Search

Abstract The Manchar Lake wetland complex, Pakistan’s largest freshwater-lake, faces unprecedented ecological challenges amidst climate change and human pressures, necessitating urgent, data-driven conservation strategies. This study employs cutting-edge multi-sensor remote sensing techniques to quantify and analyze the dynamic changes in this critical ecosystem from 2015 to 2023, aiming to provide a comprehensive understanding of wetland dynamics for informed management decisions. Integrating Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 multispectral imagery, we assessed changes in wetland extent, vegetation health, and land-use patterns using spectral indices and topographic data. Our methodology achieved classification accuracies exceeding 92% across all study years, revealing significant ecosystem fluctuations. Water body extent exhibited a non-linear trend, expanding from 318.5 km² (5%) in 2015 to 397.0 km² (7%) in 2019, before contracting to 369.9 km² (6%) in 2023. This pattern was corroborated by MNDWI values. Concurrently, vegetation covers dramatically increased from 405.5 km² (7%) in 2019 to 1081.6 km² (18%) in 2023. The Enhanced Vegetation Index (EVI) reflected this trend, decreasing from 0.61 in 2015 to 0.41 in 2019, before recovering to 0.53 in 2023. Land use changes were substantial, with agricultural areas increasing from 118.4 km² (2%) in 2015 to 498.0 km² (8%) in 2023. SAR data consistently supported these observations. Topographic analysis, including the Topographic Wetness Index (TWI), provided crucial insights into wetland distribution and resilience. This comprehensive analysis highlights the complex interplay between natural processes and human influences shaping the Manchar-Lake ecosystem, underscoring the urgent need for adaptive management strategies in the face of rapid environmental change.

Cucurbits comprise a vast group of vegetables grown worldwide, including Pakistan. The sponge gourd (Luffa aegyptiaca) is a summer vegetable in Asia. Because of its monoecious nature, sponge gourd necessitates more pollination, and fruit production occurs only in the presence of insect pollinators. This study compared the foraging behavior and pollination effectiveness of the most abundant sponge gourd floral visitors, including five solitary bees and a giant honeybee, Apis dorsata. The foraging behavior was assessed regarding visitation rate, visitation frequency, and time spent per flower, while pollination effectiveness was assessed regarding pollen deposition and fruit set in a single visit. The bees constituted 91% of total pollinator abundance, followed by the flies (8%). Apis dorsata was the most abundant visitor, followed by Xylocopa sp., Lassioglossum sp., and Amegilla sp. Solitary bees, including Amegilla sp. and Nomia sp., demonstrated greater single-visit efficiency in pollen deposition and fruit set than A. dorsata and syrphid fly. Conservation of Amegilla sp. and Nomia sp. can enhance fruit production for sponge gourd and other vegetables cultivated in Punjab, Pakistan, by providing floral resources and nesting places.

Insects are becoming increasingly popular as a sustainable and nutritious alternative protein source in poultry feeds, due to their high protein content, low environmental impact, and efficient feed conversion rates. Using insect-based feeds can reduce the need for traditional protein sources like soybean meal (SBM), which often contribute to environmental issues such as deforestation and high water consumption. The current experiments were devised to assess the impacts of the partial replacement of SBM with the American cockroach Periplaneta americana and black soldier fly Hermetia illucens on the performances, hematology, gut morphometry, and meat quality of male broilers (Ross 308). A total of 350, 1-day-old chicks weighing 40.05 ± 0.27 g were divided into 7 dietary treatments (5 pens/treatment and 10 birds/pen) at random, i.e., a 4, 8, or 12% SMB replacement with P. americana and H. illucens. Soybean meal was used as a basal diet and taken as a control. The results indicated that broilers fed on 12% P. americana or H. illucens showed significant improvements (p < 0.05) in feed conversion ratio, live weight, and daily weight gain. Hematological traits significantly improved (p < 0.05). A gut histology showed increased villus height, villus width, crypt depth, and villus height/crypt depth ratios, indicating improved nutrient absorption. Broiler meat fed on 12% P. americana meal had significantly higher redness and yellowness (p < 0.05). Substituting soybean meal with up to 12% P. americana or H. illucens meal in poultry feed can enhance the broilers’ growth performance, hematology, gut morphometry, and meat quality. Hence, these findings imply that P. americana or H. illucens meal are viable and constructive alternative protein sources in poultry nutrition, offering a sustainable approach to meet the increasing demand for animal protein across the world.

The primary challenge facing the global animal industry is the scarcity of protein feed resources. Various insects are gaining prominence as innovative feed sources due to their economic, environmentally friendly, and nutritious attributes. The purpose of the present study was to determine the effects of a partial replacement of soybean meal with fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) and black soldier fly Hermetia illucens (Diptera: Stratiomyidae) on the growth performances, blood parameters, gut histology, and meat quality of broilers. A total of 350 1-day-old (40 ± 0.15 g) male chicks (Ross 308) were randomly assigned to seven experimental meals. Each treatment was repeated five times with 50 birds per dietary treatment. The seven dietary treatments included 4, 8, and 12% replacements of SBM with larvae of S. frugiperda and H. illucens. SBM was the basal diet considered the control. The data showed that broilers fed 12% S. frugiperda or H. illucens exhibited a significantly higher (p < 0.05) live weight, average daily weight gain, and improved the feed conversion ratio. Meals with 12% S. frugiperda or H. illucens significantly enhanced (p < 0.05) haematological and gut histological parameters, including villus height, crypt depth, villus width, and villus height/crypt depth ratios. The meat of broilers fed the 12% S. frugiperda diet showed significantly higher (p < 0.05) lightness and yellowness. Replacing soybean meal up to 12% with either S. frugiperda or H. illucens larvae improves the growth performance, blood haematology, gut morphometry, and meat quality traits of broilers.

Abstract Introduction After flood occurrences, remote sensing images provide crucial information for mapping flood inundation extent. Optical satellite images can be utilized to generate flooded area maps when the flooded areas are free from clouds. Materials and Methods In this study flooded area was calculated using a variety of water indices and classification algorithms, calculated on Landsat data. Pre-flood, during flood, and post-flood satellite data were collected for in-depth flood investigation. The delineation of inundated areas was done using the Normalized Difference Water Index (NDWI), Modified Normalized Difference Water Index (MNDWI), and Water Ratio Index (WRI). In order to detect and compare flooded areas with water indices, the supervised maximum likelihood algorithm was also used for land use and land cover mapping. Results The results of the investigation allowed for a flooded area and recession. The analysis revealed that the flooded area covered about 68% of the study area, and remained standing for seven weeks. We used the misclassified areas approach, as determined, using the classified results, to improve the results of the flooded areas, generated through the use of each of the 3 water indices. The result showed that the MNDWI images showed better accuracy of above 90%, which reflects the reliability of the results. Conclusion This proposed remote sensing (RS) technique provides a basis for the identification of inundated areas with less misclassified areas, which enable an emergency response to be targeted, for newly flooded areas. Thus, the present study provides a novel rapid flood mapping perspective and provides a considerable contribution to flood monitoring.

Abstract Background Genetically modified (GM) crops have become a common tool for managing insect pests of economic importance. However, before their commercialization, bio-safety evaluation on non-target arthropods such as pollinators and biological control agents is a pre-requisite to save services rendered by them in agro-ecosystem. Results In the present experiment, the potential adverse effects of Bt protein (Vip3Aa) were studied on the life table parameters (pupation and emergence rates, 7-day larval weights, larval development time, and adult weight) of a predatory beetle, Propylea japonica (Thunberg) (Coleoptera: Coccinellidae) in the laboratory. P. japonica was exposed to Bt protein incorporated in synthetic diet at the rate of 200 µg/g of fresh weight of diet. Temporal stability, bioactivity and the uptake of insecticidal protein were confirmed by enzyme-linked immunosorbent assay and a sensitive insect bioassay. The results indicated that pupation and adult emergence rates did not differ significantly from that of negative control (pure synthetic diet). Similarly, the fresh weight of male and female adults emerged in Vip3Aa treatment (2.87 mg and 3.86 mg, respectively) did not vary significantly from that of the negative control treatment (2.66 mg, 3.75 mg). However, the time taken by the larvae to complete their development (12.70 days) was significantly extended than that of the negative control (10.21 days). In contrast, the tested life-table parameters of P. japonica were adversely affected when fed on synthetic diet containing boric acid (positive control) indicating experimental fitness to detect adverse effects. Conclusions On the basis of the results, it is suggested that GM crops expressing Bt protein (Vip3Aa) are safe for non-target insects such as P. japonica and are compatible with other biological programs for the integrated management of insect pests.

Abstract Background The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae), is a serious threat to date palms across the globe, causing heavy yield losses. The pest inflicts damage to palms stem and destroys vascular system; resultantly lower the vigor and affect the growth and yield. For ecological farming system, biological control of the pest is gaining increased interest due to hosts’ specificity, safety to human, animal and non-target organisms, and their compatibility to environment. Results In laboratory assay, Beauveria bassiana, Heterorhabditis bacteriophora and Bacillus thuringiensis var. kurstaki (Bt-k) alone and in combination against sixth instar larvae and adults of four distinct populations of RPW were applied. H. bacteriophora was more effective, followed by B. bassiana and Bt-k in alone treatments. While in combined treatments, the highest mortality was recorded for H. bacteriophora + B. bassiana combination (100% for both stages), followed by H. bacteriophora + Bt-k, (larvae 100%; adults 94.24%) and B. bassiana + Bt-k treatments (larvae: 87.01%; adults: 80.53%). Maximum rate of mycosis (larvae 85.74%; adults 69.07%), sporulation (larvae 189.22 conidia ml−1; adults 164.56 conidia ml−1), cadavers affected by nematodes (larvae 92.4%; adults 81.29%) and nematode production (larvae 178.78 IJs ml−1; adults 153.44 IJs ml−1) was observed where B. bassiana or H. bacteriophora was applied alone and the lowest (larvae 122.78 IJs ml−1; adults: 103.22 IJs ml−1) was recorded for H. bacteriophora + B. bassiana combination. Conclusions Entomopathogens can be effectively used alone and/or in integration to control RPW populations. Natural capability of entomopathogens to infect and disseminate into other hosts makes them excellent biocontrol agents to be incorporated in the IPM plan of RPW and to make palm growers confident with the use of the most promising microbial control agents.

Thirteen insecticides- Stake 40WV (triazophos), Polo 500SC (diafenthiuron), Actara 25WG (thiamethoxam), Chlorfenapyr 36SC (chlorfenapyr), Maximal 60WG (nitenpyram + pymetrozine), Crown 20SL, Lescenta 80WG (fipronil + imidacloprid), Fyfanon 57EC (malathion), Talstar 10EC (bifenthrin) Momentum 50WG (nitenpyram + chlorfenapyr), Jozer 202SL (imidacloprid + acetamaprid), Tresta 20SC (clothianidin) and Closer 240SC (sulfoxaflor)- were evaluated for efficacy in a controlled mango nursery experiment against an active infestation of Scirtothrips dorsalis at the Mango Research Institute, Multan during 2018 and 2019. The data was recorded before the treatments were applied, then 24, 72, 168 h after treatment. Treatments with percent mortality greater than 70 % were considered to be effective controls. Percent mortality was 74.14 % for chlorfenapyr, 70.58 % for Momentum, and 70.51 % for Crown at post-treatment on an cumulative average of 24, 72 and 168 h of both the study years. Medium percent mortality was; 69.52 % for Jazor; 59.59 % for Maximal; 57.38 % for Actara; and 45.11 for Lescenta. All other treatments had percent mortality estimates of less than 30 %. It is concluded that chlorfenapyr, Momentum and Crown are suggested to be used on mango nursery against S. dorsalis for better management since among the treatments in the trial efficacious control was found at 24, 72 and 168 h post-treatment.

Female and male solitary bees usually differ in their behavioral and morphological attributes and consequently in their pollination effectiveness. The current study was carried out at the research farm of The Islamia University of Bahawalpur, Pakistan, to compare the foraging behavior and pollination efficiency of female and male Andrena savignyi Spinola, 1838 on Brassica campestris. The impact of different environmental factors (temperature, relative humidity, light intensity and wind speed) on foraging behavior was also studied. Andrena savignyi was the most abundant floral visitor of B. campestris and comprised 52.17% of the floral visitors. Female individuals fed on both nectar and pollen while male fed on nectar. Visitation frequency, visitation rate, pollen harvest and pollen deposition of females were significantly higher than that of males because of their larger size and more dry weight. The maximum abundance of females was recorded at 12:00 pm followed by a sharp decline until 4:00 pm whereas males attained their maximum abundance at 2:00 pm. The female pollinated flowers resulted in greater pod weight, pod length, number of seeds per pod, seed weight per pod and germination percentage than the males. Our results suggest that females of A. savignyi deliver better pollination of B. campestris than males in terms of its reproductive success and germination percentage. Future studies should emphasis on exploring the biology and ecology of A. savignyi with special focus of its artificial nesting.

Remote sensing images are an essential tool for mapping the amount of flood inundation after flood events. For early flood estimation, flood mapping is a crucial component. This study used an integration of geospatial techniques to evaluate the flood extent in District Dera Ghazi Khan, Pakistan. The modified normalized difference water index (MNDWI) was utilized to estimate the flood extent using Landsat data. For a thorough flood investigation, pre-flood, during, and post-flood images were obtained. The analysis enabled us to delineate flood extent as well as flood duration. The result showed that the flood continued for nearly 5 weeks in the study area. This proposed geospatial technique provides a framework for the identification of inundated areas, which allows emergency responses to be focused on newly flooded areas. Hence, the current study offers a novel perspective on flood mapping and significantly contributes to flood monitoring.

The research was focused on the ability of wheat aphids Sitobion avenae, harboring bacterial secondary symbionts (BSS) Hamiltonella defensa or Regiella insecticola, to withstand exposure to fungal isolates of Beauveria bassiana and Metarhizium brunneum. In comparison to aphids lacking bacterial secondary symbionts, BSS considerably increased the lifespan of wheat aphids exposed to B. bassiana strains (Bb1022, EABb04/01-Tip) and M. brunneum strains (ART 2825 and BIPESCO 5) and also reduced the aphids’ mortality. The wheat aphid clones lacking bacterial secondary symbionts were shown to be particularly vulnerable to M. brunneum strain BIPESCO 5. As opposed to wheat aphids carrying bacterial symbionts, fungal pathogens infected the wheat aphids lacking H. defensa and R. insecticola more quickly. When treated with fungal pathogens, bacterial endosymbionts had a favorable effect on the fecundity of their host aphids compared to the aphids lacking these symbionts, but there was no change in fungal sporulation on the deceased aphids. By defending their insect hosts against natural enemies, BSS increase the population of their host society and may have a significant impact on the development of their hosts.

Improvement in physical and biochemical properties of fruits through cross-pollination is a highly variable phenomenon. It mainly depends on the species of the pollinator and the nature of the crop being pollinated. It is therefore imperative to quantify the relative pollination effectiveness of an insect species for a certain crop species. In the present study, pollination effectiveness of two native bees (i.e., Apis dorsata and A. florea) and two syrphid flies (i.e., Eristalinus aeneus and Eupeodes corollae) were evaluated in terms of physical properties of strawberry fruits at Multan, Pakistan. The physical parameters of resultant fruits included length, pole, equator, fruit set ratio, number of days to reach market maturity, and shelf life. The biochemical properties of fruits resulted from open-pollinated plants (free insect visits) and caged plants (no insect visits) were also compared. The biochemical parameters included TSS (total soluble solids), TA (titratable acidity), vitamin C, and pH. Apis dorsata was the most abundant pollinator, followed by E. aeneus and E. corollae. Based on single-visit effectiveness, A. dorsata proved to be the most effective pollinator, in terms of physical properties, of strawberry fruit. Eristalinus aeneus outcrossed A. florea in terms of fruit set (%). The open-pollinated plants showed better physical and biochemical properties (26% higher TSS, 34% higher TA, but 25% lower pH value) in terms of fruits than the caged plants. Conservation of A. dorsata and E. aeneus can enhance physical and biochemical properties of strawberry fruits in the region.

We report the nesting biology and ecology of Megachile cephalotes Smith, 1853 for the first time in Pakistan. Wooden and bamboo trap nests were deployed at three different locations in Bahawalpur district, Pakistan, from January 2020 to May 2021. A total of 242 nests of M. cephalotes were occupied in all three locations with the maximum abundance in the Cholistan Institute of Desert Studies. Megachile cephalotes remained active from March to September (the spring and summer seasons). In a nest, females made 7–8 brood cells each having a length of 1.2–2.3 cm. Plant resin was used to construct cells and mud or animal dung to plug the nest entrance. A vestibular cell was also made between the outermost brood cell and the nest entrance that ranged from 1.4 to 2.5 cm in length. No intercalary cells were observed in the nests. The males took 65.3 days to become adults, while the females took 74.78 days. The sex ratio was significantly biased toward females in all three locations. Grewia asiatica was the predominant pollen grain species found in the brood cells. Megachile cephalotes were observed collecting resin from Acacia nilotica, Prosopis juliflora, and Moringa oleifera. Three cleptoparasites of this species were also recorded: Euaspis carbonaria, Coelioxys sp., and Anthrax sp. This study set up a background to encourage new studies on artificial nesting and provides tools for proper biodiversity management and conservation.

Assessment of resource partitioning in pollinators at a particular place can be used to conserve plant communities by minimizing their inter-specific competition. Current study was conducted to investigate the occurrence of this phenomenon among plant communities under sub-tropical conditions for the first time in Pakistan. We considered the entire available flowering plant and floral visitor communities in the study area-Lal Suhanra forest of Bahawalpur, Pakistan- along with different variations among them based on morphology, color and symmetry (functional groups) i.e. four functional groups among insects and nine among plants. Weekly floral visitor censuses were conducted during spring season -from the first week of March to the fourth week of May 2018. Thirty individuals of each plant species -in bloom- were observed for floral visitors in each census. Plant species with different floral shapes, colors and symmetry did not show any significant resource partitioning. The Non-metric multidimensional scaling analysis followed by one-way ANOSIM test showed non- significant differences among all the pair of floral shapes, colors (except white and yellow) and symmetry (R-value < 0.168). However, SIMPER test suggested that flies were the most common group that contributed more towards within group similarities of different floral shapes (19 to 21% similarity), colors (16 to 30%) and symmetry (19%) followed by long-tongue bees i.e. 14 to 21%, 9 to 19% and 18%, respectively. Our results suggest that plant communities under sub-tropical conditions of Pakistan exhibit a generalist pollination system with no significant resource partitioning in pollinator species. Therefore, plant communities may have high competition for pollinator species which exhibits fewer implications of species loss on overall pollination process. Our study provides the basis for understanding the partitioning of pollinator guilds under sub-tropical conditions. Future studies should focus on functional traits in more detail at the community and the population scales for their possible impact on resource partitioning.

Abstract Syrphid flies, Ischiodon scutellaris (Fabricius) and Episyrphus balteatus (DeGeer), are among the most common aphidophagous species in wheat growing areas of Punjab, Pakistan. Exploit predatory species efficiently in any biological control program requires an in-depth understanding of predator and prey interactions. The present study was conducted aiming to explore and compare the predatory potential of these predatory species against the wheat aphid, Schizaphis graminum (Rondani) along with their relative fitness at different temperatures in terms of duration of lifecycle stages under laboratory conditions. The shortest egg and pupal durations were observed at 33 °C, followed by 27 and 23 °C. Females of both species had longer life span (20.4 and 22.4 days) compared to the respective males (17.2 and 16.2 days). The pupal stage for I. scutellaris was significantly shorter than for E. balteatus at different temperatures; but statistically insignificant differences were found for any other life stage. The larvae of I. scutellaris consumed significantly more aphids (438.16) than E. balteatus (398.37) during their larval life span, and this difference was significant during the 1st and 3rd instars. However, the average daily prey intake of both species was found similar until the 10th day after hatching, and thereafter, I. scutellaris consumed significantly higher numbers of aphids/day. Obtained results may offer a baseline data for future conservation studies on biological control of aphids.

Abstract Wheat aphid, Sitobion avenae (Fab.), is a serious pest of wheat crop across the world. The present study was conducted to evaluate the potentials of the water plant extracts of Azadirachta indica (neem) or Eucalyptus camaldulensis and the entomopathogenic fungi (EPF); Beauveria bassiana or Metarhizium anisopliae against the aphid species. After 5 days of applications, the combined mixture of B. bassiana and eucalyptus extract caused the maximum mortality rate (87%). While the combination of B. bassiana with neem extract showed the least rate (54%). Fecundity was negatively affected by the single and combined treatments of EPF and botanicals extracts. The lowest fecundity (7 nymphs per female) was recorded when the aphid was treated by the binary mixture of B. bassiana and eucalyptus extract. Correspondent maximum fecundity (29 nymphs per female) in 5 days was recorded in control treatment, while 23 nymphs were produced by a single female when treated with the binary mixture of B. bassiana and neem extract. The results indicated that EPF and botanical extracts (neem or eucalyptus) caused significant reduction in survival and fecundity of S. avenae. Therefore, they may be used as promising natural alternatives to synthetic insecticides against the wheat aphid species.

Phalsa, Grewia asiatica is a multi-purpose crop while cross-pollination can significantly improve its reproductive success. Megachile bees (Megachilidae) are the most important group of pollinators of G. asiatica. In this study we observed the foraging behavior of Megachile cephalotes and its ultimate impact on reproductive success of phalsa at Bahawalpur (Punjab), Pakistan. Although visitation rate and stay time were statistically similar in both the sexes but visitation frequency (2.06±0.14 individuals/120 seconds) and pollen deposition (39.35±3.17 pollen grains /stigma/visit) of females were significantly higher than that of males (0.44±0.06 individuals/120 seconds and 12.05±1.19 pollen grains/stigma/visit, respectively). The environmental factors (i.e. ambient temperature, relative humidity, sunlight intensity and wind speed) greatly influenced -either positively or negatively- both the sexes (Pearson’s correlation). Female pollinated fruits were significantly greater in weight (0.41±0.017 g) followed by open (0.31±0.012 g) and male (0.27±0.011 g) pollinated fruits. Percent weight loss remained significantly lower in female pollinated fruits than open and male pollinated fruits until12 hours after harvest. Fruit wrinkling significantly increased with the increase in post-harvest intervals in open, female and male pollinated fruits while fruit color changed only in female pollinated fruits. The results of present study suggest female M. cephalotes as the efficient pollinators of G. asiatica in terms of it reproductive success and post-harvest parameters. Future studies should focus biology and ecology of M. cephalotes with special focus on its artificial nesting.

Aphids are major pests of wheat crop in Pakistan inflicting considerable economic losses. A better knowledge of landscape scale spatial distribution of aphids and their natural enemies could be used to improve integrated pest management programs. Therefore, the present study aimed to document spatio-temporal variations in populations of wheat aphids and their natural enemies in Pakistan. The 2-year survey study was carried out at ten experimental farms located in five districts of four contrasted agro-ecological zones of eastern Pakistan (Punjab area) i.e. District Chakwal in arid zone, Gujranwala in rice-cropped zone, Faisalabad in central mixed-cropped zone, and Khanewal and Multan in cotton-cropped zone. The dominant aphid species i.e. Schizaphis graminum, Rhopalosiphum padi, R. maidis and Sitobion avenae varied significantly among the five districts surveyed. The population of S. graminum was observed more abundant in arid, R. padi in rice, S. avenae in aird and rice, and R. maidis in cotton-I zones. Aphids ended their population dynamics on 25th March in central mixed-cropped zone and 12th April in other three zones. Various species of natural enemies, mainly Coccinella septumpunctata, C. undecimpunctata, Menochilus sexmaculata, Chrysoperla carnea, Syrphidae and parasitoid mummies were inconsistently observed in four agro-ecological zones. The population of C. septumpunctata, was observed more abundant in rice zone, C. undecimpunctata and C. carnea in cotton-I and arid zones, M. sexmaculata in cotton-I and II zones, Syrphidae in cotton-I zone and parasitoid mummies in rice and arid zones. There were no clear relationships between aphid and the natural enemy populations. The present study may serve as a baseline regarding distribution of wheat aphids and their natural enemies and the results provided insights for further studies on the potential top-down (natural enemies) versus bottom-up (fertilization and irrigation regimes) forces in management of wheat aphids in eastern Pakistan.

In flood-prone areas, the delineation of the spatial pattern of historical flood extents, damage assessment, and flood durations allow planners to anticipate potential threats from floods and to formulate strategies to mitigate or abate these events. The Chenab plain in the Punjab region of Pakistan is particularly prone to flooding but is understudied. It experienced its worst riverine flood in recorded history in September 2014. The present study applies Remote Sensing (RS) and Geographical Information System (GIS) techniques to estimate the riverine flood extent and duration and assess the resulting damage using Landsat-8 data. The Landsat-8 images were acquired for the pre-flooding, co-flooding, and post-flooding periods for the comprehensive analysis and delineation of flood extent, damage assessment, and duration. We used supervised classification to determine land use/cover changes, and the satellite-derived modified normalized difference water index (MNDWI) to detect flooded areas and duration. The analysis permitted us to calculate flood inundation, damages to built-up areas, and agriculture, as well as the flood duration and recession. The results also reveal that the floodwaters remained in the study area for almost two months, which further affected cultivation and increased the financial cost. Our study provides an empirical basis for flood response assessment and rehabilitation efforts in future events. Thus, the integrated RS and GIS techniques with supporting datasets make substantial contributions to flood monitoring and damage assessment in Pakistan.

The yearlong association of two native honey bee species (Apis dorsata and A. florea) with 49 plant species was recorded in a planted forest and adjacent agricultural landscape at Multan, Pakistan. The study resulted in 588 interactions of A. dorsata with 40 plant species and 454 interactions of A. florea on 38 plant species. The most visited plants species by A. dorsata included Helianthus annuus, Citrus reticulata, Trifolium alexandrinum, Moringa oleifera and Calotropis procera, while the most visited plant species by A. florea included C. procera, Mangifera indica, T. alexandrinum, Coriandrum sativum and H. annuus. The peak abundance of bees and floral resources (i.e. number of plant species in flowering and abundance of floral units) was recorded during early March to late May followed by a gradual decline until December. Monthly abundance of both bee species was positively related to the floral resources, negatively related to relative humidity while it was not significantly related to temperature. The current study may serve as a baseline to track the degradation in ecosystem service of cross pollination and making new conservation strategies at local scale while future research should focus on tempo-spatial variations in foraging preferences, floral constancy and effect of foraging competition on crop pollination in different ecological regions of Pakistan.

This study was conducted in an effort to understand the effects of spatial variations in pollinator assemblage due to habitat isolation on the reproductive performance of perennial plant species. Variations in pollinator assemblage structure (abundance, diversity and Shannon-Wiener index) were studied at three widely isolated (100 to 200 km apart) nature reserves of Southern Punjab, Pakistan, in order to explore its effects on reproductive performance of Prosopis juliflora. Species richness and abundance were highest in Pirowal Sanctuary followed by Chichawatni Sanctuary and Chak Katora forest reserve. The pollination system of P. juliflora was highly generalized with 77 insect visitor species in four orders among all the three sites. However, pollinator assemblage varied significantly in composition among the sites. Out of the four reproductive parameters considered, the number of pods per raceme and germination varied significantly among the three locations. The reproductive performance of P. juliflora in terms of number of pods per raceme and germination improved with abundance of pollinators.