Debora Barbosa Lima

Chemical contaminants can disrupt predator-prey dynamics in agroecosystems, particularly through intraguild predation (IGP), a key interaction influencing population structure and dynamics. The objective of this study was to investigate intraguild predation between Amblyseius largoensis (Muma) and Euseius alatus DeLeon (Mesostigmata: Phytoseiidae), with particular emphasis on how an extraguild food resource (pollen), sublethal exposure to the acaricide abamectin, and their combined effects influence predator feeding behavior, oviposition, and population dynamics. Adult females of both predators were exposed to intraguild prey (eggs and larvae) in the presence or absence of extraguild food (pollen) and abamectin residues. In addition, population-level experiments were conducted to evaluate long-term interaction outcomes. Experimental results revealed that both feeding activity and oviposition of the two predator species were significantly affected by the presence of pesticide residues and the availability of pollen as an extraguild food source. Population dynamics assays indicated that A. largoensis was the dominant species; however, exposure to pesticide residues reduced the longevity of both predator populations.

Phoresy, a common dispersal strategy among arthropods, involves complex relationships between hosts and symbionts that influence ecological dynamics. Investigating the structure of phoretic mite communities and their population fluctuations is particularly relevant for widely distributed agricultural pests, such as the coconut palm weevil, Rhynchophorus palmarum . This study investigated the community of phoretic mites associated with R. palmarum in its native Neotropical range, aiming to characterize population patterns, evaluate the influence of host attributes, and analyze interspecific dynamics. A total of 14 mite taxa were recorded, all exhibiting high prevalence and strong aggregation. The mite Centrouropoda cf. brasiliana stood out as the dominant species, with individual loads exceeding 2,800 mites per beetle. Although host sex and body size did not affect total phoretic load, body size selectively influenced the abundance of certain taxa ( Lasioseius sp., Macrocheles mammifer , Gamasina sp. 1, and Crenamargo binuseta ). The temporal variation of C. cf. brasiliana were negatively modulated by C. binuseta and Rhynchopolipus rhynchophori , suggesting mechanisms of competitive exclusion or microhabitat partitioning. These findings highlight a complex community in which biotic interactions play a central role in structuring the phoretic acarifauna of R. palmarum , emphasizing the need for further investigations into the functional effects of these relationships.

Odour and contact chemical traces play central roles in the sexual communication of mites, mediating partner encounter and recognition of the female reproductive status. We investigated the mating behavior of Raoiella indica Hirst and the role of female-associated chemical cues in male attraction. Behavioral observations were conducted under controlled laboratory conditions, and three complementary bioassays were performed: (i) detailed recording of courtship and copulation sequences, (ii) two-choice tests to evaluate male preference for arenas associated with females at different reproductive stages, and (iii) assays testing male responses to substrate-borne traces left by females. Our objective was to describe the mating sequence of R. indica and assess how odor and contact traces contribute to male. Mating followed a stereotyped sequence composed of four stages. Males showed preference only for arenas associated with teleiochrysalis females, whereas no preference was observed for virgin or mated adult females. In contrast, males were attracted to traces left by virgin females but not to those left by recently mated females. These results indicate that male orientation in R. indica is mediated by stage-specific chemical cues and that contact traces provide reliable information about female reproductive status. Overall, our findings expand knowledge of chemical communication and mating strategies in R. indica , offering new insights into the behavioral ecology of tenuipalpid mites.

Bioclimatic variables are ecologically sensitive indicators that help define the physiological tolerance limits of animals. Mites, being minute organisms, often face constraints due to their limited mobility, restricting them to narrow environmental ranges. Nonetheless, certain species, such as the red palm mite (RPM), Raoiella indica Hirst, exhibit efficient dispersal capacities. This phytophagous invasive mite commonly disperses via wind currents, especially during dry periods. However, abandoning the host plant carries risks, as individuals may become exposed to adverse environmental conditions. In this study, we examined how temperature and relative humidity, combined with different substrates—host plants (Cocos nucifera), non-host plants (Canavalia ensiformis), and inert material (plastic pots—Bio-Serv incorporation cells)—affect the survival of R. indica. Our findings were: (1) elevated temperatures and low humidity significantly decreased R. indica survival when away from the host plant; (2) under tropical-like conditions (27 °C and 75% RH), mites survived for an average of 3.5 days; and (3) in greenhouse settings, R. indica longevity was 53 days on the host plant, 1 day on the non-host plant, and 3 days on inert material. These results indicate that both climatic conditions and substrate type critically influence R. indica survival following dispersal events.

The red palm mite (RPM), Raoiella indica Hirst (Acari: Tenuipalpidae), is an invasive species in several American countries and has a wide range of hosts, causing significant damage, mainly to coconut and banana crops. Previous studies conducted in America have focused on the biological control of RPM through predatory mites and insects. Stethorus tridens Gordon (Coleoptera: Coccinellidae) is considered a promising biocontrol agent of phytophagous mites it has been observed on several cultures, and has a high predatory capacity. The aim of this study was to investigate S. tridens preferences among different developmental stages of RPM and estimating the functional and numerical responses of S. tridens over its most preferred prey-stage. Furthermore, the prey preference of S. tridents was examined between eggs of Tetranychus evansi Baker and Pritchard (its natural prey) and eggs of RPM through two-choice and non-choice experiments. The results showed that S. tridens prey on all developmental stages of RPM, with a marked preference for eggs over other stages of RPM. The functional response of this predator was type III, as consumption increased rapidly at intermediate egg densities. Predation on RPM eggs was unable to stimulate S. tridens reproduction, even at the highest densities. When we compared the food preference of S. tridens to eggs of T. evansi and RPM, we found that the predator preferred tetranychids. The results of this study suggested that RPM can be used as alternative prey to S. tridents, serving as a source of energy and allows for maintenance but not its reproduction.

Damage by herbivores often modifies plant structure and physiology, which may change the behaviour and performance of future herbivores. Here, we studied such interactions among the major coconut pest, the mite Aceria guerreronis (Acari: Eriophyidae), and two minor pests, the mite Steneotarsonemus concavuscutum (Acari: Tarsonemidae) and the moth Atheloca bondari (Lepidoptera: Pyralidae). All these species develop in the meristematic zone of coconuts, which is difficult to access because of the small opening between the epicarp and perianth. Both mites cause necrosis on the epicarp of the nuts, which may facilitate access to the meristematic zone by caterpillars of the moth. However, the caterpillars co‐occur predominantly with A. guerreronis and not with S. concavuscutum. We show that caterpillars did not colonize nuts without mites and colonized nuts with A. guerreronis most frequently, in agreement with the openings caused by this mite and caterpillar size. When the opening between epicarp and perianth was artificially increased, caterpillars also colonized nuts without mites and nuts with S. concavuscutum. When offered a choice, caterpillars preferred nuts with easy access to the meristematic region, regardless of the presence of mites. Caterpillars performed better on the A. guerreronis‐infested nuts than on other nuts, but moth females did not preferentially oviposit in coconut bunches infested with mites. Hence, caterpillars, not adults, select suitable feeding sites within a bunch of coconuts, and A. guerreronis facilitates the infestation of coconuts by A. bondari. We discuss how damage by mites affects the relevance of A. bondari as a coconut pest.

The spider mite Tetranychus neocaledonicus André (Acari: Tetranychidae) is a potential threat to the cultivation of lima bean (Phaseolus lunatus L.). In many countries, lima beans are grown by small-holder farmers with limited access to inputs and technologies. In such systems, the implementation of control practices, such as chemical treatments that require costly equipment and supplies, becomes unviable. Therefore, the development and use of resistant plant genotypes could provide a promising alternative for small producers. Accordingly, the present study aimed to identify and evaluate T. neocaledonicus-resistant genotypes of lima bean. A total of 30 lima bean genotypes were evaluated using the instantaneous increase rate (ri) of T. neocaledonicus reared on individual host genotypes, and T. neocaledonicus fertility life tables were generating by rearing mites on host genotypes with the two highest ri values (IFCE-085 and IFCE-091, considered highly susceptible) and two lowest ri values (IFCE-084 and IFCE-090, considered resistant). Only the IFCE-090 genotype adversely affected immature T. neocaledonicus individuals, by reducing their survival rate, net reproductive rate (Ro), finite rate of increase (λ), and intrinsic rate of increase (rm) and by increasing their mean generation time (T) and time to reach adulthood. The results demonstrate the variation in the susceptibility of lima bean genotypes to T. neocaledonicus and identify the IFCE-090 genotype as a potential source of mite resistance.

Oligonychus punicae has potential for development in several species of eucalyptus. In this study was evaluated the preference for permanence and oviposition of O. punicae in different eucalyptus species. Additionally, we evaluated its dynamics and population distribution, as well as injuries in strains of Eucalyptus urophylla in a clonal minigarden. The preference for permanence and oviposition of O. punicae was evaluated using a test with and without choice in six species of Eucalyptus. We also analyzed the dynamics, population distribution and injury levels by O. punicae on E. urophylla in a clonal minigarden. We collected samples for 24 months and counted the number of eggs, immature and adult individuals. We calculated the Morisita dispersion index. We estimated injuries on leaves of E. urophylla using visual notes. In the test with choice, Eucalyptus urophylla was the preferred host of O. punicae for permanence and oviposition. In the test without choice, the oviposition of O. punicae in eucalyptus species did not differ statistically until 24 hours of evaluation. However, there was a significant difference after 48 hours, with greater oviposition on Eucalyptus brassiana, Eucalyptus tereticornis and Eucalyptus grandis. In the population survey, we collected 3,293 mites. The population peak of O. punicae occurred in March and April 2018 and April 2019. Oligonychus punicae presented an aggregate distribution and caused injuries of 20% on average in leaves. These results are important to guide management strategies in specific infestation foci and optimizing the use of phytosanitary products.

Integrated control tactics are often necessary for pest management. This is especially true for organisms such as the two-spotted spider mite, Tetranychus urticae Koch. The management of this mite pest species relies on pesticide use, but its short life cycle associated with high selection pressure results in frequent problems of acaricide resistance and population outbreaks. Therefore, combining acaricides and natural enemies is an appealing strategy for managing this pest species. The predatory mite Neoseiulus idaeus Denmark & Muma (Phytoseiidae) is important in arid environments, where other natural enemies show low efficacy. Thus, we investigated the effects of representative acaricides used for managing spider mites around the world in several crops (i.e., abamectin, fenpyroximate, and azadirachtin), on the functional and numerical responses of the phytoseid predator N. idaeus to increasing egg densities of its prey. Acaricide exposure did not affect the type of N. idaeus functional response or attack rate (a). However, acaricide exposure decreased the amount of consumed prey and increased prey handling time (Th). All acaricides affected the numerical response of the predator, which reduced oviposition rates. Therefore, caution is required in attempts to integrate the control methods.

The introduction and establishment of an invasive species in a new habitat represents a major threat to biodiversity and ecosystem structure. A recent example of a mite that has become an invasive species is the red palm mite, Raoiella indica Hirst (Acari: Tenuipalpidae). After its introduction in the Americas, this species has considerably expanded the number of hosts and has been reported as a key pest of some of these. In the present study we investigated the possibility of mitefauna alteration on coconut leaflets (abundance and diversity) mediated by the introduction and establishment of R. indica. A survey was conducted over a period of 1 year in two areas of coconut cultivation: one infested and one free of R. indica. The results of the present study suggest that the introduction of R. indica modifies the mitefauna existing in coconut leaflets. Differences were detected in the abundance and diversity of mites at the level of the taxonomic categories (family and species) and at the level of the trophic groups (predators, herbivores and mites with undefined feeding mode). Additionally, in plants infested by the invasive species, a similar pattern was observed between the fluctuation of the phytoseiid mites and other tenuipalpid mites. In these plants, the density of the tenuipalpid mites (including R. indica) was also the variable that most contributed to explain the fluctuation of phytoseiid mites. This suggests that the invasive species, R. indica, acts as a keystone species, structuring the mitefauna in coconut plants.