In 2012, we tested the relative efficacy of four commercial types of insect traps (panel; standard multiple-funnel; modified multiple-funnel; and sea, land, and air Malaise [SLAM]) for capturing bark and woodboring beetles (Coleoptera) in a pine stand in northcentral Georgia. All traps were baited with ethanol, α-pinene, ipsenol, and ipsdienol lures. The SLAM trap outperformed the panel trap for diversity and abundance of Cerambycidae. Mean catches of Asemum striatum (L.) in SLAM traps were greater than those in all other traps. SLAM traps caught more Acanthocinus obsoletus (LeConte) and Xylotrechus sagittatus (Germar) than standard multiple-funnel funnel and panel traps. The greatest numbers of Monochamus titillator (F.) were in SLAM and modified multiple-funnel traps. In contrast, SLAM traps were inferior to all other trap types in trapping bark beetles (Curculionidae: Scolytinae). More Dendroctonus terebrans (Olivier), Hylastes porculus Erichson, and Hylastes salebrosus Eichhoff were captured in panel traps than the other types of traps. Catches of Ips avulsus (Eichhoff), Ips calligraphus (Germar), Orthotomicus caelatus (Eichhoff), and Pityophthorus spp. were the same in panel, standard multiple-funnel, and modified multiple-funnel traps. Our data suggest that combinations of trap types should be considered in maximizing the effectiveness of detection programs for pine bark and woodboring beetles.

Eastern hemlock, Tsuga canadensis (L.) Carriere, is an important component of riparian zones in Appalachian forests. Tree mortality caused by hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae) could impact aquatic macroinvertebrate populations. Our study examined larval populations of Ephemeroptera, Plecoptera, and Trichoptera occurring in the headwaters of two creeks in the Sumter National Forest (Oconee Co., SC). Larval populations were initially sampled in King Creek (2006) and Crane Creek (2007) in separate studies. When those studies were conducted, there was no noticeable decline in hemlock health along either creek. However, by 2009 hemlock mortality along both creeks was obvious, and the Ephemeroptera, Plecoptera, and Trichoptera community was resurveyed on both creeks. This is the first study comparing aquatic macroinvertebrate populations before and after A. tsugae infestation. Ephemeroptera, Plecoptera, and Trichoptera larvae were identified to genus, and analyzed at the functional feeding group level. In both creeks, collector filterers and scrapers were significantly more abundant in the initial survey than in 2009. Generic diversity within each creek was examined using the total Ephemeroptera, Plecoptera and Trichoptera community, and was based on the indices of: richness (D0), Shannon exponential (D1), and inverse Simpson (D2). The only diversity measure that differed significantly between the original survey and 2009 was the Shannon exponential index for Crane Creek which was significantly higher in 2009 than 2006

Host adaptability and insecticide resistance of insects are closely related to detoxification metabolism-related proteins. In this study, the distribution and expression of glutathione s-transferase (GST) in Agrilus zanthoxylumi Hou (Coleoptera: Buprestidae) were studied. Based on the transcriptome data of A. zanthoxylumi, five GST genes were screened and cloned. The transcription levels of the five GST genes in male and female adult head, thorax, abdomen, legs and wings were determined by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) in order to provide a theoretical basis for the functional study of the gene. The results showed that all five GST genes had highly conserved N-terminal domain or C-terminal domain, belonging to two subfamilies of Delta or Sigma. The phylogenetic tree results showed that the evolutionary relationship of GST genes between A. zanthoxylumi, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), and Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae) was the closest; RT-qPCR results showed that the five GST genes were differentially expressed in different tissues and sexes, and its expression level in each tissue of the male was higher than that of the female as a whole, especially in the head. The results of this study can provide basic data for analyzing the mechanism of detoxification resistance of A. zanthoxylumi and provide reference for its biological control and resistance research.

Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a generalist pest of food crops and turfgrasses. Insecticides such as diamides provide longer residual control of some grass-feeding caterpillars relative to pyrethroids. The objective was to compare the responses of fall armyworm larvae to residues of commonly used insecticides on hybrid bermudagrass (Cynodon dactylon (L.) × C. transvaalensis Burtt-Davy). A field experiment determined mortality of free-ranging fall armyworms exposed for 1–3 h on turfgrass at 1, 7, 14, 28, and 42 d after a foliar application. A laboratory experiment determined the mortality of larvae fed grass clippings harvested from treated plots at 1, 3, 7, 14, 28, and 42 d after application. Larvae crawled similar or greater distances across bermudagrass treated with bifenthrin and permethrin relative to nontreated grasses. After crawling on bermudagrass treated with chlorantraniliprole or cyantraniliprole 14 d after application, larval mortality was ≥77%. Mortality of larvae fed pyrethroid-treated clippings was ≤40% and no different from control larvae regardless of residue age. Larvae fed bermudagrass with 1 to 7 d old residues of cyantraniliprole or indoxacarb resulted in significantly greater mortality than larvae fed nontreated clippings. No residues of cyantraniliprole or indoxacarb older than 7 d resulted in mortality significantly greater than larvae fed nontreated clippings. Larvae fed chlorantraniliprole-treated clippings of all residue ages produced larval mortality greater than larvae fed nontreated clippings. These experiments support previous reports of extended residual control from chlorantraniliprole against other grass-feeding caterpillar species. The diamides protect turfgrass from larvae better than pyrethroids.

Because turfgrass is maintained in various settings, such as golf courses, lawns, and commercially grown in sod farms, it is critical to understand its major insect pests and management practices. A survey was conducted to determine the major insect pests and current management practices in the commercial turfgrass industries in Georgia. A total of 32 respondents representing golf courses and sod farms participated in the survey. A significantly greater number of respondents represented golf courses (75% of 32 respondents) than sod farms (25%). The respondents (n =31) identified fall armyworm, Spodoptera frugiperda J.E. Smith (32.5%), white grubs, Phyllophaga spp. (20.8%), mole crickets (Orthoptera: Gryllotalpidae; 16.9%), and others (22%) as major pests in comparison to billbugs, Sphenophorus spp. (7.8%) and chinch bugs, Blissus spp. (0%). Of 31 respondents, 64.5% applied insecticides two to five times and 22.5% respondents applied insecticides 5–10 times for insect management each year. Among nonchemical tools (n=24), most respondents opted to do nothing (70.8%) than use biological control (0%), host plant resistance (25%), or other management tools (4.2%).

The pine sawyer beetle, Monochamus alternatus Hope, is a devastating wood borer of several species of pine trees, and the main transmitting vector of the pine wood nematode, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle (Aphelenchida: Parasitaphelenchidae). To explore new techniques for prevention and control of this destructive beetle, a novel gene vacuolar ATPase subunit H (V-ATPase H) was chosen as RNA interference (RNAi) target gene. Relative expression of V-ATPase H in different tissues and silencing efficiency in an in vitro RNAi experiment was assayed by using reverse transcription–quantitative polymerase chain reaction. The results indicated that the mRNA abundance of V-ATPase H in the gut was significantly higher than that in fat body, residual body, and hemolymph. Double-stranded RNA (dsRNA) targeting V-ATPase H was able to silence the expression of target gene effectively at 24 h posttreatment. Expression of immunity-related genes was examined after treatment with dsRNA targeting V-ATPase H, and transcript levels were compared with the control. The results showed that RNAi suppression of V-ATPase H inhibited the expression of immunity-related genes. This is the first demonstration of an in vitro RNAi experiment in any insect hemolymph that provides a novel environment for evaluating RNAi in insects, as well as shows potential for developing RNAi-mediated strategy for the control of M. alternatus.

Metabolic detoxification is a common mechanism of insecticide resistance, in which detoxifying enzyme genes are overexpressed. Aphis glycines Matsumura (Hemiptera: Aphididae) is one of the major soybean pests in the United States and has developed resistance to pyrethroid insecticides after almost two decades of use. To date, there are no validated reference genes to normalize expression of detoxification genes for pyrethroid resistance in A. glycines. From a literature review, a list was compiled of genes from 36 gene families (68 sequences) frequently used as reference genes in gene expression analysis in Hemiptera. Exon–exon junction primers were designed for the best alignment matches to a draft A. glycines genome and were assayed in a three-phase screening. The first screen eliminated nonamplifying primers. The second screen used nine A. glycines populations varying in resistance to pyrethroids and eliminated primers with inconsistent amplification or low amplification efficiency, and quantitatively assessed the stability of expression in the 14 remaining candidates using NormFinder and a generalization of BestKeeper. The third screen quantitatively validated these results on the best candidates. Six genes were identified with the greatest stability across technical and biological replication and the nine populations. The genes identified as the most suitable reference genes for the study of detoxifying enzymes related to pyrethroid resistance in soybean aphid were: actin, RPL9 (ribosomal protein L9), RPS9 (ribosomal protein S9), AK (arginine kinase), RNAPol2 (RNA polymerase II), and RPL17 (ribosomal protein L17). Our findings will support studies related to insecticide resistance in A. glycines.

Spruce beetle, Dendroctonus rufipennis Kirby (Coleoptera: Curculionidae), causes significant mortality of mature spruce, Picea spp. (Pinales: Pinaceae), in western North America. We evaluated the effectiveness of two formulations of bole injections of emamectin benzoate (TREE-äge^® G4 and TREE-äge R10; Arborjet, Inc., Woburn, MA) alone and combined with propiconazole (Propizol^®; Arborjet, Inc.) for protecting Engelmann spruce, Picea engelmannii Parry ex Engelm., from mortality attributed to colonization by D. rufipennis. Treatments were injected 16–19 July 2017, and levels of Pi. engelmannii mortality were determined for 2018 and 2019. Each experimental tree (n = 30, including an untreated control group) was baited with aggregation pheromone (frontalin) June–September 2018. All surviving treated Pi. engelmannii and a second untreated control group were baited June–September 2019. Both TREE-äge G4 and TREE-äge R10 significantly reduced levels of Pi. engelmannii mortality compared with the untreated control; however, protection was limited to one field season. Protection was increased to two field seasons by combining TREE-äge G4 and TREE-äge R10 with Propizol. The addition of Propizol, a triazole fungicide, likely reduced the progression of blue stain within treated Pi. engelmannii increasing tree health and resistance to D. rufipennis.

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important pests of cultivated plants. Its control is mainly based on the application of acaricides with concomitant adverse environmental and human health effects. Consequently, we examined the potential of using temperature as an alternative. To that end, we conducted bioassays of the temperature-mortality response of eggs, larvae, protonymphs, deutonymphs, and adult females of T. urticae. Groups of 20 individuals from each stage were placed on 4-cm diameter bean leaf (Phaseolus vulgaris L.) discs. A stream of air at the designated temperature was passed over the disc at a rate of 3.7 ± 1 m s^–1) for 2 ± 1 s. Mortality was evaluated at 24 h (larva, protonymph, deutonymph, and female) or 72 h (egg) after exposure. Based on preliminary mortality responses, we selected 10 temperatures with a response range between 0 and 100% mortality. Those were 30, 35, 40, 45, 47, 50, 53, 55, 60, and 65°C [SD, ± 1.5 for each]). In total, 30 replications were conducted, and each repetition included these temperatures and untreated controls. The median lethal temperature ranged from 41.8°C for adult females to 46.9°C for eggs. The lethal temperature to kill 95% of the exposed individuals ranged from 55°C for females to 62.5°C for eggs. There were no survivors at 65°C (eggs), 60°C (larva, protonymph, and deutonymph), or 55°C (adult females).

The nonbiting midges are tiny insects with a wide distribution around West Lake, China. In this study, the seasonal dynamics of the local dominant midge species was investigated. Phylogenetic trees of this species also were analyzed to discover its evolutionary history. Ultraviolet (UV) light traps were used for surveillance around West Lake in the period from April 2017 to November 2018. External morphological identification was performed using a stereomicroscope. Two genes of adult female midges that encoded the cytochrome oxidase subunit I (COI) and internal transcribed spacer 1 (ITS-1) were sequenced and aligned online using GenBank nucleotide database and the Molecular Evolutionary Genetics Analysis (MEGA) software 10.1.7. According to the field surveillance in 2017–2018, Forcipomyia bikanni Chan and LeRoux (Diptera: Ceratopogonidae) is the representative dominant species of West Lake, with its activity peaking in August and October. The COI and ITS-1 gene sequences of F. bikanni (XH01-5) were 523 bp and 315 bp, respectively. The final phylogenetic tree of the COI implied that F. bikanni (XH01-5) has 97.9% significant similarity with conspecific F. bikanni (LC015045) from the adjacent Fujian Province, China (E-value ≤ 0.1%). Furthermore, the ITS-1 sequences with 98% likelihood showed the highest linkage between F. bikanni (XH01-5) and F. townsvillensis (Taylor) (HM775502-HM775504) with different branches. Thus, the final unrooted phylogenetic trees of COI and ITS-1 are essential tools for reconstructing the evolutionary histories of nonbiting midges.

Many biological control agents have been released to manage the water hyacinth, Pontederia (Eichhornia) crassipes (C. Martius) Solms-Laubach (Pontederiaceae). They include two Eccritotarsus sources from Brazil and Peru. Distinguishing features between the two were found, necessitating their redescription. The Brazil source remained Eccritotarsus catarinensis (Carvalho), whereas the Peru source is Eccritotarsus eichhorniae Henry. Our objectives in this laboratory study were to assess the mate choice in the two species and, thus, determine which species performs better than the other. Mate choice in the form of no-choice, bichoice, and multichoice tests were conducted within and between species in a 3:1, 2:1, and 1:1 sex ratios. The E. catarinensis pair had short copula latency but long copula duration in multichoice experiments, whereas the E. eichhorniae pair had short copula latency but long copula duration in no-choice experiments. In no-choice and bichoice experiments, E. eichhorniae♀ and E. eichhorniae♂ outcompeted E. catarinensis♀ and E. catarinensis♂. In multichoice experiments, E. catarinensis♂ outcompeted E. eichhorniae♂, whereas E. eichhorniae♀ outcompeted E. catarinensis♀. Despite being shown to be more fecund, E. eichhorniae is likely not to outcompete E. catarinensis where the two species co-occur and that E. catarinensis♂ and E. eichhorniae♀ will outcompete their counterparts. Previous research indicated that when E. catarinensis♂ and E. eichhorniae♀ are crossed, they produce few offspring, underscoring the need to confirm if the two species will coexist, compete, or displace each other in their natural habitats. Our findings further support that prezygotic reproductive isolation mechanisms led to the speciation of these species.

The Asian citrus psyllid, Diaphorina citri (Kuwayama) (Hemiptera: Liviidae), is a severe pest of citrus orchards worldwide. Its control is based mainly on the use of conventional insecticides, and resistance to many of those compounds is widespread. Phenotypic bioassays to detect resistance compare the response of a field-collected population with a laboratory-reared population that is susceptible to insecticides. This comparison usually does not involve a susceptible field-collected counterpart since its existence is currently rare. We found an isolated field population of D. citri living on a wild host, orange jasmine (Murraya paniculata [L.] Jack). Considering its lifetime fly capacity, gene flow with any insecticide-treated population was nonexistent or negligible. Thus, we determined the response in fourth-instar nymphs and unsexed 2- to 5-d-old adults in bioassays of commercial formulations of the commonly used insecticides chlorpyrifos, malathion, imidacloprid, and spinosad. In the bioassays, insects were placed on leaf discs previously immersed for 10 s in the respective insecticide concentrations. For adults, the lowest concentration–mortality response was with chlorpyrifos (lethal concentration 50 [LC₅₀] of 0.72 mg L^-1 and lethal concentration 95 [LC₉₅] of 1.02 mg L^-1). The highest toxicity response was with malathion (LC₉₅ of 0.05 mg L^-1). The highest toxicity response with fourth-instar nymphs was observed with spinosad (LC₅₀ of 0.007, LC₉₅ of 0.021 mg L^-1). The estimated LC₅₀ and LC₉₅ values for chlorpyrifos, malathion, and spinosad were lower than those documented worldwide for these insecticides in susceptible populations of D. citri.

The availability of resources can have important effects on the fighting behaviors of insects, but the physiological mechanism that might underlie the effect of resources is unclear. Nitric oxide (NO) is a gaseous neurotransmitter that is capable of directly diffusing into cells and acting as a messenger. Several studies have reported that NO may be involved in modulating the fighting behavior of insects. In the present study, we investigated the effect of different resources on the fighting behavior of Velarifictorus aspersus Walker male crickets (Orthoptera: Gryllidae), and tested whether this effect is regulated by NO. We found that when a burrow or female was available, the fighting level and fighting duration were significantly greater in males compared with those when no resources were available, thereby suggesting that the presence of a valuable resource motivated male crickets to fight more aggressively. In a novel environment, treatment with an NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) significantly increased the fighting level and fighting duration in male crickets, and males treated with L-NAME won more fights against males treated with water. However, when a burrow or female was available, treatment with L-NAME did not affect the fighting level and fighting duration in males, and males treated with L-NAME lost more fights against males treated with water. These results suggest that NO may have different effects on modulating the fighting behavior of male V. aspersus crickets under different resource conditions.