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A new species, Hemiptarsenus jilinus Tao, sp. nov., is described and illustrated. All the type specimens were reared from Chromatomyia horticola (Goureau) (Diptera: Agromyzidae), a leafminer attacking the plants Ixeris polycephala Cass. and Pterocypsela indica (L.) Shih, in Jilin Province, north-eastern China. A key to Chinese species of the genus is provided.

Background: Amino acids are one of the major constituents in Panax ginseng, including neutral amino acid, acidic amino acid, and basic amino acid. However, whether these amino acids play a role in ginsenoside conversion during the steaming process has not yet been elucidated. Methods: In the present study, to elucidate the role of amino acids in ginsenoside transformation from fresh ginseng to red ginseng, an amino acids impregnation pretreatment was applied during the steaming process at 120°C. Acidic glutamic acid and basic arginine were used for the acid impregnation treatment during the root steaming. The ginsenosides contents, pH, browning intensity, and free amino acids contents in untreated and amino acid–treated P. ginseng samples were determined. Results: After 2 h of steaming, the concentration of less polar ginsenosides in glutamic acid–treated P. ginseng was significantly higher than that in untreated P. ginseng during the steaming process. However, the less polar ginsenosides in arginine-treated P. ginseng increased slightly. Meanwhile, free amino acids contents in fresh P. ginseng, glutamic acid-treated P. ginseng, and arginine-treated P. ginseng significantly decreased during steaming from 0 to 2h. The pH also decreased in P. ginseng samples at high temperatures. The pH decrease in red ginseng was closely related to the decrease in basic amino acids levels during the steaming process. Conclusion: Amino acids can remarkably affect the acidity of P. ginseng sample by altering the pH value. They were the main influential factors for the ginsenoside transformation. These results are useful in elucidating why and how steaming induces the structural change of ginsenoside in P. ginseng and also provides an effective and green approach to regulate the ginsenoside conversion using amino acids during the steaming process. Keywords: amino acids, ginsenoside transformation, red ginseng, steaming treatment

Previous studies have shown that many kinds of microorganisms, including bacteria, yeasts, and filamentous fungi, can convert parent ginsenosides into minor ginsenosides. However, most microorganisms used for ginsenoside transformations may not be safe for food consumption and drug development. In this study, 24 edible and medicinal mushrooms were screened by high-performance liquid chromatography analyses for their ability to microbiologically transform protopanaxadiol (PPD)-type ginsenosides. We observed that the degradation of ginsenosides by Schizophyllum commune was inhibited by high concentrations of sugar in the culture medium. However, the inhibition was avoided by maintaining sugar concentration below 15 g L-1. S. commune showed a strong ability to convert PPD-type ginsenosides (Rb1, Rc, Rb2, and Rd) into minor ginsenosides (F2, C-O, C-Y, C-Mc1, C-Mc, and C-K). The production and bioconversion rates of minor ginsenosides were significantly higher than those previously reported by food microorganisms. The fermentation process is efficient, nontoxic, eco-friendly, and economical, and the required biotransformation systems are readily available. This is the first report about the biotransformation of major ginsenosides into minor ginsenosides through fermentation by edible and medicinal mushrooms. Our results provide a green biodegradation strategy in transformation of ginsenosides using edible and medicinal mushrooms.

Background The parasitoid wasp, Trichogramma dendrolimi, can enter diapause at the prepupal stage. Thus, diapause is an efficient preservation method during the mass production of T. dendrolimi. Previous studies on diapause have mainly focused on ecological characteristics, so the molecular basis of diapause in T. dendrolimi is unknown. We compared transcriptomes of diapause and non-diapause T. dendrolimi to identify key genes and pathways involved in diapause development. Results Transcriptome sequencing was performed on diapause prepupae, pupae after diapause, non-diapause prepupae, and pupae. Analysis yielded a total of 87,022 transcripts with an average length of 1604 bp. By removing redundant sequences and those without significant BLAST hits, a non-redundant dataset was generated, containing 7593 sequences with an average length of 3351 bp. Among them, 5702 genes were differentially expressed. The result of Gene Ontology (GO) enrichment analysis revealed that regulation of transcription, DNA-templated, oxidation-reduction process, and signal transduction were significantly affected. Ten genes were selected for validation using quantitative real-time PCR (qPCR). The changes showed the same trend as between the qPCR and RNA-Seq results. Several genes were identified as involved in diapause, including ribosomal proteins, zinc finger proteins, homeobox proteins, forkhead box proteins, UDP-glucuronosyltransferase, Glutathione-S-transferase, p53, and DNA damage-regulated gene 1 (pdrg1). Genes related to lipid metabolism were also included. Conclusions We generated a large amount of transcriptome data from T. dendrolimi, providing a resource for future gene function research. The diapause-related genes identified help reveal the molecular mechanisms of diapause, in T. dendrolimi, and other insect species.

Background The parasitoid insect Trichogramma dendrolimi can successfully enter diapause at the prepupal stage. Thus, diapause is an efficient preservation method during the mass production of T. dendrolimi . Previous studies on diapause have focused mostly on ecological characteristics, so the molecular mechanism of diapause in T. dendrolimi is mostly unknown. In this study, we compared transcriptomes of diapause and non-diapause T. dendrolimi to identify genes involved in the development of diapause. Results Transcriptome sequencing was performed using different samples, including diapause prepupae, pupae after diapause, normal prepupae, and pupae. This initially yielded a total of 87,022 unigenes with an average length of 1,604 bp. By removing redundant sequences and those without significant BLAST hits, a non-redundant dataset was generated, containing 7,593 sequences with an average length of 3351 bp. Among the differentially expressed genes, 1,204 were specifically expressed during the diapause stage, and 820 were significantly up-regulated. The result of GO enrichment analysis revealed that binding, oxidation−reduction process, and ribosome biogenesis were significantly affected. Ten genes were selected for validation using a quantitative real-time PCR (qPCR). The changes showed the same trend between the qPCR and RNA-Seq results. Based on previous studies and our data, several genes were identified to be involved in diapause, including UDP-glucuronosyltransferase ; Glutathione-S-transferase , ATGs , zinc finger protein genes, cell cycle-related genes, Trehalase , trehalose transporter , hsp68 , p53, and DNA damage-regulated gene 1 ( pdrg1 ), and genes related to lipid metabolism were also included. Conclusions In this study, we generated a great amount of transcriptome data from T. dendrolimi , providing a resource for gene function research. The diapause-related genes that we identified establish a valuable basis for future studies on the molecular mechanisms of diapause, not only for T. dendrolimi, but for other species as well.

International audience; Trichogramma parasitoids are important biological control agents for insect pest management. However, efficient means for mass production of Trichogramma parasitoids are needed, particularly for T. ostriniae, which often fail to form emergence holes on host eggs of Chinese oak silkworm, Antheraea pernyi, because of the hard chorion. In the present study, we evaluated the possibilities to enhance adult emergence of T. ostriniae by utilizing emergence holes made by T. dendrolimi during multiparasitism on host eggs of A. pernyi and other biological parameters such as pre-emergence time, parasitism rate, and emergence rate of the two parasitoids, which were also evaluated between the two parasitism regimes of multi- and monoparasitism. Our data showed that multiparasitism on host eggs of A. pernyi significantly facilitated the emergence of adult T. ostriniae. Generally, both Trichogramma species favored parasitizing A. pernyi eggs, with multiple parasitoid adults emerged per host egg. The overall performance of T. dendrolimi was similar between the two parasitism regimes, although a significantly higher number of unemerged adults were found in the multiparasitized eggs than in the monoparasitized. For T. ostriniae, significantly more adults emerged, and a higher emergence rate was recorded on host eggs multiparasitized with T. dendrolimi than that on monoparasitized. Furthermore, significantly fewer unemerged adults were found in multi- than monoparasitized host eggs. The results of this study provided useful information on the feasibility of mass production of T. ostriniae via multiparasitism with T. dendrolimi on large eggs of A. pernyi.

Background Trichogramma dendrolimi Matsumura is widely used as a biological control agent for control of lepidopteran agricultural pests in China and can be successfully reared using the large eggs of the Chinese silkworm, Antheraea pernyi. In this study, biological parameters of diapaused, non-diapaused, and cold-stored T. dendrolimi were investigated for two generations on host eggs of A. pernyi under laboratory conditions. Results The cold-stored T. dendrolimi performed more poorly than diapaused and non-diapaused T. dendrolimi based on biological parameters. In the F1 generation, the non-diapaused T. dendrolimi had a higher emergence rate, longer longevity, and a lower proportion of deformed individuals than diapaused T. dendrolimi. In the F2 generation, the diapaused T. dendrolimi had a lower proportion of unemerged parasitoids than non-diapaused T. dendrolimi. However, the diapaused T. dendrolimi had a higher number of parasitized hosts than non-diapaused T. dendrolimi in both generations. In the F1 generation, the index of population trend (I) was found to be similar for diapaused (140.792) and non-diapaused (141.542) T. dendrolimi and was approximately 3.4 times that of cold-stored T. dendrolimi (41.698). In the F2 generation, the diapaused T. dendrolimi showed the largest I (146.791), followed by non-diapaused (136.859) and cold-stored T. dendrolimi (59.607). Conclusion In a 3-year augmentative field release from 2014 to 2016, diapaused T. dendrolimi showed effective parasitism on eggs of the Asian corn borer, Ostrinia furnacalis. These results indicated that diapaused T. dendrolimi can be an efficient alternative method for mass rearing of T. dendrolimi for long-term cold storage. © 2017 Society of Chemical Industry.

The Asian corn borer (ACB) Ostrinia furnacalis is a voracious pest of corn in Asia. The egg parasitoid Trichogramma ostriniae is an important biological control agent of ACB. The possibility of mass-producing T. ostriniae on the factitious host Chinese oak silkworm, Antheraea pernyi, via multiparasitism with T. chilonis has been previously reported. Here, we evaluated the fitness parameters of A. pernyi-reared T. ostriniae via multiparasitism and its potential to parasitize ACB eggs of different ages (12 h and 24 h) in comparison to T. ostriniae reared on eggs of rice moth, Corcyra cephalonica. The results showed that rearing host species affected body size, longevity and lifetime fecundity of T. ostriniae. The A. pernyi host produced T. ostriniae of larger body size (female: 641.8 µm, male: 556.1 µm) than C. cephalonica-reared T. ostriniae (female: 482.1 µm; male: 457.6 µm). Consequently, the A. pernyi-reared T.ostriniae females lived longer (14.1 d) and were more fecund (180.7) than were C. cephalonica-reared T. ostriniae females (longevity: 10.2 d; lifetime fecundity: 140.1). In addition, A. pernyi-reared T. ostriniae females parasitized greater numbers of target ACB eggs at different ages (12 h: 43.2; 24 h: 41.0) than did C. cephalonica-reared T. ostriniae (12 h: 35.2; 24 h: 31.4). These results demonstrated that the rearing host species impacted the performance of T. ostriniae in biological control of ACB and that the fitness of A. pernyi-reared T. ostriniae females was higher than that of C. cephalonica-reared T. ostriniae females, which should render them more effective biological control agents of ACB.

Trichogramma spp. (Hymenoptera: Trichogrammatidae) parasitoids have been commonly used as biological control agents in insect pest management. Host quality is believed to influence parasitism, host preference, and suitability for parasitoids. To date, limited studies have compared the parasitism of Trichogramma parasitoids on fertilized, unfertilized, and sterilized host eggs. Hence, we studied the performance of three Trichogramma egg parasitoids, Trichogramma japonicum Ashmead, Trichogramma chilonis Ishii, and Trichogramma leucaniae Pang & Chen, on fertilized, unfertilized, and ultraviolet (UV)-irradiated fertilized (UVF) eggs of rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae). In a no-choice test, T. japonicum and T. leucaniae parasitized significantly more fertilized or UVF than unfertilized hosts, and T. chilonis parasitized significantly more UVF than either fertilized or unfertilized hosts. In a choice test, all three Trichogramma parasitoids parasitized UVF hosts the most, and unfertilized hosts the least. There were similar percentages of adult emergence and female progeny among fertilized, unfertilized, and UVF hosts for all three Trichogramma parasitoids, except that T. japonicum had significantly lower adult emergence on fertilized hosts. We also found that all three Trichogramma parasitoids developed slower on unfertilized hosts. Regardless of host treatments, T. leucaniae had the longest developmental time and T. chilonis had the shortest. We conclude that Trichogramma parasitoids prefer parasitizing UVF eggs of C. cephalonica without negative effects on their emergence and sex allocation.

Background Encarsia formosa Gahan is the most important parasitoid exploited for the control of whitefly pests of vegetable crops. However, the non-target effects of recently developed insecticides for controlling whiteflies toward this biocontrol agent is little documented. Here we evaluated the susceptibility of E. formosa adults and juveniles to eight commonly used insecticides against whiteflies. Results Residual toxicity tests on glass showed that E. formosa adults were susceptible (over 98% mortality after 6 h treated) to field concentrations of the tested neonicotinoids (imidacloprid, acetamiprid, nitenpyram and thiamethoxam), abamectin, cyantraniliprole, and sulfoxaflor at their field concentrations. Pyriproxyfen was harmless to both adult and pupae of E. formosa. A risk quotient analysis showed that toxicity of pyriproxyfen to E. formosa adults was the lowest, followed by acetamiprid and cyantraniliprole. In the leaf residues test, mortality of E. formosa adults under all insecticides decreased when the residue age increased. Interestingly, E. formosa experiencing contact with the residues of most insecticides, except pyriproxyfen and abamectin, parasitized significantly more hosts 5-days after treatment, suggesting a hormetic effect on parasitism. Conclusion The risk assessment of insecticides indicated that pyriproxyfen and cyantraniliprole were the least toxic to E. formosa. Our results suggest that the inclusion of the insecticides in sustainable integrated pest management programs of whiteflies should be carefully evaluated on a case-by-case basis. © 2019 Society of Chemical Industry.

The Chinese oak silkworm, Antheraea pernyi, is an important alternate host for mass production of Trichogramma parasitoids, which play a vital role in the biological control of lepidopterous pests in China. The quality of A. pernyi eggs is particularly important for mass production of these parasitoids. In this study, a pathogenic bacterium, isolated and purified from A. pernyi eggs that had turned gray in color, was identified as Serratia marcescens. We used morphology, biochemistry and 16S rDNA analysis to characterize the strain, which was named “APE strain”. Serratia marcescens APE strain was determined to be the causal bacterium associated with the disease in the eggs, verified by a test based on Koch’s Postulates. We tested the pathogenicity of S. marcescens APE strain on A. pernyi eggs; the percentage of diseased (gray) eggs reached 57.78% when uninfected eggs were exposed to a concentration of 1 × 109 cfu/mL bacterial suspension for 7 h. S. marcescens was transmitted mechanically by Trichogramma parasitoids. The transmission rate was 25.56%. In a horizontal transmission test, the highest percentage of uninfected eggs that developed infections was 51.43% after being treated with contents of diseased eggs for 12 h. In a vertical transmission test, the number of infected eggs per treated adult female was 63.8–92.3 after treatment with different S. marcescens concentrations, significantly lower than the 304.3 eggs per female in the control group. Furthermore, the percentage of infected (gray) eggs produced by adult moths exposed to bacteria in the larval stage was 80.5–85.3%.

International audience; Host quality varies with size, age, and species, and influences the parasitism preference of parasitoids and the fitness of their offspring. However, it is still unclear whether parasitoids have the ability to recognize fertilized and unfertilized host eggs. We studied the performance of three Trichogramma species, T. japonicum, T. chilonis, and T. leucaniae, on both fertilized and unfertilized eggs of their host Corcyra cephalonica at different host ages. In no-choice tests, three Trichogramma species parasitized significantly more fertilized than unfertilized eggs when host age was 0 days old. In choice tests, all parasitoids parasitized significantly more fertilized than unfertilized eggs at all host ages. Furthermore, the frequency of fertilized eggs visited by Trichogramma parasitoids were significantly higher than those of unfertilized eggs. The number of unfertilized eggs visited by parasitoids without ovipositing was approximately 3.7 times greater than those of fertilized eggs. In addition, all Trichogramma parasitoids developed significantly faster on fertilized than unfertilized eggs at all host ages. In summary, we find that Trichogramma were able to recognize fertilized and unfertilized host eggs in parasitism, which is conducive to biological control programs, since unfertilized eggs enlarge the host reservoir for parasitoid augmentation.

Pod borers are economically important soybean pests in temperate and tropical regions. However, the biological control of these pests using their natural insect enemies has been poorly studied to date. Indigenous natural populations of three Trichogramma (Hymenoptera: Trichogrammatidae) species, Trichogramma chilonis Ishii, Trichogramma ostriniae Pang & Chen, and Trichogramma leucaniae Pang & Chen, were collected from Leguminivora glycinivorella (Matsumura) (Lepidoptera: Tortricidae) eggs in soybean fields in China. In this study, we compare the parasitic capacities and suitabilities of three indigenous Trichogramma species on L. glycinivorella eggs at various ages. Host eggs of all ages were accepted by T. chilonis, T. ostriniae, and T. leucaniae. T. chilonis tended to parasitize 0-2-d-old eggs more than 3-4-d-old eggs. There were no significant differences in parasitism between the 0-2-d-old eggs and the 1-4-d-old eggs for T. ostriniae and T. leucaniae. For eggs at various ages, T. chilonis parasitized the smallest number of eggs, while T. leucaniae and T. ostriniae exhibited similar parasitic capacities. With 0-d-old host eggs, T. ostriniae developed over the longest time period (8.7 d), and T. leucaniae produced the most female progeny (87.9%). Both T. leucaniae and T. ostriniae had similar developmental times, survival rates and percentages of female progeny with 1-3-d-old eggs. These results show that T. leucaniae can parasitize host eggs at varying ages with the best development and suggest that it may be a valuable biological control agent for soybean pod borers.

In this study, dynamic changes in ginsenoside content and ratios in the Panax ginseng root were investigated with different cultivation ages and different collection months, using high-performance liquid chromatography (HPLC). Our data indicate that changes in ginsenoside Ro and malonyl ginsenosides content were dependent on the ginseng cultivation age (p < 0.05); especially, the Ro content varied from 0.16 to 4.91 mg/g, with a difference about 30-fold. Further, we found that the samples of 5 and 6-year-old P. ginseng had high Ro/Re ratio, whereas two and three-year-old P. ginseng possessed low Ro/Re ratio. Thus, the Ro/Re ratio can be used as a characteristic marker for differentiating the age of the root. The relative content of ginsenosides Rg1 and Re were affected by the ginseng’s harvest season. The Re content was higher than the Rg1 content in May and June, but lower than the Rg1 content from August to October. Thus, the Rg1/Re ratio can be used as a characteristic marker for differentiating the ginseng’s harvest seasons. These results indicate that the chemical characteristics of P. ginseng at different cultivation ages and harvest seasons are clearly different, which may cause differences in pharmacological activities and therapeutic effects. In addition, we developed HPLC coupled with hierarchical cluster analysis and principal component analysis methods to identify the cultivation age and harvest season of P. ginseng using characteristic ginsenosides. Our results showed that this method can be used to discriminate the cultivation age and harvest season of P. ginseng.

Diapause variation is a key factor affecting the development and success of parasitoids employed as biological control agents. Trichogramma dendrolimi Matsumura is mass-reared for biocontrol purposes in several countries around the world. Here we investigated the rate of diapause induction in three populations of T. dendrolimi from different regions in China: Heilongjiang (44 degrees 55' N, 128 degrees 26' E; HLJ), Liaoning (40 degrees 18' N, 123 degrees 22' E; LN), and Jiangsu province (32 degrees 30' N, 120 degrees 09' E; JS). We measured the rates of diapause induction for populations from each region when exposed to temperatures of 8, 10, 12, and 14 degrees C, for periods ranging from 5 to 35 d. Results showed that both the temperature and exposure duration influenced diapause induction in the three populations of T. dendrolimi. The HLJ and LN populations showed the highest percentage of diapause under 12 and 10 degrees C, regardless of time period tested. After 20 d at 12 and 10 degrees C, 97.42% and 95.94% of individuals of HLJ and LN, respectively, entered diapause. After treatment for 20-35 d under 8 degrees C, or 15-25 d under 10 degrees C, the diapause rate of LN was higher than those of the other two populations. In contrast, the higher temperatures (1214 degrees C) induced diapause rapidly and steadily in HLJ. The diapause rate of JS was low for all temperatures and time periods. After 30 d at 12 degrees C, the JS population reached its highest diapause rate (29.56%). Our results showed significant variance in diapause rates among geographically distinct populations of T. dendrolimi in response to various abiotic conditions.

The striped stem borer, Chilo suppressalis (Walker), is one of the most economically important rice pests worldwide. However, biological control of this pest using natural-enemy insects has been rarely documented to date. With the objective of screening suitable candidate species for controlling the striped stem borer, we investigated the effect of the age of host eggs on the host selection and suitability by four indigenous Trichogramma species on their native host, C. suppressalis. The results indicated that the differently aged eggs of C. suppressalis were all accepted by T. japonicum, T. dendrolimi and T. chilonis, and there was a clear tendency to parasitize older eggs less under no-choice and choice conditions. The number of parasitized host eggs by T. ostriniae also decreased with the increasing host age in the no-choice test, but more 2-day-old host eggs were parasitized in the choice test. When 0-, 2-day-old eggs were offered, T. dendrolimi, T. japonicum and T. chilonis exhibited similar parasitism ability, whereas T. ostriniae appeared to have a stronger ability to attack the older host eggs (4-day-old). Trichogramma japonicum developed and emerged on parasitized C. suppressalis eggs of all ages tested, while showing a better adaptation to younger host eggs with significantly faster developmental time, higher survival and more female progeny on 0-day-old eggs. No adults for each of the other three Trichogramma species emerged from parasitized 4-day-old host eggs, and they had similar developmental time, survival and female progeny on parasitized 0-, 2-day-old host eggs with an exception of female progeny for T. chilonis. On 0-day-old host eggs, T. japonicum developed faster and T. ostriniae had lower progeny survival than the other three Trichogramma species evaluated, respectively. The current study provides useful information to select suitable Trichogramma species for controlling the striped stem borer, C. suppressalis.

Panax ginseng contains many chemical components, including acidic ginsenosides and organic acids. However, whether these acidic substances play a role in ginsenoside transformation during steaming treatment has not yet been explored. In this paper, the content of neutral ginsenosides, acidic ginsenosides, and their degradation products in unsteamed and steamed P. ginseng were simultaneously quantified by high-performance liquid chromatography. We observed that neutral ginsenosides were converted to rare ginsenosides during the root steaming but not during the individual ginsenoside steaming. In contrast, acidic malonyl ginsenosides released malonic acid and acetic acid through demalonylation, decarboxylation, deacetylation reactions during the steaming at 120 °C. These malonyl ginsenosides not only were converted to rare ginsenosides but also promoted the degradation of neutral ginsenosides. Further studies indicated that a low concentration of organic acid was the determining factor for the ginsenoside conversion. The related mechanisms were deduced to be mainly acidic hydrolysis and dehydration. In summary, acidic ginsenosides and organic acids remarkably affected ginsenoside transformation during the steaming process. Our results provide useful information for precisely understanding the ginsenoside conversion pathways and mechanisms underlying the steaming process.

Trichogramma spp. are egg parasitoids largely used worldwide for biological control of lepidopteran pests. Host quality (related to host size and age, host species, etc.) can influence parasitism preference and fitness of the parasitoid offspring. However, few studies have documented the performance of Trichogramma parasitoids when they parasitize nonfertilized eggs of their lepidopteran hosts. In the present study, we investigated the performance of three indigenous Trichogramma species ( Trichogramma japonicum Ashmead, Trichogramma dendrolimi Matsumura, and Trichogramma chilonis Ishii) on fertilized and nonfertilized eggs of their native host, Chilo suppressalis (Walker). The results showed that the three Trichogramma species tested could recognize fertilized and nonfertilized eggs of C. suppressalis . The different fertilization status eggs of C. suppressalis were all accepted by T. japonicum , T. chilonis , and T. dendrolimi with a clear tendency that they preferred to parasitize fertilized eggs whether under no-choice or choice conditions. All Trichogramma species successfully completed development in parasitized eggs of C. suppressalis regardless if the host eggs were fertilized or not. There was similar adult emergence rate, development time, and female progeny between fertilized and nonfertilized eggs for all Trichogramma species with an exception of development for T. chilonis . Trichogramma chilonis had shorter developmental time in fertilized eggs than in nonfertilized ones. Whether in fertilized or nonfertilized eggs, T. dendrolimi had longer development time than other two Trichogramma species. However, T. dendrolimi had the largest percentage of female progeny on fertilized eggs, followed by T. japonicum , and T. chilonis had the least percentage of female progeny. The present study indicates that Trichogramma parasitoids (i) can distinguish fertilized vs. nonfertilized host eggs, and (ii) could use nonfertilized host eggs for successful offspring development (despite showing lower preference for such eggs) [corrected].

The striped stem borer, Chilo suppressalis (Walker), is one of the most economically important rice pests worldwide. However, biological control of this pest using natural enemies has rarely been documented. Indigenous natural populations of four Trichogramma species (i.e., T. japonicum, T. chilonis, T. dendrolimi, and T. ostriniae) were collected from the eggs of C. suppressalis in paddy fields. With the objective of screening suitable candidate species for controlling the striped stem borer, parasitism by these four Trichogramma species of the eggs of their native host, C. suppressalis, was evaluated at five temperatures (18, 22, 26, 30, and 34 °C) and four relative humidity (RH) regimes (30, 50, 70, and 90 %). The temperature and the humidity significantly affected the ability of all of the Trichogramma species to parasitize the eggs of their host. T. chilonis parasitized more eggs at 26 °C than at the other temperatures. By contrast, T. dendrolimi, T. ostriniae, and T. japonicum performed best within a wider temperature range. The host number parasitized was highest at 70 % RH and differed significantly among the Trichogramma species at all of the temperatures and humidities tested, except at 30 °C and 50 % RH. Generally, T. dendrolimi and T. japonicum performed better than the other species at 18–26 and 30–34 °C, respectively, whereas T. ostriniae parasitized the fewest host eggs at 30–70 % RH. Both T. dendrolimi and T. japonicum appear to be promising candidates for augmentative release against C. suppressalis in northeastern China.

The multicolored Asian ladybird beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is considered an important generalist predator that can be used as a biological control agent against Hemiptera Sternorrhyncha, Thysanoptera, and the eggs and larvae of Lepidoptera, Coleoptera and Diptera. There are currently abundant natural resources of overwintering H. axyridis in Asia and North America. Given its potential as a biological control agent, methods can be developed to increase its effectiveness for pest control. The availability of an adequate cold storage method would enable the use of field-collected pre-wintering ladybirds for pest suppression in the following season. We studied the effect of cold storage (30, 60, 90, 120 and 150 days stored at −3, 0, 3 and 6°C) on survival, fecundity and predation in field-collected populations. The survival of both female and male ladybirds decreased significantly as storage duration increased at −3°C and 0°C. The ladybirds showed more than 80% survival when they were stored for 150 days at 3°C and 6°C. Long-term cold storage had different effects on the fecundity of H. axyridis at different temperatures. Prolonged cold storage at both 3°C and 6°C shortened pre-oviposition duration and had no adverse effect on reproductive capacity as compared to that of unstored individuals. The adults that experienced 90-day storage at 0°C had the shortest pre-oviposition duration and the largest reproductive capacity. The individuals that were stored for 150 days at 3°C consumed significantly more aphids than the unstored ones. Generally, 3–6°C is a suitable temperature for cold storage of the ladybird without any reduction in fitness. This study will help the exploitation and application of pre-wintering H. axyridis for the biological control of insect pests.

A new saponin, malonylginsenoside Ra3, was isolated from the fresh root of Panax ginseng, along with four known ginsenosides. The new compound was identified as (20S)-protopanaxadiol-3-O-(6-O-malonyl-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranoside-20-O-beta-D-xylopyranosyl(1-->3)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside on the basis of extensive 1D and 2D NMR as well as HRESI-MS spectroscopic data analysis.

Ethnopharmacology relevance Ginseng (Panax ginseng C. A. Meyer) has been recorded to treat ‘Xiao-ke’ (emaciation and thirst) symptom in many ancient Chinese medical literatures (such as ‘Shen Nong Ben Cao Jing’) for thousands of years. ‘Xiao-ke’ symptom, in general, indicates diabetes mellitus. Aim of the study Malonyl ginsenosides (MGR) are natural ginsenosides which exist in both fresh and air-dried ginseng. The objective of this study is to determine the antidiabetic function of MGR on type 2 diabetes. Materials and methods High fat diet-fed and streptozotocin-induced diabetic rats were treated with 50 and 100 mg/kg/d of MGR or vehicle for 3 weeks. The effects of MGR on fasting blood glucose (FBG), intraperitoneal glucose tolerance test (IPGTT), serum insulin (SI), insulin tolerance test (ITT), body weight, total cholesterol (TC), and triglyceride (TG) levels in type 2 diabetic rats were measured. Results After 3 weeks of treatment, MGR administration showed significantly lower FBG levels compared to the diabetic control group. In glucose tolerance test, IPGTT data showed that both MGR 50 and 100 mg/kg groups significantly increased the glucose disposal after glucose load. The ITT also showed improvement of insulin sensitivity during 120 min of insulin treatment. In addition, MGR reduced TG and TC contents while showed no effect on body weight in diabetic rats. Conclusion The findings from this study suggest that MGR can alleviate hyperglycemia, hyperlipemia and insulin resistance of type 2 diabetes.

Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae) is an important egg parasitoid of several major insect pests. To better understand its host finding mechanisms, the antennal sensilla of female wasp were investigated by scanning electron microscopy. Sensilla chaetica were found mainly on radicle and pedicel segments of the antennae. i-Type sensilla, s. campaniformia, and corneous sensilla were detected on the leeward side, while s. coeloconica and lance sensilla were presented on the windward side of the antennae. S. trichodea and s. basiconica were more abundant on the leeward side than on the windward side of the antennae. More s. placodea were found on the windward side than on the leeward side of the right antenna, while the opposite results were observed on the left antenna. Overall, more s. placodea were found on the right antenna than that on the left antenna. The numbers of s. trichodea and s. basiconica on the clava or the third flagellum antennomere of the right antenna were more than those of the left antenna, whereas their distribution patterns on the other corresponding antennomeres were reverse. Our results showed that there is a strong asymmetrical antennal sensilla distribution quantitatively and spatially between the left and right antennae. Placoid sensilla are present more on the right antenna than on the left antenna. S. campaniformia, corneous sensilla, and i-type sensilla were found only on the leeward side of the antennal clava, while their external morphology and potential functions were described and discussed in detail for the first time.

To clarify the effects of malonyl ginsenosides (MGR) on evaluation and quality control of Panax ginseng, the contents of neutral and malonyl ginsenosides from P. ginseng were examined by high-performance liquid chromatography equipped with UV-VIS detector (HPLC-UV) during extraction, processing and storage. Several solvents, including water, ethanol, methanol, and n-butanol were used in the cold-soaked extraction (CSE). Among the four extraction solvents, methanol was found to be the most efficient. CSE was compared with other extraction methods such as Soxhlet extraction (SE), heat reflux extraction (HRE), ultrasonic-assisted extraction (UAE), and microwave-assisted extraction (MAE). The content of MGR showed significant differences, higher in CSE and UAE; lower in MAE and HRE; no MGR could be detected after SE. However, the total contents of neutral and malonyl ginsenosides were not different. Meanwhile, white ginseng, stored at 25°C in air of low humidity, showed a marked decrease in the concentration of MGR from 1.19% to 0.63% but with an increase in the neutral ginsenosides from 1.12% to 1.53% after 0-9-month storage. The results indicated that MGR changed dynamically in P. ginseng with different extraction solvents, extraction methods and increasing storage time. The total ginsenosides was not only underestimated but also determined imprecisely by ignoring malonyl ginsenosides. On the basis of our results, we suggest that malonyl ginsenosides should be transformed into the corresponding neutral ginsenosides during sample preparation for quality control and evaluation of P. ginseng. Then the content of six neutral ginsenosides in samples was used as the true level of total ginsenosides. The results reported here might provide useful information for accurate evaluation and quality control of P. ginseng.

An Aspergillus niger strain was isolated from the soil around ginseng fruit. In vitro enzyme assays showed that this strain had the ability to transform total ginsenosides (TGS) into several new products. In a further biochemical study, a beta-glucosidase gene isolated from this strain, bgl1, was expressed in Saccharomyces cerevisiae. His-tagged BGL1 protein (approximately 170 kD) showed the ability to transform ginsenoside Rf into Rh(1).