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Sap-sucking insect pests have been a severe threat to horticultural and agricultural crops all over the world. Asian citrus psyllid Diaphorina citri Kuwayama (Psyllidae: Hemiptera) and cotton aphid Aphis gossypii Glover (Aphididae: Hemiptera) are destructive sap-sucking pests of citrus and cotton, respectively. Extensive use of persistent synthetic insecticides against these pests poses issues of environmental contaminations and health hazards and suggests looking for alternate biorational plant protection measures such as botanical pesticides. This study evaluated the potential toxicity of acetone extracts of 40 indigenous plant species of Soon valley and surrounding salt range (Punjab, Pakistan) against D. citri and A. gossypii using standard twig-dip and leaf-dip bioassay methods, respectively. Results of initial screening bioassay showed the highest mortality of D. citri by 10% extracts of Mentha longifolia (L.) Huds. (93%), Melilotus officinalis (L.) Pall. (91%), Nerium indicum Mill. (89%), Datura alba L. (88%) and Salvia officinalis L. (81%). Second bioassay conducted against A. gossypii using different concentrations (5, 10, 20 and 40%) of the most effective botanical extracts revealed that the extract of S. officinalis was most toxic (LC50 = 18.59%), followed by N. indicum (LC50 = 20.27%) and M. longifolia (LC50 = 20.73%). Similar trend of effectiveness was observed regarding their LT50 values. Overall study results demonstrated the biocidal potential of the extracts of indigenous plant species of Soon valley against D. citri and A. gossypii, and suggest their further biochemical characterization and practical implication in future IPM programs against these and other sap-feeding insect pests. [ABSTRACT FROM AUTHOR]

The aim of study was to find the bio-potential of parthenium (Parthenium hysterophorus L.) derived extract effect on weed density and early growth response of maize crop. The experiment was laid out in randomized complete block design (CRD) with three replications. For experiment, soil was collected from weed infested field. The present results showed that parthenium derived extract at higher concentration (100%) greatly reduced weed density as well as also affect the maize growth i.e. chlorophyll content, leaf area, plant height, shoot biomass, root biomass. In addition, at lower concentration (25% and 50%) enhance maize chlorophyll content, leaf area, plant height, shoot biomass and effectively control weed density. The present study explained the bio potential of parthenium derived extract and play a key role in sustainable weed management. [ABSTRACT FROM AUTHOR]

Contemporary non-target effects of conventional synthetic insecticides necessitate evaluating biorational insecticides owing differential chemistry and modes of action than the conventional ones. This laboratory study comparatively evaluated some selected differential chemistry insecticides against some destructive and economically important insect pests i.e. mango mealybug (Drosicha mangiferae Green), mango leafhopper (Idioscopus clypealis Lethierry), Asian citrus psyllid (Diaphorina citri Kuwayama) and subterranean termites (Odontotermes obesus Rambur). Standard twig- and filter paper-dip bioassay methods were used against sap-feeding pests and termites, respectively. Factorial analyses of variance revealed a significant impact of tested insecticidal formulations and exposure time on the mortality all insect pest individuals. The most effective differential chemistry insecticides against mango leafhopper, citrus psyllids, mango mealybugs and subterranean termites were nitenpyram, clothianidin, thiamethoxam and imidacloprid (causing 74-79% cumulative corrected mortality), thiamethoxam, imidacloprid, clothianidin and spirotetramat (causing 78-85% cumulative mortality), spirotetramat, acetamiprid and thiamethoxam (causing 68-90% cumulative mortality), and chlorantraniliprole, pyriproxyfen and chlorfenapyr (causing 80-85% cumulative mortality), respectively. Overall study findings suggest these above mentioned non-conventional insecticides to be incorporated in the biorational management of these insect pests. [ABSTRACT FROM AUTHOR]

Leafworm Spodoptera litura Fabricius is a highly polyphagous pest of food, forage, vegetable and horticultural crops. This sporadic species is becoming an emerging threat to the potato crop in central Punjab and is being evidenced infesting potato crop in Sargodha, Faisalabad and Okara districts. This in-vitro study assessed the comparative feeding preference, food consumption and utilization rates and larval development of S. litura on different white and red skinned potato cultivars. Feeding bioassays revealed that all parameters including leaf weight loss, larval weight gain, relative food consumption and growth rates and conversion efficiency of the ingested food were statistically significant (P ≤ 0.05). Exotic potato cultivars Diamant, Desiree and Asterix exhibited maximum leaf consumption and larval weight gain (i.e. 264.61, 259.37 and 233.01 mg and 121.46, 120.17, 120.13 mg, respectively) concomitantly with maximum values of relative growth rate (RGR), relative consumption rate (RCR) and ingested food conversion efficiency (ECI). Cultivars Lady Rosetta, Cardinal, Ajax, Kuroda and Sante exhibited intermediate values. Minimum feeding preference and susceptibility to S. litura was shown by the native potato cultivars Faisalabad Red and Faisalabad White with minimum food consumption, larval weight gain, RGR, RCR and ECI values, and hence are recommended to indigenous potato growers for commercial cultivation in areas where S. litura threatens potato crop. [ABSTRACT FROM AUTHOR]

Okra (Abelmoschus esculentus (L.) Moench) is a summer vegetable and ranks among the major vegetables in tropical world including many Afro-Asian countries. However, this crop is attacked by many species of insect pests among which the most destructive species are okra fruit and shoot borers (Helicoverpa armigera and Earias vittella, Lepidoptera: Noctuidae) which cause considerable loss to okra crop each year. As screening of plant material against insect pests is a cost-effective and eco-friendly pest management approach, this in-situ study evaluated 12 genotypes of okra for their relative tolerance or susceptibility against lepidopterous shoot and fruit borers under the indigenous agro-climatic conditions of Sargodha district. The experiment was conducted at research area College of Agriculture, University of Sargodha, Pakistan in April 2017 and was repeated again in April 2018. Experimental design was Randomised Complete Block Design and each treatment had three independent replications. Weekly data regarding the shoot and fruit infestation by lepidopterous borers were collected from randomly selected plants from each plot and were subjected factorial analyses of variance. Results revealed a significant differential response of okra genotypes to the incidence of shoot and fruit infestation by these okra borers. Genotypes sabzpari and green wonder were comparatively the most resistant or tolerant to borers' infestation exhibiting minimum shoot and fruit infestations (12-14 and 8-13%, respectively); while genotypes pusa swani and parbhani karanti were the most susceptible with maximum shoot and fruit infestations (36-40 and 20-21%, respectively). Moreover, crude protein content of fresh okra fruits was found significantly and negatively correlated with the mean percent fruit infestation. We therefore recommend sabzpari and green wonder to the indigenous farmers for commercial okra production and for better combating okra shoot and fruit borer infestations. [ABSTRACT FROM AUTHOR]

Biopesticides are emerging as eco-friendly control practice against many insect pests. Termites are notorious pests of crops, timber, and trees and the chemical insecticides, hazardous to environment, are used for their control. The current study was aimed at determining the toxicity potential of plants present in Salt Range of Pakistan against subterranean termite, Odontotermes obesus. The extracts of identified plants were prepared with Soxhlet apparatus and rotary evaporator. Screening bioassays were performed to determine the most potent plants under laboratory conditions and toxicity bioassays were carried out to determine the LT50 and LC50 against termites. Out of 40 plant extracts assayed, seven extracts were toxic with more than 50% combined mortality against termites. Salvia officinalis with LC50 of 71 mg/L after 72 h followed by Mentha longifolia, Maerua arenaria, Periploca aphylla, and Rhamnus smithii, Sonchus asper and Nerium indicum were determined as antitermite species. Repellent activity of the extracts was also determined and higher termite control was linked both with toxicity and repellent action of plant extracts. These plants have potential to control the termites and could be used for non-chemical control of termites. [ABSTRACT FROM AUTHOR]

Mango mealybug Drosicha mangiferae (Pseudococcidae: Hemiptera) is one of the most damaging insect pests of a wide range of horticultural crops. This sap-feeding insect pest causes substantial loss to different fruit crops, particularly to citrus. For its management, citrus farmers rely on extensive and irrational applications of synthetic insecticides. Due to which, D. mangiferae have attained resistance against most these chemicals. This laboratory study was aimed to determine the toxicity of some selected conventional insecticidal formulations concurrently being used by the farmers against D. mangiferae infestation. Using standard twig-dip method, toxicity bioassays were conducted against 2nd instar nymphs of D. mangiferae. Treatments included nine conventional synthetic insecticides from three insecticidal groups. Results revealed that both treatments i.e. insecticidal formulations (F9,245 = 93.05, P < 0.001) and time intervals (F9,245 = 158.72, P < 0.01) and their 9, 245 4, 245 interaction (F36,245 = 5.73, P < 0.001) had a significant impact on the mortality of 2nd instar 36, 245 mealybug nymphs. The most effective synthetic insecticides against D. mangiferae individuals were lambda-cyhalothrin, methidathion, profenofos and deltamethrin with mean mortality and LT50 values of 45.00±4.57% and 49.01 h, 44.67±3.96% and 49.83 h, 50 40.00±4.07% and 58.98 h and 35.67±4.11% and 74.86 h, respectively. These insecticides may be incorporated in future pest management programs against D. mangiferae mealybugs. [ABSTRACT FROM AUTHOR]

Tribolium castaneum (Herbst.) is a cosmopolitan stored grains insect pest posing severe threat to post-harvest storage of grain foods such as sorghum, which is a major staple crop of Pakistan. This study was done to assess some quantitative and qualitative losses incurred by T. castaneum to some advanced sorghum genotypes viz; Hegari, F-114, J.S-2002, M.R.Sorghum-2011 and P.C-1 and to screen out the most resistant genotype against T. castaneum. Quantitative (insect pest adult emergence, damaged grains percentage, frass weight and grains weight loss) and quantitative (crude protein, fat, ash and fiber contents) were determined after a 90-d incubation of sorghum grains in dark at three different temperatures i.e. 28, 32 and 35oC. M.R.Sorghum-2011 was found the most susceptible genotype, while the genotype Hegari was found the most resistant one against T. castaneum. On average basis, maximum adult emergence and frass weight were recorded in M.R.Sorghum-2011, while these were minimum in Hegari genotype. Regarding qualitative losses, minimum losses of T. castaneum infestation were recorded in Hegari followed by J.S-2002, F-114 and P.C-1, while high nutritive losses were observed in M.R.Sorghum-2011. Furthermore, qualitative losses to sorghum grains were high for all genotypes at 32oC, followed by 35oC and were least at 28oC. The results will aid in future breeding programs for finding promising sorghum genotypes and for better assessment of storage losses due to T. castaneum. [ABSTRACT FROM AUTHOR]

Sucking pests (insects and mites) deteriorate significantly cotton crop both in terms of quantity and quality. Screening plant material under prevailing agro-climatic conditions is an essential element of integrated pest management. The present study aimed at evaluating eight genotypes of cotton (Gossypium hirsutum L.) under agro-climatic conditions of Faisalabad region against sucking pest complex (whitefly, jassid, thrip and red-spider mite). Secondary objective was to assess the influence of weather factors (temperature, relative humidity, and rainfall) on population dynamics of major sucking insect/mite pests on some advanced cotton genotypes (viz. NIBGE-I, IR-443, IR-448, NK, FH-901, FH-925, NIAB-999 and NIAB-98). Data of these insect/mite pests were taken on per leaf basis under unsprayed conditions and were subjected to statistical analysis which showed that mean population incidence on all genotypes was significant for all the four sucking insect/mite pests. Among genotypes, NIAB-98 was least attractive to whitefly infestation while both IR-genotypes were relatively less attractive to mite infestation. Similarly, both NIAB-genotypes were found most attractive to cotton jassid and NK genotype was less attractive to thrips infestation as compared to other genotypes. Moreover, the influence of all three weather factors was not significant on overall trend of sucking insect/mite pests. [ABSTRACT FROM AUTHOR]

In the tropics, termites are major players in the mineralization of organic matter leading to the production of greenhouse gases including nitrous oxide (N2O). Termites have a wide trophic diversity and their N-metabolism depends on the feeding guild. This study assessed the extent to which N2O emission levels were determined by termite feeding guild and tested the hypothesis that termite species feeding on a diet rich in N emit higher levels of N2O than those feeding on a diet low in N. An in-vitro incubation approach was used to determine the levels of N2O production in 14 termite species belonging to different feeding guilds, collected from a wide range of biomes. Fungus-growing and soil-feeding termites emit N2O. The N2O production levels varied considerably, ranging from 13.14 to 117.62 ng N2O-N d-1 (g dry wt.)-1 for soil-feeding species, with Cubitermes spp. having the highest production levels, and from 39.61 to 65.61 ng N2O-N d-1 (g dry wt.)-1 for fungus-growing species. Wood-feeding termites were net N2O consumers rather than N2O producers with a consumption ranging from 16.09 to 45.22 ng N2O-N d-1 (g dry wt.)-1. Incubating live termites together with their mound increased the levels of N2O production by between 6 and 13 fold for soil-feeders, with the highest increase in Capritermes capricornis, and between 14 and 34 fold for fungus-growers, with the highest increase in Macrotermes muelleri. Ammonia-oxidizing (amoA-AOB and amoA-AOA) and denitrifying (nirK, nirS, nosZ) gene markers were detected in the guts of all termite species studied. No correlation was found between the abundance of these marker genes and the levels of N2O production from different feeding guilds. Overall, these results support the hypothesis that N2O production rates were higher in termites feeding on substrates with higher N content, such as soil and fungi, compared to those feeding on N-poor wood. [ABSTRACT FROM AUTHOR]