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Resources play an important role in shaping the evolution of plant defensive strategies. How resource availability influences overall phytochemical diversity within species, and how this in‐turn affects herbivore damage is not well understood. Using Monarda fistulosa, a species that produces diverse terpene compounds and distinct chemotypes (i.e. thymol or carvacrol), we addressed three questions: 1) how do phytochemical components (i.e. total concentration, Shannon diversity, and chemotypes) vary between distinct populations from two large, widely separated regions that differ in climate and productivity? 2) How do these components influence attack by different herbivore species? 3) What are the growth costs of higher phytochemical levels in different chemotypes? Seeds were collected from 12 populations spread across two regions that differ in precipitation‐driven productivity, six from a low‐productivity environment in Montana and six from a high‐productivity environment in Wisconsin, and grown in a common garden in Wisconsin. We analyzed terpene concentrations, quantified the number of herbivores and damage, and measured plant above‐ground biomass. Plants from Montana exhibited higher terpene concentrations but lower diversity, whereas those from Wisconsin displayed lower terpene concentrations but higher diversity. Plants from Wisconsin received more damage from a specialist seed predator and leaf‐chewing herbivores, although abundance of a specialist aphid was lower, compared to plants from Montana. Total terpene concentration emerged as the primary predictor of herbivore damage, although some differences were observed between region of origin and with terpene richness. Herbivores exhibited mixed responses to phytochemistry; some herbivores were negatively affected, while a specialized leaf galler responded positively. Costs of producing defenses were evident by negative correlations between plant biomass and total terpene concentration (but not chemical richness or Shannon diversity). Our study revealed that regional differences in productivity can influence the evolution of phytochemical concentration and diversity, which, in turn, affects plant damage and incurs growth‐related costs. [ABSTRACT FROM AUTHOR]

Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) is a polyphagous pest impacting numerous economic crops. This impact is facilitated by its long-range dispersal capacity, which can lead to the colonization of new cultivated areas in the agricultural landscape and the potential spread of insecticide-resistant populations. Despite these negative implications, it is unclear how ecological and morphological factors influence H. zea flight capacity. Here, we investigated the dispersal capacity and morphophysiological determinants of the flight performance of H. zea. Tethered flight mill experiments were conducted to examine the impact of mating status, age [young (2-day-old), middle-aged (3- to 6-day-old), or old (7- to 9-day-old)], and sex on the flight capacity of moths under controlled conditions. We found that the flight capacity was not influenced by mating status or the number of mature eggs. Males flew faster than females, and middle-aged moths' flight had higher performance (speed, time, and distance) than young and old moths. Body size and wing-to-thorax ratio negatively influenced the moth flight time. Male's body size was larger than females, but they had a smaller forewing area and smaller wing-to-thorax ratio. Middle-aged moths exhibited the highest likelihood of engaging in migratory movements (> 10 km). Finally, oogenesis-flight syndrome was not detected, confirming the hypothesis of facultative migration in this species. Our results enhance our understanding of the factors influencing the flight behavior of H. zea, which can be used to predict the long-range capacity of infestation of this species, and the spread of resistance genes to management tools, such as insecticides and Bacillus thuringiensis (Bt) toxins expressed in transgenic crops. [ABSTRACT FROM AUTHOR]

BACKGROUND: Transgenic Bt technology in soybean, with plants expressing Cry1Ac, has been adopted as an insect pest management tool. It was first adopted in large areas of South America and Asia in 2013. The risk of resistance in target pests to this technology demands insect resistance management (IRM) programs. In Brazil, a structured refuge (area of non‐Bt soybean) planted adjacent to the Bt soybean crop has been an important IRM recommendation, particularly for the primary lepidopteran defoliators Anticarsia gemmatalis (Lepidoptera: Erebidae) and Chrysodeixis includens (Lepidoptera: Noctuidae). The overall goal of this study was to validate IRM recommendations to Bt soybean. The objectives were to document the impact of soybean phenology, cultivar choice and non‐Bt soybean defoliation on moth oviposition. In addition, a mark‐release‐recapture study estimated the dispersal capacity of these species. Five field experiments per species were performed for 3 years. RESULTS: Our results revealed an increase in A. gemmatalis and C. includens oviposition, respectively, on Bt plants as a consequence of the difference in plant growth stage at the time of oviposition. Defoliation of non‐Bt plants significantly increased the oviposition preference of both moth species for Bt plants. The mark‐release‐recapture experiment indicated an average dispersal distance of ~300 m from the release point for A. gemmatalis, with maximum recapture at 1000 m. CONCLUSION: Overall, our findings emphasize the importance of planting synchronization of Bt soybean and the structured refuge. In addition, when operational aspects in large soybean areas challenge this recommendation, the priority should be for planting the refuge area first. This approach will minimize the impact of selective oviposition of A. gemmatalis and C. includens. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background: Schizophrenia (SZ) is a multifactorial chronic psychiatric disorder with a worldwide prevalence of 1%. Altered expression of PLCβ occurs in SZ patients, suggesting alterations in the PLCβ/IP3/Ca2+ signaling pathway. This cascade regulates critical cellular processes in all cell types, including the neuronal lineage; however, there is scarce evidence regarding the functionality of this transduction signaling in neuronal cells derived from SZ patients. Objective: We evaluated the functionality of the PLCβ/IP3/Ca2+ pathway in olfactory neuronal precursor cells (hONPCs) obtained from SZ patients. Methods: Cryopreserved hONPCs isolated from SZ patients and healthy subjects (HS) were thawed. The cellular types in subcultures were corroborated by immunodetection of the multipotency and lineage markers SOX-2, Musashi-1, nestin, and β-III tubulin. The PLCβ/IP3/Ca2+ pathway was activated by GPCR (Gq) ligands (ATP, UTP, serotonin, and epinephrine). In addition, PLCβ and IP3R were directly stimulated by perfusing cells with the activators m-3M3FBS and ADA, respectively. Cytosolic Ca2+ was measured by microfluorometry and by Ca2+ imaging. The amount and subcellular distribution of the PLCβ1 and PLCβ3 isoforms were evaluated by confocal immunofluorescence. IP3 concentration was measured by ELISA. Results: The results show that the increase of cytosolic Ca2+ triggered by GPCR ligands or directly through either PLCβ or IP3R activation was significantly lower in SZ-derived hONPCs, regarding HS-derived cells. Moreover, the relative amount of the PLCβ1 and PLCβ3 isoforms and IP3 production stimulated with m-3M3FBS were reduced in SZ-derived cells. Conclusions: Our results suggest an overall functional impairment in the PLCβ/IP3/Ca2+ signaling pathway in SZ-derived hONPCs. [ABSTRACT FROM AUTHOR]

Two species may share a mutualistic interaction if the benefits gained by the interaction outweigh the costs incurred. In this study, we tested experimentally how the identity of ants (pinned) and floral visitors of an extrafloral nectary (EFN)-bearing plant can affect plant fitness. We quantified ant activity and floral visitor visitation overlap over time, floral visitor behaviour, amount of floral resources collected, and plant fitness as influenced by the ant species identity in an EFN-bearing plant from Brazilian Cerrado savanna, Qualea multiflora (Vochysiaceae). We found that: (i) ant activity and floral visitation overlap greatly in time; (ii) floral visitors vary in their response to the presence of ants; (iii) different ant species have different impacts on floral visitors; (iv) ants affected the amount of floral resources collected by pollinators, but their levels were contingent on ant identity; and (v) plant fitness components (fruit production, seed weight, and seed size) were most strongly affected by the largest and most aggressive ant species. Our results suggest that the balance of the trade-off between the beneficial effects of ant protection against herbivorous insects and the negative consequences for plant fitness by deterring pollinators depends on the species identity of both the ants and the floral visitors to the plant. [ABSTRACT FROM AUTHOR]

Insect migrations have ecological and economic impacts, particularly in agriculture. However, there is limited knowledge about the migratory movements of pests at the continental scale, which is an important factor influencing the spread of resistance genes. Understanding the migratory patterns of economic pests, like Helicoverpa zea (Boddie), is essential for improving Integrated Pest Management (IPM) and Insect Resistance Management (IRM) strategies. In this study, we used stable hydrogen isotopic ratios in wing tissue as a biogeochemical marker to examine migratory patterns and estimate the native origins of H. zea individuals collected across a wide latitudinal gradient in North America. Samples collected at higher latitudes (Ontario, Canada and Minnesota, USA) exhibited a greater proportion (60%–96%) of nonlocal individuals, with an increased probability of origin from the southeastern United States. Populations from mid-latitudes (Florida, North Carolina, and South Carolina) showed a blend of local and nonlocal (40%–60%) individuals. Finally, 15% of the southernmost population individuals (Puerto Rico) were classified as migratory, with some having a probability of origin at higher latitudes (>30°). Overall, our results provide evidence of a northward spring/summer migration of H. zea in North America and underscore the significance of the southeastern United States as a hub for genetic flow. In addition, based on stable hydrogen isotopic ratios, there is strong evidence of reverse (southward) migration of H. zea from the continental United States to Puerto Rico. Our study highlights the implications for IPM and IRM programs and the need for management strategies that account for both northward and southward migration patterns. [ABSTRACT FROM AUTHOR]

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Extrafloral nectarized plants attract ants, which may protect them against herbivory and increase plant fruit set production. In some cases, however, ants are ineffective against herbivores. Such events occur, for instance, when herbivores present adaptations to avoid ant predation. Thus, the outputs of these interactions depend on factors such as ant identity, plant phenology and herbivore features. Here, we investigated the endophytic florivorous beetles' impact on the reproductive success of their host plants, two sympatric Banisteriopsis (Malpighiaceae) species, depending on the action of extrafloral nectaries (EFNs) visiting ants. We experimentally manipulated the presence of ants and herbivores on B. malifolia and B. laevifolia species during their reproductive period to test the effectiveness of ants‐EFNs mutualism on plant fruit set production. We performed treatments where three similar inflorescences were selected to be (I) control branch, with no manipulations, (II) beetle‐free branch, isolated with textile cover and (III) ant‐free branch, isolated at the base with atoxic wax. We hypothesized that endophytic herbivores have a negative impact on the plant reproductive success because they escape the action of ants (biotic defences). As a result, we observed (i) that florivorous Anthonomus beetles have a negative impact on Banisteriopsis reproductive success; (ii) ants fail in protecting plants against floral endophytic beetles; and (iii) most of the results were species‐specific. Our results indicate that these systems present very conditional outcomes that depend on the intrinsic factors of each plant species. [ABSTRACT FROM AUTHOR]

Context-dependence in mutualisms is a fundamental aspect of ecological interactions. Within plant-ant mutualisms, particularly in terms of biotic protection and pollination, research has predominantly focused on elucidating the benefits while largely overlooking potential costs. This notable gap underscores the need for investigations into the drawbacks and trade-offs associated with such mutualistic relationships. Here, we evaluated the role of pericarpial nectaries (PNs) in shaping the dynamics of ant-pollinator mutualisms. Specifically, we investigated whether ants visiting the PN of Palicourea rigida (Rubiaceae) could deter hummingbirds and disrupt pollination, ultimately influencing fruit production. Our research involved manipulative experiments and observation of ant-pollinator interactions on P. rigida plants in the Brazilian savannah. We found that visiting ants can deter hummingbirds and/or disrupt pollination in P. rigida, directly influencing fruit set. However, these results are species-specific. The presence of very aggressive, large predatory ants, such as E. tuberculatum, had a negative impact on hummingbird behavior, whereas aggressive mid-sized ants, such as C. crassus, showed no effects. Our study illuminates the multifaceted aspects of ant-plant mutualisms and underscores the importance of evaluating costs and unexpected outcomes within these ecological relationships. [ABSTRACT FROM AUTHOR]

To preserve ionic homeostasis (primarily Ca2+, K+, Na+, and Cl−), in the airway smooth muscle (ASM) numerous transporters (channels, exchangers, and pumps) regulate the influx and efflux of these ions. Many of intracellular processes depend on continuous ionic permeation, including exocytosis, contraction, metabolism, transcription, fecundation, proliferation, and apoptosis. These mechanisms are precisely regulated, for instance, through hormonal activity. The lipophilic nature of steroidal hormones allows their free transit into the cell where, in most cases, they occupy their cognate receptor to generate genomic actions. In the sense, estrogens can stimulate development, proliferation, migration, and survival of target cells, including in lung physiology. Non-genomic actions on the other hand do not imply estrogen's intracellular receptor occupation, nor do they initiate transcription and are mostly immediate to the stimulus. Among estrogen's non genomic responses regulation of calcium homeostasis and contraction and relaxation processes play paramount roles in ASM. On the other hand, disruption of calcium homeostasis has been closely associated with some ASM pathological mechanism. Thus, this paper intends to summarize the effects of estrogen on ionic handling proteins in ASM. The considerable diversity, range and power of estrogens regulates ionic homeostasis through genomic and non-genomic mechanisms. [ABSTRACT FROM AUTHOR]