Botanical biopesticides have an influence on tomato quality through pest control and are cost-effective for farmers in developing countries

Synthetic insecticides heavily applied to manage agricultural pests are highly hazardous to the environment and non-target organisms. Their overuse through repeated treatments in smallholder farming communities is frequent. Botanical biopesticides are ideal for sustainable pest management in agricultural environments by keeping synthetic insecticide use at a minimum. Here we evaluated a locally prepared neem seed extract (NSE) alongside emamectin benzoate against both lepidopteran pests Helicoverpa armigera (Hübner) and Spodoptera exigua (Hübner) on tomato Lycopersicon esculentum Mill under natural field conditions in Pakistan. We compared pest severity, fruit injury, quality, marketability, and cost:benefit ratio (CBR) between treatments. The concentration of azadirachtin A in the NSE was 26.5 ppm. NSE at 2% (20 mL/L) and the emamectin benzoate at the recommended field rate in Pakistan were sprayed weekly throughout the fruiting stage. The pest larvae were significantly more abundant on fruits than on flowers and leaves. Fruit injury and losses were significantly more important in untreated control compared to NSE and emamectin benzoate treatments. NSE efficacy varied with respect to the cultivars used and the seasons. Cultivar Eden harboured more pests than Adventa, and emamectin benzoate suppressed more pest individuals than NSE. Both the insecticidal treatments were comparable in terms of marketable yield productions as well as unmarketable, uninjured, and recovered fruit yields. NSE generated a higher CBR (1: 9.26) than emamectin benzoate (1: 3.23). NSE suppressed pests by acting as an antifeedant, similar to its synthetic counterpart. Smallholder growers can thus use NSE as a cost-effective solution in tomato pest management in Pakistan.

Randomized open-label controlled study of cancer vaccine OSE2101 versus chemotherapy in HLA-A2-positive patients with advanced non-small-cell lung cancer with resistance to immunotherapy: ATALANTE-1

BACKGROUND

Patients with advanced non-small-cell lung cancer (NSCLC) treated with immune checkpoint blockers (ICBs) ultimately progress either rapidly (primary resistance) or after durable benefit (secondary resistance). The cancer vaccine OSE2101 may invigorate antitumor-specific immune responses after ICB failure. The objective of ATALANTE-1 was to evaluate its efficacy and safety in these patients.

PATIENTS AND METHODS

ATALANTE-1 was a two-step open-label study to evaluate the efficacy and safety of OSE2101 compared to standard-of-care (SoC) chemotherapy (CT). Patients with human leukocyte antigen (HLA)-A2-positive advanced NSCLC without actionable alterations, failing sequential or concurrent CT and ICB were randomized (2 : 1) to OSE2101 or SoC (docetaxel or pemetrexed). Primary endpoint was overall survival (OS). Interim OS futility analysis was planned as per Fleming design. In April 2020 at the time of interim analysis, a decision was taken to prematurely stop the accrual due to coronavirus disease 2019 (COVID-19). Final analysis was carried out in all patients and in the subgroup of patients with ICB secondary resistance defined as failure after ICB monotherapy second line ≥12 weeks.

RESULTS

Two hundred and nineteen patients were randomized (139 OSE2101, 80 SoC); 118 had secondary resistance to sequential ICB. Overall, median OS non-significantly favored OSE2101 over SoC {hazard ratio (HR) [95% confidence interval (CI)] 0.86 [0.62-1.19], P = 0.36}. In the secondary resistance subgroup, OSE2101 significantly improved median OS versus SoC [11.1 versus 7.5 months; HR (95% CI) 0.59 (0.38-0.91), P = 0.017], and significantly improved post-progression survival (HR 0.46, P = 0.004), time to Eastern Cooperative Oncology Group (ECOG) performance status deterioration (HR 0.43, P = 0.006) and Quality of Life Questionnaire Core 30 (QLQ-C30) global health status compared to SoC (P = 0.045). Six-month disease control rates and progression-free survival were similar between groups. Grade ≥3 adverse effects occurred in 11.4% of patients with OSE2101 and 35.1% in SoC (P = 0.002).

CONCLUSIONS

In HLA-A2-positive patients with advanced NSCLC and secondary resistance to immunotherapy, OSE2101 increased survival with better safety compared to CT. Further evaluation in this population is warranted.

Organic farming of maize crop enhances species evenness and diversity of hexapod predators

Arthropod species diversity enhances ecosystem productivity and sustainability by increasing pollination and biological control services. Although, it is declining rapidly due to conventional agricultural intensification, organic agriculture with reduced reliance on agronomic inputs can regenerate ecosystems' resilience and restore them. Here, we report whether hexapod communities differ on both types of farming systems in small-scale field plot experiments, wherein Maize variety AG-589 was grown organically and conventionally in the 2020 and 2021 seasons. Livestock manure was applied in organic fields, whereas nitrogen and phosphorous were used as synthetic fertilizers in conventional fields. Hexapods were sampled three weeks after sowing once a week from the middle rows of subplots from both organically and conventionally grown maize. Twelve species of herbivores and four species of predators were recorded. Hexapod abundance overall and that of herbivores only was higher in conventionally cultivated maize, while predator abundance was higher in organic maize. Herbivores species diversity and evenness were significantly higher in conventional maize. Predator species diversity and evenness were significantly higher in organic maize fields. We noted predator abundance, diversity, and evenness as strong predictors to lower herbivore populations. These findings suggest that organic farming conserves natural enemies' biodiversity and regulates herbivores with increased provision of suitable habitats and prey resources for natural enemies, leading to enhanced relative abundance in their specialized niches. Thus, organic agriculture can potentially mediate better ecosystem services.

Field evaluation of synthetic and neem-derived alternative insecticides in developing action thresholds against cauliflower pests

Synthetic chemical pesticides can enhance crop yields but also have undesired effects. Alternative 'botanical insecticides' may also have non-target effects on pollinators and biocontrol services. Employing action thresholds (ATs) can reduce pesticide (whether synthetic or botanical) use compared to fixed-interval applications. Here the azadirachtin-based botanical formulation NeemAzal and a neem seed extract (NSE) were evaluated in field spraying trials alongside commonly-used synthetics (Voliam Flexi [chlorentraniliprole plus thiamethoxam] and imidacloprid) in developing ATs for the regular and cosmopolitan cauliflower pests Brevicoryne brassicae, Plutella xylostella and Spodoptera litura. We considered the size of the S. litura larvae infesting the crop in order to derive ATs. ATs per plant were higher for NeemAzal (0.55 larvae for P. xylostella and 3 larvae for large-sized S. litura) than for Voliam Flexi (0.30 larvae for P. xylostella and 0.80 larvae for S. litura) but were similar for B. brassicae (50 individuals). Higher ATs when using azadirachtin were associated with the diverse modes of action of botanicals, for instance NeemAzal and NSE deterred oviposition of S. litura. Although the exact values of ATs are likely to have regional limits, our approach can be applied for determining ATs against common lepidopteran and aphid pests in many other vegetable crop agro-ecosystems.

Eugenol, a Plant Volatile, Synergizes the Effect of the Thrips Attractant, Ethyl Iso-Nicotinate

The onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), is a polyphagous pest that causes serious damage to agricultural crops, vegetables, and ornamental plants worldwide. Farmers rely on the extensive usage of synthetic chemical insecticides to control T. tabaci. There is a dire need to develop alternative control strategies to overcome the problems posed by chemical insecticides. Efficient traps would allow sensitive monitoring and possibly mass trapping. A field experiment was conducted to evaluate the potential of three plant compounds with known release rates (ranging from 6-30 mg/d); eugenol (Eug), 1, 8-cineole (eucalyptol), and linalool in all possible combinations with a thrips attractant, ethyl iso-nicotinate (EI). A combination of EI with Eug increased the effect of EI by attracting 100% more thrips (effect size, 1.95) as compared to the control of EI alone. Catches in remaining treatments were lower and or not significantly different from EI alone. The results from our study could be used to develop improved volatile blends to be used for monitoring traps. Our data suggests that these traps could be effective even at very low populations.

Field evolved resistance to pyrethroids, neonicotinoids and biopesticides in Dysdercus koenigii (Hemiptera: Pyrrhocoridae) from Punjab, Pakistan

The red cotton bug, Dysdercus koenigii (Fabricius) is an important emerging economic pest of cotton, Gossypium hirsutum Linnaeus in Pakistan. Insecticides are the primary management tactics to suppress populations of this pest. However, resistance to insecticides evolves due to substantial and repeated applications. The resistance to pyrethroids, neonicotinoids and biopesticides have been evaluated in many pests worldwide, nevertheless lack of information in D. koenigii. Therefore, the aforementioned insecticide resistance in five field populations of D. koenigii collected from Multan, Makhdoom Rashid, Jahanian, Lodhran and Vehari districts of Punjab, Pakistan during 2015-2017 was determined by using seed dip method. Based on the present results, D. koenigii has developed moderate to very high resistance to acetamiprid (RR = 33-433) and imidacloprid (RR = 21-173), low to high resistance to emamectin benzoate (RR = 14-52), and very low to high resistance to spinosad (RR = 4.13-54), compared to the susceptible population. However, all field populations of D. koenigii remained susceptible to deltamethrin (RR = 0.62-2.17) and lambda-cyhalothrin (RR = 0.91-1.97). A rotational use of pyrethroids with provision of other integrated pest management tactics is recommended to manage insecticide resistance in D. koenigii.

Evaluating Action Thresholds for Amrasca devastans (Hemiptera: Cicadellidae) Management on Transgenic and Conventional Cotton Across Multiple Planting Dates

An action threshold (AT) based on the specific pest-crop relationship is an important element of integrated pest management (IPM) programs. We evaluated planting time-based ATs to manage a sucking pest, cotton leafhopper (Amrasca devastans; Hemiptera: Cicadellidae) in conventional (CIM-554) and transgenic (Bt.CIM-599) cotton cultivars under field conditions. Cultivars were planted on 15 March, April, and May during 2011 and 2012. Only two ATs (0.1 and 1.0 A. devastans per leaf) and an untreated control could be tested on 15 March planted cotton, as the populations of A. devastans never reached a density of two per leaf. Cotton planted on 15 March had the highest seed cotton yield, highest net and marginal rate of returns (MRRs) than other planting times. At this planting time, only one insecticidal application was needed at an AT of 1.0 A. devastans per leaf, with no significant yield loss. Four ATs (0.1, 1.0, 2.0, and 3.0 A. devastans per leaf) and an untreated control were tested for cotton planted on 15 April and 15 May. For the 15 April planting, 2.0 AT led to 3 applications as compared with 10 applications needed with 0.1 AT; without any significant yield loss, generating the highest net return and MRR for this planting date. The 15 May planting was more vulnerable to A. devastans damage and 1.0 AT generated the highest net return and MRR with four applications as compared with all other ATs. These results suggest that the use of planting time-based ATs can improve cotton yield through cost-effective applications of insecticides.

Root order-based traits of Manchurian walnut & larch and their plasticity under interspecific competition

Manchurian walnut and larch are key timber species of northeast China but information on (fine) root traits of both species is scarce. Plasticity of root traits in mixed plantations has been studied rarely although this could give important insights into mechanisms of root competition. This study examined root traits by branching order in 30-yr-old monocultures and their plasticity in mixed plantations. In monocultures, Manchurian walnut and larch differed in key fine root traits. Larch roots hold more absorptive root orders, larger diameter and lower specific root length/area. Walnut root orders featured greater cortex:stele ratios, N-concentrations and respiration rates. Under interspecific competition, the proportion of walnut root tips increased, the biomass/length of larch root orders 1-3 decreased. Larch possessed a greater morphological and anatomical plasticity of terminal root orders than walnut. Mycorrhizal colonization rates of walnut were reduced. Both species differed fundamentally in their fine root properties. Absorptive fine root orders reacted plastic under interspecific competition while traits of higher root orders remained unchanged. In mixture, larch roots possessed a greater plasticity in traits related to resource uptake (efficiency) than walnut roots whose reaction norm is suggested to be predominantly based on interference competition via juglone exudation.

Patterns of genetic differentiation among populations of Amrasca biguttula biguttula (Shiraki) (Cicadellidae: Hemiptera)

Cotton leafhopper, Amrasca biguttula biguttula (Shiraki), a serious sucking insect pest of cotton and vegetables is present throughout South and Southeast Asia. Genetic differentiation within A. biguttula biguttula populations collected from 16 cotton growing areas of Punjab, Pakistan, was examined by sequencing the barcode region of the mitochondrial cytochrome oxidase subunit 1 (COI) gene. The dendrogram obtained by neighbour joining analysis of COI sequences confirmed the presence of single species of cotton leafhopper. The overall average pairwise divergence was 0.01. Very little variation was found among populations from cotton growing areas of Punjab, Pakistan and these were most similar to populations from North India. South Indian populations were grouped together and were generally more divergent. Extensive migration of this pest species among cotton-growing areas in the Indian subcontinent may hinder genetic diversification of cotton leafhopper. Four Pakistani samples of cotton leafhopper tested positive for Wolbachia infection but were not clearly differentiated from non-Wolbachia infected samples, suggesting that Wolbachia did not cause reproductive incompatibilities.

Comparative role of neem seed extract, moringa leaf extract and imidacloprid in the management of wheat aphids in relation to yield losses in Pakistan

Wheat being staple food of Pakistan is constantly attacked by major wheat aphid species, Schizaphis graminum (R.), Rhopalosiphum padi (L.) and Sitobion avenae (F.). Due to concern on synthetic chemical use in wheat, it is imperative to search for alternative environment- and human- friendly control measures such as botanical pesticides. In the present study, we evaluated the comparative role of neem seed extract (NSE), moringa leaf extract (MLE) and imidacloprid (I) in the management of the aphid as well as the yield losses parameters in late planted wheat fields. Imidacloprid reduced significantly aphids infestation compared to the other treatments, hence resulting in higher yield, particularly when applied with MLE. The percentages of yield increase in I+MLE treated plots over the control were 19.15–81.89% for grains per spike, 5.33–37.62% for thousand grain weight and 27.59–61.12% for yield kg/ha. NSE was the second most effective control measure in suppressing aphid population, but the yield protected by NSE treatment over the control was comparable to that by imidacloprid. Population densities of coccinellids and syrphids in the plots treated with NSE-2 were higher than those treated with imidacloprid in two out of three experiments during 2013–14. Low predator density in imidacloprid-treated plots was attributed to the lower availability of prey aphids. The efficacy of NSE against aphids varied depending on degree of synchronization among the application timing, the activity of aphids, crop variety and environmental conditions. Despite that, we suggested NSE to be a promising alternative botanical insecticide compared to the most commonly recommended imidiacloprid. Further studies should consider the side effects of biopesticides on non-target organisms in order to provide better management practices in the field.

Varietal Preferences and Within-Orchard and Tree Distribution of Newly Recorded Gall Midges, Dasineura amaramanjarae and Procontarinia mangiferae (Diptera: Cecidomyiidae), From Commercial Mango Cultivars in Pakistan

Gall midges (Diptera: Cecidomyiidae) damage mango by feeding on flowers and fruit tissues, inducing galls on leaves, and providing inoculums of anthracnose. Dasineura amaramanjarae Grover and Procontarinia mangiferae (Felt), two gall midges that damage flowers in all mango-growing areas of the world, have recently been recorded in Pakistan, and studies were conducted in 2011 and 2012 on the within-tree and orchard distribution patterns and cultivar preference of both species in Pakistan at one location (Rahim Yar Khan). Both gall midge species were found on all mango cultivars examined (Chaunsa, Fajri, Dusehri, Surkha, Sindhri, and Anwar Ratul), with the most damage occurring to Surkha and Dusehri. Research on midge distribution patterns in different parts of mango orchards (central, southern, northern, eastern, and western sides) showed these species to be found in all areas, with the greatest numbers in the central and southern regions. In addition, both species were most abundant on the lower parts of the mango tree canopy.

Influence of biochar and nitrogen on fine root morphology, physiology, and chemistry of Acer mono

Fine roots play an important role in the overall functions of individual plants. Previous studies showed that fertilization and available soil resources have a notably profound effect on fine root, but there is lack of study centered on how fine root morphology, physiology, and chemistry respond to biochar with N additions. Different levels of biochar (0, 10, 15, and 20 g) and N (0, 2, 4 and 6 g) were applied to Acer mono seedling plants in a field nursery. The root system morphology and root chemistry and physiology were evaluated in line with root length, root diameter, SRL, N and N: C and root respiration. Biochar and N significantly affected root morphology, chemistry and root respiration. Morphological, chemical and physiological parameters were found to be at their maximum with 20 g biochar and 6 g N; however, no significant effect was noted on fourth- and fifth-order roots. Furthermore, a significant increase in root respiration was recognized with the increase in root tissue N concentration and the negative relationship of root respiration with higher branch order. Thus, overall, study parameters indicate that biochar and nitrogen positively influence the Acer mono fine root, and therefore should be used to improve fine root health.

Optimizing the phosphorus use in cotton by using CSM-CROPGRO-cotton model for semi-arid climate of Vehari-Punjab, Pakistan

Crop nutrient management is an essential component of any cropping system. With increasing concerns over environmental protection, improvement in fertilizer use efficiencies has become a prime goal in global agriculture system. Phosphorus (P) is one of the most important nutrients, and strategies are required to optimize its use in important arable crops like cotton (Gossypium hirsutum L.) that has great significance. Sustainable P use in crop production could significantly avoid environmental hazards resulting from over-P fertilization. Crop growth modeling has emerged as an effective tool to assess and predict the optimal nutrient requirements for different crops. In present study, Decision Support System for Agro-technology Transfer (DSSAT) sub-model CSM-CROPGRO-Cotton-P was evaluated to estimate the observed and simulated P use in two cotton cultivars grown at three P application rates under the semi-arid climate of southern Punjab, Pakistan. The results revealed that both the cultivars performed best at medium rate of P application (57 kg ha^-1) in terms of days to anthesis, days to maturity, seed cotton yield, total dry matter production, and harvest index during 2013 and 2014. Cultivar FH-142 performed better than MNH-886 in terms of different yield components. There was a good agreement between observed and simulated days to anthesis (0 to 1 day), days to maturity (0 to 2 days), seed cotton yield, total dry matter, and harvest index with an error of -4.4 to 15%, 12-7.5%, and 13-9.5% in MNH-886 and for FH-142, 4-16%, 19-11%, and 16-8.3% for growing years 2013 and 2014, respectively. CROPGRO-Cotton-P would be a useful tool to forecast cotton yield under different levels of P in cotton production system of the semi-arid climate of Southern Punjab.

Damage Patterns, Monitoring, and Management of Procontarinia mangiferae (Diptera: Cecidomyiidae) in Pakistan

Since 2005, mango has been damaged by a group of new pests, the gall midges, in all mango-growing areas of Pakistan. Little is known about these pests in Pakistan. In this report, we present information on the occurrence, damage patterns, methods for monitoring, and management of Procontarinia mangiferae (Felt), a mango gall midge found in the country. At the study site (Rahim Yar Khan, a district of the province Punjab, Pakistan), the pest was active from January/February to April as eggs, larvae, and adults on mango inflorescence buds, branches (axillaries), and immature fruits. Females of P. mangiferae oviposited in inflorescence tissues, and larvae, after feeding on plant tissues, dropped to the soil under the mango trees for pupation from February to April. Mango trees in commercial orchards were more heavily damaged by P. mangiferae than were isolated trees in farmer fields (66.7%). The adults of P. mangiferae were captured on sticky traps of all tested colors, and were in flight from January to May. Captures per trap were highest on yellow traps, followed by green, blue, and clear traps. Control of mango gall midge was effectively provided by the synthetic insecticide bifenthrin (Talstar 10 EC) and also by application of neem seed kernel extract on the tree canopy if integrated with raking the soil under the mango tree canopy.

Impact of neonicotinoid seed treatment of cotton on the cotton leafhopper, Amrasca devastans (Hemiptera: Cicadellidae), and its natural enemies

BACKGROUND

Neonicotinoid seed treatments suppress populations of pest insects efficiently and can enhance crop growth, but they may have negative effects on beneficial arthropods. We evaluated the effects of either imidacloprid or thiamethoxam on the abundances of a sucking pest, the cotton leafhopper (Amrasca devastans), and its arthropod predators under field conditions. We also evaluated the impact of seed treatment on transgenic cotton plant growth, with pests and natural enemies present or absent.

RESULTS

Imidacloprid and thiamethoxam reduced pest abundance, with greater effects when dosages were higher. Treatment at recommended doses delayed the pest in reaching the economic damage threshold by around 10-15 days (thiamethoxam) and 20 days (imidacloprid). Recommended doses also enhanced plant growth under all tested conditions; growth is affected directly as well as via pest suppression. Neonicotinoid applications reduced abundance of beneficial arthropods, with lower populations after higher doses, but negative effects of imidacloprid were not apparent unless the manufacturer-recommended dose was exceeded.

CONCLUSION

Imidacloprid applied at the recommended dose of 5 g kg(-1) seed is effective against A. devastans and appears to be safer than thiamethoxam for natural enemies, and also enhances plant growth directly. We caution, however, that possible sublethal negative effects on individual beneficial arthropods were not evaluated. © 2015 Society of Chemical Industry.

Fitness cost and realized heritability of resistance to spinosad in Chrysoperla carnea (Neuroptera: Chrysopidae)

The common green lacewing Chrysoperla carnea is a key biological control agent employed in integrated pest management (IPM) programs for managing various insect pests. Spinosad is used for the management of pests in ornamental plants, fruit trees, vegetable and field crops all over the world, including Pakistan. A field-collected population of C. carnea was selected with spinosad and fitness costs and realized heritability were investigated. After selection for five generations, C. carnea developed 12.65- and 73.37-fold resistance to spinosad compared to the field and UNSEL populations. The resistant population had a relative fitness of 1.47, with substantially higher emergence rate of healthy adults, fecundity and hatchability and shorter larval duration, pupal duration, and development time as compared to a susceptible laboratory population. Mean relative growth rate of larvae, intrinsic rate of natural population increase and biotic potential was higher for the spinosad-selected population compared to the susceptible laboratory population. Chrysoperla species are known to show resistance to insecticides which makes the predator compatible with most IPM systems. The realized heritability (h 2) value of spinosad resistance was 0.37 in spinosad-selected population of C. carnea.

Identification of plant semiochemicals and characterization of new olfactory sensory neuron types in a polyphagous pest moth, Spodoptera littoralis

Phytophagous insects use blends of volatiles released from plants to select hosts for feeding and oviposition. To behaviorally analyze complex blends, we need efficient and selective methods for elucidating neuron types, their ligands, and specificity. Gas chromatography-combined single sensillum recordings (GC-SSRs) from antennal olfactory sensilla of female moth, Spodoptera littoralis revealed 38 physiologically active peaks in the headspace volatile blends from both larvae-damaged cotton plants and lilac flowers. Using GC-combined mass spectrometry, 9 new physiologically active compounds were identified from damaged cotton and 11 from lilac compared with earlier electrophysiological studies using antennae of female S. littoralis. We characterized 14 novel classes of olfactory sensory neurons (OSNs). Among these, we found the first 2 ligands for a frequent type of short trichoid sensillum, for which no ligands were identified earlier. By using GC-SSR, a substantial increase in functional classes of OSNs and active compounds, 40% and 34% more, respectively, compared with recent studies using GC-electroantennogram or SSR using single compounds was detected. Compared with the estimated number of corresponding antennal olfactory receptors, the OSN classes now correspond to 83% of a likely maximum. The many specialist OSNs observed may facilitate behavioral confirmation of key plant volatiles in blends.

Increased fitness and realized heritability in emamectin benzoate-resistant Chrysoperla carnea (Neuroptera: Chrysopidae)

The common green lacewing Chrysoperla carnea is a key biological control agent employed in integrated pest management (IPM) programs for managing various insect pests. A field collected population of C. carnea was selected for emamectin benzoate resistance in the laboratory and fitness costs and realized heritability were investigated. After five generations of selection with emamectin benzoate, C. carnea developed a 318-fold resistance to the insecticide. The resistant population had a relative fitness of 1.49, with substantially higher emergence rate of healthy adults, fecundity and hatchability and shorter larval duration, pupal duration, and development time compared to the susceptible population. Mean population growth rates; such as the intrinsic rate of natural population increase and biotic potential were higher for the emamectin benzoate selected population compared to the susceptible population. The realized heritability (h(2)) value of emamectin benzoate resistance was 0.34 in emamectin benzoate selected population of C. carnea. Chrysoperla species which show resistance to insecticides makes them compatible with those IPM systems where emamectin benzoate is employed.

A cross sectional survey of knowledge, attitude and practices related to house flies among dairy farmers in Punjab, Pakistan

BACKGROUND

House flies are of major public health concerns in areas with poor sanitation and hygienic conditions. Unfortunately, sanitation and hygiene have always been ignored in dairy farms particularly in the developing or low-income countries. Management of these flies mostly depends on the awareness regarding associated hazards and protective measures taken by the people to minimize risks associated with flies. The present study therefore explores the knowledge, attitude and practices taken by dairy farmers in Punjab, Pakistan against house flies.

METHODS

The present study was based on a cross sectional self administered survey to a convenience sample of 173 small scale dairy farmers in four localities - Multan, Lahore, Shorkot and Faisalabad - of Pakistan. The relationships between socio-demographics, knowledge and preventive practices were investigated through logistic regression analysis and chi-square test of association.

RESULTS

Considerable number of dairy farmers 71/173 (41.04%) had no idea about the problems associated with house flies. Although 77/173 (44.51%) dairy farmers reported house flies as disease transmitters, only 23 (29.87%) farmers were familiar with diseases and 22 (28.57%) had somewhat idea of the mode of disease transmission. We found a positive association between dairy farmer's education level and overall knowledge of house flies in multivariate analysis. Farmer's education level and knowledge of the house flies breeding sites had a positive association with the adoption of house fly prevention practices by the respondents. However, knowledge of the problems associated with house flies and preventive measures had no association with house fly prevention practices.

CONCLUSION

The present ethnoentomological survey provides information about knowledge, attitude and practices of dairy farmers related to house flies in Punjab, Pakistan. We conclude that the farmers' education level and knowledge of the breeding sites had a positive association with the adoption of prevention practices against house flies. The study also highlights the need of targeting the lack of knowledge of dairy farmers for the successful management of house flies.

Evidence of field-evolved resistance to organophosphates and pyrethroids in Chrysoperla carnea (Neuroptera: Chrysopidae)

The toxicity of some of the most commonly used insecticides in the organophosphate and pyrethroid classes were investigated against different Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) populations collected over three consecutive years (2005-2007). The populations were tested using leaf dip bioassays for residual effects and topical applications to measure the response of larvae that would come into direct contact with field application of insecticides. In leaf dip assays, the LC50 (micrograms per milliliter; 120 h) values for chlorpyrifos and profenofos were in the range of 59.3-1,023 and 180.02-1,118 respectively. The LC50 values for lambda-cyhalthrin, alphamethrin, and deltamethrin were 359.08-2,677, 112.9-923.5, and 47.81-407.03, respectively. The toxicity for the above insecticides in topical application was similar to toxicity in leaf dip assays. The susceptibility of a laboratory population, which was locally developed and designated as (Lab-PK), to deltamethrin was comparable with another susceptible laboratory population. Resistance ratios for five field populations were generally low to medium for deltamethrin, but high to very high for chlorpyrifos, profenofos, lambda-cyhalthrin and alphamethrin compared with the Lab-PK population. Our data also suggested that the five field populations had multiple resistance to two classes of insecticides. The populations showed resistance to two organophosphates tested and to lambda-cyhalthrin and alphamethrin; however, resistance to deltamethrin was only found at two locations. This pattern indicates occurrence of two divergent patterns of resistance within pyrethroids. The resistance to the insecticides was stable across 3 yr, suggesting field selection for general fitness had also taken place in various populations of C. carnea. The broad spectrum of resistance and stability of resistance to insecticides in C. carnea in the current study suggested that it could be a prime candidate for mass releases and compatible with most spray programs.