scholarly journals Effectiveness of Insecticides to Control Small and Large Larvae of Helicoverpa armigera (Hübner, 1805) (Lepidoptera: Noctuidae)

2020 ◽  
Vol 12 (6) ◽  
pp. 90
Author(s):  
M. C. S. Vieira ◽  
E. C. S. Vieira ◽  
P. G. Silva ◽  
I. F. da Silva ◽  
C. J. Ávila ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Larval Mortality ◽  
Randomized Design ◽  
Lambda Cyhalothrin ◽  
Helicoverpa Armígera ◽  
Completely Randomized Design ◽  
And Control ◽  
Lepidoptera Noctuidae ◽  
Control Water ◽  
Bean Leaves

Helicoverpa armigera (Hübner, 1805) (Lepidoptera: Noctuidae) is a cosmopolitan pest with wide geographical distribution in Brazil. This pest was officially registered in 2013 on cotton, soybean, corn, and some weeds, although this species may have been present in the country since 2008. The objective of this work was to evaluate the efficiency of eight insecticides (seven chemicals and a biological product) to control small and large H. armigera caterpillars. The experiment was conducted under laboratory conditions (T 22±1 °C; RH 70±10%; 12h photoperiod), with nine treatments (g a.i./ha dose): flubendiamide (72), chlorantraniliprole + lambda-cyhalothrin (30 + 15), chlorfenapyr (288), spinetoran (18), indoxacarb (120), emamectin benzoate (10), metomil (322.5), Bacillus thuringiensis (500), and control (water). A completely randomized design was used with four replications for each size of caterpillars (small and large), and each repetition (plot) consisted of five H. armigera caterpillars fed with bean leaves immersed in the different treatments evaluated. The larval mortality evaluations were performed at one, three, five, and seven days after contact with the treated bean leaves, determining the control efficiency (E%) through the formula of Abbott (1925). All chemical and biological treatments tested caused significant mortality of small and large H. armigera caterpillars, reaching a control percentage of 100% at seven days after treatment, demonstrating the possibility of using the insecticides tested to control this pest under field conditions.

scholarly journals VIABILITAS DAN EFEKTIVITAS FORMULA NEMATODA Steinernema sp. TERHADAP HAMA PENGGEREK BUAH KAPAS Helicoverpa armigera HUBNER

2020 ◽  
Vol 18 (4) ◽  
pp. 151
Author(s):  
HERI PRABOWO ◽  
IGAA INDRAYANI
Keyword(s):  
Helicoverpa Armigera ◽  
Insect Pests ◽  
Infective Juvenile ◽  
Distilled Water ◽  
Insect Pathology ◽  
Randomized Design ◽  
Helicoverpa Armígera ◽  
Completely Randomized Design ◽  
Biological Pesticide ◽  
And Control

<p>ABSTRAK<br />Entomopatogen dari genus Steinernema berpotensi digunakan<br />sebagai pengendali berbagai serangga hama, terutama ordo Lepidoptera,<br />seperti  Helicoverpa  armigera.  Penggunaan  Steinernema  untuk<br />pengendalian H. armigera akan menguntungkan karena aman terhadap<br />lingkungan, mudah diproduksi massal, toleran terhadap berbagai macam<br />pestisida, dapat aktif mencari serangga sasaran, tidak menyebabkan<br />resisten dan resurjensi, serta dapat diaplikasikan dengan alat semprot<br />standar. Namun, formula pestisida hayati mengandung Steinernema masih<br />sangat terbatas. Tujuan penelitian adalah membuat formula Steinernema<br />sp. yang efektif terhadap hama penggerek buah kapas (H. armigera).<br />Penelitian dilaksanakan di laboratorium Patologi Serangga, Balai<br />Penelitian Tanaman Pemanis dan Serat, Malang mulai bulan Mei-Juli<br />2010. Larva instar III Steinernema sp. dibuat dalam 6 macam formula<br />perlakuan dengan bahan pembawa (carrier) berbeda-beda, yaitu (1)<br />suspensi (akuades + sukrosa), (2) pellet-2 (sekam padi), (3) pellet-1<br />(tanah liat + arang), (4) agar + spon, (5) kapsul (Ca-alginat), dan (6)<br />kontrol (akuades). Setiap formula diinokulasikan 10 6 juvenil infektif (JI).<br />Masing-masing perlakuan disusun dalam rancangan acak lengkap (RAL)<br />dengan tiga kali ulangan. Penurunan jumlah juvenil infektif (JI) pada<br />setiap formula yang diamati per minggu selama ± 4 minggu. Isolat yang<br />digunakan untuk penelitian ini berasal dari Asembagus. Untuk<br />mengevaluasi efektivitas formula, larva H. armigera diperlakukan dengan<br />JI yang berasal dari masing-masing formula setiap minggu selama empat<br />minggu. Perlakuan ini menggunakan rancangan acak lengkap dengan<br />empat ulangan. Jumlah penurunan JI setiap minggu selama empat minggu<br />setelah perlakuan. Persentase JI yang hidup pada pellet-1, suspensi, pellet-<br />2, agar + spon, kapsul, dan kontrol berturut-turut sebesar 53; 12,4; 44;<br />63,8; 17,6; dan 5%. Pada minggu pertama sampai minggu keempat setelah<br />perlakuan terlihat bahwa formula yang paling baik mempertahankan JI<br />adalah agar + spon dan kemudian berturut-turut diikuti oleh pellet-1,<br />pellet-2, kapsul, suspensi. Steinernema sp. yang disimpan selama empat<br />minggu dalam berbagai bentuk formula terhadap H. armigera berkisar<br />antara 80-99%. Formula agar dan spon paling baik untuk menyimpan<br />Steinernema sp. selama empat minggu, karena formula ini memberikan<br />tingkat viabilitas dan efektivitas Steinernema sp. paling tinggi.<br />Kata kunci : efektivitas, formula, Helicoverpa armigera, Steinernema sp.,<br />viabilitas</p><p>ABSTRACT<br />Entomopathogenic nematodes genus Steinernema for are potential<br />to be used as a control for various insect pests, especially ordo<br />Lepidoptera, such as Helicoverpa armigera. The use of Steinernema to<br />control H. armigera is beneficial because it is environmentally friendly,<br />easy to produce, tolerant to several pesticides, actively search the target<br />insect, does not cause resistance and resurgence, and can be applied by<br />using standard sprayer. Unfortunately, biological pesticide containing<br />Steinernema is still limited. The study was aimed at formulating a<br />biological agen containing Steinernema sp. to control the cotton bollworm<br />weevil (H. armigera). The experiment was conducted at insect pathology<br />laboratory, Indonesian Sweetener and Fiber Crops Research Institute,<br />Malang from May to July 2010. Steinernema sp. instar III larvae was<br />formulated in six different forms such as Pellet-1 (clay+carbon),<br />suspension (distilled water+sucrose), Pellet-2 (rice husk), agar+sponge,<br />capsule (Ca-alginate), and control (distilled water). Each formulation was<br />inoculated with 10 6 Infective Juvenile (IJ). Each treatment was arranged in<br />completely randomized design (CRD) with three replicates. Each<br />formulation observed showed decrease in IJ number every week for + 4<br />weeks. Isolates used for this research were originated from Asembagus<br />experimental station. For evaluation of the formulation effectiveness, H.<br />armigera larvae was treated using IJ from the formula weekly for four<br />weeks. On the first week after treatment, the percentages of living IJ in<br />Pellet-1, suspension, Pellet-2, agar+sponge, capsule, and control were 53;<br />12.4; 44; 63.8; 17.6; and 5%, respectively. Effectiveness of Steinernema<br />sp. stored for four weeks in various formulations against H. armigera<br />ranged from 80-99%. The best formula of Steinernema sp for storage was<br />agar+sponge because of its ability to viability and effectiveness of<br />Steinernema sp.<br />Key words: effectiveness, formulation, Helicoverpa armigera, viability,<br />Steinernema sp.,</p>

scholarly journals Standardization of Pheromone Traps for the Mass Trapping of Helicoverpa Armigera (Hubner) Hardwick in Tomato

2017 ◽  
Vol 5 (1) ◽  
pp. 45-49
Author(s):  
K. D Shah ◽  
R. C Jhala ◽  
S. R Dhandge
Keyword(s):  
Helicoverpa Armigera ◽  
First Year ◽  
Mass Trapping ◽  
Pheromone Traps ◽  
Larval Population ◽  
Randomized Design ◽  
Helicoverpa Armígera ◽  
Large Plot ◽  
And Control ◽  
Helicoverpa Armigera Hubner

An experiment was carried out during rabi 2011 and summer 2012 in Large Plot Completely Randomized Design with four treatments viz., pheromone traps @ 30, 40, 50 /ha and control withten replications to standardize the requirement of pheromone traps for mass trapping of Helicoverpa armigera (Hubner) Hardwick infesting tomato [Solanum lycopersicum Linnaeus] crop. The results revealed that the highest moth catches were recorded (9630 moths /ha) during first year, while 9405moths /ha were recorded during second year with an average of 9518 /ha during two consecutive years. The treatment of 50 traps /ha recorded significantly lowest population of eggs (0.78 /10 twigs), lowest larval population (1.32 /10 twigs) resulting in lowest fruit damage (3.71%).

scholarly journals Susceptibility of African Bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae) to selected pyrethroid Insecticides on Cotton

2021 ◽  
Author(s):  
Zemedkun Alemu
Keyword(s):  
Helicoverpa Armigera ◽  
Agricultural Research ◽  
Pure Water ◽  
Synthetic Pyrethroids ◽  
Cotton Production ◽  
Pyrethroid Insecticides ◽  
Lambda Cyhalothrin ◽  
Helicoverpa Armígera ◽  
Production Areas ◽  
Lepidoptera Noctuidae

Abstract AbstractHelicoverpa armigera is a major threat for all cotton production areas in Ethiopia. Pests control with insecticides from a single chemistry group is common practice in most cotton farms, which may help to the development of insecticide resistance. The studies aimed to determine the susceptibility of the field population of H. armigera to pyrethroid insecticides. The experiment was carried out at Werer Agricultural Research Center under the laboratory condition using larva immersion and square dip methods. The selected insecticides were tested in seven dilutions levels. In each dilution 30 larvae of 3rd instars, H. armigera were treated in three replications along with pure water. A low level of resistance was detected for all tested locations to alphacypermethrin and a high resistance ratio to lambda-cyhalothrin and deltamethrin for Gewane and Werer populations. Aplhacypermethrin was the most toxic insecticide and its LC50 was low compared to other tested synthetic pyrethroids. Whereas, deltamethrin was the least toxic insecticide with high LC50. The LC50 value of the Goffa-Sawla population was significantly different among the populations for Werer, Upper-Awash, and Gewane in both bioassay methods. The study concluded that Helicoverpa armigera might have resistant to deltamethrin in Werer and Gewane populations. Further studies on the monitoring of resistance are recommended.

scholarly journals Effect of plant growth regulators on growth, yield and fruit quality of strawberry (Fragaria x ananassa Duch.) under protected conditions

2017 ◽  
Vol 9 (3) ◽  
pp. 1676-1681
Author(s):  
Yash Thakur ◽  
J. S. Chandel ◽  
Pramod Verma
Keyword(s):  
Fruit Quality ◽  
Fruit Size ◽  
Foliar Spray ◽  
Growth Yield ◽  
Fruit Weight ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
And Control ◽  
Control Water

A field trial was conducted during 2015 and 2016, to study the effect ofgrowth regulators on growth, flowering, yield and fruit quality of strawberry cv. Chandler. The experiment was laid out in completely randomized design with 16 treatments viz.CPPU at 1, 2 and 4 ppm, GA3 at 25, 50 and 75 ppm, Promalin at 2, 4 and 6 ppm, GA4+7 at 5, 10 and15 ppm, NAA at 10, 20 and 30 ppm and control (water spray) and each treatment was replicated thrice. The results revealed that the plants sprayed with 15 ppm GA4+7 two weeks before flowering significantly reported highest plant height (33.43 cm), leaf area (239.70 cm2), number of flowers (31.94), fruit set (87.45 %), number of fruits per plant (29.02), yield (540.01 g/plant), fruit length (53.63 mm) and fruit diameter (37.19 mm) and fruit weight (23.70 g) as compared to control. This treatment resulted in 196.36 % increase in yield and 56.22 %in fruit weight over control. Plants sprayed with 6 ppm promalin also showed significant improvement in vegetative growth, fruit size, yield and fruit quality, which resulted in 137.92 % increase in yield and 51.81 % increase in fruit weight over control. Hence, it is concluded that foliar spray of 15 ppm GA4+7 applied 2 weeks before flowering is beneficial in improving growth, yield and fruit quality of strawberry plants.

scholarly journals FIRST RECORD OF Xanthopastis timais IN AMARYLLIS AND EFFECT OF SOURSOP EXTRACT ON LARVAL MORTALITY

2017 ◽  
Vol 30 (2) ◽  
pp. 420-426
Author(s):  
LÍGIA BROGLIO MICHELETTI ◽  
SÔNIA MARIA FORTI BROGLIO ◽  
EURICO EDUARDO PINTO DE LEMOS ◽  
ROSEANE CRISTINA PREDES TRINDADE ◽  
ELLEN CARINE NEVES VALENTE
Keyword(s):  
Larval Stage ◽  
Larval Mortality ◽  
Ethanol Extract ◽  
First Record ◽  
Annona Muricata ◽  
Laboratory Bioassay ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
First Time ◽  
Lepidoptera Noctuidae

ABSTRACT The aim of this study was to report the occurrence of Xanthopastis timais (Cramer, 1780) (Lepidoptera: Noctuidae) in amaryllis (Hippeastrum hybridum Hort., Amaryllidaceae), as well as estimating lethal concentrations (LC50 and LC99) of soursop seed extract, Annona muricata L. (Annonaceae), against its larvae. The experiment was carried out at the Laboratory of Entomology of the Research Center for Agricultural Sciences, Federal University of Alagoas, in Rio Largo-AL, Brazil. First, we collected caterpillars from amaryllis plants that were reared until pupal and adult stages (parental generation). Next, part of the adults was used for species identification, and the rest were bred to produce next generation (F1), being after that applied in a laboratory bioassay. The lab trial was performed in a completely randomized design, with six treatments and five replications containing three second-instar caterpillars. These larvae were fed pieces of amaryllis leaf (4 x 4 cm), which were previously soaked in treatments for 30 seconds and, air -dried on absorbent papers for one hour. Each treatment consisted of one concentration of ethanol extract of soursop seeds (0.0, 1.0, 0.5, 0.25, 0.125 and 0.0625% w/ v) with distilled water and DMSO at 1% (v/ v), for solutions. We noted that the lethal concentrations LC50 and LC99 were 0.29% (w/ v) and 2.27% (w/ v), respectively. In view of our results, we can state that larval stage of X. timais were influenced by extract application in terms of survival, mortality, larvae weight and larval stage length. Besides of that, it was the first time this species was recorded in Alagoas state.

scholarly journals Behavioral aspects of Helicoverpa armigera in the cotton vegetative phase1

2019 ◽  
Vol 49 ◽  
Author(s):  
Sandra Maria Morais Rodrigues ◽  
Nubia do Carmo Santos ◽  
Rafael Major Pitta ◽  
Janaína de Nadai Corassa
Keyword(s):  
Helicoverpa Armigera ◽  
Oviposition Behavior ◽  
Cotton Crop ◽  
Vegetative Phase ◽  
Plant Parts ◽  
Floral Buds ◽  
Randomized Design ◽  
Helicoverpa Armígera ◽  
Completely Randomized Design ◽  
Cotton Cultivar

ABSTRACT Helicoverpa armigera (Hübner) is part of an important complex of insects-pests that attack the cotton crop. This study aimed to identify the preferential plant parts for the oviposition of moths, as well as the movement and feeding behavior of caterpillars, in the vegetative phase of the cotton cultivar BRS 369 RF. Plants emitting floral buds were used to study the oviposition behavior of moths. For this, a completely randomized design, with three treatments (adaxial and abaxial sides of the leaf and floral buds) and twenty replications (plants in pots), was used. In order to evaluate the behavior of the caterpillars in the cotton vegetative phase, another 3 × 5 factorial design, with nine replications, was used. The treatments were three ages (first, second and third instars) combined with five behaviors (walking, resting, waving, eating and drop-off). In this trial, the period of the day when caterpillars are more active was also evaluated. It was observed that H. armigera moths prefer to lay their eggs on the adaxial leaf side and on the last two nodes of the plant, in a descending direction. The adaxial leaf side is also the part of the plant preferred by caterpillars for walking, eating and resting, being this last behavior the most frequent in all instars. In general, the caterpillars walk more in the morning.

Pyrethroid resistance of Helicoverpa armigera (Lepidoptera: Noctuidae) in Pakistan

1997 ◽  
Vol 87 (4) ◽  
pp. 343-347 ◽  
Author(s):  
M. Ahmad ◽  
M. I. Arif ◽  
M. R. Attique
Keyword(s):  
Helicoverpa Armigera ◽  
General Trend ◽  
Pyrethroid Resistance ◽  
Physiological Mechanisms ◽  
Resistance Factors ◽  
Lambda Cyhalothrin ◽  
The Status ◽  
Helicoverpa Armígera ◽  
Moderate Resistance ◽  
Lepidoptera Noctuidae

AbstractThe status of pyrethroid resistance in some field populations of Helicoverpa armigera (Hübner) from Pakistan was determined using an IRAC leaf-dip method. Resistance factors varied between populations, and the general trend was for a moderate to high resistance to cypermethrin and cyfluthrin; a low to moderate resistance to deltamethrin and alpha-cypermethrin; and a comparatively low resistance to bifenthrin, lambda-cyhalothrin and zeta-cypermethrin. Depending on which physiological mechanisms are shown to be present in Pakistani field strains, the latter group of pyrethroids may serve as useful tools in the management of insecticide resistance.

scholarly journals PATOGENISITAS DUA ISOLAT LOKAL JAMUR Nomuraea rileyi (FARLOW) SAMSON TERHADAP Helicoverpa armigera HUBNER (LEPIDOPTERA: NOCTUIDAE)

2020 ◽  
Vol 19 (1) ◽  
pp. 1
Author(s):  
IGAA. INDRAYANI ◽  
HERI PRABOWO ◽  
SRI MULYANINGSIH
Keyword(s):  
Helicoverpa Armigera ◽  
Block Design ◽  
Larval Mortality ◽  
Host Population ◽  
Cotton Leaf ◽  
Nomuraea Rileyi ◽  
Larval Weight ◽  
Randomized Block Design ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae

<p>ABSTRAK<br />Epizootik Nomuraea rileyi telah berkembang secara alami dalam<br />populasi lebih dari 30 spesies serangga inang, termasuk H. armigera.<br />Penelitian ini dilakukan di Laboratorium Patologi Serangga Balai<br />Penelitian Tanaman Pemanis dan Serat Malang mulai Januari hingga<br />Desember 2011, tujuannya untuk mengetahui patogenisitas dua isolat lokal<br />jamur entomopatogen N. rileyi terhadap larva H. armigera. Penelitian<br />terdiri atas dua faktor perlakuan, faktor 1 adalah dua isolat lokal N. rileyi,<br />yaitu ML 01 dan LG 02, dan faktor 2 adalah konsentrasi konidia, yaitu: 2,2<br />x 10 5 ; 4,5 x 10 5 ; 2,2 x 10 6 ; 4,5 x 10 6 ; 2,2 x 10 7 ; 4,5 x 10 7 ; 2,2 x 10 8 ; 4,5 x<br />10 8 konidia/ml, dan kontrol. Setiap perlakuan disusun dalam Rancangan<br />Acak Kelompok Faktorial dengan tiga kali ulangan. Aplikasi jamur pada<br />larva H. armigera dilakukan dengan metode kontaminasi permukaan<br />media yang berupa daun kapas muda (1cm 2 ) di dalam ruangan bersuhu<br />25±1⁰C dan kelembapan 75-80%. Parameter yang diamati adalah<br />mortalitas larva, LC 50 dan LT 50 , serta bobot larva. Hasil penelitian<br />menunjukkan bahwa tingkat patogenisitas isolat ML 01 terhadap larva H.<br />armigera lebih tinggi dibandingkan dengan isolat LG 02. Isolat ML 01<br />menyebabkan mortalitas larva H. armigera antara 51,13-85,56% (LC 50  =<br />2,5 x 10 2  Konidia/ml) dan isolat LG 02 antara 43,36-78,90%, (LC 50  =<br />5x10 6  Konidia/ml). LT 50 isolat ML 01 antara 5,2-5,5 hari, sedangkan isolat<br />LG 02 antara 6,8-7,0 hari, terutama pada konsentrasi 2,2-4,5 x 10 8<br />konidia/ml. Terdapat korelasi positif yang erat antara konsentrasi konidia<br />dan mortalitas larva baik pada isolat ML 01 (r=0,975) maupun LG 02<br />(r=0,980), demikian pula antara konsentrasi konidia dan kehilangan bobot<br />larva pada isolat ML 01 (r=0,982) dan LG 02 (r=0,972).<br />Kata kunci: Helicoverpa armigera, Nomuraea rileyi, patogenisitas, isolat,<br />mortalitas</p><p>ABSTRACT<br />The epizootic of the fungi Nomuraea rileyi has naturally developed<br />in more than 30 species of insect host population, including cotton<br />bollworm, H. armigera. A study on pathogenicity of two local isolates of<br />Nomuraea rileyi (Farlow) Samson fungi against Helicoverpa armigera<br />(Hubner) (Lepidoptera: Noctuidae) was conducted at Insect Pathology<br />Laboratory of Indonesian Sweeteners and Fibers Crops Research Institute<br />(ISFCRI) in Malang from January to December 2011 in order to find out<br />the pathogenicity of the isolates against H. armigera larvae. This study<br />consists of two factors as treatment. The first factor was N. rileyi isolates,<br />e.g. ML 01 and LG 02, and the second factor were eight conidia<br />concentrations, viz. 2.2 x 10 5 ; 4.5 x 10 5 ; 2.2 x 10 6 ; 4.5 x 10 6 ; 2.2 x 10 7 ; 4.5<br />x 10 7 ; 2.2 x 10 8 ; 4.5 x 10 8 conidia/ml, and one untreated control.<br />Treatments were arranged in Factorial Randomized Block Design with<br />three replications. Suspense of conidia was applied by surface<br />contamination method of cotton leaf as medium at 25±1⁰C of temperature<br />and 75-80% of humidity. Parameter observed were larval mortality, LC 50 ,<br />LT 50 , and larval weight. Result showed that ML 01 isolate was more<br />pathogenic against H. armigera larvae than LG 02 isolate based on larval<br />mortality, LC 50 , and LT 50 . Percentage of mortality of H. armigera larvae<br />due to ML 01 and LG 02 infection were 51.1- 85.56% and 43.36-78.90%,<br />respectively. The LC 50 of ML 01 and LG 02 isolates was 5.2-5.5 days and<br />6.8-7.0 days, respectively.There are closest positive correlation between<br />conidia concentration and percentage of mortality on ML 01 (r = 0.975)<br />and LG 02 (r = 0.980) isolates as well as between conidia concentration<br />and larval weight loss on ML 01 (r = 0.982) and LG 02 (r = 0.972)<br />isolates.<br />Key words: Helicoverpa armigera, Nomuraea rileyi, pathogenicity,<br />isolate, mortality</p>

scholarly journals Need for growing non-Bt cotton refugia to overcome Bt resistance problem in targeted larvae of the cotton bollworms, Helicoverpa armigera and Pectinophora gossypiella

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Muhammad Rafiq Shahid ◽  
Muhammad Farooq ◽  
Muhammad Shakeel ◽  
Misbah Ashraf ◽  
Zia Ullah Zia ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Larval Mortality ◽  
Pectinophora Gossypiella ◽  
Bt Cotton ◽  
Insect Larvae ◽  
Plant Parts ◽  
Arthropod Species ◽  
Bt Resistance ◽  
American Bollworm ◽  
Helicoverpa Armígera

Abstract Background The effectiveness of Bacillus thuringiensis (Bt) cotton against target arthropod larvae is decreasing day by day. The comparative effect of Bt expression among Bt cotton varieties and different plant parts was observed against the cotton bollworms: Helicoverpa armigera and Pectinophora gossypiella larvae. Results In the present study, larval mortality of H. armigera was higher than P. gossypiella among selected Bt cultivars. Median lethal concentration (LC50) values were 8.91, 13.4, 14.0, and 36.4 for P. gossypiella, while 5.91, 4.04, 2.37, and 8.26 for H. armigera of FH-142, MNH-886, IR-3701, and FH-Lalazar, respectively. These values depicted that P. gossypiella had more Bt resistance problem than H. armigera larvae. The host range of both targeted insect larvae was different from each other due to the polyphagous feeding nature of the larvae of H. armigera that feed on different host plants, but P. gossypiella attacked only cotton with monophagous feeding habit. It was also notable from results that Bt expression in reproductive parts where the attacked pink bollworm was lower than the American bollworm, so the former had the maximum chance of resistance due to repeated exposure to Bt. Conclusions It was concluded that farmers be advised to follow the practice of growing non-Bt as a refuge crop to reduce the problem of Bt resistance in the target arthropod species.

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