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BACKGROUND: The Oriental tobacco budworm, Helicoverpa assulta, a specialist herbivorous insect that exclusively feeds on plants of the Solanaceae family, causes considerable damage to crops, such as tobacco and hot pepper. The absence of a genome sequence for this species hinders further research on its pest management and ecological adaptation. RESULTS: Here, we present a high‐quality chromosome‐level genome of a Korean strain of H. assulta (Pyeongchang strain, K18). The total assembly spans 424.4 Mb with an N50 length of 14.54 Mb and 37% GC content. The assembled genome (ASM2961881v1) comprises 31 chromosomes, similar to other congeneric generalist species including H. armigera and H. zea. In terms of genomic assembly quality, the complete BUSCOs and repeat content accounted for 98.3% and 33.01% of the genome, respectively. Based on this assembly, 19 485 protein‐coding genes were predicted in the genome annotation. A comparative analysis was conducted using the identified number of protein‐coding genes in H. armigera (24154) and H. zea (23696). Out of the 19 485 predicted genes, 137 genes in 15 orthogroups were found to have expanded significantly in H. assulta, while 149 genes in 95 orthogroups contracted rapidly. CONCLUSION: This study revealed specific gene expansions and contractions in H. assulta compared to those in its close relatives, indicating potential adaptations related to its specialized feeding habits. Also, the comparative genome analysis provides valuable insights for the integrated pest management of H. assulta and other globally significant pests in the Heliothinae subfamily. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Chickpeas are one of the most important pulse crop in the world, and production in Brazil is small, but ramping up. In regions where cultivation is recent, such as the state of Rio de Janeiro, it is important to evaluate the agronomic performance of different chickpea cultivars, their adaptability to edaphoclimatic conditions and phytosanitary aspects. Pests can vary from one location to another and pose risks to the crop. Caterpillars are the main pests of chickpea in Brazil and throughout the world. Thus, this work aims to evaluate the occurrence of caterpillars associated with chickpea culture in an experimental area, in the state of Rio de Janeiro, Brazil. Four chickpea cultivars were evaluated (BRS Aleppo, BRS Cícero, BRS Cristalino and BRS Toro), using randomized block distribution and four replications per treatment. The greatest rate of damaged pods occurred in the BRS Aleppo and BRS Cristalino cultivars with 62%, while BRS Toro showed 48% and BRS Cícero 25%. Two species of Lepidoptera identified as Chloridea virescens and Helicoverpa armigera (Lepidoptera: Noctuidae) were found attacking the chickpea pods (Lepidoptera: Noctuidae). Of these, 14 (64%) were C. virescens and eight (36%) were H. armigera. This is the first report of these two species in chickpeas in the state of Rio de Janeiro. [ABSTRACT FROM AUTHOR]

The South American bollworm, Helicoverpa gelotopoeon (Dyar), is a member of the Heliothinae complex in Northwestern Argentina and one of the most important pests affecting soybean in the country. Currently, management of Heliothinae pest species is based on the use of insecticides and transgenic Bt crops. However, many species in the Heliothinae complex have developed resistance to these control tactics. In this regard, studies of population structure and genetic diversity studies in these agricultural insect pests are of great importance for the effective implementation of management strategies. Mitochondrial DNA is one of the types of molecular markers available for insect studies successfully employed for population genetic studies in Lepidoptera. The aim of this study was to evaluate the genetic diversity and population structure of five H. gelotopoeon populations collected from different regions and crops in Argentina using analysis of three mitochondrial DNA regions. Results of genetic variability and gene flow analyses among H. gelotopoeon populations indicated, in general, a certain genetic structure in studied populations. Possible causes for this genetic structure include differences among regions, host plants and year of sampling. Additional studies contemplating the impact of biological and ecological features are necessary in understanding the source of genetic structure in these H. gelotopoeon populations. [ABSTRACT FROM AUTHOR]

Heliothine moths (Family Noctuidae : Subfamily Heliothinae) are ubiquitous crop pests with three documented species combinations known to hybridize: Helicoverpa zea x Helicoverpa armigera, H. armigera x Helicoverpa assulta, and Heliothis virescens x Heliothis subflexa. Hybrids can have advantageous traits, such as increased host range, resistance to insecticides, and increased mating success, posing serious threats to agriculture. However, deleterious traits of hybrids, such as developmental abnormalities or sterility, can be exploited for pest management. In this review, the characteristics of F1 hybrids and backcrosses are examined through a historical lens. Topics reviewed include developmental characteristics, sex pheromone synthesis and perception, mating and calling behavior, sperm morphology, gene expression, electrophysiological responses, structures of the central and peripheral nervous systems, hybrid sterility, and applications in pest control. Recommendations for future studies based on existing gaps of knowledge are given, as are proposed pest management strategies.

The tobacco budworm Chloridea (Heliothis) virescens (F.) (Lepidoptera: Noctuidae) has been recently reported in corn crops. However, there is no information regarding the biology of this species feeding on corn cobs. Additionally, the relationship between temperature and tobacco budworm feeding habits is important to project the adaptation of the insect in corn crops at different times and regions. This study aimed to investigate the development of C. virescens feeding on corn cobs, under controlled laboratory conditions, at three temperatures (25 ± 1 ºC, 28 ± 1 ºC and 31 ± 1 ºC). Although adult budworms were observed at all temperatures, the larval development period was reduced at 31 ± 1 ºC, resulting in a lower grain consumption. On the other hand, biological parameters such as larval and pupal viability, pupal weight and sex ratio did not vary with temperature. During the adult stage, a similar fecundity was recorded at all temperatures; however, the egg viability was zero. The optimal temperature for the C. virescens development was between 25 ± 1 ºC and 28 ± 1 ºC. The temperature of 31 ± 1 ºC affects the eggs development, preventing the next generation of tobacco budworms.

Biology and life table of Heliothis peltigera (Denis & Schiffermüller, 1775) (Lepidoptera: Noctuidae), an important safflower pest, studied on two safflower varieties (Balcı and Dinçer) in the laboratory (25 ± 1 °C temperature, 65 ± 5% relative humidity and 16: 8 photoperiod). The longer pre-adult time of H. peltigera was found on Dinçer variety than Balcı variety, as 33.97±0.16 days, and 32.82±0.23 days, respectively. While the higher intrinsic rate of increase (r) (0.134±4.59 d-1), and the finite rate of increase (λ) (1.144±0.005 d-1) were estimated on Balcı variety, also shortest mean generation times were found on Balcı variety (37.49±0.34 days) than Dinçer variety (0.119±5.123 d-1, 1.126±0.005 d-1, and 39.25±0.40 days, respectively). According to these results, it was determined that Balcı variety was more suitable host plants than Dinçer variety for H. peltigera. These basic informations obtained in this study on H. peltigera will be useful for pest control and prefer to produce Dinçer variety that could be reducing of H. peltigera. [ABSTRACT FROM AUTHOR]

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of SHILAP Revista de Lepidopterologia is the property of Sociedad Hispano-Luso-Americana de Lepidopterologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In intensive soybean cropping systems, early-season pest insects such as lepidopteran larvae can seriously compromise crop establishment. Using a polyphagous global pest ̶ ̶ the Old World bollworm Helicoverpa armigera (Lepidoptera: Noctuidae), we determined the potential of seed treatments with diamide or neonicotinoid-carbamate mixture for systemic plant protection and residual efficacy against noctuid larvae. In controlled edaphoclimatic conditions, we infested differently aged soybean plants and recorded plant damage and insect mortality, growth, development, and fecundity to assess lethal and sublethal post-exposure effects. The seed treatments reduced plant damage by 50% during 1–7 days after plant emergence. The lowest damage (<25% defoliation) occurred on plants treated with chlorantraniliprole or cyantraniliprole. These diamides caused larval mortality >80% until 14 days after soybean emergence, which was the window of residual control efficacy. Carbofuran or thiodicarb + imidacloprid caused less than 50% larval mortality and minor plant protection against the larvae. There were sublethal effects on the growth, development, and fecundity of the insects surviving on plants of the insecticide seed treatments. The diamide seed treatments reduced the overall insect fitness for a longer time after plant emergence than did the other treatments. Therefore, soybean seed treatment with chlorantraniliprole or cyantraniliprole is potentially efficacious against noctuid larvae in the VE–V1 soybean growth stages (emergence until the first trifoliate), causing lethal and sublethal effects on the insects. Judicious use and effective resistance management for these systemic compounds are relevant as they are helpful for seed treatment and foliar applications against diverse targets. Helicoverpa armigera can compromise soybean crop establishment in intensive systems. Soybean seed treatment with chlorantraniliprole or cyantraniliprole is potentially efficacious against noctuid larvae in the first 14 days (VE-–V1 soybean growth stages), causing lethal and sublethal effects on the insects. [Display omitted] • Helicoverpa armigera can compromise soybean crop establishment in intensive systems. • Insecticide seed coating was studied for protection and residual control of H. armigera. • Damage was lowest on plants treated with chlorantraniliprole or cyantraniliprole (diamides). • Diamides had >80% efficacy for 14 d; imidacloprid + thiodicarb or carbofuran did not. • (Sub)lethal effects reduced the insect fitness; the diamides suppressed population growth. [ABSTRACT FROM AUTHOR]

Chloridea subflexa and Chloridea virescens are a pair of closely related noctuid species exhibiting pheromone-based sexual isolation and divergent host plant preferences. We produced a novel Illumina short read C. subflexa genome assembly and an improved C. virescens genome assembly, which offer opportunities to study the genomic basis for evolutionarily important traits in this lepidopteran family with few genomic resources. We then examined the feasibility of reference-assisted assembly, an approach that leverages existing high quality genomic resources for genome improvement in closely related taxa and applied it to our Heliothine genomes. Our work demonstrates that reference-assisted assembly has the potential to enhance contiguity and completeness of existing insect genomic resources with minimal additional laboratory costs. We conclude by discussing both the potential and pitfalls of reference-assisted assembly according to the intended downstream assembly application. • We produced an updated, highly contiguous Chloridea virescens assembly and a novel Chloridea subflexa short read assembly. • Reference-assisted assembly improved newly generated and publicly available short read Heliothine genome assemblies. • Genome contiguity and completeness are enhanced by reference-assisted assembly without added costs of experimental finishing. • Gaps may be introduced into the target assembly if the reference assemblies are low quality or from distantly related taxa. [ABSTRACT FROM AUTHOR]