An experiment was conducted at Malakabad (Gadera) Dargai Malak and KPK to study the effect of different levels of nitrogen and phosphorus on the yield of maize varieties in randomize complete block design with split plot arrangement.

Chemosensory proteins (CSPs) play imperative functions in chemical and biochemical signaling of insects, as they distinguish and transfer ecological chemical indications to a sensory system in order to initiate behavioral responses. The brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae), has emerged as the most destructive pest, causing serious damage to rice in extensive areas throughout Asia. Biotic characteristics like monophagy, dual wing forms, and annual long-distance migration imply a critical role of chemoreception in N. lugens. In this study, we cloned the full-length CSP8 gene from N. lugens. Protein sequence analysis indicated that NlugCSP8 shared high sequence resemblance with the CSPs of other insect family members and had the typical four-cysteine signature. Analysis of gene expression indicated that NlugCSP8 mRNA was specifically expressed in the wings of mated 3-day brachypterous females with a 175-fold difference compare to unmated 3-day brachypterous females. The NlugCSP8 mRNA was also highly expressed in the abdomen of unmated 5-day brachypterous males and correlated to the age, gender, adult wing form, and mating status. A competitive ligand-binding assay demonstrated that ligands with long chain carbon atoms, nerolidol, hexanal, and trans-2-hexenal were able to bind to NlugCSP8 in declining order of affinity. By using bioinformatics techniques, three-dimensional protein structure modeling and molecular docking, the binding sites of NlugCSP8 to the volatiles which had high binding affinity were predicted. In addition, behavioral experiments using the compounds displaying the high binding affinity for the NlugCSP8, revealed four compounds able to elicit significant behavioral responses from N. lugens. The in vivo functions of NlugCSP8 were further confirmed through the testing of RNAi and post-RNAi behavioral experiments. The results revealed that reduction in NlugCSP8 transcript abundance caused a decrease in behavioral response to representative attractants. An enhanced understanding of the NlugCSP8 is expected to contribute in the improvement of more effective and eco-friendly control strategies of BPH.

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Zinc (Zn) fertilization could be a viable approach for minimizing cadmium (Cd) accumulation in the food chain. The present study was carried out to investigate the role of various Zn fertilization treatments (control, foliar application at tasseling stage, foliar application at milky stage, rubber ash application, soil application of ZnSO4) and cultivars (Pop 2004B, Pop 2006, Azam, Sarhad (W), Pahari) on grain yield, grain Zn, and grain Cd concentrations in maize. All Zn fertilization treatments resulted in a significantly higher grain yield, higher grain Zn concentration, and reduced grain Cd concentration. The application of rubber ash remained the best among all Zn fertilization treatments as it resulted in a higher grain yield of 62% and a reduced grain Cd concentration by 57% compared to control. Contradictions were apparent between cultivars, and the cultivars which recorded a higher grain yield had a lower Zn concentration in their grains and vice versa. Regarding Cd accumulation, all cultivars except Azam, retained less Cd with increased grain Zn concentration. Future studies should focus on breeding/selection of high yielding and high quality cultivars. Furthermore, the feasibility of rubber ash maybe tested under different climatic and edaphic conditions against other heavy metals and other crops as well.

Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) is a major pest of several economically important crops with worldwide distribution. Use of insecticides is the principal strategy for its management, which has subsequently led to insecticide resistance and control failures. Functional response of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) at larval and adult stages was evaluated in this study, using S. litura eggs as the prey at various temperatures varying between 15 and 35 °C. Based on logistic model findings, linear parameters of various predatory stages of H. axyridis at various temperatures were significantly negative, which indicate a type II functional response. The theoretical maximum number (T/Th) of eggs consumed increased with increasing temperature for all predatory stages. According to the random predator equation, the coefficients of attack rate increased and that of handling time decreased as the temperature increased. The 4th instar and adult stages were superior candidates for biocontrol of the target prey, typically at higher temperatures. The maximum attack rate (0.546 ± 0.058 h) and lowest handling time (0.189 ± 0.004 h−1) were exhibited by the females at 30 and 35 °C, respectively, whereas these parameters were inferior for early instars. These findings clearly depict that the 4th instar and adult predators are efficient egg consumers and can serve as potential suppressors of S. litura field populations. The limitations of the predictions formulated by functional response trials are also discussed.

Chemoreception is a key process for insects. Odorant messages diffuse through the air and are translated into physiological signals by chemosensory receptor neurons in sensilla that are mainly located on insect antennae. We sequenced the antenna transcriptome of Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae), which is a serious pest of stored grains throughout regions with warm climates, and performed transcriptome analysis on R. dominica antennae. We obtained 57 million 90-base pair-long reads that we assembled into 37 877 unigenes with a mean size of 1007 base pairs. Predicted protein sequences were matched with Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) (79.1%), Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae) (1.7%), Megachile rotundata (Fabricius) (Hymenoptera: Megachilidae) (1.3%), Acyrthosiphon pisum Harris (Hemiptera: Aphididae) (1.2%), and other (16.7%) homologues. In chemosensory gene families, we identified transcripts that encoded the following putative genes: 12 odorant-binding proteins (OBPs), four pheromone-binding proteins (PBPs), eight chemosensory proteins (CSPs), five sensory neuron membrane proteins (SNMPs), six odorant receptors, and eight ionotropic receptors. The diversity of the predicted OBPs, PBPs, and CSPs are also discussed. These findings will advance our understanding of olfaction process by this pest.

A two-sex life table is a useful tool for studying the fitness of predators. Previous studies of Orius strigicollis Poppius (Heteroptera: Anthocoridae) fitness have not been done on Pectinophora gossypiella (Lepidoptera: Gelechiidae) using a two-sex life table tool. This study reports the fitness of the minute predatory flower bug, O. strigicollis when feeding on the cotton pest P. gossypiella using a two-sex life table tool. Different densities (5, 10, and 15 eggs) of P. gossypiella eggs were used to calculate the feeding capacity and fitness of O. strigicollis in the laboratory at 28 °C ± 1, 75 ± 5% RH and 16:8 (L:D). The results concluded that O. strigicollis is an efficient predator of P. gossypiella. The maximum growth capacity of the predatory bug O. strigicollis was attained when it was fed on 10 and 15 P. gossypiella eggs. Furthermore, shorter generation and development time were also observed in the case of 15 eggs of P. gossypiella. These results suggest that O. strigicollis has considerable predatory potential and prefers feeding on P. gossypiella eggs than on the first instar larvae at the fourth instar or the female stage. Although the field potential of O. strigicollis is still unknown, this study will support future investigations in terms of field applications.

The Japanese pine sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae), is a major pest of pines and it is also the key vector of the exotic pinewood nematode in China. In the present study, we cloned, expressed, and purified a chemosensory protein (CSP) in M. alternatus. We surveyed its expression in various developmental stages of male and female adult tissues and determined its binding affinities for different pine volatiles using a competitive binding fluorescence assay. A CSP known as CSP5 in M. alternatus was obtained from an antennal cDNA library and expressed in Escherichia coli. Quantitative reverse transcription polymerase chain reaction results indicated that the CSP5 gene was mainly expressed in male and female antennae. Competitive binding assays were performed to test the binding affinity of recombinant CSP5 to 13 odour molecules of pine volatiles. The results showed that CSP5 showed very strong binding abilities to myrcene, (+)-β-pinene, and (-)-isolongifolene, whereas the volatiles 2-methoxy-4-vinylphenol, p-cymene, and (+)-limonene oxide have relatively weak binding affinity at pH 5.0. Three volatiles myrcene, (+)-β-pinene, and (-)-isolongifolene may play crucial roles in CSP5 binding with ligands but this needs further study for confirmation. The sensitivity of insect to host plant volatiles can effectively be used to control and monitor the population through mass trapping as part of integrated pest management programs.