Earias Vitella Research Articles

Toxicity of PDKV Bt strains against okra shoot and fruit borer Earias vitella (Fab.)

Toxicity of PDKV Bt strains against okra shoot and fruit borer Earias vitella (Fab.)

Management of Okra Shoot and Fruit Borer Earias vitella (Fab.) by Different Insecticides on Okra

The okra shoot and fruit borer (Earias vittella) is a significant pest affecting okra crops. It bores into the shoots and fruits, causing stunted growth and reduced yield. To combat this pest the present study was conducted during Kharif, 2023 at Rainfed Agriculture Research Farm, Department of Entomology, Bundelkhand University Jhansi. The investigation was carried out to evaluate the efficacy of different insecticides against okra shoot and fruit borer Earias vitella (Fab.), Nine insecticides including control (untreated) were sprayed three times on the okra crop resulted all treatments were significantly effective over control. Among all treatments emamectin benzoate 5% SG was found best effective to control the shoot and fruit infestation caused by E. vitella in all three sprays followed by fluebendiaminde 480% EC and spinosad 45% SC. Among all treatments maximum C:B ratio was obtained from the emamectin benzoate 5% SG (147.56 qt/hac and 1:1.57) followed by spinosad 45% SC (1:1.46), indoxacarb 14.5% SC (1:1.37).

Comparative Efficacy of Insecticides and their Combinations against Okra Shoot and Fruit Borer, Earias vitella (Fabricius)

The research was conducted on okra crop to check the efficacy of some insecticides and their combinations against okra shoot and fruit borer, Earias vittella (Fab.). The study was carried out during kharif 2023 at Central Research Farm of Sam Higginbottom University of Agriculture Technology and Sciences, Prayagraj (U.P.) with eight treatments including untreated check which were replicated thrice. All the treatments were found to be superior over untreated control, neem oil 3%, spinosad 45 SC, cypermethrin 25 EC, profenophos 50 EC, spinosad 45SC + neem oil 3%, cypermethrin 25EC + neem oil 3%, profenofos 50 EC + cypermethrin 25 EC were tested to compare the efficacy against Earias vitella and their influences on yield of okra. Here the best and the most economic treatment was profenofos 50 EC + cypermethrin 25 EC followed by cypermethrin 25EC + neem oil 3%, spinosad 45SC + neem oil 3%, spinosad 45 SC, cypermethrin 25 EC, profenophos 50 EC and the least effective treatment was neem oil 3%. The highest yield among the treatments was noticed in profenofos 50 EC + cypermethrin 25 EC (140quintal/hac.) and the lowest in neem oil 3% (75quintal/hac.) with cost benefit ratio 1:4.7 and 1:2.0, respectively.

Studies on population dynamics of major pests of okra

Okra [Abelmoschus esculentus (L.) Moench] is known tobe infested by many insect pest among them the most important onesare sucking pests like aphids, leafhopper, whitefly and fruit borerslike Earias vitella and Helicoverpa armigera. Controlling these pestsis very much important to obtain good yield, hence knowledge aboutthese pest incidence needed for taking up management practices. Inthis context, okra was sown during last week of November (rabi2020-21) and observations were recorded at weekly interval. Peakincidence of aphid (23.44 aphids/3 leaves) and leafhopper (16.97leafhopper/3 leaves) noticed during last week of December, whitefly(12.70 whiteflies/3 leaves) during second week of March. Fruit borersduring third week of February and second week of March with percent fruit damage of 44.9 (Earias vitella) and 13.59 (Helicoverpaarmigera).Sucking pests incidence more up to 10th week old crop,there after the population declined. In case of fruit borers, theypersisted upto end of the season

Random Mutagenesis to Enhance the Toxicity of Bacillus thuringiensis Cry Proteins Against Earias Vittella (F.)

Insecticidal proteins derived from Bacillus thuringiensis (Bt) are widely utilized in a variety of insect control applications,including sprays and transgenic crops.The development of resistance in pests, on the other hand, can lessen the effectiveness of Bttoxins. In this study, we made efforts to enhance the toxicity of two cry proteins Cry1Ac and Cry2Aa through random mutagenesis against cotton bollworm (Earias vitella), one of the most destructive cotton pests in Pakistan. Random mutagenesis is an important tool for elucidating protein structure-function relationships and for modifying proteins to enhance or change their characteristics. We focused on whole cry proteins for random mutagenesis througherror-prone PCR and constructed a recombinant library of cry proteins. Sequence analysis of eight mutants showed the mutations of 34 different nucleotides in Cry1Ac and Cry2Aa genes. All mutants were spared for toxicity bioassays against 2nd instar larvae of spotted bollworm. Cry1Ac mutant RM1AcM4 (D242E) and Cry2Aa mutants RM2AaM2 (T354A, T492R, F511L, G585E, D606Y) showed enhanced toxicity as compared to proteins without mutation. These two mutants comprise the mutations in domain-II of cry proteins important in specificity determining regions on midgut receptors in insect pests.

Biorational Management of Major Chewing Pests of Okra

Field experiments were conducted to evaluate the efficacy of microbial agents, and neem based and biorational insecticides against major lepidopteran pests of okra, viz., shoot and fruit borer Earias vitella (F) and leaf roller Haritalodes derogata (F) during summer and kharif 2022. The experiment was laid out in randomized block design (RBD) with nine treatments and three replications. Results indicated that spinosad 45SC was the most effective with highest marketable yield. Thus, spinosad 45SC can be used for the effective management of E. vitella and H. derogate in okra.

Efficacy of Pongamia Oil Soap against <i>Earias vitella</i> and <i>Helicoverpa armigera</i> in Okra

Field evaluation of pongamia oil soap against Earias vitella and Helicoverpa armigera infesting okra was carried out during 2018-19 at the Instructional farm in College of Agriculture, Padannakkad. The treatments consisted of 0.6, 1 and 2% pongamia oil soap, Neem oil soap (0.6%); soap solution (0.5%); quinalphos (0.05%) and control (water). Fourteen days after the third application the shoot damage was found lowest in quinalphos 25EC 0.05% (7.32) followed by pongamia oil soap 2% (12.86) and fruit damage was found lowest in quinalphos 25EC 0.05% (6.41) followed by pongamia oil soap 2% (9.60). The reduction in fruit and shoot damage may be due to the feeding deterrency of pongamia oil which remained effective for seven days and thereafter declined.

Biology and Morphometric Study of Okra Shoot and Fruit Borer <i>Earias Vitella</i> (F.)

Investigations on biology of shoot and fruit borer (Earias vitella) on okra revealed that the freshly laid eggs were spherical, bluish green and finally become brownish. These measured 0.52± 0.02 x 0.51± 0.02 mm.The incubation period was 3.35± 0.76 days, and larval stage passed through four instars. The first,second, third and fourth instar was 2.16± 0.71, 1.43± 0.50, 2.26± 0.73 and 3.30±1.02 days, respectivelywith the total larval period of 9.13± 1.71 days. These were measured 1.77± 0.28, 2.60± 0.40, 6.45± 0.56 and14.15± 2.12 mm long respectively and 0.27± 0.03, 0.36± 0.08, 1.24± 0.07 and 3.23± 0.51 mm, respectivelyin breadth. The pre-pupa lasted for 1.43± 0.50 days. The male and female pupa measured 9.78± 0.46 mmand 3.14± 0.31 mm, 10.14± 0.69 mm and 3.37± 0.09 mm, respectively, with duration of 7.90± 0.92 and7.53± 0.50 days, respectively. The adult male measured 9.13± 0.41 mm in length and 21.02± 0.98 mm inbreadth with expanded wings. Whereas, female 10.71± 1.14 mm in length and 22.30± 1.48 mm in breadthwith expanded wings. The preoviposition, oviposition and post-oviposition periods were 1.50± 0.68, 6.00±1.33 and 4.30± 1.53 days, respectively. The fecundity was 265.00± 86.75 eggs/ female. The total lifecycleof male was 30.51± 6.00 days, while in female it was 32.60± 5.59 days.

Field Efficacy of Insecticides Against Okra Shoot and Fruit Borer <i>Earias Vitella</i> (F.)

A field experiment was carried out during kharif 2018 and 2019 to evaluate the efficacy of insecticides against okra shoot and fruit borer Earias vitella (F.). Out of nine insecticides, profenophos 50EC @ 500g a.i./ ha at fortnightly interval was found to the best giving maximum protection (2.55% shoot and 5.69% fruit damage) followed by spinosad 45SC @ 50g a.i./ ha and thiamethoxam 25WG @ 25g a.i./ ha. Amongst the botanicals used, Yam Bean Seed Extract- YBSE (5%) was found to be better. Application of profenophos 50EC (@ 500 g a.i./ha) led to maximum fruit yield (152.9 q/ ha) while the neem oil 3% yielded the least (131.1 q/ ha). Among the plant products, YBSE (5%) yielded maximum (136.2 q/ ha). The benefit-cost ratio was at its maximum (12.78:1) with profenophos 50EC, and it was closely followed by acetamiprid 20SP (11.57:1) and thiamethoxam 25WG (10.11:1).

Kairomonal effect of scales from Earias vitella F. and Corcyra chephalonica Stainton on biology of Trichogramma chilonis (Ishii)

The hexane extracts of scales of male and females of Earias vitella F. and Corcyra chephalonica Stainton were evaluated along with standard octacosane on the performance of Trichogramma chilonis under laboratory conditions and potted plants. Results revealed that eggs of C. cephalonica treated with hexane extract of female E. vitella and C. cephalonica scales at 10000 ppm resulted in maximum parasitism of 81.99% and 75.99% by T. chilonis, respectively, as against 40.66% in untreated (only hexane). Maximum emergence of 71.03% was observed in eggs treated with female extracts of C. cephalonica female followed by E. vitella (70.08%). Similar was the trend with fecundity and longevity with extract of female C. cephalonica. The effect of kairomones on parasitism evaluated with potted plants revealed significantly more parasitism when stapled egg cards of C. cephalonica on cotton and pigeonpea were treated with extract of female E. vitella scales (66.66 and 70.05%, respectively).

Evaluation of insecticides against lepidopteran pests of okra

Field experiment for the evaluation of insecticides was conducted at the Agricultural Research Station, S D Agricultural University, Ladol during kharif 2018- 2020. Results revealed that least fruit damage caused by Earias vitella F (9.84%) and Helicoverpa armigera Hübner (12.86%) was observed with emamectin benzoate 5SG at 0.0025%. Emamectin benzoate 5SG at 0.0025% gave maximum fruit yield and incremental cost benefit ratio. The pesticide residue analysis with emamectin benzoate 5SG at 0.0025% showed that the residues were below limit at 5 days after the spray. Also, only below MRL residue (0.223 ppm) of spinosad 45SC at 0.0169% was observed.

Preliminary studies on parasitization potential of Braconid Wasp (Bracon hebetor Say) against certain Lepidopteran insect pest

A study on parasitization percentage of Bracon hebetor Say on certain lepidopteran insect pest on Rice moth (Corcyra cephalonica Stainton), Tomato fruit borer (Helicoverpa armigera Hubner),Tobacco leaf eating caterpillar (Spodoptera litura Fabricius) and okra fruit borer (Earias vitella Fabricius), studied at ordinary room temperature under invitro conditions and revealed that C. cephalonica was the most suitable host for the development of B. hebetor among the host species tested regarding the parasitization percentage was high in C. cephalonica followed by S. litura, H. armigera and E. vitella.

Biochemical constituents in okra cultivars affect the infestation of shoot and fruit borer, Earias vitella F.

Biochemical constituents in okra cultivars affect the infestation of shoot and fruit borer, Earias vitella F.

Efficacy of insecticides against shoot & fruit borer, Earias vitella fab. on okra, Abelmoschus esculentus L. (moench)

Experiment was investigated on efficacy of insecticides against shoot & fruit borer, Earias vitella Fab. on okra, Abelmoschus esculentus L. (Moench) was carried out in the Vegetable Research Farm, Maharajpur, Department of Horticulture, JNKVV, Jabalpur, Madhya Pradesh during the year 2018 (July to October). Result revealed that on the basis of overall mean fruit damage, all the insecticidal treatments recorded significantly less fruit damage as compared to control (39.17%). Among the treatments Emamectin benzoate 5 SG @ 200 g/ha was found to be most effective as it recorded minimum fruit damage (10.29%) followed by Flubendiamide 20 WDG @ 150 g/ha (11.25%). All the insecticidal treatments recorded significantly higher marketable fruit yields as compared to the control (35.87 q/ha). Among the treatments Emamectin benzoate 5 SG @ 200 g/ha recorded significantly highest fruit yield (82.05 q/ha) followed by Flubendiamide 20 WDG @ 150 g/ha (80.34). Maximum increase in fruit yield over the control was registered in Emamectin benzoate 5% SG @ 200 g/ha (46.32 q/ha) this was followed by Flubendiamide 20 WDG @ 150 g/ha (44.62 q/ha). Maximum net profit was registered in Emamectin benzoate 5% SG @ 200 g/ha (Rs. 65,778) this was followed by Flubendiamide 20 WDG @ 150 g/ha (Rs. 62,508). Maximum cost benefit ratio was obtained in Acetamiprid 20 SP @ 50 g/ha (1:22.61) this was followed by Lambda-cyhalothrin 5 EC @ 400 ml/ha (1:20.50).

Efficacy of Biorational Insecticides Against Spotted Boll Worm Earias spp. in Okra

Experiment was carried out at the farmer’s field in the districts of Amritsar and Jalandhar to evaluate the efficacy of chlorantraniliprole 18.5SC, pyridalyl 10 EC and emamectin benzoate against the fruit borer Earias vitella in okra during 2019. The results revealed that after 7 and 10 days of treatment, chlorantraniliprole 18.5SC (125 and 150 ml/ ha) were found significantly superior and at par with pyridalyl 10EC (500 and 625 ml/ ha) and emamectin benzoate (175 g/ ha). Similar results were obtained with fruit yield wherein chlorantraniliprole 18.5SC (125 and 150 ml/ ha) was at par with pyridalyl 10EC (500 and 625 ml/ ha) and emamectin benzoate (175 g/ ha). Thus, chlorantraniliprole 18.5SC (125 ml/ ha) and pyridalyl 10EC (500 ml/ ha) can be alternative to the usually recommended insecticides against E. vitella.

Survival and Virulence of Native Strains of <i>Steinernema carpocapsae</i> and <i>Heterorhabditis bacteriophora</i> in Formulations

In this study, entomopathogenic nematodes (EPN) isolated from cotton ecosystem viz., Steinernema carpocapsae (strain APKS2) and Heterorhabditis bacteriophora (strain KKMH1) were evaluated in formulations of alginate gel, talc, sponge and water concentrates. The survival or longevity of infective juveniles (IJs) in these formulations was evaluated under in vitro at storage temperatures of 5 and 25 °C. Simultaneously the virulence of these stored EPN infective juveniles (IJs) was evaluated against the spotted boll worm Earias vitella through in vitro bioassays. The results revealed that S. carpocapsae (APKS2) and H. bacteriophora (KKMH1) formulated in alginate gel survived 70-100% up to 3 months with 55-100% infectivity at 5°C and survived 52-100% with 42.5-100% virulence for 2.5 months at 25°C. In talc formulation, these EPN remained alive to an extent of 55-100% with 70-100% virulence at 5°C and stayed alive 45-100% with 52.5-100% virulence at 25°C for 2 months. In sponge formulation, EPN strains survived 55-100% with 67.5-100% infectivity for 7 weeks at 5°C, but with 50-100% survivals and 62.5-100% virulence at 25°C. EPN strain S. carpocapsae (APKS2) can be stored in water at 5°C up to 8 weeks with viability of 50% and infectivity 60%. At 25°C, it can be stored for 5 weeks with survival of 62% and infectivity of 62.5-100 %. It is inferred from the results that alginate and talc formulations at storage temperature of 5°C is better for long term storage of S. carpocapsae strain APKS2 and H. bacteriophora strain KKMH1. Thus, the results revealed that S. carpocapsae (strain APKS2) and H. bacteriophora (strain KKMH1) can be formulated in sponges for use within 2 months and can be kept as water concentrate if they would be utilized in 2-3 weeks.

Evaluation of Biological Approaches for Controlling Shoot and Fruit Borer (Earias vitella F.) of Okra Grown in Peri-Urban Area in Bangladesh

Irrational applications of insecticides on vegetable crops are very common in Bangladesh, resulting in harmful consequences for the environment and human health. Therefore, a study was conducted to evaluate the efficacy of biological and botanical insecticides on okra shoot and fruit borer grown in open fields. Four insecticides were used in this study, namely Bacillus thuringiensis (Bt), Spinosad 45 SC, Abamectin 1.8 EC, and Azadirachtin 1% EC an untreated control. The experiment used a randomized complete block design (RCBD) with three replications. The results showed that the rate of shoot infestation was the lowest in the Spinosad-treated plot (3.80%), and the highest was in the control (20.67%). The lowest fruit infestation (3.56%) was recorded in the treated plot of Spinosad. The rate of reduction of fruit infestation over control was 80.69, 60.14, 56.45, and 55.58% in the plots treated with Spinosad, Bt, Azadirachtin, and Abamectin, respectively. Consequently, the Spinosad-treated plot attained the highest yield (8.65 t ha−1), which was followed by the plots treated with Azadirachtin (6.74 t ha−1), Bt (6.28 t ha−1), and Abamectin (6.12 t ha−1). The highest net return and benefit–cost ratio (BCR) were 542.36 US$ and 2.64, obtained respectively from the Spinosad-treated plot. The second highest BCR (1.70) was obtained from the Azadiratin-treated plot, and the lowest BCR (1.18) was recorded in the Abamectin-treated plot. Therefore, the studied insect management practices could be incorporated to attain higher yields and economic benefits for growing okra in Bangladesh.

Population Dynamics of Shoot and Fruit Borer Earias Vitella on Okra

Field experiment to evaluate the population dynamics of okra shoot and fruit borer Earias vitella F., was conducted at the Research Farm, Tirhut College of Agriculture, Dholi, Muzaffarpur, Bihar during kharif 2018 and 2019. The observations revealed that its shoot infestation initiated from 29th standard week (SW) (3.84%) and reached its peak (10.09%) during 31st SW. The fruit damage was first noticed during 31st SW (4.91%), continued till 41st SW (6.44%) reaching peak (29.30%) at 34th SW. The larval count on fruit was of a maximum (7.13 larva/ 25 fruit) during 31st SW. The maximum and minimum temperature and relative humidity at 7 hr were found positively correlated with fruit damage (r = 0.512, 0.286 and 0.217, respectively). The larval counts exhibited a positive and significant relationship with maximum temperature (r = 0.549) while that of minimum temperature (r = 0.327) and relative humidity at 7 hr (r = 0.211) were positive and nonsignificant. The weather factors collectively infulenced 64.10, 87.10 and 86.90% of shoot and fruit damage and larval counts, respectively.

Efficacy of new insecticides against okra shoot and fruit borer, Earias vitella (Fb.) (Lepidoptera: Noctuidae)

A field study conducted to evaluate the efficacy of new molecules against okra shoot and fruit borer, Earias vitella (Fb.) during rabi and summer season revealed that Chlorantraniliprole 8.8% + Thiamethoxam17.5% SC @ 0.7 ml/l significantly reduced the percentage of shoot and fruit damage. No shoot and fruit infestation was recorded at seven and fourteen days after treatment. It was on par with the standard check Chlorantraniliprole 18.5 SC @ 0.3 ml/l followed by Novaluron 10 EC @ 2 ml/l and Lamdacyhalothrin 4.6% + Chlorantraniliprole 9.3% ZC. Chlorantraniliprole 8.8% + Thiamethoxam17.5% SC treated plots recorded highest total yield of 469.86 and 594.31 g/plant respectively. Maximum marketable yield was also recorded from Chlorantraniliprole 8.8% + Thiamethoxam17.5% SC treated plots respectively. Chlorantraniliprole 8.8% + Thiamethoxam17.5% SC also showed high benefit-cost ratio of 2.42 and 3.12 during rabi and summer season respectively.

Earias vittella management by utilizing obnoxious weeds extracts of Jammu and Kashmir Himalayas, India

All the three agro-ecological zones (sub-tropical, intermediate and temperate) of the Jammu province were surveyed for potential pesticidal plants. Methanol extracts of all the thirteen plants / plant parts and fractions were assessed for insecticidal activity. Eight treatments (T3 –Boerhavia diffusa stem methanolic extract, T6 –Boerhavia diffusa roots methanolic extract, T7 –Boerhavia diffusa roots hexane fraction, T12 –Arisaema flavum stem + leaves methanol extract, T13 –Arisaema flavum stem + leaves hexane fraction, T14 –Arisaema flavum stem + leaves acetone fraction, T15 –Arisaema flavum roots / tubers methanol extract and T17 –Arisaema flavum roots / tubers acetone fraction) recorded cent percent mortality of first instar larvae, within four hours. All the extracts / fractions evaluated against Earias vitella exhibited contact toxicity, and ovicidal action. The growth indices were also affected. Few extracts / fractions were so toxic that they exhibited 100% control. When larvae were fed on extract / fraction treated food for growth indices studies, in many cases larvae died. These extracts/ fractions have great potential to be developed as botanical pesticide. Active pesticidal compounds from few promising plants may be extracted and further studied for their pesticidal activity. The present studies suggest that the plant extract may be fractionated for better results.