Insecticidal potential of traditionally important plant, Zanthoxylum armatum DC (Rutaceae) against cabbage butterfly, Pieris brassicae (Linnaeus)

304-311Cabbage butterfly, Pieris brassicae (Linnaeus) is one of the most destructive pests of brassicaceous crops. Zanthoxylum armatum DC (Rutaceae) is versatile, traditionally important and edible medicinal plant, known to have insect repellent and larvicidal properties against many pests. Thus, the insecticidal potential of Z. armatum was evaluated against P. brassicae. N-hexane fraction of different plant parts of Z. armatum was extracted by using standard Soxhlet extraction method. Median lethal concentrations and time (LC50 and LT50) were determined by contact and oral toxicity tests by using Probit analysis. Pericarp and leaf extracts were found toxic to the caterpillars by contact. LC50’s of pericarp and leaf extract (by contact) was found to be 0.15% and 0.22%, respectively at 72 h. The relative toxicity of pericarp extract was recorded to be 1.50, when Azadirachtin 0.15 EC was considered as a unit. With sub-lethal concentrations, the developmental time was delayed; while percentage of pupation and adult emergence was significantly affected in treated caterpillars. In semi-field study, egg-laying of the female butterfly was significantly reduced and larval mortality was considerably higher (up to 53.33%) within 72 h after treatment in plants treated with Z. armatum extracts. In field trial, significant reduction (67.92%) in larval population was observed within 5 days of spraying of Z. armatum extracts

Loungu (Carpenter worm): Indigenous Delicious Insects with Immense Dietary Potential in Nagaland state, India

145-151Carpenter worms of genus Cossus (Lepidoptera: Cossidae) are common wood-boring insects that can cause significant damage to several economically important plant species across the globe. Nevertheless, these worms are a popular delicacy among the indigenous population of Nagaland state of India since age old days. The carpenter worms (locally known as ‘Loungu’) are culturally significant during the Te-l Khukhu festival of Southern Angami region, annually held during July. The direct larval consumption is also cited for medicinal value. Rearing of carpenter worm is gaining popularity in hill tracts of Nagaland, because of its potential as a viable source of income for the rural population. The present study aimed to determine the eventual nutritional value of the larva by approximating its nutritional potential for the first time. Proximate analysis presents a significantly higher value of crude fat (37%), crude protein (48%), crude fibre (12.90%) and an appreciable calorific value. Close correlation between increased polyphenol value with its higher antioxidant capacity and pigment content is strongly evident. Nevertheless, the larva also provides appreciable quantities of dietary minerals reflected in terms of higher zinc and iron content. Analysis of thin layer chromatography undertaken in the study interestingly identified some of the essential amino acids, viz., methionine, lysine, leucine, histidine, threonine etc. This is the first report pioneering other detail studies to establish the significant value of carpenter worm larvae as an exotic dietary supplement among the indigenous Naga population, thereby providing more impetus for its promotion and commercialization

Mitochondrial DNA and trade data support multiple origins of Helicoverpa armigera (Lepidoptera, Noctuidae) in Brazil

The Old World bollworm Helicoverpa armigera is now established in Brazil but efforts to identify incursion origin(s) and pathway(s) have met with limited success due to the patchiness of available data. Using international agricultural/horticultural commodity trade data and mitochondrial DNA (mtDNA) cytochrome oxidase I (COI) and cytochrome b (Cyt b) gene markers, we inferred the origins and incursion pathways into Brazil. We detected 20 mtDNA haplotypes from six Brazilian states, eight of which were new to our 97 global COI-Cyt b haplotype database. Direct sequence matches indicated five Brazilian haplotypes had Asian, African, and European origins. We identified 45 parsimoniously informative sites and multiple substitutions per site within the concatenated (945 bp) nucleotide dataset, implying that probabilistic phylogenetic analysis methods are needed. High diversity and signatures of uniquely shared haplotypes with diverse localities combined with the trade data suggested multiple incursions and introduction origins in Brazil. Increasing agricultural/horticultural trade activities between the Old and New Worlds represents a significant biosecurity risk factor. Identifying pest origins will enable resistance profiling that reflects countries of origin to be included when developing a resistance management strategy, while identifying incursion pathways will improve biosecurity protocols and risk analysis at biosecurity hotspots including national ports

Population Genetic Structure of the Cotton Bollworm Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) in India as Inferred from EPIC-PCR DNA Markers

Helicoverpa armigera is an important pest of cotton and other agricultural crops in the Old World. Its wide host range, high mobility and fecundity, and the ability to adapt and develop resistance against all common groups of insecticides used for its management have exacerbated its pest status. An understanding of the population genetic structure in H. armigera under Indian agricultural conditions will help ascertain gene flow patterns across different agricultural zones. This study inferred the population genetic structure of Indian H. armigera using five Exon-Primed Intron-Crossing (EPIC)-PCR markers. Nested alternative EPIC markers detected moderate null allele frequencies (4.3% to 9.4%) in loci used to infer population genetic structure but the apparently genome-wide heterozygote deficit suggests in-breeding or a Wahlund effect rather than a null allele effect. Population genetic analysis of the 26 populations suggested significant genetic differentiation within India but especially in cotton-feeding populations in the 2006-07 cropping season. In contrast, overall pair-wise F(ST) estimates from populations feeding on food crops indicated no significant population substructure irrespective of cropping seasons. A Baysian cluster analysis was used to assign the genetic make-up of individuals to likely membership of population clusters. Some evidence was found for four major clusters with individuals in two populations from cotton in one year (from two populations in northern India) showing especially high homogeneity. Taken as a whole, this study found evidence of population substructure at host crop, temporal and spatial levels in Indian H. armigera, without, however, a clear biological rationale for these structures being evident

Population Genetic Structure of the Cotton Bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in India as Inferred from EPIC-PCR DNA Markers

Helicoverpa armigera is an important pest of cotton and other agricultural crops in the Old World. Its wide host range, high mobility and fecundity, and the ability to adapt and develop resistance against all common groups of insecticides used for its management have exacerbated its pest status. An understanding of the population genetic structure in H. armigera under Indian agricultural conditions will help ascertain gene flow patterns across different agricultural zones. This study inferred the population genetic structure of Indian H. armigera using five Exon-Primed Intron-Crossing (EPIC)-PCR markers. Nested alternative EPIC markers detected moderate null allele frequencies (4.3% to 9.4%) in loci used to infer population genetic structure but the apparently genome-wide heterozygote deficit suggests in-breeding or a Wahlund effect rather than a null allele effect. Population genetic analysis of the 26 populations suggested significant genetic differentiation within India but especially in cotton-feeding populations in the 2006–07 cropping season. In contrast, overall pair-wise F (ST) estimates from populations feeding on food crops indicated no significant population substructure irrespective of cropping seasons. A Baysian cluster analysis was used to assign the genetic make-up of individuals to likely membership of population clusters. Some evidence was found for four major clusters with individuals in two populations from cotton in one year (from two populations in northern India) showing especially high homogeneity. Taken as a whole, this study found evidence of population substructure at host crop, temporal and spatial levels in Indian H. armigera, without, however, a clear biological rationale for these structures being evident