Search

The purpose of study was to investigate university students' attitudes towards English language learning apps and examine whether there is any significant difference in their attitudes depending on their personal variables such as their gender, major, grade, nationality, and so on. This study also explored students' perceptions of English language learning apps that they have used. Participants were college students living in Korea and China. Data were collected by means of a questionnaire and an interview. Results showed that both Korean and Chinese students generally held positive attitudes towards English language learning apps, although Chinese students showed more positive attitudes than Koreans. The main reasons that they liked to use English language learning apps were their convenience, ubiquity, and rich resources. On the other hands, it was revealed that the lack of communication and feedback was the main problem of using such apps. Both Korean and Chinese students stated that it was an effective way to use English language learning apps to practice pronunciation, vocabulary, listening, and reading skills. Findings of this research suggest that English language learning apps should be developed to inspire users/students' learning interest and foster learner autonomy. [ABSTRACT FROM AUTHOR]

Plutella xylostella and Pieris rapae are the key components of a pest complex that attacks Brassica crops in the Democratic People’s Republic of Korea (DPRK). We examined the spatial distributions of these insects within crops both as individual species and when combined as a standard insect that was derived from their relative feeding rates. The influence of standard co-operative management practice and an integrated pest management (IPM) strategy on the dispersion of the standard insect was tested. Iwao’s m* − m relation was then used to describe the distribution of standard insects by management categories and of Pieris rapae using all data. Pest management practices only affected the distribution of the species when they were combined into standard insects. Enumerative sampling plans were therefore designed for standard insects based on population data derived from IPM-managed fields and for Pieris rapae from population data from all experimental fields. The presented plans have the potential to make a significant contribution to managing lepidopteran pests in the DPRK. The approach will be useful in the design of sequential sampling plans for other geographical regions where these pests co-occur and can also contribute to the development of sequential sampling plans for other pest complexes for which standard insects can be derived. [ABSTRACT FROM AUTHOR]

Brassica crops, principally varieties of Brassica oleracea and Brassica campestris, account for over half the total vegetable production in the Democratic People''s Republic of Korea (DPRK). The crops are attacked by a complex of insects and the two major pest species, Plutella xylostella L. (Lepidoptera: Plutellidae) and Pieris rapae L. (Lepidoptera: Pieridae) represent the principal constraints to Brassica crop production. On co-operative farms pests are managed by scheduled application of broad spectrum insecticides and there is no attempt to conserve or utilize endemic natural enemies. The natural enemy complexes attacking P. xylostella and P. rapae in summer white cabbage (Brassica oleracea var. 6–21) on three co-operative farms in the south west of DPRK were studied. The hymenopteran parasitoids Cotesia vestalis Haliday (=plutellae Kurdjumov) (Braconidae), Oomyzus sokolowskii Kurdjumov (Eulophidae) and Diadromus collaris Gravenhorst (Ichneumonidae) attacked P. xylostella while Cotesia glomeratus L. (Braconidae), Cotesia rubecula Marshall (Braconidae) and Pteromalus puparum L. (Pteromalidae) and an unidentified species of Exorista (Diptera: Tachinidae) attacked P. rapae. The generalist epigeal predatory fauna was dominated by Lycosidae (most abundant species: Lycosa t-insignata) and Carabidae (most abundant species: Chlaenius naeviger Morawitz, C. pallipes Gebler, Calathus helensis Schaller). Larval and pupal parasitism rates of both P. xylostella and P. rapae increased during the early summer months but natural enemy exclusion experiments showed that generalist predators were the most important natural enemy guild attacking P. xylostella populations in the agro-ecosystem. In a step towards the development of conservation biological control strategies, field experiments compared current pest management practice with pest threshold based interventions using commercial formulations of Bacillus thuringiensis var. aizawai (Bt). The Bt-natural enemy strategy significantly increased crop yields and the impact of both parasitoid and predator natural enemies on pest populations. However, even under the threshold based Bt regimes, natural enemy impact remained relatively low. The ecology of the major pests and their natural enemies is discussed and recommendations for improved biological control and more effective management of key Brassica pests are made within the constraints posed by current agricultural circumstances in DPRK. [Copyright &y& Elsevier]