On the development and reproduction of four major agricultural insect pests including B. tabaci, M. persicae, P. xylostella and T. urticae, electron-beam was irradiated with different doses of 30, 50, 70, and 100 Gy. The effect of electron beam was investigated with respect to the longevity, egg hatching, emergence, and fecundity. Eggs hatching of B. tabaci, P. xylostella and T. urticae were more inhibited as increased irradiation doses. Especially B. tabaci and T. urticae eggs were perfectly inhibited to hatch at a dose of 100 Gy. However, these pests showed no lethal effect on the nymph/larva, pupa, and adult stages. When irradiated on the eggs of B. tabaci, P. xylostella and T. urticae, the emergence was inhibited from nymphs/larvae to adults. Individually, B. tabaci emerged adult did not lay eggs at a dose of 70 Gy. Besides, fecundity of P. xylostella emerged adult decreased at a dose of 100 Gy. On the contrary, irradiation did not affect the longevity of P. xylostella adult. When irradiated on B. tabaci, P. xylostella, Myzus persicae and T. urticae nymphs/larvae, emergence was inhibited at doses of 70 and 100 Gy, and decreased the fecundity and inhibited the hatching of laid eggs. However, the longevity of adults did not affect

This study was performed to investigate attraction effect of six plant essential oils and to confirm their electrophysiological response against Lycorma delicatula. Among the tested oils, spearmint oil (94.1%) significantly attracted L. delicatula at a dose of 1.25㎕/cm2 by using an olfactometer. In dose response to spearmint oil, a dose of 2.5㎕/cm2 was very effective. GC-MS analysis revealed that the active components responsible for the effective attraction effect of spearmint oil were carvone (70.6%) and limonene (54.8%). Of the two active components, carvone was more significant than limonene with reference to attraction activity against L. delicatula. Analysis by GC-EAD showed, major components of spearmint oil that elicited response in L. delicatula antennae, indicating the potential role of the essential oil as attractant that determine the choice of the attraction material. In the field test, spearmint oil exhibited attraction effect up to 5 days. This effect was different in accordance with test places and treatment dose.

To control pest of Brassicaceae leafy vegetable(leaf broccoli, Red Mustard Leaf, Tatsoi) which grows at vinyl house in IKSAN, Jeollabuk-do, the non-treatment was set as negative control, and treatment was divided into Parasitic natural treatment group and general treatment group. And incidence density of pest was surveyed and control effect was analyzed. As a result, in case of spring plants, the leaf damage ratio was decreased by 31% in Leaf broccoli, 30% in Red mustard leaf and 27% in Tatsoi compared to untreatment. In case of autumn plants, it was decreased by 32%, 41% and 17% respectively. The key pests were Plutella xylostella, Pieris rapae, Myus persicae Sulzer, Thrips palmi and Striped cabbage flea-beetle. Compared with the untreatment, the incidence density of each was significantly controlled. Other pests include Spodoptera exigua, Macdunnoughia purissima, Macdunnoughia purissima which showed high incidental density sometimes. In case of spring plants, the number by treatment was increased by 117% in Leaf broccoli, 85% in Red mustard leaf and 1,000% in Tatsoi. In autumn plants, it was increased by 132%, 257% and 1,077% respectively. The used Parasitic natural and eco-friendly materials were Cotesia glomerata, lacewing, ladyburg, Orius laevigatus, Encarsia formosa, Entomopathogenic nematode, Chungjigi and Togkaki. During early development of each pest, the Parasitic naturals were grazed 2~3 times at the interval of 7~10days. During the peak time, eco-friendly materials were sprayed 1~2 times. Based on this, comprehensive management model was drafted by period for each Brassicaceae vegetables pest.

To control Thrips tabaci in Korean leek and green onion which grow at vinyl house in IKSAN, Jeollabuk-do, the non-treatment was set as negative control. In general treatment group, 120 mesh gauze was installed on the side window after planting(May, 2nd) and, in spring, Orius strigicollis (1.0/m2) was grazed 3 times every 7 days from mid of May which is early development stage and In the mid of June, which is the peak stage, plant extracts were sprayed one time. In autumn, O. strigicollis was grazed 3 times every 7 days from mid of September which is early development stage, and in the mid of October, which is the peak stage, plant extracts were sprayed one time. The result shows that the leaf damage ratio was decreased by 22% in Korean leek and by 27% in green onion compared to the untreatment. And the control value of Thrips tabaci shows 78.7% in korean leak and 90.6% in green onion. The density control effect of Thrips tabaci was significantly controlled under max 6.2/plant in general treatment group compared max 25/plant in the untreatment and this result was similar in green onion. The yields by general treatment was increased by 85% in Korean leek and 56% in green onion, compared with non-treatment yields, which was 900kg/10a in Korean leek and 1,287kg/10a in green onion.

Entomopathogenic fungi are widely available as biological control agents for controlling insect pests in agriculture and forestry. The fungal culture broth contains various pathogenesis-related components such as blastospores, mycelium and insecticidal enzymes such as chitinase, Pr1- and Pr2-proteases, which have been reported to play an important role in penetrating insect cuticles. In this study, we tried to evaluate the utility of culture broth from Beauveria bassiana SFB-205 to control lepidopteran pests. High level of insecticidal activity correspond to over 90% of mortality were observed when the culture broth of B. bassiana SFB-205 was inoculated to the Spodoptera litura larvae together with the B. thuringiensis K1. The freeze-dried culture broth showed synergistic effects in insecticidal activity against larvae of S. exigua and S. litura when treated with corresponding baculoviruses, SeNPV and SlNPV. Active ingredient of the B. bassiana SFB-205 culture broth was identified to chitinase, which have truncated form by insertional mutation compared to previously reported chitinases.

Bacillus thuringiensis 1-3 (Bt 1-3) which was isolated from a Korean soil sample showed high insecticidal activity against Aedes aegypti as well as Plutella xylostella. The isolate was determined to belong to ssp. aizawai (H7) type by an H antiserum agglutination test and produced bipyramidal-shaped crystal proteins with a molecular weight of 130 kDa. PCR analysis with cry gene specific primers showed that Bt 1-3 contained cry1Aa, cry1Ab, cry1C, cry1D and cry2A gene, differing from spp. aizawai (reference strain) which contains cry1Aa, cry1Ab, cry1C and cry1D. We modified the plasmid capture system (PCS) to clone plasmid from Bt 1-3 through in vitro transposition. Fifty-three clones were acquired and their sizes were approximately 10 kb. Based on the sequence analysis, they were classified according to similarities with four known Bt plasmids, pGI3, pBMB175, pGI1 and pGI2, respectively. One of pGI3-like clones, named as pBt1-3, was fully sequenced and its 20 putative open reading frames (ORFs), Rep-protein, double-strand origin of replication (dso), single-strand origin of replication (sso), have been identified. The structure of pBt1-3 showed high similarity with pGI3 which is one of rolling-circle replication (RCR) group VI family.

Baculovirus chitinase gene (ChiA) is a late gene and is essential for liquefying host insect at the late stage of infection for its hydrolyzing chitin function. In previous report, baculovirus ChiA can offer many interseting new opportunities for pest control. Recently, a putative chitinase gene (ChiA) was identified in the Spodopter litura nucleopolyhedorvirus (SlMNPV-K1) genome. The open reading frame (ORF) contains 1,692 nucelotides (nt) and encodes a protein of 563 amino acids (aa) with a predicted molecular weight of 62.62 kDa. To conform the insecticidal activity of ChiA from SlMNPV-K1, we constructed a baculovirus transfer vector, pBac-SlChiA, and this transfer vector was co-transfected with the bApGOZA DNA into sf9 cell to generate corresponding recombinant viru which designed Ap-SlChiA. Western blot analysis indicate that SlMNPV-K1 ChiA was successfully expressed. We found the chitinase activity of recombinant virus was enhanced 53% than wide type AcMNPV by chitinase assay, and the recombinant virus showed higher evidently insecticidal activity against 3rd instar larvae of Spodotera exigua than wide type AcMNPV (4.5 time). These results suggested that the chitinase gene from SlMNPV-K1 could be successfully applied to improve pathogenicity of bauclovirus

Autographa californica nucleopolyhedrovirus (AcMNPV) has a large doublestrand DNA genome of approximately 134 kbp and comprises 156 open reading frames (ORFs). To elucidate DNA replication cascade of AcMNPV, we developed a novel baculovirus genome that can be maintained in Escherichia coli as a plasmid and can infect susceptible lepidopteran insect cells. This genome, named bAc-MK, contains a mini-F replicon and a kanamycin resistance marker. Using a convenient Tn7 transposon-based system, pPCS-S, which contains an ampicillin resistance gene, 56 single ORF-truncated mutants were generated by random insertion into bAc-MK genome. These single ORF-truncated mutants were independently transfected into Sf9 cells to verify viral replication. Interestingly, both lef-1 and p48 knockout mutants showed normal viral replication in infected cells, which are reported to essential for viral replication. These results suggest that these single ORF-truncated mutants are useful for elucidation of viral replication cascade.

Through an application of plasmid capture system (PCS) to Bacillus thuringiensis plasmid DNAs, we acquired 21 polymorphic clones of putative genomic DNA of bacteriophage. The genome size of phage 1-3 (PhBT1-3) was determined to be 46,517 base pairs (bp) with 35.43% G + C content and 83% coding region. Sixty-five putative open reading frames (ORFs) with more than 50 codons were found in the new phage genome. In accordance with this genome finding, the phage particles and its DNA were confirmed from the supernatant of B. thuringiensis 1-3. Morphological characterization and infectivity assay demonstrated that PhBT1-3 belongs to the family Siphoviridae and it showed infectivity to three B. thuringiensis type strains, galleriae, entomocidus, and morrisoni. Based on these results, we screened the existence of phages in B. thuringiensis type strains by PCR with terminase small subunit-specific primers. Ten of 67 type strains showed PCR products and the similarity of those putative amino acids was more than 70%. Furthermore, we verified the existence of various shaped phages from the supernatants of 10 B. thuringiensis type cultures. In conclusion, we characterized a putative genome of phage, PhBT1-3 from B. thuringiensis 1-3, and confirmed the distribution of phages in the group of 67 B. thuringiensis type strains.

A new Bacillus thuringiensis isolate 19-22 (Bt 19-22) exhibited high anti-fungal activity against barley powdery mildew (Blumeria graminis f. sp. hordei). The cry gene content of Bt 19-22 comprised cry1Aa, cry1Ab, cry1Ac and cry1D which have high insecticidal activity against lepidopteran larvae. We tried to confer a dipteran insecticidal activity to Bt 19-22 for constructing a recombinant strain which has multiple functions, anti-fungal and dual insecticidal activity. The insecticidal cry11Aa gene of B. thuringiensis was constructed under cry1Ac promoter in an E. coli-B. thuringiensis shuttle vector (pPro11A). The plasmid, pPro11A was introduced into Bt 19-22 isolate by electroporation and four transformants which had different cry gene contents were identified by PCR with cry11Aa and cry1-type specific primers. Among them, a Bt 19-22 transformant (11A/19-22 No. 7) expressed Cry11A protein (approximately 70 kDa) successfully without change of its inherent characteristics such as Cry protein expression and antifungal activity. The insecticidal activity of 11A/19-22 No. 7 was checked against Plutella xylostella and Culex pipiens. These results suggests that the recombinant strain shows dual insecticidal activity against lepidopteran and dipteran larvae as well as antifungal activity.

The hemipteran whitefly Bemisia tabaci (Gennadius) is one of the most destructive pests damaging more than 600 agricultural crop species worldwide. The B and Q biotypes are most widely spread in Korea but they are not distinguishable based on morphological characters. Carboxylesterase 2 (Coe2) was determined to be 5.9 times more expressed in B biotype compared to Q biotype. Comparison of deduced amino acid sequences of Coe2 (595 a.a.) showed a total of 3.85% polymorphisms between B and Q types but no differences in major active sites. Quantitative real-time PCR revealed that both B and Q biotypes possess a single copy of coe2, suggesting that the overexpression of Coe2 in B biotype is likely due to overtranscription. To determine the putative role of Coe2 in insecticide tolerance, esterases were separated by native isoelectric focusing (IEF) and inhibited by various insecticides. The putative Coe2 band was apparently inhibited by pyrethroid and organophosphate insecticides, but not by imidacloprid. These findings suggest that overexpression of Coe2 confers chemical defense against pyrethroid and organophosphate insecticides, perhaps by sequestration.

The toxicity of methanol extract from 28 plants toward four agricultural insect pests were examined using contact toxicity bioassay with spray methods. At a concentration of 1,000 ppm Achyranthes japonica whole body was observed strong activity against Myzus persicae. Paeonia lactiflora root and Corydalis turtschaninovii rhizome methanol extract were observed strong activity toward Tetranychus urticae. Catalpa ovata leaf and Ginkgo biloba leaf and stem methanol extracts were revealed high activity toward Nilaparvata lugens. Actium lap root methanol extract was observed moderate activity against Plutella xylostella. High or moderate insecticidal activity of plant extracts were listed in Fig.1. These plant resource, particularly plant methanol extract or insecticidal constituents, merit further as potential insect pest control agents or leads because of their great activity as a insecticide.

The rice leaf roller, Cnaphalocroci smedinalis Guenée (Lepidoptera: Pyralidae) is a leaf-feeding pest of rice world-widely distributed. For better understanding of the pest insect, geographic sequence variation of the species were performed using the mitochondrial A+T-rich region, with the samples collected from seven Korean and six Chinese localities. A total of 94 haplotypes obtained from 187 individuals showed the length variation, ranging from 339 bp to 348 bp. The maximum divergence of 4.57% appears to evidence a substantial sequence variation, indicating the applicability of this molecular marker to the study of geographic variation. Overall, a high per generation migration ratio (Nm = 3.67742 ~ infinite), a low level of genetic fixation (FST = 0 ~ 0.11969), and no discernable isolated population were noted in the most C. medinalis populations. AMOVA analysis to find out allocation of genetic variability of C. medinalis populations has shown allocation of majority of variation to the within-population, rather than among-populations and between-region, suggesting that the C. medinalis populations in both China and Korea are largely well connected. This result is consistent with current knowledge of the dispersal ability of the species. The structure analysis of the A+T-rich region has shown that the typical structural elements found in other lepidopteran insects also is well preserved in the C. medinalis A+T-rich region (i.e., a poly-T stretch and a microsatellite-like A/T repeat).

The perilla leaf pyralid moth, Pyrausta panopealis Walker (Lepidoptera: Pyralidae), is a serious pest damaging to leaf perilla. In order to establish the life parameters of P. panopealis for eventual purpose of control, the developmental span of each stage were investigated under five temperature regimes (20℃ ~ 3 0℃). In addition, the larvicial efficacy of several on-the-market environment-friendly agricultural materials (EFAMs) was tested. The width of head capsule at each larval stage measured to be the mean of 0.21, 0.32, 0.47, 0.64, and 0.98 mm, respectively. The larval period of P. panopealis was longest at 20ºC as 27.0 days and shortened as temperature goes up to 30ºC as 11.3 days. Survivorship of the larval P. panopealis was the highest at 30ºC as 80%, whereas that of other temperatures ranged from 40% (20ºC) to 62.5% (27.5ºC), indicating that the P. panopealis appears to favor higher temperature. In addition to larval period, the duration of egg, prepupa, and pupa stages also shortened as temperature goes up, whereas the duration of adult stage increased as temperature goes up: from 4.1 days at 20 ºC to 6.1 days at 30ºC. After the perilla leaf pyralid moths were successfully stabilized in indoor environment the larvicidal efficacy of the ten EFAMs that were previously selected from the result of other moth species was tested aimed at 4th instar larvae for 48 hrs. Seven of the ten tested showed more than 90% of mortality within 12 hrs and reached nearly up to 100% within 24 hrs, but the remaining three showed less than ~70%.

Cuticular hydrocarbons (CHCs) were analyzed using GC and GC-MS, and compared with developmental stages of the bean bug, Riptortus pedestris. Carbon numbers on each developmental stages differed from 14-19 in eggs to 4th nymph, 25 in 5th nymph, and over 30 in last nymph that until adult emergence. Carbon numbers are increased to 16-17 carbons over time in newly emerged adults, 18-22 in 1 and 3 days after emergence, respectively; 23-27 in 6 days after emergence; approximately 30 in over 10 days after emergence. Carbon numbers increased as passed days after emergence. Riptortus pedestris consisted of n-nonacosane on almost all developmental stages, and followed by n-hentriacontane and 13,17-;15,19-demethyltritriacontane. Eggs, however, consisted of unknown compounds with high proportion and followed by n-heptacosane, and newly emerged adults also has a high proportion of n-heptacosane. From the above results, CHCs on developmental stages of the bean bug consist of n-alkane with saturated hydrocarbons (36-65 %), followed mono- or di- methylalkanes. However, newly emerged female and male adults mostly consisted of methyl-alkane. The major constituents of CHCs on the developmental stages of Riptortus pedestris is differently proportioned, but hardly showed the difference in their composition.

The black soldier fly (BSF), Hermetia illucens, is known as a beneficial insect and feeds on organic materials derived from animals and human, resulting in reduction of food waste and conversion of organic materials. Despite of a lot of study about the BSF, there is a less information about composition of digestive enzyme of the BSF larva. Experimentally, there is no evidence about characterization of digestive enzyme of the BSF. We investigated biochemical property of digestive enzyme released from the salivary and gut of the BSF. Through digestive enzyme assay, we found that the BSF has amylase, lipase and protease activity in gut extracts, resulting in that the BSF belong to polyphagous insect group. In the BSF gut, trypsin-like protease activity showed one peak at various temperature and pH condition. This result means the BSF has probably a similar form of trypsin-like enzymes. On study of comparison of enzyme activity between the BSF and the housefly using the apiZYM kit, the BSF had more strongly digestive enzyme activity than one of the housefly about leucine arylamidase, alpha-galactosidase, beta-galactosidase, alpha-mannosidase and alpha-fucosidase. This finding supports that the BSF can ingest raw waste far more efficiently than any other known species of fly as reported previously.

Apolipophorin-III (apoLp-III) is a hemolymph protein whose function is to facilitate lipid transport in an aqueous medium in insects. Recently, apolipophorin-III in Galleria mellonella and Hyphantria cunea was shown to play an unexpected role in insect immune activation. We show here a novel possible function/role of the apoLp-III in insects. To investigate the genes which have a relationship with apoLp-III in fall webworm larvae, we reduced endogenous Hc apoLp-III mRNA levels in larvae via RNA interference (RNAi). The RNAi-mediated Hc apoLp-III reduction resulted in the reduction of antioxidants, like MnSOD, catalase, and glutathione S transferase as well as immune proteins. In particular, expression of MnSOD commonly decreased in fat body, midgut, and hemocytes following the knockdown of Hc apoLp-III, which induced an elevated level of superoxide anion in Hyphantria cunea larvae. The observed effect of Hc apoLp-III RNAi suggests that Hc apoLp-III is related to the action/expression of antioxidants, especially MnSOD.

A new insect member of the STAT family of transcription factors (HcSTAT) has been cloned from the lepidopteran, Hyphantria cunea. The domain involved in DNA interaction and the SH2 domain are well conserved. The gene is transcribed at a low level during all stages of development, and transcribed in hemocyte, fat body, midgut, epidermis, and Malpighian tubule. Especially, hemocyte and Malpighian tubule showed transcriptional activation of HcSTAT upon Gram-negative and -positive bacteria challenge. Gram-negative and -positive bacteria challenge specifically results in nuclear translocation of HcSTAT protein and induction of DNA-binding activity that recognizes a STAT target site in H. cunea hemocyte. In vivo treatment with sodium orthovanadatetranslocates HcSTAT to the nucleus in hemocyte cells.

The phylogenetic relationships among true butterfly families (superfamily Papilionoidea) have been a matter of substantial controversy, and that debate has led to several competing hypotheses. Two of the most compelling of those hypotheses involve the relationships of (Nymphalidae + Lycaenidae) + (Pieridae + Papilionidae) and (((Nymphalidae + Lycaenidae) + Pieridae) + Papilionidae). In this study, approximately 3,500 nucleotide sequences from cytochrome oxidase subunit I (COI), 16S ribosomal RNA (16S rRNA), and elongation factor-1 alpha (EF-1α) were sequenced from 83 species belonging to four true butterfly families, along with those of eight outgroup species belonging to the skipper family (superfamily Hesperioidea). These sequences were subjected to phylogenetic reconstruction via Bayesian Inference (BI), Maximum Likelihood (ML), and Maximum Parsimony (MP) algorithms. All phylogenetic analyses among the four true butterfly families strongly indicated a sister relationship between the Nymphalidae and Lycaenidae on one hand, and relatively strongly indicated a sister relationship between the Pieridae and Papilionidae on another hand, thus supporting the hypothesis: (Nymphalidae + Lycaenidae) + (Pieridae + Papilionidae).

The silkworm (Bombyx mori), as an industrial insect, possesses a high economic value. Casual discrimination and accumulated genetic information of silkworm varieties are essential ground for the practical utilization and long-term conservation. In this study, nine available microsatellite loci were successfully genotyped from ~50 silkworm strains preserved in Korea. According to genotyping analysis, we obtained 3 ~ 16 alleles per locus, with an average of 7.4, the observed heterozygosity ranging from 0.04 to 0.98, and the polymorphic information content (PIC) ranging from 0.06 to 0.88, revealing that some loci are highly variable. Among 54 strains 13 strains were casually identified by the presence of 17 strain-specific apomorphic alleles. Furthermore, 30 among remaining strains contained strain-specific allele combinations that are also apomorphic to each strain, allowing us to discriminate each of these from other strains by genotyping of multiple loci. These results collectively suggest that the silkworm microsatellite DNA is actually and potentially important molecular marker for the discrimination of the silkworm strains that are preserved as hundreds in Korea, as more loci are genotyped.