Competitive interactions in Ginkgo and crop species mixed agroforestry systems in Jiangsu,China

Intercropping Ginkgo and crop species in southern China is receiving increasing attention because it offers potential advantages for resource utilization, higher economic income to farmers and increased sustainability in crop production, We carried out a 2-year field intercropping system composed of Ginkgo with wheat, broad bean, and rapeseed, respectively, to determine the competitive interactions between the different species, and productivity and the economic yield of each intercropping system. The density of Ginkgo and crop species was varied systematically in a two-way density matrix composed of three monoculture densities and nine intercropping of all possible pairwise combinations of monoculture densities. Intercropping systems were assessed on the basis of several intercropping indices such as land equivalent ratio, relative crowding coefficient, relative competition intensity and vector competition analysis. The results showed that the combined biomass production of the component crop species was significantly greater in the Ginkgo/crop mixtures than in monocultures crops (Ginkgo, broad bean, wheat, and rapeseed). Ginkgo: rapeseed ratio 24:12, Ginkgo: bread bean ratio 24:5, and Ginkgo: wheat ratio 24:200 had the best total biomass production. Ginkgo: rapeseed (and broad bean) ratio 24:5 and Ginkgo: wheat ratio 24:200 in respective Ginkgo/crop mixtures had the maximum economic yield. Vector competition analysis showed that Ginkgo/rapeseed mixture exhibited an antagonistic interaction type and therefore is not suitable for intercropping. Ginkgo/broad bean mixture demonstrated the most beneficial effects among the three intercropping systems.     

Characterization of priming,induced resistance,and tolerance to Spodoptera frugiperda by silicon fertilization in maize genotypes

Fall armyworm (FAW) Spodoptera frugiperda is considered the main defoliating insect pest of maize in many countries. Silicon (Si) applied to plants has been shown to increase the resistance to insects, especially in grasses such as maize. This study characterized the effects of Si fertilization regarding priming, induced resistance, and tolerance to FAW in a landrace variety and hybrid of maize. Si was applied in soil of potted-plants as H₄SiO₄ at 2 t ha^?1 when maize plants were at V2 stage, and when they reached V3 two FAW neonates were placed in the plant’s whorls to cause herbivory. FAW performance was evaluated on excised leaf sections in the laboratory and on plants with larvae infesting V4-stage plants in the greenhouse. Concentrations of H₂O₂, malondialdehyde, and Si, and the activities of antioxidant enzymes were recorded and correlated to Si-based responses on plant growth, and FAW injury and performance. As main results, there was reduced FAW injury and larval weight gain in Si-treated plants subjected to herbivory. Greater root dry mass was observed in the landrace variety with Si and without herbivory. Landrace plants showed higher shoot weights than the hybrid under FAW infestation. Si-fertilized plants showed higher H₂O₂ concentrations. The highest peroxidase activities occurred in Si-treated plants without herbivory, and the catalase and superoxide dismutase activities were highest in Si-treated plants without herbivory or herbivory-injured plants without Si. In conclusion, Si-based defense in maize to FAW involve mixed effects of priming and tolerance, and were more pronounced in the landrace variety.

     

One new species and one new record species of Acerophagus(Hymenoptera: Encyrtidae) from China with a key to Chinese species

Two species of Acerophagus from Yunnan Province, China, are reported. One species, A. ovaliclavus sp. nov., is described as new to science, and one species, A.solidus Hayat is reported as new to China. A key to all described species from China based on females is given.All the type materials are deposited in the insect collections of Northeast Forestry University, China.     

Description of a new species and new distributional data for two species of Aphytis(Hymenoptera: Aphelinidae) from China

Aphytis tridentatus Gao and Li sp. nov. is described and illustrated from southwest China, and A.bangalorensis Rosen and De Bach is newly recorded from China. New distributional data for A. chionaspis Ren are also provided.     

Performance of larval parasitoid,Bracon brevicornis on two Spodoptera hosts: implication in bio-control of Spodoptera frugiperda

Successful pest management using parasitoids requires careful evaluation of host-parasitoid interactions. Here, we report the performance of larval ecto-parasitoid wasp, Bracon brevicornis (Wesmael) on important agricultural pests, Spodoptera litura (Fabricius) and S. frugiperda (J.E. Smith). Biology of B. brevicornis was studied on different host instars under laboratory and cage setup. In no-choice assay, the parasitoid development was highest on fifth-instar S. litura larvae as the wasp laid?~?253 eggs with 62% hatching, 76% pupae formation and 78% adult emergence. Similarly, these parameters were highest on fifth instar S. frugiperda larvae (293 eggs, 57% hatching, 80% pupae formation, 70% adult emergence). In two-choice assay, B. brevicornis preferred fourth or fifth over third instar larvae of both hosts. Successful parasitism depends on host paralysis and suppression of host immunity. B. brevicornis interaction downregulated cellular immunity of both hosts as shown by reduced hemocyte viability and spreading. The percent parasitism rate of B. brevicornis was unaltered in the presence of host plant, Zea mays in cage study. 76 and 84% parasitism was observed on fifth-instar larvae of S. litura and S. frugiperda, respectively. We evaluated the performance of B. brevicornis as a biocontrol agent on S. frugiperda in maize field. Our results show 54% average reduction in infestation after release of B. brevicornis. Taken together, we report the performance of B. brevicornis on important insect pests for the first time in laboratory and field conditions. Our findings indicate that B. brevicornis is a promising candidate for integrated pest management.

     

A new species,first report of a male and new distributional records for five species of Oligosita Walker(Hymenoptera:Trichogrammatidae) from China

Seven species of the genus Oligosita, a wellknown cosmopolitan genus of the family Trichogrammatidae that comprise egg parasitoids of coleopteran, hemipteran, lepidopteran and thysanopteran insects, are reviewed. Oligosita xinyangensis sp. nov.(Hymenoptera, Trichogrammatidae) is described in detail and illustrated;the male of O. nigroflagellaris Lin is reported for the first time. New distributional data are provided for O. japonica Yashiro, O. mediterranea Nowicki, O. pallida Kryger, O. polioptera Lin and O. shibuyae Ishii from China, and a key to all the Chinese species of the genus is given.     

A new species of Paraphaenodiscus Girault (Hymenoptera:Encyrtidae) from China

Paraphaenodiscus tricolor sp. nov. is described as new to science from China. A short key to described species from China based on females is given.     

First report of Platystethynium with description of a new species and two other new records from China (Hymenoptera: Mymaridae)

Platystethynium glabrum Jin et Li sp. nov. is described from China, and the genus is new to Chinese insect fauna. Diagnostic characters for the new species are given in comparison with the apparently closely related P.onomarchicidum. Two other mymarid species are also newly recognized from China: Mymar africanum Annecke and Anagroidea marina Triapitsyn et Berezovskiy.     

中国跳小蜂科六新记录属六新记录种(膜翅目:小蜂总科)

记述了采自吉林，辽宁，河北，山东，福建等省的6种跳小蜂，即巴库小雅跳小蜂Baeocharis pascuorum Mayr，茧蜂伊思跳小蜂Echthrodryinus azureus(Mercet)。黄色伊伦跳小蜂Erencytus dewitzi Mahdihassan,柯木玛赫跳小蜂Mahencyrtus comora Walker。栖桔副暗跳小蜂Parablatticida citri(Mercet)。玛娜利捷行跳小蜂Trechnites manaliensis Hayat,Alam et Agarwal，除玛娜利捷行跳小蜂出自梨木虱Psylla chinensis，茧蜂伊思跳小蜂寄主有误外，其余4种为扫网采集，这6种跳小蜂在我国属首次报道。主要寄生各种树木上的介壳虫和木虱。这6个属也是中国分布新记录属。     

Bt cotton and the predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) in the management of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) resistance to lambda-cyhalothrin

Journal of Pest Science - This study sought to provide relevant information for developing effective programs to manage Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) resistance to...     

Two new species,new distributional data and a key to Chinese species of Pseudoligosita(Hymenoptera: Trichogrammatidae)

Eight species of Pseudoligosita(Hymenoptera:Trichogrammatidae)from China are reviewed,including two new species:P.processa sp.nov.and P.qiluensis sp.nov.New distributional data for six species and a key to all the Chinese species of the genus are provided.     

The implications of homozygous vip3Aa20- and cry1Ab-maize on Spodoptera frugiperda control

Journal of Pest Science - Historically, Bt maize hybrids have been produced with the Bt alleles in a hemizygous state. Homozygous Bt transgenes increase the expression of Bt proteins in plants;...     

Arbuscular mycorrhizal association of indigenous agroforestry tree species and their infective potential with maize in the rift valley, Ethiopia

Tree species in agroforestry are important source of inoculum for companion agricultural crops. Agroforestry trees can serve as a source of Arbuscular mycorrhiza (AM) inoculants to intercropped annuals. We studied spore abundance, root colonization of Albizia gummifera (J.F. Gmel.) and Croton macrostachyus (Hochst Ex Del.) trees and their effect on colonization of maize. Soil and root samples were collected from field standing trees from under and outside the canopy of trees and maize crops in the main rainy season. The number of spore count was significantly higher under the canopy of A. gummifera (791/100 g of dry soil) and C. macrostachyus (877/100 g of dry soil) trees than outside the canopy (547 and 588/100 g of dry soil, respectively). The level of root colonization of C. macrostachyus (45 %) was higher than A. gummifera (41 %). Root colonization of maize crops grown under the canopy of A. gummifera and C. macrostachyus trees was significantly higher than outside the canopy (P < 0.001). Maize seedlings grown on non-sterilized soils collected under and outside the canopy of A. gummifera and C. macrostachyus trees recorded higher root colonization, plant height, shoot and root dry weight than grown on sterilized soils (P < 0.001). The percentage of AM colonized roots of Zea mays seedlings was significantly positively correlated with the number of spore counts for field soils. The rhizospheres of indigenous agroforestry perennial species are important source of inoculum for annuals. The integration of perennials and annuals in an agroforestry system enhances the maintenance of soil quality in the tropics.     

上皱姬蜂属中国一新纪录种

记述发现于河南省的上皱姬蜂属Epirhyssa Cresson 1865中国1新纪录种：北海道上皱姬蜂Epirhys sasapporensis Uchida,1928。     

Establishment and early growth of introduced indigenous tree species in typical plantations and shrubland in South China

Unsuccessful colonization by indigenous tree species into established plantations has retarded the succession of artificial plantations to more natural, secondary forests in South China. To understand how to improve colonization by seedlings of indigenous species, we determined how performance of indigenous seedlings is affected by seedling species (the shade-intolerant Castanopsis chinensis, the moderately shade-intolerant Michelia chapensis, and the shade-tolerant Psychotria rubra), the site into which the seedlings were transplanted (a mixed-legume plantation, a eucalyptus plantation, a mixed-native plantation, a mixed-conifer plantation, and a shrubland), and site preparation (removal or retention of understory vegetation and litter). Seedling survival and growth were generally increased by removal of understory vegetation and litter. C. chinensis and M. chapensis grew better in the mixed-legume and mixed-conifer plantations, while P. rubra grew better in mixed-native and mixed-conifer plantations. Responses of the transplanted seedlings to environmental factors were species specific. The effects of light on seedling survival and growth were correlated with the shade tolerance of the species. Soil moisture was important; it was positively correlated with survival but negatively correlated with growth of C. chinensis seedlings. Growth of C. chinensis and M. chapensis was positively correlated with soil potassium, while growth of P. rubra was positively correlated with soil organic matter but negatively correlated with soil hydrolyzed nitrogen. These findings suggest that we should select suitable native species under the different plantations before improvement of plantations. Light and soil moisture are most important environmental factors for the selection of species specific. Site preparation and fertilizer are needed during the improvement of those plantations.     

黑龙江省郭公虫科(鞘翅目)分类研究及一中国新记录种记述

本文报道了黑龙江省7种郭公虫科昆虫,包括1中国新记录种Orthrius striatulus （Motschlsky）.所有种类均列出了分布及成虫照片,中国新记录种还简要介绍了其鉴别特征.     

Early growth and seasonal chemical composition of three indigenous multipurpose tree species (MPTS) in Abeokuta,Nigeria

A study was carried out to evaluate the growth parameters and nutritive qualities of Moringa oleifera, Millettia griffoniana and Pterocarpus santalinoides. The main objective of the study was to assess the potential of the MPTS in supplementing the feed of ruminant animals during the dry season when grasses are scarce and their quality generally fall short of animal requirements. Leaf samples were randomly collected from the trees for estimation of the proximate composition, neutral detergent fibre, acid detergent fibre and gas production using the in vitro technique. Samples were collected three times to represent seasonal variations as follows: November: Early Dry; February: Mid Dry and April: Late Dry seasons. Gas production was recorded at 3, 6, 9, 12, 15, 18, 21, 24, 48, 72 and 96 h of incubation. Mortality rate was less than 5%. M. oleifera recorded the best overall growth respectively followed by P. santalinoides and M. griffoniana. P. santalinoides and M. oleifera retained more leaves in the dry season than M. griffoniana. The dry matter (DM) and ether extract (EE) contents of the MPTS were significantly (P < 0.05) affected by seasons and plant species while there were significant (P < 0.05) species effects on the CP and ADF values. The gas production values and the fermentation parameters indicated the presence of potentially degradable nutrients in the MPTS, which underscores the importance of the tree species as sources of nutrient for ruminant animals during the dry season.     

Two new species of Colpoma on trees from China

Two new species of Colpoma are described from China. Colpoma intermedium on Pinus armandii is macroscopically similar to species of Colpoma while asci and ascospores are similar to those of species of Therrya. Colpoma sinense on Rhododendron sp. differs from other Colpoma species by conspicuous lip cells embedded in a gelatinous matrix.     

中国夜蛾科二新记录种及一大陆新记录种记述

本文报道了分布于黑龙江省塔和地区的2个中国夜蛾科新记录种：北方纬夜蛾Atrachea japonica （Leech, 1889） 和暗绿丫金翅夜蛾Autographa macrogamma （Eversmann, 1842）,同时首次将以新种记述于韩国和台湾省的中文夜蛾Neustrotia rectilineata Ueda, 1987在大陆予以报道.对标本材料的外部形态特征、生殖器图片和世界性分布予以记述.所用标本材料收藏在东北林业大学林学院昆虫实验室.