Nymphal Mortality Research Articles

Synergistic Effects of Insecticides and Wetting Agents on Mango Mealybug (Drosicha mangiferae Green) Management

The experiment was conducted at the Entomology Laboratory of Sher-e-Bangla Agricultural University to understand the efficacy of different insecticidal combinations with wetting agents against the nymphs and the adults of devastating mango mealybug. The treatments consisted of T1 = Nitro 505 EC + Petroleum oil, T2 = Nitro 505 EC + Ethyl alcohol, T3 = Nitro 505 EC + Detergent, T4 = Capture 75 WG + Petroleum oil, T5 = Capture 75 WG + Ethyl alcohol, T6 = Capture 75 WG + Detergent, T7 = Imitaf 20 SL + Petroleum oil, T8 = Imitaf 20 SL + Ethyl alcohol, T9 = Imitaf 20 SL + Detergent. The study examined the mortality rate of mealybugs by treating these combinations. Treatment T8 consistently showed the highest nymphal mortality rates across different application times, significantly outperforming other treatments. Conversely, T6 exhibited the lowest control of first instar nymphs, with notably fewer nymphs controlled after 48 hours compared to other treatments. T3 and T9 also showed significant results in nymphal mortality, gradually increasing over time. While T2 initially showed high nymphal mortality, it revealed statistically similar results to T1, T5, T4, T7, and T8. T9 performed the poorest, with the lowest control of second instar nymphs after 48 hours, while T3 and T6 also demonstrated lower efficacy. Regarding adult mealybugs, mortality rates were lower compared to nymphs, attributed to the development of a protective waxy layer. Treatment T5 showed the highest control of adult mealybugs, followed by T2, with statistically significant differences observed. T6 exhibited the lowest control, significantly different from T5. Despite slight increases over time, all treatments resulted in significantly lower numbers of adult mealybugs compared to the initial 12-hour application period. Overall, the study highlights the differential efficacy of treatments in controlling mealybug nymphs and adults, with T8 (Imitaf 20 SL + Ethyl alcohol) showing consistent effectiveness against nymphs and T5 being most effective against adult mealybugs.

Copper Accumulation Through Diet Versus Direct Water Exposure Routes in a Dragonfly Nymph/Mosquito Larvae Laboratory Food Chain.

Aquatic organisms can uptake metals directly from contaminated water or by consuming contaminated prey. Knowing the relative importance of these routes is critical to understand how metals enter and move through aquatic food webs. We previously established that nymphs of the aquatic dragonfly Erythemis simplicicollis accumulate elevated copper (Cu) concentrations when living in contaminated wetlands, but the route of uptake was not identified. In this study, we evaluate copper accumulation with a model two-trophic-level laboratory food chain comprised of E. simplicicollis dragonfly nymphs as predators and Aedes aegypti mosquito larvae as prey to gain better insight into Cu accumulation dynamics in these aquatic insect predators. Treatments consisted of dragonfly nymphs exposed to copper through diet (A. aegypti larvae prey exposed to 100µg/L Cu-contaminated water), water (100µg/L Cu), diet + water, and a control. Each treatment included 15 replicates, and 10 pretreatment nymphs were analyzed. Exposures lasted 32days or until nymph death. Copper accumulation in nymphs and nymph mortality was compared among treatments. Eating contaminated prey did not elevate copper concentrations in E. simplicicollis. In contrast, highest copper concentrations accumulated in E. simplicicollis when exposed to contaminated water, in both the water-only and in the diet + water treatments. Additionally, mortality was greater when exposed to copper-contaminated water. Even though the nymphs did not trophically accumulate Cu, direct uptake of Cu from water provides a point of Cu entry into a food chain.

Control Effectiveness of Kaolin Clay and Neem on Agonoscena pistaciae in Pistachio Orchards

The pistachio psyllid (Agonoscena pistaciae) is a major pest threatening pistachio production in Siirt province, Türkiye. This study evaluated the efficacy of a clay mineral, kaolin, and a botanical insecticide, neem extract, in managing this pest, aiming to reduce the reliance on chemical pesticides. Field experiments were conducted to compare the performance of these treatments with that of the synthetic insecticide spirotetramat SC 100 at various application rates. The results demonstrated that kaolin significantly reduced oviposition rates, achieving up to 100% deterrence, while neem extract exhibited substantial nymph mortality rates of up to 84.75%. These findings highlight the potential of mineral- and plant-based alternatives as effective components of integrated pest management strategies for pistachio psyllid control, offering sustainable and environmentally friendly solutions for minimizing economic losses and pesticide residues in pistachio production.

A comparative study on the efficacy of nano-formulated Melia azedarach (L.) ethanolic extract and cyantraniliprole in controlling greenhouse whitefly (Trialeurodes vaporariorum Westwood) populations

The greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hem.: Aleyrodidae), is a highly reproductive polyphagous pest that affects a wide range of ornamental and greenhouse plants. This study assessed the insecticidal efficacy of a specific ethanol extract formulation from Melia azedarach fruit (DMSO-Melia) and cyantraniliprole against the egg and nymph stages of T. vaporariorum under laboratory conditions. The DMSO-Melia formulation, which reduced particle size, showed enhanced insecticidal activity. The results indicated that neither treatment had a significant impact on egg hatch rates. In the nymph mortality experiments, two separate observations were made. The first showed a mortality rate of 52.97 ± 6.80% for cyantraniliprole and 29.58 ± 3.58% for DMSO-Melia. The second observation revealed mortality rates of 59.45 ± 7.14% for cyantraniliprole and 39.00 ± 5.33% for DMSO-Melia. The cyantraniliprole treatment significantly increased nymph mortality compared to DMSO-Melia in both experiments (p ≤ 0.05). While cyantraniliprole was more effective in inducing nymph mortality, the DMSO-Melia formulation demonstrated promising results.

Temperature-Dependent Modeling and Spatial Predictions for Identifying Geographical Areas in Brazil Suitable for the Use of Cordyceps javanica in Whitefly Control.

Lalguard C99 WP, based on the Cordyceps javanica BRM 27666 strain, is registered in Brazil for whitefly control. Spatial prediction is crucial for optimizing its field use and efficacy. In this study, the optimal temperature for mycelial growth and conidial production of C. javanica is 25-30 °C, with no growth at 33-35 °C. The highest nymphal mortality occurred at 25 and 30 °C, showing lower LT50 values at 30 °C. Mycelial growth was similar at 15, 20, 25, 30, and 35 °C when the fungus was exposed for 6 h and then transferred to a 27.4 °C environment; however, growth was slower at 35 °C with daily 6 h exposure alternating over 18 h at room temperature (mean of 28.5 °C). When the second instar whitefly nymphs were exposed for 6 h or 6 h daily at 15, 20, 25, 30, and 35 °C, followed by 7 days at fluctuating temperatures (mean of 28.4-30.2 °C), nymphal mortality was similar across temperatures. Although other abiotic factors (solar radiation, humidity, rainfall, etc.) must be considered for fungal efficacy, spatial predictions based on fluctuating temperatures indicated that C. javanica is suitable for use throughout Brazil, though its performance varied at constant temperatures in different locations.

Biological control of Schistocerca gregaria and Locusta migratoria migratorioides using Entomopathogenic bacteria

This study investigated the potential of indigenous entomopathogenic bacterial (EPB) strains from Egypt to control the two most prevalent locust species, Schistocerca gregaria (Forsskål) (Orthoptera: Acrididae), and Locusta migratoria migratorioides (Reiche & Fairmaire) (Orthoptera: Acrididae). To assess the efficacy of the EPB strains, experiments were conducted in the laboratory, semi field, and field. The results showed that Xenorhabdus nematophila (Thomas et Poinar) BA2 (Enterobacterales: Morganellaceae) and Photorhabdus luminescens (Thomas et Poinar) EGAP3 (Enterobacterales: Morganellaceae) were the most effective strains against S. gregaria and L. migratoria migratorioides in laboratory settings. Under semi-field conditions, X. nematophila BA2 recorded nymphal mortality rates of 89.31% and 85.00% against the 2nd and 5th nymph instars of S. gregaria, respectively, and P. luminescens EGAP3 showed nymphal mortality rates of 88.00% and 80.00% against the 2nd and 5th nymph instars of S. gregaria, respectively. In field trials, X. nematophila BA2 exhibited the highest nymphal mortality rate of 88.70% at 7 days after spraying. Overall, the findings of this study suggest that X. nematophila BA2 and P. luminescens EGAP3 are promising candidates for environment-friendly, safe locust pest management. Further research is needed to explore and develop these bacteria for commercial use in agriculture.

Rapid screening for resistance to Sitobion avenae (F.) and Rhopalosiphum padi (L.) in winter wheat seedlings and selection of efficient assessment methods.

Sitobion avenae (F.) and Rhopalosiphum padi (L.) are harmful pests of wheat [Triticum aestivum (L.)]. No genetic resistance against the aphids has been identified in commercial wheat varieties and resistance phenotyping can be time-consuming and laborious. Here, we tested a high-throughput phenotyping method to screen 29 commercial winter wheat varieties for alate antixenosis and antibiosis. We validated this method using comprehensive behavioural analyses, including alate attraction to volatile organic compounds (VOCs) and a feeding bioassay using an electrical penetration graph (EPG), subsequently highlighting possible sources of resistance. We observed differences in alate behaviour upon assessing alate settlement on wheat seedlings and attraction towards VOCs, revealing the importance of visual and early post-alighting cues for alate host selection. Aphid settlement was four times higher on the most preferred variety than on the least preferred variety. Using an EPG bioassay, we identified phloem feeding and stylet derailment parameters linked to resistance. We found antibiosis assessment on detached leaves to be an inadequate screen because it produced results inconsistent with intact leaves assessment. Alate and nymph mortality were identified as key traits signifying antibiosis, showing significant positive relationships with alate reproduction and nymph mean relative growth rate. Overall, antixenosis and antibiosis varietal responses were consistent for both aphid species. Alate settlement on wheat seedlings was a more efficient antixenosis screen than an olfactometer assay using VOCs. In addition to assessing alate and nymph survival for antibiosis, this allows for more rapid phenotyping of large numbers of genotypes to identify novel aphid resistance genes for varietal improvement. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Applying a saponin complex of Pseudalbizzia inundata (Mart.) Koenen & Duno as surfactants of Beauveria bassiana (Balsamo) Vuillemin conidia to control Bemisia tabaci Gennadius

ABSTRACT Biosurfactants secondary plant metabolites, such as saponins, could be an efficient green alternative dispersant for entomopathogenic fungi propagules. This work aimed to evaluate the potential of a saponins’ complex extracted from Pseudalbizzia inundata (Mart.) Koenen & Duno (PSC) to disperse conidia of Beauveria bassiana IBCB66 (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) as also its’ insecticidal activity against Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). Despite a negligible effect on fungal germination and mycelial growth at the highest concentration of PSC (1,000 mg L-1), conidia production was significantly inhibited, resulting in a biological index of 52.03 at the higher dose, which characterises PSC as moderately toxic to B. bassiana. However, no effect was detected on the viability of conidia produced in media added with PSC. When applied directly on cowpea leaves, the saponins did not show an insecticidal effect on B. tabaci eggs and nymphs. PSC solution produced an adequate dispersion of B. bassiana IBCB66 conidia, causing nymph mortality higher than 90%, similar to Triton X-100, and adult mortality of 60% with a median survival time (ST50) of 8 days. A probit analysis of dose-effect of IBCB on both surfactants showed no difference between PSC solutions and Triton according to the parallelism test, with LC50 of 2.35 and 1.44 × 107 conidia mL-1 for PSC and Triton, respectively. These findings underscore the potential of PSC as a safe and effective substitute for synthetic surfactants to disperse the conidia of entomopathogenic fungi.

Effect of O. ficus-Indica endorhizosphere-associated- bacteria on the survival and mortality of carmine cochineal (Dactylopius opuntiae)

ABSTRACT The false carmine cochineal scale, Dactylopius opuntiae (Cockerell), Hemiptera: Dactylopiidae, is the most aggressive pest of Opuntia ficus-indica (L.) Mill, in many countries. The aim of this study is to evaluate the efficacy of culturable endorhizosphere bacteria isolated from the root of this cactus in terms of their potential antagonism as a biological control agent against this pest under laboratory and greenhouse conditions. Among 62 bacteria isolated from the cactus O. ficus-indica endorhizosphere, four bacterial isolates exhibited the highest insecticidal activities against nymphs and adult females of D. opuntiae. Under laboratory conditions, bacterial solutions of the strain ‘BME8’ Bacillus halotolerans and ‘Bm3C’ Priestia aryabhattai were sprayed onto D. opuntiae at concentrations 107 and 108 CFU.mL−1, respectively, which caused 100% mortality in adult females and nymphs within 24 h of treatment. While in greenhouse conditions, spraying the bacterial solution of the BME8 strain at 109 CFU.mL−1 on the covered cochineals, seemed to be the most effective, the number of insects declined by 59% after 7 days of application. The strain ‘Bm4D’ Bacillus licheniformis and ‘Bm1A’ Bacillus subtilis, played a key role in hydrolyzing the hydrophobic wax protecting females, which is the most important tool in controlling against D. opuntiae females. Furthermore, the strain ‘Bm1A’ Bacillus subtilis spray, was considered the second most efficient treatment in the greenhouse. The survival rate was 55% at 109 CFU.mL−1 after only 7 days of treatment. Enzymatic activity assays showed that all strains BME8, Bm1A and Bm4D (except Bm3C) exhibited α-amylase, pectinase and chitinase activities.

The efficiency of using some integrated control methods in controlling the mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococ-cidae)

This study evaluated the efficiency of some integrated pest control methods to control the mealybug Phenacoccus solenopsis Tinsley under laboratory conditions. It was done by testing the efficiency of some methods, such as insecticides Conan and Actrara, entomopathogenic fungi Beauveria bassiana, Nano Calcium silicate, and mineral oil. This experiment was carried out in the insect laboratory for postgraduate studies at the College of Agriculture, University of Kerbala. The results prove that insecticides Conan and Actara significantly affect both nymphs and adults, where the average percentage of nymphs mortality within 24 hours of treatment was 100%. The concentrations of the Conan pesticide were (300 - 400 - 500 mg/L) Whereas the Actara pesticide was in concentrations (0.20 – 0.25 – 0.30 ml/L) respectively. Likewise, the rate of mortality of adults within 24 hours of treatment with Actara and its three concentrations used (0.20 - 0.25 - 0.30 ml/L) and Conan with three concentrations as well (300 - 400 - 500 mg/L) reached 100%. Based on the study's results, both insecticides, Conan and Actara, can be used due to their superiority in mortality rates. In contrast, the mortality rate was 100% in both nymphs and adults within 24 hours of treatment compared to the other treatments used.

An evaluation of novaluron on Southern green stink bug (Hemiptera: Pentatomidae) nymphs and sublethal effects on fecundity in adults.

Stink bug species emerged as major insect pests of cotton in the mid-southern United States following the eradication of the boll weevil and the introduction of genetically modified Bt cotton for lepidopteran pests. Considering the limited number of chemical classes available for insect control, further insights into other chemistries are necessary to inform management strategies with the overall goal of establishing and maintaining the most cost efficient and efficacious control programs for stink bugs in Alabama. The insect growth regulator, novaluron, has shown control of tarnished plant bugs, but little research has been done on its effect in stink bugs. The objective of our study is to evaluate the effects of novaluron, in a laboratory setting, on adult fecundity, nymphal mortality, and yield and damage in the field. We hypothesized that novaluron would have a direct effect on mortality in nymphs and could decrease fecundity in adult stink bugs. Although the effect on fecundity was counter to our hypothesis, this study shows effective control of nymphs in our model insect, the southern green stink bug, Nezara viridula (Hemiptera: Pentatomidae). Future evaluation of proper timing of novaluron applications could make this a valuable tool for residual control of stink bugs in cotton.

AKH/AKHR signalling system induced antioxidant response mediated by entomopathogenic fungi in Nilaparvata lugens (Stål)

AKH/AKHR signalling system induced antioxidant response mediated by entomopathogenic fungi in Nilaparvata lugens (Stål)

Efficacy of Ethanolic Extract of <i>Schanginia aegyptiaca</i> and <i>Artemisia herba-alba</i> Against Aphid <i>Aphis gossypii</i> glover on Okra

Aphis gossypii Glover is an important pest of okra. This study evaluates the effect of alcohol extract of Schanginia aegyptiaca and Artemisia herba-alba on the mortality of nymphs under laboratory conditions. The results showed that the S. aegyptiaca was superior to the A. herba-alba plant extract in producing aphid mortality. Rate of nymphal mortality on plants treated with a concentration of 20 mg/ ml of S. aegyptiaca extract reached 73.32, 81.32, and 92.00% at the periods 24, 48, and 72 hr, respectively.

Flupyradifurone application: A promising approach to curtail tomato leaf curl New Delhi virus (ToLCNDV) transmission vectored by Bemisia tabaci in potato farming

Flupyradifurone application: A promising approach to curtail tomato leaf curl New Delhi virus (ToLCNDV) transmission vectored by Bemisia tabaci in potato farming

Field evaluation of symbiont-targeted control of Halyomorpha halys in hazelnut crop

Field evaluation of symbiont-targeted control of Halyomorpha halys in hazelnut crop

Lethal and Sublethal Effects of Afidopyropen and Flonicamid on Life Parameters and Physiological Responses of the Tobacco Whitefly, Bemisia tabaci MEAM1

The tobacco whitefly, Bemisia tabaci MEAM1, is a destructive pest that damages plants by sucking plant juice and transmitting viruses. B. tabaci insecticide resistance contributes to population resurgence, and new insecticides are continually needed. Flonicamid and afidopyropen are selective pesticides with high insecticidal activity against piercing–sucking pests and safety to non-target species. We determined the toxicity of flonicamid and afidopyropen to B. tabaci, investigated the sublethal effects on life parameters, and studied physiological responses to them. Flonicamid and afidopyropen were highly toxic to B. tabaci, with LC50 values of 12.795 mg/L (afidopyropen) and 25.359 mg/L (flonicamid) to nymphs and 4.711 mg/L (afidopyropen) and 11.050 mg/L (flonicamid) to adults. Sublethal concentrations (LC10 and LC20) reduced the longevity and fecundity of the B. tabaci F0 generation. Transgenerational effects were caused by exposure to sublethal concentrations of flonicamid and afidopyropen. Nymph mortality increased, development was delayed, fecundity decreased, and adult longevity was shortened. Population parameters such as the intrinsic rate of growth (r), net reproductive rate (R0), and finite rate of growth (λ) were significantly decreased compared to the control. The activity of detoxifying enzymes, such as GSTs and P450, were induced by flonicamid and afidopyropen at 72 h, while CarE was inhibited. The expression levels of eleven P450 genes and four GST genes were significantly higher than in the control. In conclusion, flonicamid and afidopyropen have excellent acute toxicity and continuous control effects on B. tabaci. Higher GST and P450 activities and gene expression levels may play important roles in the detoxification metabolic process.

Isolation, identification, biological characteristics, and pathogenicity of an entomogenous fungus against the Egyptian mealybug, Icerya aegyptiaca (J.) (Hemiptera: Monophlebidae)

BackgroundIn this study, an entomogenous, fungus was isolated from the Egyptian mealybug, Icerya aegyptiaca (J.) (Hemiptera: Monophlebidae) on the parasol leaf tree, Macaranga tanarius, in China where evaluated as a biocontrol fungus to reduce the population of the target insect. The strain was identified as Aspergillus parasiticus by morphological and phylogenetic analysisand named ZHKUAP1. The biological characteristics, pathogenicity, and field control effect of the strain were determined.ResultsThe most suitable medium for the mycelial growth of strain ZHKUAP1 was PPDA medium, with an optimum temperature of 30 °C and pH 7, in addition to glucose and peptone as carbon and nitrogen sources. The optimum sporulation conditions were the PPDA medium at 30 °C and pH 6, using the soluble starch and beef extract as carbon and nitrogen sources. The mycelial growth and spore production of strain ZHKUAP1 were stopped at 70 °C and above, indicating that it was not resistant to high temperatures. High concentrations of spore suspension, against young insect age, resulted high corrected mortality, as well as decreased the median lethal time. When the spore concentration was 1 × 108 cfu/ml, the corrected mortality of the second nymph was 88.33%, and the LT50 was 0.66 day. After 10 days of inoculation, the LC50 of the second instar nymph was the smallest, reaching 4.07 × 104 cfu/ml. On the 10th day of the field experiment, the corrected mortality was 76.45%, indicating that the A. parasiticus strain ZHKUAP1 had strong pathogenicity on I. aegyptiaca population.ConclusionsThe indoor toxicity of the strain to I. aegyptiaca was determined, and the field control effect of the pathogen was explored on this basis. The results have important application prospects in the biological control of I. aegyptiaca.

Diversity study of Beauveria bassiana species for finding the most virulent strain to manage Bemisia tabaci in cotton

Beauveria bassiana (Bal.-Criv.) is an important entomopathogenic fungus being used for the management of various agricultural pests worldwide. However, all strains of B. bassiana may not be effective against whitefly, Bemisia tabaci, or other pests, and strains show diversity in their growth, sporulation, virulence features, and overall bioefficacy. Thus, to select the most effective strain, a comprehensive way needs to be devised. We studied the diversity among the 102 strains of B. bassiana isolated from 19 insect species based on their physiological features, virulence, and molecular phylogeny, to identify promising ones for the management of B. tabaci. Strains showed diversity in mycelial growth, conidial production, and their virulence against B. tabaci nymphs. The highest nymphal mortality (2nd and 3rd instar) was recorded with MTCC-4511 (95.1%), MTCC-6289 (93.8%), and MTCC-4565 (89.9%) at a concentration of 1 × 106 conidia ml−1 under polyhouse conditions. The highest bioefficacy index (BI) was in MTCC-4511 (78.3%), MTCC-4565 (68.2%), and MTCC-4543 (62.1%). MTCC-4511, MTCC-4565, and MTCC-4543 clustered with positive loading of eigenvalues for the first two principal components and the cluster analysis also corresponded well with PCA (principal component analysis) (nymphal mortality and BI). The molecular phylogeny could not draw any distinct relationship between physiological features, the virulence of B. bassiana strains with the host and location. The BI, PCA, and square Euclidean distance cluster were found the most useful tools for selecting potential entomopathogenic strains. The selected strains could be utilized for the management of the B. tabaci nymphal population in the field through the development of effective formulations.Key points• 102 B. bassiana strains showed diversity in growth and virulence against B. tabaci.• Bioefficacy index, PCA, and SED group are efficient tools for selecting potential strains.• MTCC-4511, 4565, and 4543 chosen as the most virulent strains to kill whitefly nymphs.

Laboratory evaluation of different eco-friendly insecticides against the Egyptian fluted scale, Icerya aegyptiaca

Lac cultivation is generally carried out on a limited number of indigenous tree species found scattered in forests and cultivable land. Recent studies show that Flemingia semialata Roxb. (Leguminosae) is an excellent bushy host plant for the cultivation of the kusmi strain of lac insects. The present investigation was carried out with the objective of getting acquainted with the different eco-friendly insecticides under laboratory evaluation against the Egyptian fluted scale, Icerya aegyptica. Maximum nymphal mortality of 81.67 per cent and 78.34 per cent was observed at 0.2 per cent Pestoguard and Neemazal after 12 days of treatment, which is statistically at par with each other. 51.67 per cent mortality was achieved after 12 days of treatment at 1 per cent Uro-insecticide and Green mealikil, which is a microbial pesticide that is also effective against the Egyptian fluted scale, Icerya aegyptiaca. The mortality percentage was low after 1, 3 days and seven days, but it gradually increased after 12 days of treatment, obtaining 48.34% mortality, which is statistically at par with Uro-insecticide. All the eco-friendly insecticides used in the present experiment (Uroinsecticides, Pestoguard, green mealikil and neemazal) are effective in controlling the population of Icerya aegyptiaca. Unlike Malathion and Imidacloprid, they don’t have a quick knockdown effect; however, the mortality due to exposure significantly increases as there is an increase in days or duration of application, and they are safe for the lac insect.

Impact Analysis of Biorational Insecticides under Weeded and Non Weeded Habitat on Whitefly, Bemisia tabaci Management in Cotton Agroecosystem

Transgenic Bt cotton is effective to a high degree of, with respect to target lepidoptran bollworms, however sucking pests especially whitefly posed a serious issues in absence of bollworm in genetically modified (GM) crops. Therefore, to understand the efficacy of various biorational compounds against whitefly under non-weedy as well as weedy field conditions, studies on whitefly carried out during kharif 2018, to know the changes in number of whitefly adults as well as nymphs. Transgenic hybrid cotton variety RCH 650 was sown with a spacing of 100×45 cm and replicated four times in both non-weedy and weedy habitat. Although, standard check Dimethoate 30 EC proved it’s efficacy after first and second spray in cotton crop against whitefly. Not with standing, after the application of biorational first time as spray in 29th Standard Meteoroloical Week (SMW), Nimbecidine 300 ppm was admitted as most effective in non-weedy (66.76 and 60.65% mean mortality in whitefly adult and nymph, respectively) as well as in weedy habitat that caused 56.77 and 55.54% mean mortality in adult and nymph, respectively over a period of seven days after application. Entomopathogenic fungi Verticillium lecanii found better to control whitefly adults (42.06 and 40.63%), while Metarhizium anisopliae (42.39 and 36.01%) found more effective for nymphal mortality in non-weedy as well as in weedy habitat. One and same pattern of efficacy of biorational was reconstructed against whitefly again after second application of biorational in all the treatment selected to test against whitefly.