The cohabitation of eusocial insects in nests may involve different strategies that enable stable coexistence. The maintenance of obligatory inquilinism in termites has been attributed to the host species (Constrictotermes sp.) having a low perception of the inquiline (Inquilinitermes microcerus) due to the latter’s limited mobility and peaceful nature. In this study, we tested the hypothesis that aggressiveness in interspecific encounters is reduced when: i) one of the species involved has low mobility, and/or ii) non-nestmate individuals share similar body extracts. We conducted manipulative bioassays to evaluate the proportion of attacks between the host species and target individuals, including both the inquiline and a non-inquiline species (Nasutitermes corniger). The experimental treatments involved manipulating the mobility (immovable or free) and watery body extracts of the target species, as well as varying the host castes. Host and treated target individuals were placed in an arena, and we recorded the time elapsed until the first attack. Hosts and inquilines exhibited low levels of aggression towards each other. The host’s attacks on the inquiline were not influenced by odor or mobility but varied among castes, with greater aggressiveness observed in the presence of host workers. In contrast, the proportion of attacks by the host on non-inquilines was higher when the non-inquiline was free and retained its own odor, followed by a neutral odor, the odor of the inquiline, or that of the host. Our results suggest that low mobility and the acquisition of similar odors can reduce interspecific aggression. These findings contribute to a better understanding of the mechanisms underlying interactions between termites and other eusocial species.

Insect pests pose significant risks to stored grains worldwide, and while synthetic pesticides are effective, they have environmental and health drawbacks. Plant essential oils (EO), with insecticidal properties, offer a promising alternative. This study evaluated the toxicity of Pogostemon cablin (patchouli) EO and its nanoemulsion on nine populations of Sitophilus zeamais, a major pest of stored grain. Fifteen compounds were identified in the EO, of which patchoulol was the major compound (55.04 %). The EO was tested through topical, contact, and fumigation exposures. Repellency and population growth effects were also assessed. The EO demonstrated fast insecticidal action, with an average median lethal time (LT50) of 53 h. All populations showed similar responses, with the Vi & ccedil;osa population being the most susceptible, and Sete Lagoas the most tolerant. EO and nanoemulsion concentrations required to cause 50 % mortality ranged from 0.30 to 6.37 mu L mL(-1) (contact) and 0.029-0.037 mu L mL(-1) (fumigation). The EO and its nanoemulsion were effective repellents against the Vi & ccedil;osa population at LC50 and LC70 levels across all exposure times. For the Sete Lagoas population, repellency was also observed, except for LC50 at 4, 6, and 8 h, and LC70 after 24 h. Increasing nanoemulsion concentrations reduced reproductive index (ri) and grain consumption in both populations. Population decline (ri < 0) began at 50.15 mu L kg(-1) (Vi & ccedil;osa) and 67.29 mu L kg(-1) (Sete Lagoas). These results highlight the potential of P. cablin EO for managing S. zeamais in stored grain.

Global climate change and the accelerated urbanization process of coastal habitats have resulted in a drastic reduction in biodiversity, including lepidopteran fauna. Restinga areas have been strongly impacted by urbanization, but data on species composition, endemism, or extinction risks, mainly for its entomofauna, remains scarce. Studies involving Lepidoptera communities are fundamental to management and conservation plans of insect fauna and the ecosystem services. In this study, we evaluated whether seasonal variations influence the community structure of diurnal butterflies and moths at the Restinga of Barreto Municipal Natural Park (PNMRB) in Macaé, Rio de Janeiro, Brazil. We actively searched for butterflies and diurnal moths between 2019 and 2020 and captured them using an entomological net. We tested whether species richness and abundance varied between different periods of the day (morning and afternoon) and seasons (dry and rainy season). We sampled a total of 236 individuals representing 40 butterflies and diurnal moth from eight families. Species abundance and richness were higher during the dry season, when average temperature, relative humidity and rainfall are lower. We observed two peaks of species abundance during the day, one at 10:00 am and the other at 2:00 pm. Nymphalidae was the family with the greatest richness and abundance and the most abundant species were Ascia monuste orseis (Godart 1819), Heliconius sara apseudes (Hubner 1813) and Dryas iulia alcionea (Cramer 1779). The lepidopteran fauna of PNMRB presented a clear seasonal pattern, showing that climatic fluctuations related to variations in average temperature and rainfall can negatively affect this important group of pollinating insects. The survey of Lepidoptera diversity in the PNMRB can increase the knowledge about climatic effects on the temporal distribution and conservation of Neotropical Lepidoptera.

Leaf‐cutting ants (LCAs) are abundant and cause considerable damage to agricultural and forest crops in the Neotropical region and are commonly controlled using sulfluramid‐based ant baits. However, this active ingredient is a precursor of perfluorooctane sulfonic acid (PFOS), a persistent, human‐made pollutant that poses serious environmental and health risks. Several studies have highlighted more natural alternatives to conventional pesticides as a strategic approach for safer management. In this context, the aim of the present study was to conduct a review through scientific, technological and molecular mapping of the main plant species and their major compounds used in the alternative control of LCAs using plant essential oils (PEOs). Seven plant families used for the extraction of PEOs were identified: Aristolochiaceae, Euphorbiaceae, Lamiaceae, Myrtaceae, Piperaceae, Verbenaceae and Winteraceae. Additionally, 28 patents related to the use of PEOs against pest insects, including LCAs, were identified. Although Brazil has the highest number of scientific publications on this topic, the number of registered patents does not follow the same trend. This review emphasizes the need to translate scientific knowledge into technological solutions to make alternative products available for the control of LCAs. This is essential to uphold the commitment made under the Stockholm Convention, which seeks to eliminate or restrict the use of Persistent Organic Pollutants.

Leafcutter ants are one of the most destructive and economically important herbivores in both forest and agricultural crops, due to their abundance and wide distribution. The most used method for controlling this pest is still through synthetic formicides, due to their high efficiency. However, essential oils represent an alternative, as they are biodegradable and selective and have a toxic effect on a wide range of organisms, including leafcutter ants. The combination of insecticidal activity of a product and possible fungicidal activity constitutes an effective strategy against these insect pests, since both agents of this mutualistic interaction (both organisms are benefited) are affected, ensuring quicker collapse of the colony. The aim of this study was to evaluate the insecticidal and fungicidal activity of Cymbopogon citratus essential oil applied on Atta sexdens colonies under laboratory conditions. A nebulized spray system with three concentrations (15, 30 and 60%) and a control treatment were used to evaluate the effect of C. citratus on A. sexdens colonies. The C. citratus essential oils showed both insecticidal activity against the leafcutter ants (A. sexdens) and fungicidal activity against their symbiotic fungi. Colonies exposed to this essential oil showed considerable reduction in the weight of fungal mass, and mortality of both the queen and worker ants, which proves to be promising for the development of new insecticides for management of this insect pest.

The coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae), is one of the most important coffee pests, and is present in almost all countries producing this crop, causing annual losses of US$350 million. Natural factors regulate H. hampei populations in coffee crops. Ecological life table analysis is a robust tool that allows the estimation of the mortality caused by these factors. Therefore, the main objective of this study was to determine the critical stage and the key mortality factors affecting H. hampei in the field. Data for constructing life tables were collected over 2 years in six coffee plantations in the regions of Paula C & acirc;ndido and Vi & ccedil;osa, Minas Gerais State, Brazil. The average mortality of H. hampei was 75.34% +/- 5.85%. The mortality at each developmental stage was 24.32% +/- 2.83% (eggs), 7.29% +/- 1.01% (first instar), 11.58% +/- 1.46% (second instar), 9.68% +/- 1.10% (third instar), 7.45% +/- 1.01% (pupa), and 15.02% +/- 1.29% (adult; n = 124). The mortality factors observed and quantified in this study were parasitism by Prorops nasuta (Hymenoptera: Bethylidae), predation by ants (Crematogaster spp., Pheidole spp. and Solenopsis spp.), physiological disorders and fungal infection by Beauveria bassiana and Metarhizium anisopliae. The critical mortality stage of H. hampei was the adult stage. The key factors for mortality of H. hampei adults were predatory ants, followed by B. bassiana and malformations (these insects had deformities in the head, wings, legs, or abdomen). This information is essential to conserve the activities of natural enemies and, thus maintain H. hampei natural mortality factors in coffee plantations, reducing damage to the crops and the need for excessive insecticide interventions.

The citrus blackfly (CBF), Aleurocanthus woglumi Ashby, is an exotic pest native to Southeast Asia that has spread rapidly to the world’s main centers of citrus production, having been recently introduced to Brazil. In this study, a maximum entropy niche model (MaxEnt) was used to predict the potential worldwide distribution of CBF under current and future climate change scenarios for 2030 and 2050. These future scenarios came from the Coupled Model Intercomparison Project Phase 6 (CMIP6), SSP1-2.6, and SSP5-8.5. The MaxEnt model predicted the potential distribution of CBF with area under receiver operator curve (AUC) values of 0.953 and 0.930 in the initial and final models, respectively. The average temperature of the coldest quarter months, precipitation of the rainiest month, isothermality, and precipitation of the driest month were the strongest predictors of CBF distribution, with contributions of 36.7%, 14.7%, 13.2%, and 10.2%, respectively. The model based on the current time conditions predicted that suitable areas for the potential occurrence of CBF, including countries such as Brazil, China, the European Union, the USA, Egypt, Turkey, and Morocco, are located in tropical and subtropical regions. Models from SSP1-2.6 (2030 and 2050) and SSP5-8.5 (2030) predicted that suitable habitats for CBF are increasing dramatically worldwide under future climate change scenarios, particularly in areas located in the southern US, southern Europe, North Africa, South China, and part of Australia. On the other hand, the SSP5-8.5 model of 2050 indicated a great retraction of the areas suitable for CBF located in the tropical region, with an emphasis on countries such as Brazil, Colombia, Venezuela, and India. In general, the CMIP6 models predicted greater risks of invasion and dissemination of CBF until 2030 and 2050 in the southern regions of the USA, European Union, and China, which are some of the world’s largest orange producers. Knowledge of the current situation and future propagation paths of the pest serve as tools to improve the strategic government policies employed in CBF’s regulation, commercialization, inspection, combat, and phytosanitary management.

Termite colonies are protected by the physical structure of the nest as well as by an elaborate system of recognition against intruders. Nevertheless, the defensive system does not always prevent colonization of termite nests by other species. Here, we analyzed whether the host-inquiline cohabitation could occur through mechanisms related to the specificity of chemical cue acquisition by inquilines or through avoidance, testing the hypotheses that (i) there is lower survival and greater aggressiveness between host and inquiline coming from different nests than between those from the same nest; (ii) there is lower survival between host and inquiline coming from the nests of different locals than between those species from the same local; and (ii) intestinal or body cues may be repellent for inquilines or hosts. Manipulative bioassays were conducted pairing hosts and inquilines coming from the same and different nests. Our results showed that although there was greater mortality of the host and inquiline in close contact, they showed mutual recognition of cues without displaying any aggressive behavior. The host was attracted by inquiline body cues and the inquiline was attracted by the host’s intestinal and body cues. Hosts did not distinguish inquilines from different nests in the same locality; however, inquilines seemed to be more habituated to their own host nests than to other nests. Our results suggest that local and genetic factors may be related to cues involved in this coexistence. Therefore, under natural conditions, we hypothesized that mechanisms, such as segregation and camouflaging, could maintain cohabitation.

Leaf-cutting ants are important pests of agricultural and forest crops. Currently, few insecticides are registered for the control of these insects. Natural bioactive molecules can serve as models for the synthesis of new insecticidal compounds. Such ant killer products must be sustainable and efficient, considering not only lethal effects, but also sublethal effects, which can interfere with behavior and communication between colony members. In this study, we analyzed the toxicity of the monoterpene thymol and its derivatives, as well as the sublethal effects of these compounds on the behavior of the leaf-cutting ant Acromyrmex balzani. These effects were compared with the conventional synthetic insecticide deltamethrin. Although deltamethrin showed higher toxicity (LD50 = 0.87 × 10−5 µg/mg), all other tested compounds increased ant mortality, with thymyl chloroacetate being the most toxic derivative (LD50 = 1.41 µg/mg), followed by thymol (LD50 = 2.23 µg/mg). These three most toxic compounds interfered differentially in the behavior of ants. Thymyl chloroacetate caused increased self-cleaning and reduced allogrooming, which may be related to an attempt to avoid contamination between nestmates. In general, thymol caused greater avoidance among ants, reduced walking speed and caused disorientation in workers. On the other hand, thymyl chloroacetate (LD30) considerably increased the walking speed of the group, without changing the orientation of the individuals. Such changes may interfere with basic activities such as foraging and altering colony cohesion via different mechanisms. Thus, despite the desirable effects of deltamethrin on ant control, this insecticide is highly toxic and should be discontinued soon. Our results show that thymol and its structural modification in thymyl chloroacetate may represent potential ant killers to be used in the management of A. balzani.

Abstract The cohabitation in nests of eusocial insects may involve different strategies that allow the stable coexistence. Here, we investigated the role of mobility and whole body odors in interspecific encounters in termites. Specifically, we tested the hypothesis that aggressiveness is reduced in interspecific encounters when: i) one of the involved species has low mobility; and/or ii) non-nestmate individuals share similar whole body odor. Manipulative bioassays were conducted to evaluate the proportion of attacks between the host species (Constrictotermes sp.) and target individuals: inquiline (Inquinitermes microcerus) and non-inquiline species (Nasutitermes corniger). The treatments consisted of the manipulation of combinations between the mobility (immovable or free) and odor of the target species and variation in host castes (S: soldier, W: worker, or S + W: both castes). For odor manipulation, the body watery extract was used to treat the species with each other's odors. Host and treated target individuals were inserted into the arena to determine the time elapsed until the first attack. Hosts and inquilines exhibited low aggression towards each other. The host's attack on the inquiline varied only among castes, with greater aggressiveness in the presence of the host worker (W or S + W). The proportion of attacks by the host on non-inquilines, and vice versa, was greater when the non-inquiline was free and had its own odor, followed by a neutral odor, the odor of inquiline, or the host. Our results suggest that low mobility and acquisition of similar odors can reduce interspecific aggression. These results contribute to the understanding of the mechanisms involved in the interactions between termites and other eusocial species.

There has been an excitement toward novel eco-friendly alternatives to pest management, particularly formulations based on essential oils (EOs). Here, the biological activity of an EO-based emulsion derived from patchouli, Pogostemon cablin, was assessed against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), a devastating and invasive pest in tomato crops worldwide. Laboratory bioassays were carried out to determine and compare lethal doses, lethal times, oviposition of treated individuals, and oviposition of T. absoluta on treated leaves of tomato to pure patchouli essential oil or its emulsion containing 18% of oil. The LD50 were 10.06 and 2.57 µg of patchouli per mg of insect for the EO and emulsion, respectively. Oviposition was reduced in adults derived from the second instar treated with LD10 by 78.5% (EO) and 85.4% (emulsion). The EO and its emulsion conferred similar avoidance to adults when sprayed on tomato leaves. Therefore, both formulations present similar lethal and sublethal effects against T. absoluta. This study demonstrated a remarkable potential of an emulsion containing 18% of P. cablin oil to be employed for T. absoluta management on tomato crops. Further studies are needed to assess and guarantee open field applications.

Characteristics of preferred or alternative host plants can impact the population dynamics of polyphagous insects. Chrysodeixis includens has become an important pest in economically important crops such as sunflower, cotton, soybean, and beans. In the present study, we evaluated the effects of basil cultivars Ocimum basilicum (alternative host) on C. includens. For this, larvae were fed daily with bean leaves (preferred host-control) and five basil cultivars (Maria Bonita, Mr. Burns, Italian Large Leaf, Vermelho Rubi, and Cinnamon). Subsequently, development, survival, pupae body mass, reproductive parameters, and life table parameters of insects were evaluated. The populations of C. includens fed with leaves of the Italian Large Leaf cultivar showed similar performance to the preferential host (beans). The other host plants prolonged the duration of the larval stage and negatively affected the reproductive and demographic parameters of C. includens. Mr. Burns negatively affected the development and reduced the reproductive potential of the insect. The cultivars Maria Bonita, Vermelho Rubi, and Cinnamon had a negative effect on the development and reproductive potential of this insect. The results indicate that basil cultivars have a negative effect on the development, longevity, and reproduction of C. includens. The use of basil host plants may be a safe alternative to be used concomitantly with other strategies for the management of C. includens.

Nests of the termite Constrictotermes sp. can be cohabited by obligatory inquilines Inquilinitermes sp. Recent studies have shown that inquilines establish themselves in mature nests, possibly during the nidification transition phase of the colony (e.g., from the epigeal to the arboreal habit). It is believed that cohabitation is maintained through spatial segregation of the cohabitants since the inquilines aggregate in the central nest region. Here, we described the cohabitation between Inquilinitermes microceus (Silvestri) and a Constrictotermes species in Sergipe, Northeast Brazil. We compared the cohabitation observed in distinct regions considering hypotheses related to the entry and maintenance of the inquiline in the nests. All Constrictotermes sp. nests found in this region are epigeal, unlike already reported in other studies. Approximately 45% of the nests analyzed were associated with I. microcerus, and cohabitation seemed to be dependent on nest size. The entrance of the inquiline was not related to changes in the nidification habit from soil to trees, as suggested in other studies. In addition, inquilines were not associated with and segregated into the dark walls in the central part of the nest. The cohabitation observed here could involve mechanisms which are distinct from the mechanisms reported in other regions.

Ants belonging to the genus Solenopsis are highly significant invasive pests worldwide. The control of these insects has historically relied on the use of synthetic insecticides, which, unfortunately, has led to a range of ecological repercussions. In light of these challenges and the limited availability of registered products for managing these pests, our study set out to synthesize and assess the insecticidal properties of carvacrol derivatives. The lethal and sublethal effects caused by these derivatives were compared to the essential oil of Lippia gracilis (50.7% carvacrol) and to the base molecule—carvacrol. Carvacryl benzoate was the most toxic derivative to Solenopsis sp., with an LD50 of 3.20 μg/ mg. This compound was about 2 and 7.6 times more toxic than carvacrol at the doses needed to kill 50 and 90% of populations, respectively. The workers of Solenopsis sp. showed a rapid reduction in survival when exposed to carvacrol (LT50 = 8.43 h) and carvacryl benzoate (LT50 = 8.87 h). Insects treated with sublethal doses of the compounds did not show significant effects on self-cleaning, allogrooming and aggregation, with the exception of those treated with L. gracilis essential oil. The oil increased self-cleaning and reduced allogrooming and aggregation. Ants treated with carvacrol and carvacryl benzoate travelled greater distances and had higher movement speeds when compared to the control. These compounds exhibited decreased meanders and angular velocities. When live workers were exposed to dead individuals at the LD90 of the compounds, carvacryl benzoate was the derivative that most reduced survival due to horizontal transfer. These findings underscore the considerable potential of carvacrol derivatives, specifically carvacryl benzoate, as an alternative approach to managing ants of the Solenopsis genus.

Maize (Zea mays) is the most consumed food in the world. The leafhopper, Dalbulus maidis, (Hemiptera: Cicadellidae) is one of the most important maize pests, and due to its direct and indirect damage, it can cause losses of up to 100%. Sampling plans are essential components for integrated pest management programs. The first two components to be determined in these plans are the sampling unit and the sampling technique. The sampling unit consists of determining the plant organ to be evaluated in the sampling and the techniques are the devices used to sample populations of pests in crops. Thus, the objective of this work was to select the unit and technique to be used in the sampling of D. maidis in maize crops. For this purpose, pest populations in plants at stages V4, V6, V8, and V10 were monitored in 16 commercial crops in the Atlantic Forest and Cerrado biomes over two years. The sample units studied were the leaves at different positions in the canopy of the plants. The techniques studied were direct counting, shaking the apex of the plants in a plastic tray and using a beating cloth. In the process of selecting the unit and technique to be used in sampling populations of pests in crops, adequate criteria must be used. These criteria include precision, representativeness, sampling time and that the use of these components in the sampling plans should not cause damage to the plants. The most suitable sampling unit for evaluating these pest populations was the whorl leaves and the best technique was the direct counting. Therefore, the unit and technique selected in this work can be used in sampling plans for D. maidis in maize crops.

The global search for eco-friendly and human-safe pesticides has intensified, and research on essential oils (EOs) has expanded due to their remarkable insecticidal activities and apparent human-safe. Despite this, most of the literature focuses on short-term and simplified efforts to understand lethal effects, with only a few comprehensive studies addressing sublethal exposures. To fill this shortcoming, we explore the lethal and sublethal effects of Pogostemon cablin (Lamiaceae) EO and an EO-based emulsion (18%) using the coffee berry borer Hypothenemus hampei Ferrari (Coleoptera: Curculionidae: Scolytinae) as a model. First, we determine the toxicity of EO and EO-based emulsion using dose-mortality curves and lethal times. Second, we subjected adult females of H. hampei to sublethal doses to assess whether they affected their behavior, reproductive output, and histological features. Our findings reveal that patchoulol (43.05%), α-Guaiene (16.06%), and α-Bulnesene (13.69%) were the main components of the EO. Furthermore, the EO and its emulsion had similar toxicity, with dose-mortality curves and lethal times overlapping 95% confidence intervals. We also observed that sublethal exposure of females of H. hampei reduces reproduction and feeding, increases walking activity, and causes histopathological changes in the midgut. This study advances the knowledge of the lethal and sublethal effects of an eco-friendly substance on insects.Responsible Editor: Giovanni Benelli.

Seabirds use the extensive Brazilian coast as a migratory corridor where they explore resources for food and reproduction. The south coast of the State of Rio de Janeiro has hundreds of islands that are habitats for several species of seabirds. In this study, we analyze the abundance, richness and seasonality of birds stranded in Ilha Grande Bay, Rio de Janeiro, Brazil, an important natural and cultural heritage of humanity. The stranding record data were obtained during 5 years of beach monitoring (2016-2021), a total of 18.7 km of coastline and over 220 km (including islands and beaches outside regular monitoring). Most of the birds were found alive and sent for rehabilitation. A total of 268 seabird strandings were recorded, belonging to five orders, eight families and 19 species. Most strandings occurred in winter, with the most frequent species being Spheniscus magellanicus, Fregata magnificens and Sula leucogaster. Most species are seasonally without stranding pattern, with only six species being added throughout the annual cycle. Ilha Grande Bay is an important tourist pole in Brazil and knowledge of the diversity and dynamics of seabirds in the region can contribute to species management and conservation plans, in addition to potentialize the implementation of environmental tourism objectives and sustainable exploration of natural resources.

Natural biological control is a key factor that ensures the regulation of insect pest populations in agroecosystems. However, the indiscriminate use of pesticides has compromised this environmental service. Thus, the search for environmentally safe pesticides is an increasing requirement for sustainable food production. In this study, we analyzed the toxicity of essential oils from two accessions (CGR112 and CGR126) of Croton grewioides and its major compounds, methyl eugenol and eugenol, on the soybean pest Chrysodeixis includens. In addition, we investigated the sublethal effects of these compounds on the predatory bug Podisus nigrispinus, analyzing its developmental, reproduction and life table parameters. Essential oils and their major compounds were toxic to C. includens and P. nigrispinus. In general, the presence of eugenol made the essential oil more toxic to the pest and selective to the natural enemy. Eugenol was the most toxic compound for 2(nd) instar larvae of C. includens at LD50, followed by CGR126 essential oil from C. grewioides which was equally toxic at higher doses. The estimated lethal times for essential oils to cause mortality in 50% of the population of C. includens were less than 15 h. There was selectivity of the essential oil of CGR126 accession of C. grewioides at lethal doses above 90%. Although the treatments showed little effect on the development of P. nigrispinus, body mass and reproductive parameters were negatively affected, with the exception of the essential oil of CGR126 accession of C. grewioides. The essential oil of C. grewioides may be a promising active ingredient for the synthesis of new insecticides, which are efficient against C. includens and at the same time are safer for the natural enemy P. nigrispinus.

The success of integrated pest management programs depends on the use of feasible and efficient sampling plans. Considering that the citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), is an important citrus pest, the aim of this research was to develop a conventional sampling plan to assess adult populations of this insect in orange orchards. For this, we defined the sampling unit, number of samples, time and the cost of sampling. The third most apical leaf of the branch was the ideal unit to assess citrus blackfly adult densities and the sampling plan consisted of 58 samples. On average, the plan required 55.26 min to complete and costs US$ 1.78. The sampling plan developed here is an accurate, viable and low-cost tool that can be used in integrated pest managemant programs in orange orchards. Our methods can also be applied to study ecological and geographic parameters of this pest.

BACKGROUND A variety of abiotic and biotic factors promoting seasonal variation in the population of insect pests. Knowledge of the timing and magnitude of these factors is important for the study of population dynamics and the development of efficient pest management programs. Currently, there are few studies regarding Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) seasonal dynamics in tomato cultivation under open field conditions, either with or without insecticide application. This study aimed to investigate the effects of tomato phenology, climatic factors, and insecticide spraying on the seasonal dynamics of T. absoluta in tomato cultivation under open field conditions, using data from monitoring performed for 3 years. RESULTS Insecticide, host plant, and climatic conditions can affect T. absoluta life cycles directly over time, resulting in shifts of peaks of the pest. Insecticides for T. absoluta control reduced injury caused by larvae; however, this was not enough to reduce the density below economic injury levels (EIL) during periods of climatic conditions more suitable for population growth. Tuta absoluta densities surpassed EIL more frequently during the tomato plant fruiting stage. The highest densities of mines and damaged fruits occurred during periods of August to January and September to January in crops without and with the application of insecticides, respectively. Regarding the climatic factors, the highest densities of T. absoluta occurred during periods of increasing air temperature and low rainfall. CONCLUSION This study provides relevant insights into the factors that regulate the dynamics of T. absoluta in tomato cultivation and the decision-making process of control of this pest.