Cotton, Gossypium hirsutum (L.), is an economically important crop in the United States that is plagued by a complex of insect pests. Two key pests of cotton in the midsouthern United States are the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), and bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae). A suite of highly effective synthetic insecticides is typically used for control of these pests. However, it is unclear how the combined management of these two insect pests with biological insecticides impacts the economics of cotton production. To address this shortcoming, we conducted a field experiment in the Mississippi Delta over 2 yr to study the effects of synthetic and biological insecticides for control of the tarnished plant bug and bollworm on cotton yield. The results indicated the control of tarnished plant bug with synthetic insecticides had the most significant impact on cotton yield and net returns. The conventional tarnished plant bug treatment also significantly increased bollworm density and damage, but these increases did not significantly alter yield or net return in non–Bacillus thuringiensis (Bt) or Bt cottons. The economic benefit of a conventional approach to tarnished plant bug control with synthetic insecticides was US$438.07/ha in non-Bt and $700.88/ha in Bt cotton relative to those treated with a biological insecticide. The biological insecticides used for this study were ineffective at significantly altering yield or net return. However, for insect management in cotton to be sustainable, alternatives must be found to complement conventional synthetic insecticides.

Following the emergence of Melanaphis sorghi (Theobald) (Hemiptera: Aphididae) as a new pest of sorghum in the United States, research was conducted to identify tools and techniques successful at reducing populations and preventing economic losses in grain sorghum, Sorghum bicolor (L.) Moench. The objective of this study was to assess the efficacy of seed- and foliar-applied insecticide treatments for management of M. sorghi. Small plot experiments were replicated at two locations to evaluate residual activity of neonicotinoid seed treatments and foliar insecticides. Natural enemy presence was recorded in each of these trials to determine which predator and parasitoid species were using M. sorghi as prey. All seed treatments suppressed M. sorghi populations below a treatment threshold of 75 aphids per plant for 30% of plants for >6 weeks after planting. Foliar insecticides including flupyradifurone, sulfoxaflor, and thiamethoxam provided 3–4 weeks of population suppression, irrespective of M. sorghi pressure. Fifteen natural enemy species were identified in this study, and community structure varied temporally and geographically. In general, natural enemy species richness was correlated with aphid abundance. We identified the most efficacious insecticides available for management of M. sorghi and determined that they should be compatible with biological control and integrated pest management programs.

Accurate identification and classification of insect species, especially those with significant economic and ecological implications, have historically presented challenges. Migratory locusts, Locusta migratoria manilensis (Meyen) (Orthoptera: Acrididae), are notorious for their destructive impact on crops. Traditional morphological methods often face limitations in distinguishing closely related species and require taxonomic expertise. However, the emergence of DNA barcoding as a powerful tool for species identification has revolutionized the field of entomology. DNA barcoding utilizes a standardized DNA sequence, a molecular barcode, which serves as a distinct genetic signature for rapid and accurate species identification. In this study, DNA barcoding techniques were employed to identify and differentiate the migratory locust subspecies manilensis, in both its solitary and gregarious forms, as well as to determine its phylogenetic relationship with other related species within the Acrididae family. GenBank reference sequences were used to identify the locusts at the molecular subspecies level. Although the COI marker did not exhibit significant differences between the solitary and migratory forms, it was valuable in resolving the identification of L. migratoria subspecies. This lack of significant differences may be attributed to limited genetic variation of COI at the subspecies level and substantial genetic similarities between the solitary and migratory forms, likely stemming from a recent common ancestor. Nonetheless, using COI remains beneficial for subspecies identification in migratory locusts.

In India, the invasive fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), has emerged as the most devastating pest of maize, Zea mays L., and is expanding its host range. In this study, we assessed its preference for feeding and oviposition in both choice and nonchoice bioassays including maize, sorghum, castor, cowpea, cotton, banana, and marigold as hosts. At 24 h after release in choice tests, the number of larvae was greatest on maize ears and lowest on cotton (Gossypium hirsutum L.) leaves among the host plants tested. In nonchoice tests, third-instar larvae that fed on maize leaves and ears had the shortest growth periods (2.05 and 2.2 d, respectively) and the longest on marigold (Tagetes erecta L.) flowers (5.2 d). In oviposition preference tests, maize was the most preferred host, with the greatest number of egg masses deposited in choice and nonchoice tests compared with other hosts. Thus, maize was the most preferred host for fall armyworm in our tests, but fall armyworm may also survive on plants other than maize during the nongrowing season, posing a risk to other economically important crops in its expanded range in India.

Species diversity is undergoing rapid reductions globally. Identifying the causes underlying species diversity patterns and biodiversity hotspots is critical for developing conservation strategies. In this study, the 4,594 occurrence records of 854 Typhlocybinae (Heteroptera: Cicadellidae) species in China were used to investigate the factors affecting species richness and endemism patterns as well as identify species diversity hotspots to establish their conservation status. Generalized linear models and hierarchical partitioning were used to assess the effects of 6 environmental factors on species richness and endemism. Species diversity hotspots were obtained by integrating the 10 grids with highest levels of species richness and endemism; the conservation status of these hotspots was assessed via gap analysis. We found that species richness and endemism distribution of Typhlocybinae in China were heterogeneous, mainly concentrated in southern and central areas. The results also showed that plants were the most important environmental factors affecting species richness and endemism patterns, followed by niche conservatism. The 10 hotspots were identified; however, they were not fully protected by the existing nature reserves. This study highlights the importance of plants and niche conservatism in shaping species richness and endemism patterns of Typhlocybinae. Moreover, establishment of new nature reserves in hotspot areas with a conservation gap is required.

This study investigated the repellent property of ‘Bhut Jolokia’ chilli pepper, a Capsicum chinense Jacquin cultivar, against the rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae), in stored wheat, Triticum aestivum L., in laboratory assays using a modified cup bioassay apparatus. Contact and fumigation repellency assays were conducted with the Bhut Jolokia chilli dry powder at concentrations of 3 and 5% (w/w) of the total weight of grain and the Bhut Jolokia chilli ethanol extract at volumes of 3 and 5 ml. In the contact repellency test, the number (mean ± SE) of test insects repelled (7.90 ± 0.23) increased with increasing concentration (5%) and time interval (24 h), whereas in the fumigation repellency test, the mean number of repelled insects increased (8.2 ± 0.2) with increasing volume (5 ml) and decreased (3.80 ± 0.13) with increasing time interval (60 min). Gas chromatography–mass spectrometry (GC-MS) analysis identified that the active compounds present in the Bhut Jolokia chilli ethanol extract were the capsaicinoids capsaicin (21.50%) and dihydrocapsaicin (4.44%) and the noncapsaicinoids n-hexadecanoic acid (29.34%), n-pentadecylacetamide (12.92%), and others. Our findings provide a preliminary assessment of the repellent property of Bhut Jolokia chilli against S. oryzae in stored wheat under laboratory conditions and serve as an impetus for continued research.

Field efficacy trials determined that flonicamid was more effective than spiromesifen and the negative control compound acetamiprid against Aphis craccivora Koch on faba bean, Vicia faba L. Flonicamid and spiromesifen residues in bean tissue and in soil were determined with high-performance liquid chromatography and gas chromatography-mass spectrometry. Using a spike level of 0.1–1 mg/kg, the recovery of flonicamid from bean tissue was 89.2% and from soil 81.4%. Spiromesifen recovery was 99.4% from bean and 90.3% from soil. The relative standard deviations ranged from 2.54 to 8.14%. According to the dissipation kinetics, the half-life of flonicamid residue in beans was 1.93 d and 1.96 d in soil, while that of spiromesifen in beans was 2.35 d and in 2.59 d in soil.

Imidacloprid has been one of the most widely used insecticides for managing the sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in the United States since the U.S. Environmental Protection Agency first registered it in 1994. A major whitefly control failure occurred in the state of Georgia in 2017 when B. tabaci;–induced economic losses in horticultural and field crops surpassed approximately US$160 million. Vegetable growers have historically used imidacloprid for whitefly management, which likely led to the insecticide control failures of whiteflies in spring vegetables. Despite this, only a single site documentation of imidacloprid resistance in adults from 2007 in Georgia exists, making the current status unknown. Thus, it is likely that Georgia has an ongoing risk of imidacloprid-resistant B. tabaci; infestations. No multicounty, extensive survey for imidacloprid dose response in whitefly exists for the state of Georgia. Therefore, an adult mortality bioassay of a range of imidacloprid concentrations was used to evaluate B. tabaci; populations from several counties in South Georgia, where most of these economic losses occurred. This included a maximum dose concentration representing the current highest labeled rate. Dose response to the insecticide was not uniform across locations, with whiteflies in several areas displaying unexpected susceptibility to imidacloprid. Median lethal concentrations (LC₅₀s) ranging from 0.02 to 196.05 mg of active ingredient per liter in Georgia whitefly populations were substantially lower than the reference Florida whitefly population. This baseline information for the state is critical to future evaluations of this insecticide in resistance management programs.

Tetranychus merganser Boudreaux (Acari: Tetranychidae) is one of the most economically important mite pests of papaya (Carica papaya L.) crops grown along the Gulf of México. Control of this mite depends mainly on chemical insecticides. This research aims to evaluate the effects of different concentrations (0.1, 0.5, 1, 5, 10, and 15% [v/v]) of the ethanolic extract of Magnolia alejandrae García-Morales and Iamonico (Magnoliaceae) leaves on T. merganser adult females, as well as to obtain information about the chemical composition of the extract. The ethanolic extracts contained some phytochemicals such as phenolic compounds, alkaloids, glycosides, ketones, terpenes, and quinones. Females treated with 0.1 and 15% (v/v) of the extract showed mortality of 0.0% and 33.3% at 72 h, respectively, as compared to the control treatment. The mites treated with 15% (v/v) of the extract decreased their oviposition rate (5.90, 5.35, and 4.77 eggs/female), compared to the control treatment (13.27, 13.95, and 14.39 eggs/female) at 24, 48, and 72 h, respectively, which led to a reduction in the growth rate. The feeding damage caused by T. merganser was reduced at high concentrations. Magnolia alejandrae leaf ethanolic extract has potential for development as a control agent for T. merganser.