Diet impacts on the biological aspects of pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae) under controlled laboratory conditions.

BACKGROUND: Pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae) is a native pest of Asia and preferably invasion on cotton (Gossypium hirsutum L.) crop as a commendatory host plant. Commercially, G. hirsutum is known as white gold and is an important cash crop all over the globe. Limited studies were published to focus on certain dietary compositions against different cotton pests. Therefore, the present study was undertaken in the laboratory under controlled conditions (temperature: 27 ± 2°C and relative humidity: 60 ± 10%) to determine the impact of three different treatment diets (wheat germ meal, okra, and chickpea) on the biological aspects (lifetime, developmental period) of P. gossypiella. RESULTS: Results revealed that the shortest larval time of P. gossypiella was observed on the okra feed diet while the longest period was recorded on the wheat germ diet. Meanwhile, the pupation delay was noted on the wheat germ diet. The dietary influence was also observed on adult stages of female and male P. gossypiella (43.00 and 37.50 days respectively) and compared with a standard diet (56.50 and 52.50 days respectively). Furthermore, larval weighed more on the okra and chickpea diet followed by the wheat germ diet, whereas highest pupal weight was observed on the standard diet followed by the chickpea diet and okra diet. CONCLUSION: Developmental parameters were significantly variant across all treatment diets, whereas the higher significant difference was reported on the okra diet. Therefore, the existing data of this study offers fruitful interventions for the future as a modified diet for large-scale and rapid mass production of P. gossypiella larvae.

New promising high yielding cotton Bt-Variety RH-647 adapted for specific agro-climatic zone.

The Bt-cotton RH-647 was developed by Cotton Research Institute CRI, Khanpur has been acknowledged for its possesses superior plant characteristics and potential to yield out under harsh agro-climatic conditions of cotton productive district of Rahimyar Khan in Bahawalpur Division and southern Punjab in 2016. RH- 647 for its novel plant structure and improved fiber quality heat and drought tolerant to withstand successfully sustain yield out in harsh, highly variable hot and dry climatic conditions of and harsh seasoned. RH-647 was developed through one-way hybridization of elite parental genotypes accompanied by pedigree selection method through gene pyramiding technique for incorporation of excellent combinations of fiber traits and CLCuV disease tolerance with higher yield potential right from F1 population. The superior plant combinations were selected in F2-F6 generations were entirely based on phenotypic plant traits and progeny yield potential in field, plant shape, number of bolls per plant, average boll weight (g) and fiber quality traits over standard varieties. The single plant progenies were selected 56 sister lines were tested for Bt-gene (Cry1 Ac) were evaluated for high yielding performance for this superior cross and finally RH-647 as superior breeding line was bulked in year 2010. The strain was evaluated in Randomized Complete Block Design in preliminary yield trials (PYT) and two years in Advance Yield Trials (AYT) trials and Zonal Varietal trials for two years. The superior line 647/10 was ensued for performance in variety attestation tests as RH-647. RH-647 performed best in two years varietal trials (NCVT and PCCT and DUS) conducted for two successive growing seasons (2014-2015 and 2015-2016). RH-647 yielded out significantly compared with standard varieties MNH-886, FH-142 and CIM 602. After completion of mandatory trials in year 2016, RH-647 was approved as new Bt. cotton variety "RH-647". RH-647 is early in maturity with high yield potential and best suited for wheat-cotton cropping pattern. It has fluffy opening and is easy to pick, strongly tolerant to CLCuV disease, high Ginning out turn GOT% (40.2%) with improved fiber traits; staple length (28.3 mm), fiber strength (4.2ug/inch) is duly capable to fulfill all industrial requisitions.

Knock down of Whitefly Gut Gene Expression and Mortality by Orally Delivered Gut Gene-Specific dsRNAs.

Control of the whitefly Bemisia tabaci (Genn.) agricultural pest and plant virus vector relies on the use of chemical insecticides. RNA-interference (RNAi) is a homology-dependent innate immune response in eukaryotes, including insects, which results in degradation of the corresponding transcript following its recognition by a double-stranded RNA (dsRNA) that shares 100% sequence homology. In this study, six whitefly 'gut' genes were selected from an in silico-annotated transcriptome library constructed from the whitefly alimentary canal or 'gut' of the B biotype of B. tabaci, and tested for knock down efficacy, post-ingestion of dsRNAs that share 100% sequence homology to each respective gene target. Candidate genes were: Acetylcholine receptor subunit α, Alpha glucosidase 1, Aquaporin 1, Heat shock protein 70, Trehalase1, and Trehalose transporter1. The efficacy of RNAi knock down was further tested in a gene-specific functional bioassay, and mortality was recorded in 24 hr intervals, six days, post-treatment. Based on qPCR analysis, all six genes tested showed significantly reduced gene expression. Moderate-to-high whitefly mortality was associated with the down-regulation of osmoregulation, sugar metabolism and sugar transport-associated genes, demonstrating that whitefly survivability was linked with RNAi results. Silenced Acetylcholine receptor subunit α and Heat shock protein 70 genes showed an initial low whitefly mortality, however, following insecticide or high temperature treatments, respectively, significantly increased knockdown efficacy and death was observed, indicating enhanced post-knockdown sensitivity perhaps related to systemic silencing. The oral delivery of gut-specific dsRNAs, when combined with qPCR analysis of gene expression and a corresponding gene-specific bioassay that relates knockdown and mortality, offers a viable approach for functional genomics analysis and the discovery of prospective dsRNA biopesticide targets. The approach can be applied to functional genomics analyses to facilitate, species-specific dsRNA-mediated control of other non-model hemipterans.