Pink Bollworm Pectinophora Gossypiella Research Articles

Effect of temperature on the biological parameters of pink bollworm, Pectinophora gossypiella Saunders (Lepidoptera: Gelechiidae)

Pink bollworm (PBW) Pectinophora gossypiella is an important pest cotton worldwide. There are multiple factors which determines the occurrence and distribution of P. gossypiella across different cotton growing regions of the world, and one such key factor is ‘temperature’. The aim was to analyze the life history traits of PBW across varying temperature conditions. We systematically explored the biological and demographic parameters of P. gossypiella at five distinct temperatures; 20, 25, 30, 35 and 40 ± 1 °C maintaining a photoperiod of LD 16:8 h. The results revealed that the total developmental period of PBW shortens with rising temperatures, and the highest larval survival rates were observed between 30 °C and 35 °C, reaching 86.66% and 80.67%, respectively. Moreover, significant impacts were observed as the pupal weight, percent mating success, and fecundity exhibited higher values at 30 °C and 35 °C. Conversely, percent egg hatching, larval survival, and adult emergence were notably lower at 20 °C and 40 °C, respectively. Adult longevity decreased with rising temperatures, with females outliving males across all treatments. Notably, thermal stress had a persistent effect on the F1 generation, significantly affecting immature stages (egg and larvae), while its impact on reproductive potential was minimal. These findings offer valuable insights for predicting the population dynamics of P. gossypiella at the field level and developing climate-resilient management strategies in cotton.

Activity of insecticide detoxification enzymes in Pectinophora gossypiella (Saunders): Implications for insect pest management in cotton crops

The pink bollworm Pectinophora gossypiella is one of the most important endocarpic pests in cotton. In the management of this pest, the intensive use of synthetic insecticides has led to the reduction of its sensitivity to certain active ingredients. It is in this perspective that the study was conducted to determine the enzymes involved in the metabolism of insecticides in P. gossypiella. Insects were collected in five localities (Bouaké, Bouaflé, Vavoua, Sésuéla and Kounahiri) with high pest pressure in the southern cotton zone. The collected insects were ground for the determination of enzymes involved in insecticide metabolism. The analyses showed a significant increase in glutathione-δ-transferase activity in populations of Bouaké compared to the other localities. However, individuals from Séguéla expressed more esterase (alpha and beta) and oxidase activities. Alpha and beta esterase activities were also more expressed in Bouaflé individuals. The high enzymatic activity of esterases and oxidases in individuals from Séguéla and Bouaflé reflects a low sensitivity to insecticides in which esterases and oxidases are involved in the metabolism. On the other hand, in Bouaké, only glutathione- δtransferases are involved in the detoxification of insecticides.

Studies on the response of normal and irradiated pink bollworm males towards pheromone source

Sterile Insect Technique (SIT) is the right eco-friendly method to overcome the pink bollworm Pectinophora gossypiella (Saunder) menace. In SIT attractiveness of released moths to their natural counterpart is most important as such this ability was examined in our study. For this, newly emerged five virgin female gamma irradiated with 0–250 Gy were used. These females were placed inside small plastic vial provided with aeration and suspended inside the delta traps by providing 10% honey solution. Traps were placed in the field during evening. Moth catches in each trap were counted and removed daily and these observations continued up to 5 days. In a same manner irradiated males were released separately inside the field cage to know its attractiveness to virgin female. The results indicated that attraction of male moths to irradiated virgin females decreased significantly with increasing doses of radiation i.e., at 200 and 250 Gy. The number of males captured per female was greatest on day 2nd due to its peak sexual activity, i.e., 25.60, 23.05, 19.45, 14, 9.4 and 5.9 moths at 0, 50, 100, 150, 150, 200, and 250 Gy, respectively. Gamma radiation also affected the irradiated males to find their natural mates at a higher dose; however, the maximum number of 5.30, 5.95 and 5.10 irradiated male moths were attracted to the natural pheromone secreted by female moths at 50, 100 and 150 Gy respectively, compared to the 6.80 moths at 0 Gy. The results on attractiveness of irradiated male moths towards virgin female-baited traps were considered a good measure of male competitiveness.

Biology of pink bollworm Pectinophora gossypiella (Saunders) on cotton as influenced by temperature

A laboratory experiment was conducted to study the biology of pink bollworm Pectinophora gossypiella (Saunders) on cotton at four different temperature levels. It was found that males have a considerably shorter total life cycle duration on cotton at 35±1°C (29.5 days) followed by 30±1°C (37.2 days), 25±1°C (46.9 days) and highest at 20±1°C (50.8 days). Similarly, minimum total life cycle duration of female P. gossypiella was recorded at 35±1°C (30.2 days) followed by 30±1°C (38.0 days), 25±1°C (47.3 days) and maximum at 20±1°C (51.7 days). The highest fecundity was observed at 30±1°C (106.2) followed by 25±1°C (100.1), 35±1°C (60.1) and lowest at 20±1°C (55.2). Male as to female sex ratio was highest at 35±1°C (1:1.5) followed by 25±1°C (1:1.4), 30±1°C (1:1.3) and lowest at 20±1°C (1:1.2). These findings revealed that variation in temperature significantly influences the life cycle duration, fecundity and sex ratio of pink bollworms on cotton, with higher temperatures accelerating development and enhancing reproductive success.

Laboratory evaluation of toxicity of selected insecticides against egg and larval stages of cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

BackgroundThe cryptic nature of pink bollworm Pectinophora gossypiella (Saunders) larvae enables its reduced vulnerability to insecticidal control. Further, the development of resistance against Bacillus thuringiensis (Bt) toxins posed a serious threat to transgenic cotton cultivation. This necessitated determining the critical timing of spray applications on the control effectiveness. This study assessed the influence of egg age (freshly laid vs. three-day-old) and the location of larvae (directly exposed to the insecticide residues on the boll rind vs. burrowed inside the bolls) on insecticide control efficacy.ResultsThe results revealed a significant decrease in the ovicidal activity of tested insecticides with an increase in the age of eggs from one day old to three days old (paired t-test, P < 0.05). The larvae directly exposed to the insecticide residues on the boll rind were more susceptible (> 80% mortality) than the larvae exposed after they had burrowed inside the bolls (< 49% mortality). The inhibitory effects of tested insecticides on developmental biology were more pronounced in the experiment on pre-larval release insecticide treatment compared with insecticide treatment given post-larval release and entry inside the bolls.ConclusionEgg age influences the insecticide susceptibility, as does the larval location, directly exposed vs burrowed inside the bolls. Older eggs and the larvae that had burrowed inside the green bolls of cotton were relatively less susceptible to the insecticide treatments. The toxic effects of insecticides on egg and larval stages were primarily ephemeral. These findings are significant for devising a comprehensive strategy for pink bollworm management on a sustainable basis.

Demonstration and Adoption of Integrated Pest Management Strategies for the Management of Pink Bollworm Pectinophora gossypiella (Saunders) in Cotton

The present study was carried out in the farmers’ fields of Bhadradri Kothagudem, Telangana, India during Kharif (June–December) seasons of 2018, 2019 and 2020 to demonstrate the integrated pest management strategies for the management of pink bollworm and to know its rate of adoption among the farming community. The treatments consisted of technology demonstration and farmers’ practice. During three years of study, the population of pink bollworm has showed increasing trends. More than 10% of the rosette flowers were observed during the crop period starting from 36th SMW and continued up to 48th SMW. The green boll damage caused by PBW ranged between 2.1–19.2 in the demo plot, while the range was 2.2–20.6 in the control. Average population in pheromone traps was 4.48, 5.31 and 5.34 trap-1 during 2018, 2019 and 2020 respectively. Standard weeks 36–38 (3rd September–23rd September) 51–3 (17th December–21st January) were minimum or no activity periods due to low temperature, while standard weeks, 40–44 (1st October–4th November) were high activity periods during these study years. The population of pheromone traps correlated with temperature and rainfall had shown negative and non-significant correlation during 2018 and 2020, while positive and non-significant correlation during 2019. Cotton seed yield in the technology demonstrated plot was higher (1965, 2055 and 2095 kg ha-1) compared to farmers practice (1607, 1708 and 1725 kg ha-1) during 2018, 2019 and 2020 respectively. By adopting the IPM strategies against this pest, farmers’ can avoid the yield losses up to 22.3%. Nearly 65% of the respondents had medium level of adoption on management practices for the control of PBW.

Strategies for Management of Pink Boll Worm Pectinophora gossypiella (Saunders) in Cotton through Different Methods

The present study of experiment entitled on the strategies for management of pink boll worm Pectinophora gossypiella (Saunders) in cotton though different methods was conducted in famers fields as a form of Frontline Demonstration (FLD). The experiment was conducted in 30 locations in Nalgonda and Yadadri bhuvangiri distrits of Telangana during kharif 2018, 2019 and 2020 respectively. The results revealed that, due to the adoption of IPM practices in addition to good agricultural practices, the average kapas yield was high in IPM demonstration plots (1857.0 kg/ha) with 12.0% increase over the farmers’ practice (1658 kg/ha) during three years of study.&#x0D; The average gross returns of Rs.1,01,007/ha, net returns of Rs.52,027/ha, and Benefit-cost ratio of 2.05 was recorded as higher in the demonstration plot as compared to farmers practice Rs. 90,121/ha, Rs.37,430 and 1.69 respectively during the study period. The additional average net returns of Rs.14,597/ha and reduction in the cost of cultivation of Rs.1912/ha were saved per year.

Morphometrics of &lt;i&gt;Pectinophora gossypiella&lt;/i&gt; (Saunders) on Cotton as Influenced by Temperature

The morphometry of life stages of the pink boll worm Pectinophora gossypiella (Saunders) was evaluated at four temperature levels of 20, 25, 30 and 35°C to assess the impact of temperature. Measurement of larval head capsule width, body length, body width and weight on cotton at 20°C were 0.68, 0.87, 0.98 and 1.24 mm, 2.27, 5.80, 7.46 and 10.60 mm, 1.08, 1.58, 1.68 and 2.53 mm and 0.40, 2.84, 24.42 and 64.21 mg for I, II, III and IV larval instars, respectively. The mean pupal length and weight of male and female varied significantly when reared at different temperature levels.

Molecular Investigation Using RAPD-PCR Marker Field Populations of Pectinophora gossypiella Saunders (Lepidoptera: Gelechiidae) Exposed to Some Insecticide

Seasonally the cotton plant cultivated in Egyptian fields is suffering from the cotton Pink Bollworm Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) attacking fruits and buds. Insecticide applications reported control failure by the most recommended conventional classes. Monitoring pest DNA changes after sublethal exposure become the new technique to investigate. Then four insecticide treatments were screened by using the molecular marker polymerase chain reaction (PCR) inspection, using four Random amplified polymorphic deoxyribonucleic acid analysis (RAPD-PCR) primers partitioned based on band reproducibility. Result of LC50 was 0.55, 61.1, 69.3, and 0.23 for spinoteram, novaluron, metaflumezone, and dimeuron respectively. The insecticide treatments band of gel produced detected 47 loci ranging from 87 to 63 % polymorphism. The primer efficiency value of PIC =0.361, 0.34, 0.34, 0.355, and 0.262, RP = 5.30, H = 0.473, 0.434, 0.434, 0.462 and 0.31, and MI = 0.10, 0.1386, 0.138, 0.167 and 0.0582 for the same treated samples respectively. Distance and similarity were quantified based on Nei’s and genetic dissimilarity by the UPMGA method then a phylogenetic tree was constructed and grouped the entire genotypes into 2 major clusters and 6 subclusters. The RAPD primers revealed the number of alleles (Na = 0.324, 0.318, 0.318, 0.326, and 0.328), and the effective number of alleles (Ne = 0.571, 0.569, 0.558, 0.574, and 0.5784). The fixation-index (Fst) analysis narrated a very great genetic diversity (Fst = 0.626, 0.684, 0.684, 0.2, and 0.695) exists within the four treated samples respectively. The level of gene flow was (Nm = 0.239, 0.230, 0.230, 0.233, and 0.2187) respectively across the four genotypes studied. Results proved that the RAPD-PCR technique was suitable for distinguishing between insecticide treatments.

Diagnostic expression of the cotton pink bollworm Pectinophora gossypiella (Saunders) Ace1 exposed to some insecticide by the real-time PCR

The Pink Bollworm Pectinophora gossypiella (Saunders) is a devastating pest in Egyptian cotton field. Insecticide control failure may be happen due to its biological features of hide inside bolls and rarely exposed to insecticide application. Thus, a bulk of bolls infested with larvae collected from fields of Sharkia and Benysuef governorate. Moreover, exposed to py, Op sub lethal concentrations in laboratory bioassay. Toxicity features as LC50, LC90 and the slope, and RR was completed. Whereas the common target site of OP and pyrethroid is the acetylcholinesterase enzyme. Thus, the gene Ace1 encoding AChE relative expression was investigated using molecular marker of real-time PCR procedures via the steps of generating data was RNA isolation and characterization, cDNA synthesis, then generating normalization factors, and Ct data attained and analyzed using 2-ΔΔCT method to quantify the gene expression quantitatively of insecticide treated larvae tissue extracted. Data showed the most expressed ratio of samples was cypermethrin followed by deltamethrin compared with the control and the least was malathion and chlorpyrifos, thus, the most effective insecticide was malathion and the least were cypermethrin according to ct values. Hierarchical clustering combined with Heat map and principle component analysis based on various clustering systems and algorithm as distance measures were completed. Validation of reference gene in addition to gene expression stability analyzed by the three optimal gene finders and showed that deltamethrin and cypermethrin treated genes having lower mean weights and considered transcriptionally stable and ideal reference genes.

Temperature-based prediction and validation of pink bollworm, Pectinophora gossypiella infestation on cotton crop

Pink bollworm Pectinophora gossypiella infestation on cotton now a days found to be a major alarm to cotton crop in Pakistan. The effect of past and future temperatures climatic factors on the infestation rate of pink bollworm needs to be extensively studied. Field visits were organized in different areas across 17 main districts of Punjab, Pakistan, for eight consecutive years from 2012 to 2019. Based on past data, the pink bollworm infestation rate for the year 2040 was estimated. Our results showed an extensive infestation of pink bollworm on cotton throughout the visited locations between 0.1 and 35.7 % range above the economic threshold level, that cause reasonable cotton productivity losses. Based on the results of historical data of infestation rate, the nine of the 17 districts (53 %), Bahawalnagar, Bahawalpur, Faisalabad, Jahang, Mianwali, Multan, Muzaffargarh, Rahimyar Khan, and Lodhran, showed significantly (p < 0.05) higher pink bollworm infestation rate than the other cotton-growing areas. Moreover, the systematic increase level of pink bollworm infestation was predicted in 2040, especially in the five districts, Bhakar, Jahang, Khanewal, Faisalabad, and Vehari. Considering the importance of biological parameters, different temperature regimes (21 °C, 28 °C, and 35 °C) were tested for the validity of temperature-based prediction. Our results showed that growth capacity of P. gossypiella were increased at 28 °C. It revealed that, variation in weather due to current climatic condition with decreases of temperature increases P. gossypiella infestation on cotton crop. In this investigation, the effects of a severe outbreak of pink bollworm infections in Punjab's cotton-growing regions are discussed.

Species composition and population dynamics of some arthropod pests in cotton fields of irrigated and semi-arid regions of Punjab, Pakistan

The present study aimed to record seasonal dynamics and diversity of different insect pests in cotton agroecosystems. Two well-known cotton growing districts i.e. district Layyah and Vehari were selected for the study from the cotton belt of Punjab, Pakistan. Sampling was done bi-weekly for two consecutive years from July to October during 2018 and 2019. Sweep netting, visual counting, hand picking, wet finger method, beat sheets, aspirator and pitfall trapping methods were used for collection. Shannon-Wiener and Simpson indices were used to compute diversity while Menhinick and Margalef indices were used for the estimation of species richness. A total of 94,343 individuals representing 43 species, 40 genera, 28 families and 6 orders were recorded. Family Aleyrodidae dominated over other pest families. Bemisia tabaci (Gennadius, 1889) of family Aleyrodidae was the dominant species with 39.68% share among all pest species. Estimated species richness of all arthropod pest species belonging to both districts were about 94%. The densities of pests fluctuated with time. The peaks of sucking pest densities were observed in July and August while densities of chewing pests peaked in late September or early October each year. Population densities of jassids Amrasca biguttula (Ishida), armyworm Spodoptera litura (Fabricius), and pink bollworm Pectinophora gossypiella (Saunders), showed strong negative correlation with temperature, humidity and rainfall while thrips population density showed positive correlation with these parameters. Minor loss due to pests are acceptable everywhere, but it is only possible when their populations remain below their economic threshold levels. Present study will aid to design pest management strategies in cotton growing areas round the globe.

Resistance in Pink Bollworm Pectinophora gossypiella (Saunders) against Bt Cotton, a Major Threat to Cotton in India: A Brief Review

The pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae) is a primary pest of cotton in many regions of the world. In many parts of India, pink bollworm (PBW) has become resistant to BG-I (Bollgard I®) that expresses a single Bt gene (Cry1Ac) in 2009 and BG-II (Cry1Ac and cry 2Ab) in 2015. The brief review addresses the possible reasons and solutions to resistance posed by this insect. The review addresses the following points: reasons for resistance in PBW is discussed; the life-history is discussed how it’s distinctness from other bollworms; the introduction of hybrid cotton lead to insecticide treadmill in India; reduced accomplishment of the refugia recommendations also contributed to the problem; poor compliance of the bio-safety laws also led to the problem; unfavorable crop management practices prove to be an add-on to the problem. Furthermore, the possible solutions of the problem are discussed; monitoring and mating disruption; cultivation of High-density short season (HD-SS) pure line varieties; case studies of sterile insect technique (SIT) proved to be supporting in control of PBW; RNA interference technique can overcome the problem of resistance; use of chemical insecticides in different manner can change the perspective; proper cultural or farming practices can make the difference; Bio-control agents can overcome the problem; extension functionaries can help in solving the PBW problem. Therefore the management of resistance in PBW requires a broader vision and development of technology.

Performance and field efficacy of indigenous egg parasitoid Trichogrammatoidea bactrae (Hymenoptera: Trichogrammatidae) against the cotton pink bollworm Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) in transgenic Bt cotton

The pink bollworm (PBW) Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) has emerged as a major pest of transgenic Bt cotton in India. The recent outbreak of PBW caused serious damage, and the existing management strategies become inefficient to reduce the pest incidence and crop yield losses. The development of environment-friendly and sustainable management strategies against PBW is urgently needed. Thus, laboratory tests were performed to evaluate 16 indigenous trichogrammatid species/strains to manage the PBW in transgenic Bt cotton. We compared the parasitism of trichogrammatid species/strains on PBW eggs and found that Trichogrammatoidea nr. robusta (79.6%), Trichogrammatoidea bactrae Nagaraja (76.4%) and Trichogramma chilonis Ishii (73.8%) parasitized a greater percentage of PBW eggs under laboratory conditions. Furthermore, the parasitism of Tr. nr. robusta, Tr. bactrae and T. chilonis were tested in cages. Results of cage study showed that Tr. bactrae parasitized at a higher rate the PBW eggs (73.2%) followed by T. chilonis (60.5%) and Tr. nr. robusta (48.6%). Subsequently, the effectiveness of Tr. bactrae was assessed for consecutive three years (2017–2020) in transgenic Bt cotton fields. We found that the 12 sequential releases of Tr. bactrae from the flowering stage onwards showed a significant reduction in the PBW incidence. Field released with Tr. bactrae or treated with insecticides reduced the number of larvae boll−1 by 1.5 and 3, respectively, the percentage of rosette flower by 1.7 and 2.7, respectively, and the percentage of locule damage by 2 and 2.5, respectively, compared to untreated control field. A higher yield of seed cotton was obtained both in Tr. bactrae released field (27.73 q h−1) and insecticide treated cotton field (31.68 q h−1) as compared to untreated control field. Our results showed that Tr. bactrae is a potential biocontrol agent of PBW. This could be used in biological control programme and may be incorporated in integrated pest management (IPM) programme against PBW in transgenic Bt cotton.

Management of Pink Bollworm Pectinophora gossypiella (Saunders) in Cotton

Demonstrations were conducted to assess the damage potential caused by the pink bollworm Pectinophora gossypiella (Saunders) and its management strategies were worked out through technology demonstration and check (farmer’s practice). Results revealed that &gt;10% rosette flowers were observed, starting from 36th standard meteorological week (SMW) up to 2nd SMW except during 49th to 52nd SMW. In contrast, in control, maximum incidence was during October Ist fortnight (25.92%). Incidence of larvae on green bolls of Bt cotton was noticed from first fortnight of September (36th SMW) (8.4 larvae/50 bolls) with a peak during the second fortnight of December (51st and 52nd SMW) (19.2 larvae/50 bolls; the green boll damage ranged from 8.9 to 18.4 with a mean of 14.72% in treatment and 12.6 to 20.8 with a mean of 28.38% in control, respectively. Significantly higher income was obtained with the technology demonstrated plots, with high benefit cost ratio.

Arthropod Pests and Their Natural Enemies Associated with Cotton in India: A Review

Globally cotton is the most important natural fibre crop being cultivated commercially for domestic textile needs and export. Cotton plays an important role in India’s economy, occupies largest acreage and highest production in the world. In India, cotton is being grown in 10 major states divided in 3 distinct zones viz., north, central and south with varying climate and soil. Despite large acreage, cotton productivity in India is far below world average due to variety of reasons. Among them damage caused due to arthropod pests is vital. In this article authors have attempted through extensive literature survey, to provide up to date information on arthropod pests and their natural enemies associated with cotton crop in India. It is observed that, in India, cotton crop is attacked by 251 arthropod pest species (including insect and mites) belonging to 9 insect orders and 1 order from Acarina. Among these, about 12 species of insects are major pests causing significant losses to cotton crop while remaining species are either occasional, sporadic or minor in nature. Overall these pests cause economic damage to cotton crop in a range between 20-60 per cent. The major arthropod pests are sucking insects namely leafhopper Amrasca biguttula biguttula (Ishida), aphid Aphis gossypii Glover, thrips Thrips tabaci Lindeman., whitefly Bemisia tabaci (Gennadius), Cotton mealybug Phenacoccus solenopsis Tinsley, Papaya mealybug Paracoccus marginatus Williams and Granara de Willink, and Indian cotton mirid bug Creontiades biseratense (Distant). The bollworm complex is another major group of insects that attack cotton and comprises of American bollworm Helicoverpa armigera (Hubner), spotted bollworms Earias insulana (Boisduval), E. vitella (F.) and pink bollworm Pectinophora gossypiella (Saunders). Other pests like stem weevil Pempherulus affinis Faust and tobacco caterpillar Spodoptera litura F., are also categorized as major pests. A rich fauna of 368 natural enemies (including 174 species of predators and 194 species of parasitoids/parasites) play significant role as biological control agents to check arthropod pests in cotton ecosystems of India. In this review there is addition of 85 arthropod pests over previously reported 166 arthropod pests. This updated information on cotton pests and their important natural enemies may serve as an important guide to researchers and policy makers in carrying out potential pest risk assessment and devising appropriate management strategies for economically damaging cotton pests.

Protein and Aminoacid Profile in Diapausing Larvae of Pink Bollworm Pectinophora gossypiella (Saunders)

The pink boll worm Pectinophora gossypiella (Saunders) is a threat to cotton cultivation. A study conducted in the NFSM laboratory of University of Agricultural Sciences, Raichur focused on the protein and amino acid profile of the diapausing larvae. Amino acid composition of diapause and non-diapause larvae revealed that out of 17 amino acids, 14 showed a significant difference. In diapausing ones total amino acid content was found to be 603.23 ± 5.10 μg/g which was significantly higher compared to non-diapausing ones at 534.91 ± 3.19 μg/g. Likewise, protein content was more in diapausing larva destined to become female (27.15 ± 2.27 mg/100 g) as compared to non-diapausing ones (20.29 ± 2.61 mg/100 g). Thus, when larvae undergo diapause, the protein and amino acid content in larval body increases, implying that the larvae store dietary food for its survival during resting phase.

Novel RNA Viruses from the Transcriptome of Pheromone Glands in the Pink Bollworm Moth, Pectinophora gossypiella.

Simple SummaryThe pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae), is a major pest of cotton. In this study, we analyzed the mRNA from pheromone glands of two populations in Israel. We found several virus sequences that were the same in these populations. We identified these viruses based on high-throughput sequencing data and analysis of the assembled transcripts. Through analysis of the sequences, we identified several unique viral sequences representing possible novel viral species. Two of the viral sequences were found in relatively high abundance in pheromone glands. One of the virus sequences was also found through analysis of previous transcriptome sequencing data from the midgut of pink bollworm larvae. This is the first report of these unique viral sequences found in the pink bollworm, and these viruses could be developed to help control this pest around the world, but more research is needed to determine their utility as biological control agents.In this study, we analyzed the transcriptome obtained from the pheromone gland isolated from two Israeli populations of the pink bollworm Pectinophora gossypiella to identify viral sequences. The lab population and the field samples carried the same viral sequences. We discovered four novel viruses: two positive-sense single-stranded RNA viruses, Pectinophora gossypiella virus 1 (PecgV1, a virus of Iflaviridae) and Pectinophora gossypiella virus 4 (PecgV4, unclassified), and two negative-sense single-stranded RNA viruses, Pectinophora gossypiella virus 2 (PecgV2, a virus of Phasmaviridae) and Pectinophora gossypiella virus 3 (PecgV3, a virus of Phenuiviridae). In addition, sequences derived from two negative-sense single-stranded RNA viruses that belong to Mononegavirales were found in the data. Analysis of previous transcriptome sequencing data derived from the midgut of pink bollworm larvae of a USA population only identified PecgV1, but no other viruses. High viral sequence coverages of PecgV1 and PecgV4 were observed in both field and lab populations. This is the first report of viral sequences discovered from the pink bollworm. Results from this investigation suggest that the pink bollworm harbors multiple viruses. Further investigation of the viral pathogens may help to develop novel pest management strategies for control of the pink bollworm.

Incidence of Pink Bollworm Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) on Flowers (Rosette) of Bt Cotton in Andhra Pradesh, India

The pink bollworm Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) has recently emerged as a serious menace on Bt cotton in India. Extensive roving surveys were conducted in 12 locations of three major cotton growing districts of Andhra Pradesh, India, to assess the level of pink bollworm infestation in Bt cotton during 2018-19 and 2019-20. The dynamics and severity of flower damage due to pink bollworm during the 60-135 days’ crop period were evaluated based on a random sampling of flowers. Survey results revealed a widespread infestation of pink bollworm on Bt cotton flowers across the surveyed sites in a range of 11.8-19.50%. With the advancement of the crop season, a progressive increase in the flower damage was observed till 120 DAS then declined. Reasons for the enhanced flower damage and implications are discussed in this article.

Relationship between cotton planting date and two bollworms associated with their natural enemies

BackgroundCotton is the most widespread, profitable non-food crop in the world. Egypt is one of the greatest countries in producing cotton (Gossypium hirsutum L.) in the world. Many pests attacked cotton which reduced the quality and quantity of the cotton yield such as pink bollworm (Pectinophora gossypiella) (Lepidoptera: Gelechiidae) and the spiny bollworm (Earias insulana) (Lepidoptera: Noctuidae).ResultsThe insect infestation increased significantly by delaying planting date. The fewest numbers of pests attacked cotton recorded in the earliest planting date (March 23rd) with highest weight of cotton yield. The results showed that the mean rates of infestation with pink bollworm were (2.11, 3.5, 2.33 individuals/boll) for March 23rd, April 17th and May 6th, respectively, while the mean rates of infestation with bollworm were (1.60, 2.79, 1.67 individuals/boll) for March 23rd, April 17th and May 6th, respectively.ConclusionIt was concluded that planting cotton as early as on March 23rd reduces the rate of infestation of E. insulana and P. gossypiella and increases the population of its natural enemies as well. Then, it is resulting a significant increase in the quality and quantity of the yield of cotton.