Eduardo Soares Calixto

University of Florida | UF · Department of Entomology and Nematology

Phenological studies of Brazilian savanna vegetation have described a generalized phenological pattern for all species, mainly based on rainfall and temperature. Few studies have considered wind as an explanatory factor; abiotic factors may impact differently on phenophases, and one phenophase may influence the performance of another. Thus, we aim...

Plants allocate defences in order to decrease costs and maximize benefits against herbivores. The Optimal Defense Theory (ODT) predicts that continuously expressed (i.e. constitutive) defences are expected in structures of high value, whereas defences that are expressed or that increase their expression only after damage or upon risk of damage (i.e...

Interactions between ants and plants bearing extrafloral nectaries (EFNs) are among the most common mutualisms in Neotropical regions. Plants secrete extrafloral nectar, a carbohydrate‐rich food that attracts ants, which in return protect plants against herbivores. This ant–plant mutualism is subjected to temporal variation, in which abiotic factor...

Mechanisms promoting stable coexistence allow multiple species to persist in the same trophic level of a given network of species interactions. One of the most common stabilizing mechanisms of coexistence is niche differentiation, such as temporal and spatial patchiness. To understand the limits of coexistence between species we have to understand...

Plants have evolved inducible defenses that allow them to minimize costs associated with the production of constitutive defenses when herbivores are not present. However, as a consequence, some plants might experience a period of vulnerability between damage and the onset of defense and/or between the cessation of damage and relaxation of defense....

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....

The invasive land snail Bulimulus bonariensis has become a significant pest in the Southern United States. This pest poses a threat to various crops, including cotton, citrus, and peanut, leading to potential yield losses, irrigation issues, and food contamination. This study investigated the effects of tillage and calcium fertilization on snail po...

Understanding the mechanisms that enable species coexistence is a central question in ecology, as it helps to comprehend species diversity. One of the most common stabilizing mechanisms of coexistence is niche segregation, which can prevent the competitive exclusion of the fittest competitor. Niche segregation can manifest itself at various tempora...

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...

Addressing the ecological impacts of transport corridors while planning any transport network is paramount for a better of understanding ecological processes, biodiversity distribution, and ecosystem resilience. Here, we evaluated the impacts of railway edges on edaphic parameters, plant diversity, and composition in the northwestern Himalaya as a...

Main Animals not only forage for abundant and nearby resources, but their diets can also be influenced by abiotic and geographic factors. This often results in non‐random interactions among species. We investigate how seed density, distance from nest, abiotic (e.g., climate stability, temperature, precipitation) and geographic factors (e.g., latitu...

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 imp...

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...

Helicoverpa zea. Photograph by E.S. Calixto /WFREC/UF. See https://doi.org/10.1093/ee/nvae034 pgs 487-497.

Variations in plant genotypes and phenotypes are expressed in ways that lead to the development of defensive abilities against herbivory. Induced defenses are mechanisms that affect herbivore insect preferences and performance. We evaluated the performance of resistant and susceptible phenotypes of Bauhinia brevipes (Fabaceae) against attacks by th...

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 e...

Climate change is ten times faster now than in the last global warming event, 56 million years ago, with temperature and extreme weather dramatically increasing due to human activity. This rapid changes in climate affect all levels of biodiversity. However, despite their high global biodiversity, only 3 percent of global climate change literature i...

The net outcomes of mutualisms are mediated by the trade-offs between the costs and benefits provided by both partners. Our review proposes the existence of a trade-off in ant protection mutualisms between the benefits generated by the ants' protection against the attack of herbivores and the losses caused by the disruption of pollination processes...

Extrafloral nectaried plants and myrmecophytes offer resources to ants that engage in protective mutualisms. The role of different ant species in herbivore deterrence has long been analyzed by using insect baits, and ants are regarded as effective plant guards if they attack the insects. Here, by performing a literature review, we conducted a compa...

Interactions between plants and herbivores are central in most ecosystems, but their strength is highly variable. The amount of variability within a system is thought to influence most aspects of plant-herbivore biology, from ecological stability to plant defense evolution. Our understanding of what influences variability, however, is limited by sp...

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 draw...

One of the main goals of ecological studies is to disentangle the dynamics that underlie the spatiotemporal distribution of biodiversity and further functions of the ecosystem. However, due to many ecological and geopolitical reasons, many remote areas with high plant species diversity have not been assessed using newly based analytical approaches...

Abstract: Competition is an important biological filter that can define crucial features of species’ natural history, like survival and reproduction success. We evaluated in the Brazilian tropical savanna whether two sympatric and congenereric species, Qualea multiflora Mart. and Q. parviflora Mart. (Vochysiaceae), compete for pollinator services,...

Ants often interact aggressively for resources (e.g. nest sites and food) with members of their own or another species. In these competitive interactions, dominant ant species exert a strong influence on ant species coexistence and plant-associated arthropod community structure. However, few studies have experimentally manipulated the relative abun...

As plantas com nectários extraflorais (NEFs) atraem formigas, que podem protegê-las contra a herbivoria e aumentar a produção de frutos. Em alguns casos, porém, as formigas são ineficazes contra os herbívoros. Tais eventos ocorrem, por exemplo, quando os herbívoros apresentam adaptações para evitar a predação pelas formigas. Assim, os resultados de...

Herbivores often have highly variable impacts on plant fecundity. The relative contribution of different environmental factors operating at varying spatial scales in affecting this variability is often unclear. We examined how density-dependent seed predation at local scales and regional differences in primary productivity are associated with varia...

We assessed the time course of inducibility of indirect defense by ants mediated by extrafloral nectaries (EFNs) in Qualea multiflora (Vochysiaceae) between vegetative and reproductive plant parts and between different levels of foliar damage. We found that the time course of inducibility of extrafloral nectar production and ant abundance follows a...

Weeds are a major threat to agriculture and horticulture cropping systems that reduce yield. Weeds have a better ability to compete for resources compared to the main crops of various agro-ecosystems and act as a major impediment in reducing overall yield. They often act as energy drains in the managed agroecosystems. We studied weed infestation fo...

Extrafloral nectaried plants and myrmecophytes offer resources to ants that may engage in protective mutualisms. The role of different ant species in herbivore deterrence has long been analyzed by using herbivore baits, and ants are regarded as effective plant guards if they attack and/or remove the baits (mostly termites) from plants. Here, we con...

Hemiparasitic plants can directly influence host plants performance through the invasion of the vascular system. However, the extent to which host plants can influence hemiparasitic plants is poorly understood. We investigated the phenology, reproductive components (pollen grains, flower buds, flowers, and fruits), and floral visitors’ composition...

Unraveling how climate change impacts the diversity and distribution patterns of organisms is a major concern in ecology, especially with climate‐sensitive species, such as dung beetles. Often found in warmer weather conditions, beetles are used as bio‐indicators of environmental conditions. By using an altitudinal gradient as a proxy for climate c...

In plants, chemical and mechanical traits are involved in the defense against environmental stressors. In the case of Mimosa plants, touch-sensitive responses through leaf-closure provide a unique form of mechanical defense. While past research has shown that the impacts of stressors such as competition or short-term drought may cause the chemical...

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...

For millennia, ethnic knowledge has been intricately tied to local biodiversity and woven into the fabric of rural communities. Growing scientific evidence suggests that merging ethnic knowledge with new scientific findings can lead to socially acceptable and environmentally friendly approaches essential for the long-term prosperity of local commun...

In an era of climate change, quantifying forest biomass and carbon stock along elevational gradients in moun- tainous areas assumes immediate relevance for carbon budgeting and forest management. Here, we carried out extensive field studies to quantify the tree biomass and carbon stock of major forest types along a wide eleva- tional gradient (350–...

In ant–plant mutualisms mediated by plant-based liquid resources (e.g., extrafloral and pericarpial nectar), third-party exploiters are often present. Usually, the costs of having exploiters species seem to have little to no effect on ant–plant mutualistic interaction. However, little is known about how and to what extent exploiters affect mutualis...

Plants provide extrafloral nectar, which is a food resource taken by ants, especially aggressive species that may act as plant guards. To our knowledge, no study has been conducted to concurrently investigate the fluctuation of plant fitness over its whole reproductive season, recording and comparing both short periods (different samplings during t...

In an era of climate change, quantifying forest biomass and patterns of carbon stock along elevational gradients in mountainous areas are particularly important for carbon budgeting and forest management. Here, we carried out extensive field studies to quantify the tree biomass and carbon stock of 12 major forest types along a wide elevational grad...

Several anthropogenic activities can impact forest carbon (C) dynamics. In the Himalaya, insufficient studies are available on the intensity and impacts of multiple anthropogenic activities on forest C stocks. Here, we studied the changes in tree C stock in temperate forest stands of Kashmir Himalaya due to anthropogenic disturbances. We sampled fo...

Evolutionary ecological studies have postulated that interactions between species are critical drivers of species diversification, in which each type of interaction promotes diversification in different ways. For instance, studies have suggested that antagonistic associations, such as plant–herbivorous insect interactions, can be paramount for the...

Despite the fact that numerous studies have evaluated floristic features of certain regions, there are still inaccessible and understudied places within hotspot, such as the Shishi Koh Valley, Chitral mountain region of the Hindukush. Present study evaluated the taxonomic, ecological and habitat diversity of the plant communities in the study area....

Plant resources have always been valuable in human life, and many plant species are used in medicine, food, and ritual, and resource utilization is closely related to cultural diversity. Our study was conducted from June 2019 to April 2021, during which we aimed to document the local knowledge of plant resources of five ethnic groups, i.e., the Guj...

The current research was carried out to characterize the phytosociology of the forests of one of Pakistan's most valuable tree species (Deodar) across its native range. In this context, our main hypothesis was that, along the altitudinal gradient, we would find different plant communities that would be driven by different environmental variables (c...

By assessing plant species composition and distribution in biodiversity hotspots influenced by environmental gradients, we greatly advance our understanding of the local plant community and how environmental factors are affecting these communities. This is a proxy for determining how climate change influences plant communities in mountainous region...

Road edge effects consist of changes in abiotic and biotic conditions resulting from the new artificial boundaries on the vegetation that are created by a road. It is known that edge effects can have variable direct and indirect influences on the biota, can be species-specific and also site-specific. However, edge effects for most plant species and...

Plant species are distributed in different types of habitats, forming different communities driven by different sets of environmental variables. Here, we assessed potential plant communities along an altitudinal gradient and their associations with different environmental drivers in the unexplored Manoor Valley (Lesser Himalaya), Pakistan. We have...

Elevation plays a pivotal role in determining the diversity and distribution of biodiversity in mountainous landscapes, and therefore macroecological assessment of forest tree vegetation is crucial for developing scientifically-informed forest policy and management. In this study, we investigated the diversity, distribution pattern and regeneration...

The mutualism of ants and extrafloral nectary (EFN)-bearing plants is known to reduce rates of herbivory. However, ants may have negative impacts on other mutualisms such as pollination, constituting an indirect cost of a facultative mutualism. For instance, when foraging on or close to reproductive plant parts ants might attack pollinators or inhi...

Predatory social wasps are well studied in several aspects; however, foraging behaviour, especially that which takes place away from the nest at often unpredictable locations, or specialized behaviours to find and subdue prey are not well understood. In the Brazilian tropical savanna, the Polistinae wasp Brachygastra lecheguana is specialized in pr...

Citation: Haq, S.M.; Yaqoob, U.; Calixto, E.S.; Kumar, M.; Rahman, I.U.; Hashem, A.; Abd_Allah, E.F.; Alakeel, M.A.; Alqarawi, A.A.; Abdalla, M.; et al. Long-Term Impact of Transhumance Pastoralism and Associated Disturbances in High-Altitude Forests of Indian Western Himalaya. Sustainability 2021, 13, 12497. https://doi.

The ecotonal zones support populations that are acclimated to changing, fluctuating, and unstable conditions, and as a result, these populations are better equipped to adjust to expected change. In this context, a hypothesis was tested that there must be vegetation dominated by unique indicator plant species under the influence of ecological gradie...

The nomadic pastoral indigenous communities of the Ladakhi people share roots with Tibetan culture in terms of food, clothing, religion, festivals, and habits, and rely widely on plant resources for survival and livelihood. This survey was conducted during 2020–2021 to document the indigenous knowledge about plant resources of the Balti, Beda, and...

Wild animals that feed on garbage waste are a problem in ecological parks as it can substantially alter their food ecology. Wild coatis that occupy human recreation areas in parks are often observed feeding on garbage, but the ecological consequences are scarcely known. Forty-four fecal samples from females and 12 from males of wild coatis living i...

Protected areas are contributing people's livelihoods and working as the backbone of all forms of biodiversity conservation. The reformed rules and the legal local protection have come up as a means of conserving trees and associated diversity of life throughout the world. But due to the anthropogenic pressures and climate change especially in the...

Globally, biodiversity-rich forest ecosystems are facing higher risk of climate and land-use changes. Therefore, understanding the role of anthropogenic factors in affecting forest community composition and vegetation patterns assume urgent research priority and are prerequisites for conservation and sustainable management of forest ecosystems. We...

Epidermal micro-morphological investigations have drawn the consideration of many researchers because of their taxonomic usefulness, but their relationship with environment is not completely known. Keeping this in view, quantitative leaf epidermal features (number of epidermal cells and stomata, and stomata length and width) were examined in the sp...

There is increasing evidence that the outcomes of mutualistic interactions between ants and plants bearing extrafloral nectaries (EFNs) are context‐dependent. In particular, the total number, density, and size of EFNs, as well as the abundance and identity of ants attending host plants, are considered as key factors determining the nature and stren...

The physical structure of vegetation and species composition determine the storage potential of biomass and strong influence on the regional and global carbon cycle. The present study was to assess the tree structural attributes including diversity, stem density, biomass and C stocks in the forest types of Kashmir Himalaya. The highest amount of to...

Traditional knowledge on plants and their uses by tribal indigenous culture is helpful in the conservation of biodiversity. During 2017-2018, ethnobotanical investigations of the plants growing in Neelum Valley in District Bandipora (a part of Kashmir Himalaya) were carried out to collect information regarding different usages of the plants species...

The concept of ecosystem engineering, although more often used to describe the effects of a single organism on its environment, can also be applied to plant-animal interactions in order to better understand their non-trophic effects on ecosystems. Here, we provide justification for and examples of how the ecosystem engineering concept has been and...

AimThe outbreak of the new coronavirus pandemic (SARS-CoV-2) was initiated in December 2019, and within a couple of months it became a global health emergency. Given the importance to assess the evolution and transmissibility of SARS-CoV-2 and to forecast the next scenario of the pandemic, mainly in countries with limited healthcare systems, we est...