first report of PNGM infestation in Korea in 1929, the infestation area has been expanded gradually. In 1975 the distribution of PNGM and its parasitoids were surveyed throughout several infested areas in Korea. Annual survey has been made for the rates of gall formation by PNGM and parasitism by its parasitoids at the monitoring sites including newly infested area in 1975 since 1980. These data were used to examine the relationship between PNGM and its parasitoids for newly invaded areas. The gall forming rate of PNGM and the parasitism by the parasitoid were 34.8 and 1.9% in 1975, respectively, while the gall forming rate and the parasitism were 20.7 and 8.9% in 1985, respectively. The relationships of densities between PNGM and its parsitoid were weak in the early stage of dispersion, but the density of parasitoid was with an asymptotic increase along with PNGMs density increase during the observation period for 10 years.

• Korean journal of applied entomology
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• v.40 no.2
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• pp.97-103
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• 2001

The rate of gerbera (Gerbera jamesonii Bolus.) leaf damaged by Liriomyza trifolii larvae was lower than that by adults. The adults began to be attracted to yellow sticky trap immediately after transplanting and increased gradually up to early August followed by low population density from middle to late August. In the second year, adults began to be attracted from late April after transplanting and increased abrubtly from middle May and the high density was maintained till early truly. The density decreased, however, from middle July, and then followed by the high density again early September and late October The seasonal fluctuations of larva and pupa were similar to that of adults and the peaks of pupa occurred one week later than that of larvae. Larva infected by parasitoid were observed 4 weeks after transplanting. Parasitism was 65% in average from early July to late August but decreased to 50% from early September. Number of trapped adults was the highest in the yellow sticky trap among the five different colour raps. Catches at 30~60 cm above soil surface were significantly greater than that at 90 cm.

• Ecology and Resilient Infrastructure
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• v.4 no.1
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• pp.44-53
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• 2017

In order to investigate the response in fauna and biological communities of terrestrial insects to the vegetation encroachment on the sandbar, species composition, species diversity, functional species traits and community structure of land-dwelling insects sampled by a pit-fall trap were compared at the bare and vegetated sandbar of a typical sand-bed stream, the Naeseong Stream, Korea. Species diversity of the insects was increased but their density was decreased as the riparian vegetation encroached at the sandbar. In particular, indicator species of bare sandbar such as Cicindela laetescripta and Dianemobius csikii, were found at the bar sandbar. The insect communities were clearly classified at the bare and vegetated sandbar according to coverages of riparian plants. The food web of the bare sandbar was composed of detritus - detritivore and scavenger - predator consisted mainly of Coleoptera. On the other hand, the food web of the vegetated sandbar was composed of plants - sucking and chewing herbivore - parasitoid and predator. These results showed that biodiversity of terrestrial insects was increased, food web was changed from grazing to detritus food chain, and insect fauna specific bare sandbar disappeared as the riparian vegetation invaded on the sandbar of a sand-bed stream.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.641-649
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• 2022

Leaf-rolling moths were collected from soybean fields and identified as Matsumuraeses falcana and Matsumuraeses phaseoli by comparison with laboratory-reared species based on the nucleotide sequence (658 bp) of the mitochondrial cytochrome c oxidase 1 subunit gene (COX1). Ten haplotypes with 0.15-0.46% genetic distance from each other in COX1 were found in 47 samples of M. falcana, in which haplotype A was dominant (approximately 70%). Only one type of COX1 was found in 30 samples of M. phaseoli, and its sequence showed 4.11-4.61% genetic distance from those of M. falcana. Amino acid sequences translated from COX1 were identical in all samples of both species, and they showed synonymous substitutions. Larvae of both species caused damage to soybean leaves and pods and co-occurred simultaneously in the field. The average density of M. falcana was 1.5 times higher than that of M. phaseoli. The results clearly indicate that soybean was the host plant for both species. In addition, Elodia flavipalpis (Diptera: Tachinidae) was found to be a larval parasitoid of Matsumuraeses sp. through identification of the COX1 gene.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.155-160
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• 2023

In this study, we investigated the functional response of aphid parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae), on the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). Three carbon dioxide concentrations (400, 600, and 1000ppm) and seven host densities (2, 4, 8, 16, 32, 64, and 128) were used during a 24-h period. A type III functional response for A. colemani was fit separately for each CO₂ concentration. The estimated handling time (Th) under elevated CO₂ (600 ppm and 1000 ppm, 0.015 and 0.014 day) was shorter than that under ambient CO₂ (400 ppm, 0.017 day). The proportion of aphids that were parasitized showed the similar characteristic curve under three CO₂ concentrations. The highest parasitized rates for A. colemani were 0.57, 0.61, and 0.70 at 16, 32, and 32 aphid density under 400, 600, and 1000ppm, respectively. Although handling time of A. colemani was influenced by elevated CO₂ concentrations, the attach rate was not changed much.