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Subterranean termites cause significant damage to agricultural crops and wooden infrastructures worldwide. Coptotermes and Odontotermes were found as the most abundant and damaging genera of subterranean termites in Pakistan. Many conventional synthetic insecticides are being used to combat termite infestations with often unsatisfactory control results. This study assessed the comparative toxicity of some prevailing synthetic insecticides with different modes of action against subterranean termites Coptotermes heimi Wasmann (Isoptera: Rhinotermitidae) which was found as a dominant termite species in district Sargodha. Filter paper disc-based bioassays revealed that all insecticides showed a significant impact (P < 0.001) on the mortality of C. heimi workers and this mortality response was directly proportional to insecticidal concentrations and exposure times. Significantly higher mortality was recorded by chlorpyrifos (100.0%) and fipronil (95.0%) at 72 h post-exposure with minimum LC50 values of 1.29 and 2.04%, respectively. Similar trend of effectiveness was exhibited by their LT50 values. Minimum mortality of C. heimi workers was recorded by the formulations of chlorantraniliprole and abamectin. Based on overall study results, it is concluded that chlorpyrifos and fipronil are effective synthetic termiticides and are recommended to the indigenous farmers for combatting subterranean termite infestations. [ABSTRACT FROM AUTHOR]

Bacterial diseases cause colossal losses in vegetable crops and are considered major limiting factors for the commercial production of vegetables around the globe. Among bacterial diseases, angular leaf spot of cucumber caused by Pseudomonas syringae is one of the most economically important diseases that cause substantial economic loss to the cucumber crop. In this study, the in‐vitro and in‐vivo effects of different strains (X1–X15) of the nematode symbiotic bacterium Xenorhabdus nematophila was determined on the growth of P. syringae in different selected media (TB, SB, SOB, SOC, YT and LB) and at different pH levels (6.5, 7.5 and 8.5) and on the incidence of angular leaf spot disease on potted cucumber plants. According to the results, maximum growth inhibition of P. syringe (25 mm) was observed in the case of strain X12, followed by strains X10 (23 mm), X8 (21 mm) and X6 (20 mm), while maximum colony growth was observed in the control. Moreover, this P. syringae growth inhibition by the X12 strain of X. nematophila was significantly maximum in SB medium and at pH 7.5. Results of the in‐vivo experiment with potted plants showed a maximum incidence (90%) of angular leaf spot disease in control plants, while a minimum disease incidence (15%) was observed for the plants treated with two times dilution of X. nematophila culture, followed by ten times (23%) and fifty times (35%). The overall results of this study demonstrate the inhibitory effect of X. nematophila on the growth and incidence of P. syringae and underscore its putative role in the biological management of plant pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Spodoptera litura Fabricius (Lepidoptera: Noctuidae) is a deleterious agricultural pest worldwide. Field populations of S. litura manifest resistance to almost all conventional insecticides and it is imperative looking for novel biorational insecticides to control this pest. In this regard, this study bioassayed some promising biorational insecticides including botanical, microbial and non-conventional synthetic insecticidal formulations against 3rd instar larvae of S. litura. Bioassay with botanical formulations showed a significant toxicity of oil and extract formulations of neem (Azadirachta indica) causing 70-77% larval mortality in 72 h observation and exhibiting minimum medial lethal concentration (LC50) and time (LT50) values (i.e. 12.32 and 38.01 ppm and 16.67 and 11.68 days, respectively). Among microbial formulations tested, S. litura-nuclear polyhedrosis virus (NPV) and Bacillus thuringiensis kurstaki appeared as the most effective microbial treatments exhibiting minimum LC50 (3.78 × 10³ OB mL-1 and 1.22 × 107 spores mL-1, respectively) and LT50 (3.83 and 3.71 days, respectively) values. While flubendiamide, chlorantraniliprole and spinetoram exerted most significant lethal and sublethal effects on S. litura with minimum LT50 values (i.e. 19.58, 30.78 and 26.25 h, respectively). Larval development time was significantly prolonged by both half and one-fourth doses of flubendiamide and chlorantraniliprole (19.51 and 19.63 days and 17.77 and 17.20 days, respectively), while pupal duration prolonged for spinetoram and lufenuron. Similarly, significant suppression of adult lifespan was exhibited by flubendiamide (11.83 and 11.85 days) and chlorfenapyr (12.28 and 12.06 days). Overall study results advocate further consideration of these aforesaid biorational insecticides against S. litura infestations. However, assessment of their compatibility with each other and with other IPM strategies both under lab and field conditions constitutes future perspectives of this work. [ABSTRACT FROM AUTHOR]

BACKGROUND: Tomato (Solanum lycopersicum L.) is an economically important vegetable crop around the globe. Tomato yellow leaf curling (TYLC) is the most devastating viral disease posing a serious threat to tomato production throughout the tropical and subtropical world. Induction of microbe‐mediated systemic resistance in plants has been of great interest in recent years as a novel microbiological tool in disease and insect pest management. This in‐vitro study aimed to determine the effectiveness of different strains (BB252, BB72 and ARSEF‐2860) of a hypocreal fungus Beauveria bassiana against TYLCV disease and aphid Myzus persicae. Potted tomato plants exogenously treated with conidial and filtrate suspensions of B. bassiana strains and of their partially purified or purified proteins were exposed to TYLCV inoculum and aphid M. persicae. RESULTS: Results showed a significant suppression of TYLCV disease severity index by the exogenous application of conidial, filtrate and protein treatments of all B. bassiana strains and this response was directly proportional to the treatment concentration. Similarly, mean fecundity rate of M. persicae was also significantly reduced by the highest concentration of ARSEF‐2860‐derived elicitor protein PeBb1, followed by the highest concentrations of BB252‐ and BB72‐derived partially purified proteins. Moreover, these B. bassiana‐derived proteins also caused a significant upregulation of most of the plant immune marker genes associated with plant defense. CONCLUSION: Overall, the study findings suggest that these B. bassiana strains and their partially purified or purified elicitor proteins could be effective biological tools for the management of TYLCV and aphid infestation on tomato plants. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The invasive fall armyworm species, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), was first time reported in Pakistan during March 2019 causing severe damage to maize crop. As a new pest, there is little information available on its susceptibility to insecticides in Pakistan. We evaluated selective synthetic insecticides with different modes of action to control S. frugiperda larvae in the laboratory as well as under semi-field and field conditions. All insecticides performed well in controlling S. frugiperda larvae under laboratory conditions. Though, chlorantraniliprole @ 50 mL/100L (58.0–100%), abamectin @ 400 mL/100L (56.0–100%), lambda-cyhalothrin @ 250 mL/100L (52.0–100%) and chlorpyrifos @ 1000 mL/100L (52.0–98.0%) showed significantly (P < 0.05) higher mortality than other chemicals. Higher concentrations of abamectin (6000 ppm), chlorpyrifos (12000 ppm) and chlorantraniliprole (700 ppm) showed 100% larval mortality at 24 h post-exposure. Lambda-cyhalothrin (3500 ppm) showed 95% larval mortality at 24 h and 100% mortality at 48 h of application. The medium dose rate of abamectin (4000 ppm) and chlorantraniliprole (600 ppm) also showed 100% larval mortality at 48 h of application. In semi-field and field conditions, chlorantraniliprole showed 100% larval mortality at 48 h, while abamectin and chlorpyrifos showed 87–89% and 94–81% larval mortality respectively in semifield to field conditions after 72 h of application. Overall study results demonstrate the effectiveness of chlorantraniliprole, abamectin and chlorpyrifos and these synthetic insecticides should be considered as components of integrated management of S. frugiperda in Pakistan. [ABSTRACT FROM AUTHOR]

Mosquitoes are unquestionably the important arthropod vectors of diseases such as malaria, dengue, filariasis and systemic allergic reactions in humans. Southern house mosquito Culex quinquefasciatus Say is found in tropical and subtropical regions of the world and transmits many zoonotic diseases in humans and in wild and domestic animals. It is primarily controlled by the extensive use of conventional synthetic insecticides against most of which it has developed resistance. This study was aimed at determining the toxicity of selected microbial and synthetic insecticide formulations and botanical extracts against C. quinquefasciatus larvae. Among the n-hexane extracts of 40 indigenous plant species collected from Soon Valley and surrounding salt range of Pakistan bioassayed against C. quinquefasciatus larvae, eighteen botanicals exhibited more than 50% larval mortality in 48 h exposure. The most effective botanical extracts were Maerua arenaria Forsk, Nerium indicum Mill., Withania coagulans Dunal, Suaeda fruticosa (L.) Delile, Olea ferruginea Wall., Adiantum capillus-veneris L. and Dicliptera bupleuroides Nees exhibiting 87, 84, 83, 81, 79, 78 and 77% larval mortality, respectively with minimum LC50 and LC90 values. Among the microbial and synthetic insecticides, the highest larval mortality was recorded by Metarhizium anisopliae NCIM 1311 (83%) and Bacillus thuringiensis subsp. israelensis (63%), and by pyriproxyfen (86%) and indoxacarb (85%), respectively. Hence, these botanical, microbial and synthetic insecticides are recommended for the efficient control of C. quinquefasciatus larvae in field to reduce the environmental pollution caused by persistent synthetic insecticides. [ABSTRACT FROM AUTHOR]