Three chitin synthesis inhibitors (CSIs), bistrifluron, chlorfluazuron, and noviflumuron, were evaluated for their toxicity and horizontal transfer against the western drywood termite, Incisitermes minor (Hagen), when used to treat wood. In a no-choice bioassay, bistrifluron provided significantly faster kill than chlorfluazuron or noviflumuron treatments at 0.1 and 0.5% (wt/wt) rates over a 60-d period, providing 99% mortality. In a choice bioassay using 0.1% rate, bistrifluron provided a significantly faster kill than chlorfluazuron or noviflumuron treatments over a 60-d period, resulting in 96% mortality. In a transfer bioassay, a group of bistrifluron-fed termites, donors (D), was placed with a group of unexposed nestmates, recipients (R). Based on the visual marking, the food material of the donor termites was readily transferred to the recipients within 24 to 48 h. Overall, survival curves were similar between 1:19 (5% donor) and 10:10 (50% donor) D:R ratios, resulting in 100% mortality by day 90. This result indicated that lethal doses of bistrifluron were retained and effectively transferred, even from limited numbers of termites that originally ingested the compound. Implications for drywood termite management and future development are discussed.

This study investigated the translocation of cockroach bait toxicants to the Pharaoh ant, Monomorium pharaonis (L.), through feeding on cadavers of German cockroaches, Blattella germanica (L.), which were killed by commercial gel baits. The cockroaches were first treated with 1 of 4 gel baits: Advion Trio (0.6% indoxacarb, 0.1% pyriproxyfen, 0.1% novaluron), Maxforce FC Magnum (0.05% fipronil), Alpine Rotation 1 (0.5% dinotefuran), and Vendetta Nitro (0.5% clothianidin, 0.5% pyriproxyfen) before the Pharaoh ants were allowed to forage on the cadavers. The effects of the toxicants on the Pharaoh ant colonies were examined. Ants that fed on cadavers killed by Maxforce FC Magnum showed significantly higher (P < 0.05) mortality rates among queens and brood. Advion Trio initially led to the rapid reduction of queens, workers, and brood; however, the Pharaoh ant colony later recovered as the workers abandoned treated cockroach cadavers in favor of the regular diet. Examination of the queen ovaries revealed that, in the Vendetta Nitro-treated group, the size of mature oocytes was significantly reduced (P < 0.05). However, no structural damage was observed on any oocyte, as all exhibited a visible nucleus, multiple nurse cells, and well-developed follicular epithelium. The horizontal transfer efficacy of different cockroach gel bait toxicants is discussed.

Over-the-counter (OTC) insecticide products are popular, easily available, and inexpensive do-it-yourself options for home residents. In this study, we investigated the performance of OTC insecticides consisting of bait and spray products against susceptible and field-collected strains of the German cockroach, Blattella germanica (L.) (Blattodea: Ectobiidae) using several test methods. In open arena bioassays, all OTC baits tested were ineffective on field-collected German cockroaches. The least effective OTC bait was unable to kill all test cockroaches of any strains at 14 d post-treatment. Direct spray experiments demonstrated that cockroaches treated with pyrethroid spray registered significantly shorter mean knockdown times when compared to that of the natural product. On the other hand, the natural product spray caused significantly shorter mean survival time in test insects than the pyrethroid spray (<1 h vs. >1 d). The residual efficacy of spray deposits was evaluated in the Ebeling choice box and revealed that all sprays have poor residual performance against field-collected German cockroach strains. Insecticide resistance and potential avoidance behavior may have contributed to the low performance index (PI) values of pyrethroid-based sprays, as cockroaches may have survived initial contact and subsequently avoided treated surfaces. Conversely, natural product spray deposits exhibited negative PI values for most of the study period due to spatial repellency. In general, the performance of OTC insecticide products was lower on field-collected German cockroach strains than on the susceptible strain. These products are likely ineffective at controlling the German cockroach infestations in homes.

Argentine ants are a major pest in California. In this study, a biodegradable calcium alginate hydrogel with an aqueous boric acid bait was tested against Argentine ant populations in a citrus orchard and a vineyard. A new continuous method was developed to produce large quantities of hydrogel bait for the field test. Foraging activity levels of ants were compared between baited and untreated zones. For both study sites, four to five monthly bait applications throughout summer provided a greater than 80% reduction in ant activity. Based on spatial analyses by distance indices, the baited areas were characterized by gaps (areas with lower ant counts) and the untreated control zones were characterized by patches (areas with higher ant counts). This indicated area-wide suppression of Argentine ants. For the citrus orchard, post-baiting panel trap monitoring showed reductions of both ants and Asian citrus psyllid in the baited zone compared to the control. For the vineyard, mid-season soil analyses indicated that the impact of boric acid baiting on soil boron concentration was negligible. In sum, the calcium alginate hydrogel bait with boric acid as an active ingredient may provide a promising solution for Argentine ant baiting.

The western drywood termite, Incisitermes minor (Hagen), causes significant economic damage to wood structures in the United States of America, especially California. When infestation is not widespread, localized insecticide injections may be useful for remedial control. However, the extensive gallery structure of drywood termites and their tendency to aggregate at specific parts of the galleries can impact the efficacy of localized insecticide injection. Chemicals that attract termites from a distance may improve the localized insecticide injection by increasing the number of termites contacting the insecticide residues. Two volatile terpenes, α-pinene and β-pinene, commonly found in many coniferous timber trees, were applied to artificial termite galleries to determine if termites were attracted from their original aggregation site. Furthermore, we examined if adding these pinenes would improve the overall efficacy of some insecticide products for drywood termite control. Behavioral assay results showed that the treatment with pinenes increased the likelihood that drywood termites would leave their original aggregation site and contact the treated part of the gallery. When tested with the pesticide products applied in a small area away from the termite aggregation, β-pinene significantly accelerated the time course of mortality for the aqueous fipronil. The efficacy of disodium octaborate tetrahydrate dust was not influenced by the addition of pinenes. Implications for drywood termite management and future research directions are discussed.

Isocycloseram is a new insecticide in the isoxazoline class that targets insect GABA-gated chloride channels. In this study, we evaluated a cockroach gel bait formulation containing 1% isocycloseram against a susceptible strain (UCR) and 5 field-collected strains (WM, RG386, Ryan, CDR, and SY) of the German cockroach, Blattella germanica (L.) (Blattodea: Ectobiidae), and compared it with several commercial insecticide baits in the laboratory. Using the Ebeling choice box method, we also tested a residual deposit of an SC formulation of isocycloseram against the UCR, RG386, and Ryan strains. The isocycloseram bait was among the fastest-performing treatments against adult males (mean survival time: 0.9-2.7 days) and mixed stages and sexes (mean survival time: 1.4-5.4 days) across all strains. Secondary transfer effects of the bait were demonstrated in the UCR strain by exposing new adult males to individuals killed by direct bait treatment. Physiological resistance was not detected in the WM, CDR, and RG386 strains with topical treatment of a diagnostic dose (3x LD95) of isocycloseram developed using the UCR strain. However, topical assays revealed resistance ratios (RR50) of 1.6 and 3.0x in the Ryan and SY strains, respectively. The performance of a 0.05% isocycloseram residual application against the Ryan strain was improved with the addition of piperonyl butoxide.

Urban entomology is the study of arthropod and other pests of the urban environment. It has gained worldwide recognition as a distinct discipline. Its origin is associated with Walter Ebeling's publication Urban Entomology in 1975. Urbanization, invasive pests, increased demand for pest management services, and changes in legislation collided in the 1970s to create a need for research and extension activities worldwide. This resulted in urban entomology as a discipline and, within two decades, its national and international recognition. In this review, we present the factors that led to the development of urban entomology and how they have shaped its current meaning. As urbanization intensifies and the global economy increases, the demands for urban pest management will continue to grow. We discuss how these future challenges may shape and alter the discipline.

Artificial or non-nutritive sweeteners are indigestible by most animals. Some sweeteners are orally toxic to insects and have received recent interest as potential safe insecticides due to their low mammalian toxicity. In this study, we investigated the oral toxicity of sucralose on insecticide-susceptible and resistant German cockroaches, Blattella germanica (L.). In a nonchoice test, we evaluated 5, 10, and 20% sucralose solutions. Depending on the cockroach strains, mean mortality ranged from 62.5 to 92.5%, 15 to 55%, and 2.5 to 27.5% for 20, 10, and 5% sucralose, respectively. Next, we measured the impact of a 20% sucralose treatment on water loss rates in the cockroach strains. All strains lost 23.0-30.29% of body water by 6 d. Dehydrated cockroaches were more prone to be killed by sucralose than nondehydrated ones. Lastly, we evaluated the effect of 20% sucralose treatment on gut bacterial composition and found the diversity of gut bacteria in treated cockroaches was significantly reduced after 3 days, implicating a rapid change in the alimentary environment.

Argentine ants are a major pest in California. In this study, a biodegradable calcium alginate hydrogel with an aqueous boric acid bait was tested against Argentine ant populations in a citrus orchard and a vineyard. A new continuous method was developed to produce large quantities of hydrogel bait for the field test. Foraging activity levels of ants were compared between baited and untreated zones. For both study sites, four to five monthly bait applications throughout summer provided a greater than 80% reduction in ant activity. Based on spatial analyses by distance indices, the baited areas were characterized by gaps (areas with lower ant counts) and the untreated control zones were characterized by patches (areas with higher ant counts). This indicated area-wide suppression of Argentine ants. For the citrus orchard, post-baiting panel trap monitoring showed reductions of both ants and Asian citrus psyllid in the baited zone compared to the control. For the vineyard, mid-season soil analyses indicated that the impact of boric acid baiting on soil boron concentration was negligible. In sum, the calcium alginate hydrogel bait with boric acid as an active ingredient may provide a promising solution for Argentine ant baiting.

Covering 1986 to presentNatural product drug discovery at Novartis has a long and successful history of delivering life saving medicines to millions of patients. In this viewpoint, we are presenting the tools we use and challenges we face as we advance natural products from early research into development and beyond. We are leveraging our collection of 90 000 microbial strains and 20 000 isolated natural products to find new medications in an interdisciplinary approach that requires expertise in microbiology, computational biology, synthetic biology, chemistry, and process development. Technological advances, particularly in genome engineering and data science have transformed our field, accelerating discovery and facilitating sustainable compound supply. Emerging new modalities such as antibody drug conjugates, radioligand therapies and xRNA-based medications offer new opportunities for natural product-derived drugs. By taking advantage of these new modalities and the most recent research technologies, natural products will significantly contribute to the medicines of the future.

The cellular cytoskeleton relies on diverse populations of motors, filaments, and binding proteins acting in concert to enable nonequilibrium processes ranging from mitosis to chemotaxis. The cytoskeleton's versatile reconfigurability, programmed by interactions between its constituents, makes it a foundational active matter platform. However, current active matter endeavors are limited largely to single force-generating components acting on a single substrate-far from the composite cytoskeleton in cells. Here, we engineer actin-microtubule (MT) composites, driven by kinesin and myosin motors and tuned by crosslinkers, to ballistically restructure and flow with speeds that span three orders of magnitude depending on the composite formulation and time relative to the onset of motor activity. Differential dynamic microscopy analyses reveal that kinesin and myosin compete to delay the onset of acceleration and suppress discrete restructuring events, while passive crosslinking of either actin or MTs has an opposite effect. Our minimal advection-diffusion model and spatial correlation analyses correlate these dynamics to structure, with motor antagonism suppressing reconfiguration and demixing, while crosslinking enhances clustering. Despite the rich formulation space and emergent formulation-dependent structures, the nonequilibrium dynamics across all composites and timescales can be organized into three classes-slow isotropic reorientation, fast directional flow, and multimode restructuring. Moreover, our mathematical model demonstrates that diverse structural motifs can arise simply from the interplay between motor-driven advection and frictional drag. These general features of our platform facilitate applicability to other active matter systems and shed light on diverse ways that cytoskeletal components can cooperate or compete to enable wide-ranging cellular processes.

Biological processes are typically actuated by dynamic multi-subunit molecular complexes. However, interactions between subunits, which govern the functions of these complexes, are hard to measure directly. Here, we develop a general approach combining cryo-EM imaging technology and statistical modeling and apply it to study the hexameric clock protein KaiC in Cyanobacteria. By clustering millions of KaiC monomer images, we identify two major conformational states of KaiC monomers. We then classify the conformational states of (>160,000) KaiC hexamers by the thirteen distinct spatial arrangements of these two subunit states in the hexamer ring. We find that distributions of the thirteen hexamer conformational patterns for two KaiC phosphorylation mutants can be fitted quantitatively by an Ising model, which reveals a significant cooperativity between neighboring subunits with phosphorylation shifting the probability of subunit conformation. Our results show that a KaiC hexamer can respond in a switch-like manner to changes in its phosphorylation level.

We investigated insecticide resistance profiles of field populations of the German cockroach, Blattella germanica (L.), collected from central regions of Thailand. Seven strains (PW, RB, MTH, MTS, TL, AY, and SP) were evaluated with diagnostic doses (DD; 3 × LD95 generated from a susceptible strain) of deltamethrin, fipronil, and imidacloprid using topical assays and compared with a susceptible strain (DMSC). Results showed fipronil (2–27% mortality), deltamethrin (16–58% mortality), and imidacloprid (15–75% mortality) resistance in the field strains. Synergism studies with piperonyl butoxide (PBO) and S,S,S-tributyl phosphorotrithioate (DEF) in combination with the DD of insecticides significantly increased (P < 0.05) mortality of the test insects of the field strains suggesting the involvement of P450 monooxygenase and esterase pathways of detoxification. Gel bait evaluations demonstrated that all field-collected strains were resistant to Maxforce Forte (0.05% fipronil), Maxforce Fusion (2.15% imidacloprid), and Advion Cockroach Gel Bait (0.6% indoxacarb) with mean survival times ranging from 1.87–8.27, 1.77–11.72, and 1.19–3.56 days, respectively. Molecular detection revealed that the Rdl mutation was completely homozygous in all field-collected strains except in the PW strain. Field-collected strains were screened for 3 voltage-gated sodium channel (VGSC) mutations associated with pyrethroid resistance. The L993F mutation was present in 5 strains, but no C764R and E434K mutations were detected.

Due to their mutualistic relationship with plant pests, the Argentine ant is considered a major pest in subtropical fruit orchards and vineyards. Besides insecticide sprays, liquid baiting has been demonstrated as an effective method to suppress the Argentine ant populations. To improve the economic feasibility of liquid baiting, hydrogel materials have been recently tested as a carrier for liquid baits containing various insecticidal active ingredients. Here, we tested boric acid as a toxicant in the aqueous sugar bait delivered in a biodegradable calcium alginate hydrogel. Laboratory tests demonstrated that boric acid (1%) liquid bait incorporated in the calcium alginate hydrogel effectively killed Argentine ant workers. Potassium sorbate (0.25%) added to the liquid bait as a preservative did not impact the efficacy of boric acid even though it significantly reduced the degree of swelling of the hydrogel beads in the bait solution. Testing with 2-month-old bait suggested that long-term storage might impact bait efficacy even with potassium sorbate preservative.

Microbial secondary metabolites continue to provide a valuable source of both chemical matter and inspiration for drug discovery in a broad range of therapeutic areas. Beyond this, the corresponding microorganisms represent a sustainable modality for biotechnological production of structurally complex molecules at the quantities required for drug development or even commercial manufacturing. Chromobacterium vaccinii, which has recently been reported as a producer of the pharmacologically highly important Gq inhibitor FR900359 (FR), represents such an example. The characterization of an orphan biosynthetic gene cluster (BGC) located directly downstream of the frs BCG led to the discovery of eight new lipopeptides, valhidepsins A-H (1-8), produced by C. vaccinii. Their chemical structures were elucidated through analysis of 1D and 2D NMR data and high-resolution MS/MS fragmentation methods. The valhidepsins did not display significant antibiotic nor cytotoxic activities but showed surfactant properties. The cluster-compound correlation was demonstrated by generation of a knockout mutant, which abolished production of valhidepsins. This knockout mutant yielded a significantly increased isolated yield of FR.

Cyanobacteria rely on a circadian oscillator system of proteins, KaiA, KaiB and KaiC, to regulate a variety of cellular processes. Powered by ATP phosphorylation, KaiA and KaiB proteins alternately bind to KaiC, resulting in the cyclical assembly and disassembly of KaiC-KaiB complexes. By biotinylating KaiB monomers, we repurpose the KaiC-KaiB complexes to function as crosslinkers with unique time-dependent properties. To demonstrate the efficacy of these ‘circadian crosslinkers’, we design suspensions of streptavidin-coated colloids that exhibit time-dependent structural changes driven by the oscillatory assembly and disassembly of KaiB-KaiC complexes. Further, using fluorescence microscopy, image analysis and biochemical assays, we show that the rate, efficacy and oscillatory signature of crosslinking can be tuned by altering the phosphorylation state of KaiC. Our findings demonstrate that a model circadian oscillator can drive time-varying restructuring of abiotic colloidal suspensions, providing new biochemical machinery for developing self-directed, programmable, and reconfigurable biomaterials. This work may one day enable engineers to incorporate biochemical circadian clocks into future exosuits, infrastructure, and deep sea and space exploration equipment.

Composed of only three proteins, KaiA, KaiB, and KaiC, the cyanobacterial circadian clock is the simplest known biochemical oscillator that can be reconstituted in vitro. While the molecular mechanism of the three proteins has been studied in depth, how they are connected to the rest of the cellular physiology remains unclear. In order to identify previously unknown players in the broader network of the circadian system, we performed a coimmunoprecipitation (co-IP)/mass spec experiment on S. elongatus PCC 7942 cell lysate. Using KaiB in its nighttime form (fold-switched KaiB) as bait, we identified a novel clock interactor protein we named Kai-Interacting Diguanylate cyclase A (KidA), which is predicted to have four N-terminal PAS domains and C-terminal GGDEF/EAL domains. We found that KidA shortens the period of the in vivo rhythms in a dose-dependent manner and alters the entrainment to light-dark cycles. We found that an N-terminal triple-PAS domain fragment is sufficient for the period-shortening phenotype. Consistently, adding purified triple-PAS fragment to the in vitro Kai oscillator reconstituted the dose-dependent shortening of the period. Our in vitro co-IP showed that the N-terminal PAS domains of KidA can directly and specifically bind to the fold-switched form of KaiB. To understand the potential mechanism, we used a computational modeling approach where a fold-switched KaiB binder was added to the Kai oscillator model. The results showed that KidA can tune the period by shifting the equilibrium of KaiB fold-switching. The discovery of KidA suggests a potential role of PAS domain in prokaryotic timekeeping, which has been well documented only in eukaryotic clock systems. Future studies could unveil more potential of KidA, such as integration of time-of-day information and other signals via multiple PAS domains and regulation of cellular processes via cyclic-di-GMP.

Actin is a key component of the cytoskeleton responsible for vital functions ranging from motility to structural support of cells. This multifunctionality is due, in large part, to the dynamic polymerization of actin monomers into semi-flexible filaments, the depolymerization of filaments into monomers, and the changing lengths of filaments. Polymerization drives cell migration, while depolymerization and turnover mediate cell growth and restructuring. Thymosin-β4 and cofilin are two key actin-binding proteins that promote depolymerization by sequestering actin monomers or severing filaments, respectively. Here, we incorporate thymosin and cofilin into entangled actin networks and monitor the subsequent in situ depolymerization and restructuring via confocal microscopy. We use Fourier image analysis techniques to characterize the time-varying dynamics and restructuring of the networks and map their dependence on the concentrations of actin, cofilin, and thymosin. Our results not only shed light on cellular processes that rely on actin polymerization and depolymerization but also may inspire the engineering of non-equilibrium materials that leverage depolymerization as a route to dynamically transition from gel-like to fluid-like states.