This study was carried out to investigate the insecticidal properties of Beauveria bassiana, Metarhizium anisopliae and Heterorhabditis bacteriophora for their virulence against different larval instars of Rhynchophorus ferrugineus (Olivier). Both fungi were either applied alone or in combination, with H. bacteriophora simultaneously or 1 and 2 weeks after fungal application; EPN were also applied alone. Moreover, assessment of host development, diet consumption, frass production and weight gain were observed at sub-lethal dose rates. In combined treatments, additive and synergistic interactions were observed. Synergism was observed more frequently in H. bacteriophora + B. bassiana combinations than in H. bacteriophora + M. anisopliae combinations, and was higher in early instars than old instars. In 2nd and 4th instars, synergy was noted in H. bacteriophora + B. bassiana combinations at 0, 7 and 14 d intervals and in 6th instar synergy was observed only in H. bacteriophora + B. bassiana combinations (at 0 and 7 d intervals). A decrease in pupation, adult emergence and egg hatching was enhanced in the combined treatments. Furthermore, reduced weights and variation in duration of insect developmental stages were observed among entomopathogens and enhanced in H. bacteriophora + B. bassiana combinations. Larvae treated with sub-lethal concentrations exhibited reductions in food consumption, growth and frass production and weight gain.
The occurrence of entomopathogenic fungi isolated from stored grain insect pests sampled from various geographical regions of Punjab, Pakistan, was investigated. In total, 25,720 insects from six different species were evaluated, and 195 isolates from 24 different fungal species were recovered. These included the Ascomycetes Beauveria bassiana sensu lato (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) , Metarhizium anisopliae sensu lato (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae), Purpureocillium lilacinum (Thorn) Samson (Hypocreales: Ophiocordycipitaceae), and Lecanicillium attenuatum (Zare and W. Gams) (Hypocreales: Clavicipitaceae). The cadavers of red flour beetle Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae) were significantly infected with the fungi followed by rice weevil Sitophilus oryzae (L.) (Coleoptera: Curculionidae), lesser grain borer Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), rusty grain beetle Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae), and cowpea weevil Callosobruchus maculatus (F.) (Coleoptera: Bruchidae); however, the least were recovered from khapra beetle Trogoderma granarium (Everts) (Coleoptera: Dermestidae). The geographical attributes (altitude, longitude, and latitude) greatly influenced the occurrence of entomopathogenic fungi with highest number of isolates found from >400 (m) altitude, 33°–34′ N latitude, and 73°–74′ E longitude. The findings of the current surveys clearly indicated that the entomopathogenic fungi are widely distributed in the insect cadavers, which may later be used in successful Integrated Pest Management programs.
Abstract:In this paper the influence of micro-sized (3 µ m) and nano-sized (10 nm) silica (SiO 2) on mechanical, thermal, and electrical properties of silicon rubber (SiR), epoxy, and ethylene propylene diene monomer (EPDM) composites is presented. The micro-and nano-sized SiO 2 particle-filled SiR, epoxy, and EPDM composites were formulated with 20% microsilica and 5% nanosilica by weight respectively. Among these composites, SiR-SiO 2 amalgamation was performed by mixing using an ultrasonication procedure. Epoxy-SiO 2 was compounded in two steps, i.e. dispersion of fillers and mixing, whereas EPDM-SiO 2 compounding was performed with a two roll mill technique. With the addition of micro/nano-SiO 2 , the composites showed enhanced tensile strength of ∼ 2.7 MPa, improved hardness, and reduced elongation at break. Further incorporation of micro/nano-sized particles resulted in high thermal stability for SiRnano composites (SNCs) as compared to epoxy and EPDM composites. Compared to SiR and EPDM composites, epoxy-nano composites showed the highest value of dielectric strength, i.e. 38.8 kV/mm. Meanwhile, the volume and surface resistivity of SNCs were found higher as compared to other investigated samples. Promising properties of SiR nanocomposites among all the investigated samples suggest that their application is more suitable for utilization in outdoor electrical insulations.
The red palm weevil Rhynchophorus ferrugineus (Olivier) is an important pest of date palms in many regions of the world. This paper reports the first survey of insecticide resistance in field populations of R. ferrugineus in Pakistan which were collected from seven date palm growing areas across Punjab and Khyber Pakhtunkhwa (KPK) provinces, Pakistan. The resistance was assessed by the diet incorporation method against the formulated commonly used chemical insecticides profenophos, imidacloprid, chlorpyrifos, cypermethrin, deltamethrin, spinosad, lambda-cyhalothrin and a fumigant phosphine. Elevated levels of resistance were recorded for cypermethrin, deltamethrin and phosphine after a long history of insecticide use in Pakistan. Resistance Ratios (RRs) were 63- to 79-fold for phosphine, 16- to 74-fold for cypermethrin, 13- to 58-fold for deltamethrin, 2.6- to 44-fold for profenophos, 3- to 24-fold for chlorpyrifos, 2- to 12-fold for lambda-cyhalothrin and 1- to 10-fold for spinosad compared to a susceptible control line. Resistant R. ferrugineus populations were mainly found in southern Punjab and to some extent in KPK. The populations from Bahawalpur, Vehari, Layyah and Dera Ghazi Khan were most resistant to chemical insecticides, while all populations exhibited high levels of resistance to phosphine. Of the eight agents tested, lower LC50 and LC90 values were recorded for spinosad and lambda-cyhalothrin. These results suggest that spinosad and lambda-cyhalothrin exhibit unique modes of action and given their better environmental profile, these two insecticides could be used in insecticide rotation or assist in phasing out the use of older insecticides. A changed pattern of both insecticides can be used sensibly be recommended without evidence of dose rates and frequencies used.
Nineteen different isolates of the entomopathogenic fungi Beauveria bassiana sensu lato (s.l.) and Metarhizium anisopliae s.l. (Ascomycota: Hypocreales), recovered from different soil samples (field crops, fruit orchards, vegetable fields and forests) and insect cadavers were tested against Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) at two different spore concentrations (1 × 107 and 1 × 108 conidia mL−1). Three isolates of B. bassiana and two of M. anisopliae gave >88 % larval and >75 % adult mortality of R. ferrugineus on their highest dose rate respectively. More sporulating cadavers (mycosis) resulted from a high dose rate compared to low dose on both life stages of R. ferrugineus. The current study confirmed the lethal action of B. bassiana and M. anisopliae isolates with mortality levels usually directly proportional to the conidial concentration. This study further confirmed that the isolates recovered from R. ferrugineus dead cadavers gave more mortality compared to the other sources. In the virulence assay two isolates of B. bassiana caused the highest percentage of both larval and adult mortality at all exposure intervals which suggest that they may be the most promising for use in sustainable management programs aimed at microbial control in date palm orchards.
The nonlinear optical (NLO) materials are playing a crucial role in almost all aspects of photonics including imaging frequency, manipulation, photon generation, transmission and detection. The nonlinear optics aims to investigate light response in NLO media, in which the NLO response is normally weak and low energy efficient. A comprehensive summary, discussion, and correlation of the light–matter interaction in the 2D nano‐platform, like graphene and TMDCs, would be inspirational and timely needed. In this contribution, a broad overview and discussion about recent experimental evolution regarding the NLO response and its corresponding applications in various 2D materials are presented. A wide material library including graphene, transition metal dichalcogenides, black phosphorus, MXenes, semimetals, polymer materials, and hybrid structures (0D, 1D, 3D) are discussed. In this review, the qualitative description of NLO is firstly illustrated, followed by various fundamental NLO processes being highlighted. Fundamental limits of nonlinear optics and some of NLO applications are prospected. It is hoped that this comprehensive review will shed a light on the development of nonlinear optics with 2D materials to be applied in the field of photonics and optoelectronics.
Economic growth is a change in the economic process in a country in a sustainable direction for the better in a certain period. Economic growth can also be interpreted as a process of increasing the production capacity of an economy that is realized in the form of an increase in national income. PAD-Free Variables (X1) Measured using: (1) Taxes, (2) Non-taxation, Development Expenditures (X2) Measured using: (1 ) Development, (2) Growth. Economic Growth Variable (Y) Measured using: (1) Efficiency ratio, (2) Effectiveness Ratio, (3) Independence ratio, (4) Ratio of economic growth activity.This means that if the income of the region will also cause an increase in economic growth achievements. which is very flexible in terms of utilization causes the regions to be more flexible in planning the allocation of expenditure budgets for development activities in accordance with their economic agenda which includes the development of basic facilities and infrastructure that play a role in supporting optimal economic growth. Keywords: PAD, Development Expenditure, Economic Growth
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