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. 2026 Jan 29;196(1):81–89. doi: 10.1007/s00360-025-01652-x

Dehydrating microhabitats increase mite activity and intensify ectoparasitism of Drosophila

Joshua B Benoit 1,✉, Gabrielle LeFevre 1, Joy Bose 1, Ann Miller 1, David Lewis 1, Hailie Talbott 1, Chandrima Das 1, Emily Susanto 1, Lyn Wang 1, Oluwaseun M Ajayi 1, Shyh-Chi Chen 1, Michal Polak 1
PMCID: PMC12935809  PMID: 41609785

Abstract

Parasites interact with their host in variable environments that are often subject to water scarcity and dehydration. Drosophilid fruit flies and associated ectoparasitic mites interact across a range of microhabitats, typically in decaying organic matter, such as fallen fruit and cactus tissue, that dries out and deteriorates over periods ranging from days to months. Here, we report that mite parasitism of Drosophila increases with exposure to increasingly dry conditions for two fly-mite systems (D. nigrospiracula-Macrocheles and D. melanogaster-Gamasodes). In D. melanogaster, artificial selection for increasing behavioral resistance did not eliminate this effect, as previously selected lines remained relatively more resistant than non-selected controls even under dry conditions. Water balance assays confirmed that mites became dehydrated when held under dry conditions, which was also associated with increased mite activity. Exposure of D. melanogaster to mites dehydrated by exposure to low relative humidity increased parasitism, further supporting that prevalence of infestation intensifies under dry conditions. The results indicate that ectoparasitism in this system is affected by the water content of the mites. The increased motivation of mites to parasitize flies under dry conditions may serve to replenish mite water stores and facilitate dispersal to more favorable microhabitats.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00360-025-01652-x.

Keywords: Fly, Mite, Dehydration, Parasitism, Activity, Resistance

Introduction

A diverse array of parasites exploit Drosophila fruit flies as hosts, and many of these associations are well-suited for experimental studies of host-parasite interactions. In particular, naturally occurring associations between Drosophila and ectoparasitic mites (Polak and Markow 1995; Halliday 2000; Halliday et al. 2005; Perez-Leanos et al. 2017; Yao et al. 2020) serve as tractable models for investigating the behavioral mechanisms insects use to resist infestation—mechanisms that are well characterized in animals (Hart and Hart 2018). In general, mites are known to benefit from attaching to insect hosts through acquiring nutrients, increasing reproduction, and facilitating dispersal to new habitats (Walter and Proctor 2013). In Drosophila, mite attachment harms the host through direct damage to the cuticle and resource extraction, triggering wound repair, melanotic responses, and other immune responses (Benoit et al. 2020; Polak et al. 2025). The damage caused by parasitism can be severe with negative consequences for host reproduction and lifespan (Polak and Markow 1995; Polak 1996). Parasitism by mites is also associated with a suite of behavioral and physiological changes in the host, including upregulation of male reproductive effort (Polak and Starmer 1998), diminished copulation success owing to direct mechanical interference by attached mites (Polak et al. 2007), and increased metabolic rate (Brophy and Luong 2021).

Drosophila melanogaster Meigen and other fruit fly species are known to be parasitized by Gamasodes mites, with field records from Asia (Taiwan and Thailand) and Australia (Halliday et al. 2005; Yao et al. 2020; Polak 2025; Polak et al. 2025). In North America, the mite Macrocheles subbadius Berlese parasitizes Drosophila nigrospiracula Patterson and Wheeler in the Sonoran Desert (Polak and Markow 1995). This broad geographic distribution of fly–mite associations, together with their occurrence across diverse ecological settings, suggests that ectoparasitic mites exert widespread selective pressures on multiple aspects of fly biology. Flies avoid infestation by deploying rapid bursts of flight from the substrate, evasive locomotor maneuvers, and vigorous grooming once mite contact is made (Polak 2003; Polak et al. 2023). Behavioral resistance to mites is significantly heritable (Polak 2003; Luong and Polak 2007) and can be subject to strong selection (Polak and Markow 1995; Polak 1996; Benoit et al. 2025). Yet, little is known about how environmental conditions experienced by mites and flies influence the outcome of these interactions.

Exposure to dry conditions and the prevention of dehydration are significant factors influencing the survival and proliferation of terrestrial arthropods (Benoit et al. 2023). When flies and mites interact, the water content of the local substrate, such as decaying fruits, flowers, cacti, or mushrooms, often declines, eventually reaching levels that cannot sustain many small arthropods, such as Gamasodes or Macrocheles, either due to this declining water content of the substrate or the availability of prey. These observations suggest that mites may increase their rates of parasitism on fruit flies when chronically exposed to dry off-host conditions, both to obtain water and nutrients from the fly and to disperse to more favorable microhabitats. For example, one previous study of the cactophilic fruit fly species D. nigrospiracula, found that both the intensity and prevalence of M. subbadius mite parasitism increased with the age and deterioration of necrotic saguaro cactus (Carnegiea gigantea) tissue, likely due to a combination of desiccation of the necrosis and declining habitat suitability for mite foraging and reproduction (Polak and Markow 1995). For cacti (Opuntia and Cylindropuntia), there is a loss of over 50% of the water content within 40–50 days, and less than 1% water remains after 200 days (Bilderback et al. 2021). Similarly, fruit will experience water loss as decay progresses, where water content continually declines, leading to 70–80% reductions in water content of the tissue (Kider et al. 2011; Gidado et al. 2024). Several other studies suggest that ectoparasites and parasitoids increase their feeding and parasitism rates under dry conditions (Hagan et al. 2018; Bezerra Da Silva et al. 2019; San et al. 2021; Abu et al. 2024; Holmes et al. 2025). However, such interactions have yet to be directly explored in Drosophila–mite systems.

The present study investigated how dry conditions influence interactions between Drosophila fruit flies and their ectoparasitic mites. Our experiments examined two distinct fly–mite systems, D. nigrospiracula-Macrocheles and D. melanogaster-Gamasodes, for altered mite parasitism under dry conditions. This included D. melanogaster that had previously been artificially selected for parasite resistance (Polak et al. 2023; Benoit et al. 2025). Lastly, water balance and activity assays for Gamasodes mites were conducted under wet and dry conditions to establish the impact on the mites. Our findings suggest that dry conditions directly increase mite motivation to parasitize fruit flies, which are likely to obtain water and nutrients from their hosts and be carried to more favorable microhabitats.

Materials and methods

Flies, mites and selection for mite resistance

A population of D. melanogaster (Canton-S, number 64349) was obtained from the Bloomington Drosophila Stock Center and used in all experiments with this species described here, except those involving lines artificially selected for mite resistance. The selected lines were derived from a single outbred base population established with field-collected flies from Cape Tribulation, Australia (Polak et al. 2023). Artificial selection for increasing resistance, described in detail elsewhere (Polak 2003; Polak et al. 2023), was conducted using G. queenslandicus mites from a laboratory culture established with individuals harvested from field-caught flies at Cape Tribulation. The selection protocol generated three replicate lines of D. melanogaster, each showing significantly greater resistance than its paired unselected control line (Polak et al. 2023). For the present study, flies were used after 22–24 generations of selection. Cultures of D. nigrospiracula and their ectoparasitic mites M. subbadius were established from collections on Carnegiea gigantea cacti near Phoenix, Arizona, USA.

Drosophila melanogaster was cultured in 4 half-pint glass bottles per generation containing a cornmeal-agar food substrate (Webster and Polak 2025), while D. nigrospiracula was cultured in bottles with a food substrate composed of powdered potato flakes, instant Drosophila medium, and necrotic cactus (Polak 1998). All fly cultures were maintained in an environmental chamber (Percival Scientific) under standard 12 h light (24 °C):12 h dark (22 °C) conditions. Both mite species were cultured in 4 L plastic jugs (diameter 17.8 cm, height 22.9 cm) with a specialized medium (Polak 2003), and maintained separately in environmental chambers at 12 h light (25 °C):12 h dark (24 °C) conditions. The culture medium for both mite species consisted of a rich organic substrate of autoclaved wheat bran (60%) and wood shavings (40%), supplemented with autolyzed yeast (1–2%) and bacteriophagic nematodes (added from previous culture) as a food source for the mites (Polak 2003; Benoit et al. 2020; Polak et al. 2023). The culture medium was moistened with sufficient deionized water to keep it damp without water pooling. Dry stock medium used in the experiments described below consisted of autoclaved wheat bran, wood shavings, and autolyzed yeast. Flies were sexed using a dissection scope, and males were used at 7–10 days of age. Females were not used in the studies as the impact of dehydration experiments were expected to be similar between the sexes, even though females do show slightly higher rates of parasitism (Polak and Markow 1995; Horn et al. 2020).

Dehydration treatment

To generate “dry” and “wet” culture conditions, a portion of the mite-containing culture medium was replaced with either dry or hydrated stock medium. This was accomplished by first removing ~ 30–40% of the culture medium and replacing it with stock medium that was either dry or wet. The media were mixed by gently shaking the container for one minute until the mixture was homogeneous. After 24 h, the medium was observed for the presence of mites. If mites were present, the medium and mites were collected to determine their water contents. A rehydrated medium was prepared for a subset of the dry treatments by adding water to the container, allowing the mites to rehydrate for 24 h before conducting mite infestation assays.

Water content determination of media

A standard soil moisture content assay (Basimike and Mutinga 1990; Su and Puche 2003) was used to determine the proportional change in water content of the mite media as a result of making them either drier or wetter. One day after the addition of dry or wet media, the top 2 cm was removed and immediately weighed on aluminum pans. Following the determination of the initial mass (wet mass), the media were dried at 0% RH and 50 °C within a drying oven for 2 weeks. Following drying, they were weighed on three consecutive days to determine that the water lost from the soil had reached the dry mass (no additional decline in mass). Water content was determined as a percentage of the initial mass.

Mite infestation experiments

Mite infestation assays followed established methods to test for differences in susceptibility between experimental groups of flies (Polak 1996, 2003; Luong and Polak 2007; Benoit et al. 2020). Briefly, flies were placed in infestation chambers (300 mL glass jars) containing culture medium with mites (Polak 1996, 2003; Benoit et al. 2020), similar to the chambers used during artificial selection for increased resistance in D. melanogaster (Polak et al. 2023). For both D. melanogaster and D. nigrospiracula, groups of 40–50 flies were added to each infestation chamber; D. melanogaster was exposed to G. queenslandicus mites, whereas D. nigrospiracula was exposed to M. subbadius mites. Only male flies were used in the study.

To assess the effect of the moisture content of the substrate on infestation, assays compared ectoparasitism rates under dry versus wet conditions across replicate infestation chambers for each host species. Infestation chambers containing dry or wet media were run in parallel to ensure similar exposure times between treatments. Approximately the same volume of media was added to the chambers to help maintain similar numbers of mites. After exposure, flies were extracted from chambers with an aspirator, and, under CO2, the presence of mites and scars was assessed for each fly. Prevalence of parasitism ((scarred plus parasitized flies)/total flies exposed) was calculated for each group.

For the D. melanogaster selection lines, two groups of flies were exposed to mites in a common infestation chamber, one group from a given selected line and the other from its paired non-selected line. Group sizes were approximately equal, with a total of 40–50 flies per chamber. To distinguish the two groups, a minute wing clip was administered to the tip of either the right or left wing (≤ 3% of wing area) while flies were under CO2. Prior to aspirating them into chambers, flies were allowed to recover from the CO2 for 24 h. Wing clips have been previously shown to have no significant effect on fly susceptibility to mites (Polak 2003; Benoit et al. 2020). The wing that received a clip was alternated between groups across chambers. Flies were aspirated into infestation chambers and allowed to interact with mites for 6–8 h in darkness, depending on mite density in the medium. After exposure, flies were extracted from chambers with an aspirator, and under CO2 anesthesia, their identities ascertained by wing clips, and the prevalence of parasitism determined as described above.

In separate assays, mites were exposed to dehydrating conditions in the absence of culture medium. Briefly, mites were removed from the media and individually placed in mesh-covered 0.5 mL microcentrifuge tubes. The tubes were placed at either 33% relative humidity (RH, maintained with saturated MgCl2 solution in water) or 93% RH (maintained with saturated KNO3 solution in water) in glass desiccators for 6–8 h before exposing the flies to the mites. One fly and one mite were put together in a standard Drosophila polystyrene vial (25 × 95 mm), which was then kept in a desiccator at 93% RH. Incidence of parasitism was evaluated after 30 min.

Mite water content determination

Mite water content was determined using protocols previously applied to other mite species (Benoit et al. 2008; Yoder et al. 2012). Mites (deutonymphs) were collected directly from the media, and their initial mass was determined within five minutes after freezing at − 20 °C. A Cahn microbalance was used to measure the mass of individual mites to the nearest 0.1 μg. Dry mass was determined by drying mites at 0% relative humidity (using CaSO4, Drierite) at 50 °C until stable weights were obtained over three consecutive days; the final value was taken as the dry mass. Water content was defined as the difference between wet and dry mass.

Activity assays

Mite activity was assessed following methods developed for small arthropods (Fieler et al. 2021; Bailey et al. 2024; Benoit et al. 2025). As before, mites were individually placed in mesh-covered 0.5 mL microcentrifuge tubes and held either at 75% RH or 93% RH for 6 h. Groups of three mites were collected and transferred to 10-cm glass tubes, which were sealed at both ends with foam stoppers. Tubes were placed horizontally into a locomotor activity monitor (LAM, Trikinetics). Groups of three mites, rather than individuals, were used to assess activity to ensure that enough mites passed through the infrared beams that serve to detect movement (Fieler et al. 2021; Benoit et al. 2025). The activity monitor was placed in darkness at 95–98% RH within a Percival incubator. After a two-hour acclimation period, mite behavior was recorded for six hours. Activity was quantified as the number of beam crossings per hour. To minimize circadian effects, measurements were taken nightly from 8 PM to 8 AM, as mites showed marked differences in activity between day and night (Benoit et al. 2025).

Statistical analyses

R software (Version 4.3.1) was used for statistical analyses and figure development. General linear models (quasibinomial logit for proportion and gamma for non-proportion data) were used to examine statistical differences between treatments (dry vs. wet conditions) for each species. A Generalized Linear Mixed Model (GLMM—binomial logit) was used to compare the results of selection lines in relation to hydration status. In the models, the infestation chamber was added as a random effect to account for differences among chambers, due, for example, to mite density variation. In all cases, chamber effects were not significant (P > 0.2 for all models). Odds ratios were determined for each model. Statistical outputs and sample sizes are provided within the figure legends.

Results

Mite parasitism in two fly-mite systems under wet and dry conditions

When we examined the water content of wet vs. dry media, there was a significant 30–40% decline in the water content of the media (Fig. 1). When D. melanogaster was exposed to G. queenslandicus, a little over half of the flies became parasitized with mites (Fig. 2A). Dehydrating conditions resulted in a significant increase in parasitism, with 25–30% more flies harboring mites (Fig. 2A, P < 0.0001, odds ratio = 3.88). A similar effect of medium dehydration was noted for D. nigrospiracula interacting with M. subbadius mites (Fig. 2B; P = 0.0002, odds ratio = 2.33). The addition of water to the dry media resulted in a reduction in mite parasitism for D. melanogaster (Fig. 3, P < 0.0005, odds ratio after dehydration = 1.41 and after rehydration = 0.95), confirming that dry conditions contributed to increased mite infestation of the flies.

Fig. 1.

Fig. 1

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Water content of mite media under wet and dry conditions. Water content of mite media in dry or wet conditions, along with the water content of the dry stock medium (N = 3 replicate samples for each media type). all media types are significantly different (F2,6 = 648.5, P < 0.0001)

Fig. 2.

Fig. 2

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Dehydration increases mite parasitism on fruit flies. A Drosophila melanogaster (Canton S) exposed to mites (Gamasodes queenslandicus) under wet and dry conditions. N = 8 chambers per condition, F1,14 = 52.81, P < 0.0001. B Drosophila nigrospiracula exposed to mites (Macrocheles subbadius) under wet and dry conditions. N = 8 chambers per condition, F1,14 = 45.51, P < 0.0001. There was a general effect where both species showed increased parasitism under dry conditions, F2,29 = 26.32, P < 0.0001

Fig. 3.

Fig. 3

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Rehydration of media reduces parasitism to levels in wet media. Drosophila melanogaster (Canton S) exposed to mites (Gamasodes queenslandicus) under wet and dry conditions, along with those exposed to dry medium that was rehydrated for 24 h. N = 8 chambers per treatment. An increase in parasitism was noted only under dry conditions compared to both wet and rehydrated conditions, F2,21 = 10.81, P < 0.0005

Relative resistance under dry and wet conditions

A previous study performed artificial selection for increased behavioral resistance of D. melanogaster against G. queenslandicus mites (Polak et al. 2023; Benoit et al. 2025), generating the selected and non-selected lines used in the present study. When selected and non-selected flies were exposed to mites in the same chamber, dry conditions increased parasitism in both groups compared to wet conditions (Fig. 4, P < 0.005, odds ratio select = 1.16 and non-selected = 1.14). Selected flies in both environments maintained their superiority in resistance, with selected flies exhibiting 12.8% (odds ratio = 0.88) and 11.8% (odds ratio = 0.89) decreased parasitism under wet and dry conditions, respectively (Fig. 4).

Fig. 4.

Fig. 4

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Dehydration increases mite parasitism for mite-resistant and non-resistant lines. Both non-selected (A, F1,22 = 10.5, P < 0.004) and selected (B, F1,22 = 8.87, P < 0.007) lines were parasitized at higher rates under dry conditions compared to wet conditions. Selected lines were more resistant than non-selected lines under both wet (F1,22 = 13.07, P = 0.002) and dry (F1,22 = 10.83, P = 0.003) conditions. N = 12 chambers per treatment

Water content in mites under dry and wet conditions

We evaluated whether the water content of Gamasodes mites differed between wet and dry conditions. Mites exposed to dry conditions within infestation chambers had significantly lower initial (wet) mass compared to those sampled from wet conditions (Fig. 5A; P = 0.002), but dry mass did not differ between the two groups (Fig. 5B; P = 0.374). Mites from the dry medium had a 20–25% reduction in water content relative to those from the wet medium (Fig. 5C; P = 0.0003). This water balance assessment confirms that G. queenslandicus mites become dehydrated when exposed to dry conditions.

Fig. 5.

Fig. 5

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Water content of mites from wet and dry media conditions. A Initial mass. F1,28 = 23.26, p = P < 0.001. B Dry mass. F1,28 = 0.8178, P = 0.0374. C Water content of mites. F1,28 = 17.19, P = 0.001. N = 15 for mites held in wet and dry media

Activity and fly parasitization in dehydrated and hydrated mites

Dehydrated mites exhibited significantly higher activity levels than those from moist media, showing a 20–30% increase in activity (Fig. 6A, P = 0.006). When mites were exposed to the flies in a media-free chamber, the dehydrated mites were nearly twofold more likely to parasitize the flies compared to hydrated mites (Fig. 6B, P = 0.012, odds ratio = 6.25).

Fig. 6.

Fig. 6

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Activity levels and parasitism are increased in dehydrated mites. A Activity levels were higher in dehydrated mites compared to hydrated mites, N = 30 for hydrated and N = 28 for dehydrated mites. F1,56 = 8.01, P = 0.006. B Direct assessment of mite-fly interactions confirms that dehydration triggers increased parasitism. N = 6 exposures of flies to the mites for hydrated and dehydration treatments. F1,10 = 9.31, P = 0.012

Discussion

This study demonstrated that dry substrate conditions are a significant factor driving parasitism by mites. In two independent fly-mite systems, dehydration significantly increased rates of parasitism. Interestingly, even after artificial selection for resistance in D. melanogaster (Polak et al. 2023), desiccation still enhanced parasitism, although selected flies retained elevated resistance when compared to their non-selected counterparts. Water balance measurements in G. queenslandicus mites confirmed reduced body water content under dry conditions. Dehydrated mites also exhibited increased locomotor activity, which likely contributed to heightened host encounter and attachment rates as mite behavior has shifted. However, this increased activity is perhaps best interpreted as part of a broader suite of mite behaviors. These include heightened host-seeking, which directly contributes to higher parasitism rates, as well as dispersal efforts to escape desiccating conditions through independent movement to wetter microhabitats. Together, these findings indicate that desiccating conditions can intensify host–parasite interactions by affecting off-host parasite behavior.

The impact of dry conditions on arthropod pests, especially ectoparasites, has been a recent focus of several studies. In mosquitoes and ticks, dry conditions increase activity, host seeking, and feeding (Rosendale et al. 2016, 2019; Hagan et al. 2018; Manzano-Alvarez et al. 2023; Abu et al. 2024), as well as driving male mosquitoes to ingest blood (Bozic et al. 2024). In addition to increased feeding, ectoparasites often exhibit behavioral shifts in response to dehydration, including elevated general activity and heightened movement after a bloodmeal (Rosendale et al. 2016; Holmes et al. 2025). Similar patterns have been observed beyond vertebrate–arthropod systems; for instance, water deprivation in insects has been linked to increased parasitism by parasitoid wasps (Bezerra Da Silva et al. 2019). Our results align with these previous studies, showing that two species of ectoparasitic mites that naturally parasitize fruit flies exhibited increased rates of parasitism under dry conditions that demonstrably promote mite dehydration. These results support the hypothesis that dehydration is a general environmental factor capable of intensifying ectoparasitism. Importantly, the observed increase in ectoparasitism is unlikely to be the result of mite starvation. The exposure period was relatively short, and prior work indicates that more extended deprivation is required to induce increased feeding due to starvation (Luong et al. 2017). Additionally, mites likely retained access to nematode prey within the dry and wet medium, as fresh media was added to both. Thus, the increase in parasitism may more plausibly be attributed to dehydration-induced increases in mite activity, which likely enhanced host encounter rates. Further work will be required to distinguish the relative importance of dehydration versus starvation in driving elevated parasitism. Furthermore, the specific mechanisms driving the increase in parasitism, such as neurophysiological stress activation, warrant exploration in future studies.

Resistance to mites confers fitness benefits to flies by reducing the probability of infestation (Luong and Polak 2007; Polak et al. 2023; Benoit et al. 2025). However, resistance is not cost-free: in the absence of parasites, elevated resistance may incur fitness costs, such as reduced stress tolerance and diminished fecundity, as documented in this (Ewald 1995; Windsor 1998; Fitze et al. 2004; Luong and Polak 2007) and other host–parasite systems (Ewald 1995; Windsor 1998; Fitze et al. 2004; Luong and Polak 2007). These costs are usually more muted than the direct fitness consequences of parasitism, which can lead to strong physiological declines and increased probability of death (Polak and Markow 1995; Benoit et al. 2020; Polak et al. 2023). However, little is known about how the outcomes of host-ectoparasite interactions shift under suboptimal conditions. In the present study, we demonstrated that dry conditions elevated infestation rates in both selected and non-selected flies, indicating an effect of substrate moisture on the prevalence of parasitism. Interestingly, selected lines retained an advantage over their non-selected counterparts under both wet and dry conditions, indicating stability of the genetic effect on behavioral immunity across these environmental conditions.

The increased parasitism by mites when held under dry conditions is likely a critical mechanism for mite dispersal to more optimal habitats. Flies utilize a wide range of substrates, ranging from fermenting fruit, cactus, and fungi, among other organic materials (Markow and O’Grady 2006). As these organic substrates are consumed, decompose, and become dry, particularly in areas of seasonal periods of limited rainfall, they not only become increasingly suboptimal for fly survival and reproduction, but these environmental effects are also felt by the mites themselves. Depletion of available nematodes and other small invertebrate prey for the mites may lead to mite starvation, which has previously been shown to increase mite motivation to parasitize flies (Luong et al. 2017). Furthermore, egg viability is expected to decline under desiccating conditions, a pattern commonly observed in mite eggs exposed to dry environments (Benoit et al. 2007; Yoder et al. 2012), thus reducing mite survival in microhabitats that dry as they deteriorate. Given that mites commonly parasitize flies for many hours (Webster and Polak 2025), and that parasitism by mites improves mite fecundity (Luong and Subasinghe 2017), movement with the flies likely enhances mite fitness components and facilitates locating new, more optimal habitats (Polak and Markow 1995).

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (XLSX 20 KB) (20.3KB, xlsx)

Acknowledgements

The research was supported by National Science Foundation (NSF) grant 1654417 (to M.P. and J.B.B.). Partial funding for reusable equipment was provided indirectly by the National Institute of Allergy and Infectious Diseases, award numbers R01AI148551 and R21AI166633 to J.B.B.

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References

  1. Abu AEI, Becker M, Accoti A et al (2024) Low humidity enhances Zika virus infection and dissemination in Aedes aegypti mosquitoes. mSphere 9:e0040124 [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bailey ST, Kondragunta A, Choi HA et al (2024) Dehydration and tomato spotted wilt virus infection combine to alter feeding and survival parameters for the western flower thrips, Frankliniella occidentalis. Curr Res Insect Sci 6:100086 [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Basimike M, Mutinga MJ (1990). Temperature and moisture content of soils of termite mounds and animal burrows in relation to relative abundance of adult phlebotomine sandflies (Diptera: Psychodidae) in Marigat semiarid area, Baringo District, Kenya. Environ Entomol 19:486-489. 10.1093/ee/19.3.486
  4. Benoit JB, Yoder JA, Lopez-Martinez G et al (2007) Habitat requirements of the seabird tick, Ixodes uriae (Acari: Ixodidae), from the Antarctic Peninsula in relation to water balance characteristics of eggs, nonfed and engorged stages. J Comp Physiol B 177:205–215 [DOI] [PubMed] [Google Scholar]
  5. Benoit JB, Yoder JA, Lopez-Martinez G et al (2008) Adaptations for the maintenance of water balance by three species of Antarctic mites. Polar Biol 31:539–547 [Google Scholar]
  6. Benoit JB, Bose J, Bailey ST, Polak M (2020) Interactions with ectoparasitic mites induce host metabolic and immune responses in flies at the expense of reproduction-associated factors. Parasitology 147:1196–1205 [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Benoit JB, McCluney KE, DeGennaro MJ, Dow JAT (2023) Dehydration dynamics in terrestrial arthropods: from water sensing to trophic interactions. Annu Rev Entomol 68:129–149 [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Benoit JB, Bose J, Ajayi OM et al (2025) Shifted levels of sleep and activity during the night as mechanisms underlying ectoparasite resistance. NPJ Biol Timing Sleep 2:15 [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Bezerra Da Silva CS, Price BE, Walton VM (2019) Water-deprived parasitic wasps (Pachycrepoideus vindemmiae) kill more pupae of a pest (Drosophila suzukii) as a water-intake strategy. Sci Rep 9:3592 [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Bilderback AH, Torres AJ, Vega M, Ball BA (2021) The structural and nutrient chemistry during early-stage decomposition and desiccation of cacti in the Sonoran Desert. J Arid Environ 195:104636 [Google Scholar]
  11. Bozic J, Joseph RE, Krizek RS et al (2024) Revisiting the paradigm of anhematophagy in male mosquitoes. bioRxiv. 10.1101/2024.10.08.617226 [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Brophy T, Luong LT (2021) Ectoparasite-induced increase in Drosophila host metabolic rate. Physiol Entomol 46:1–7 [Google Scholar]
  13. Ewald PW (1995) The evolution of virulence: a unifying link between parasitology and ecology. J Parasitol 81:659–669 [PubMed] [Google Scholar]
  14. Fieler AM, Rosendale AJ, Farrow DW et al (2021) Larval thermal characteristics of multiple ixodid ticks. Comp Biochem Physiol A Mol Integr Physiol 257:110939 [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Fitze PS, Tschirren B, Richner H (2004) Life history and fitness consequences of ectoparasites. J Anim Ecol 73:216–226 [Google Scholar]
  16. Gidado MJ, Gunny AAN, Gopinath SCB et al (2024) Challenges of postharvest water loss in fruits: mechanisms, influencing factors, and effective control strategies—a comprehensive review. J Agric Food Res 17:101249 [Google Scholar]
  17. Hagan RW, Didion EM, Rosselot AE et al (2018) Dehydration prompts increased activity and blood feeding by mosquitoes. Sci Rep 8:6804 [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Halliday RB (2000) The Australian species of Macrocheles (Acarina : Macrochelidae). Invertebr Syst 14:273–326 [Google Scholar]
  19. Halliday RB, Walter DE, Polak M (2005) A new species of Gamasodes Oudemans from Australia (Acari: Parasitidae). Zootaxa 1001:17 [Google Scholar]
  20. Hart BL, Hart LA (2018) How mammals stay healthy in nature: the evolution of behaviours to avoid parasites and pathogens. Philos Trans R Soc Lond B Biol Sci 373:20170205 [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Holmes CJ, Chakraborty S, Ajayi OM et al (2025) Multiple blood feeding bouts in mosquitoes allow for prolonged survival and are predicted to increase viral transmission during dry periods. iScience 28:111760 [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Horn CJ, Mierzejewski MK, Elahi ME, Luong LT (2020) Extending the ecology of fear: parasite-mediated sexual selection drives host response to parasites. Physiol Behav 224:113041 [DOI] [PubMed] [Google Scholar]
  23. Kider JT Jr, Raja S, Badler NI (2011) Fruit senescence and decay simulation. Comput Graph Forum 30:257–266 [Google Scholar]
  24. Luong LT, Polak M (2007) Environment-dependent trade-offs between ectoparasite resistance and larval competitive ability in the Drosophila-Macrocheles system. Heredity 99:632–640 [DOI] [PubMed] [Google Scholar]
  25. Luong LT, Subasinghe D (2017) A facultative ectoparasite attains higher reproductive success as a parasite than its free-living conspecifics. Exp Appl Acarol 71:63–70 [DOI] [PubMed] [Google Scholar]
  26. Luong LT, Brophy T, Stolz E, Chan SJ (2017) State-dependent parasitism by a facultative parasite of fruit flies. Parasitology 144:1468–1475 [DOI] [PubMed] [Google Scholar]
  27. Manzano-Alvarez J, Terradas G, Holmes CJ et al (2023) Dehydration stress and Mayaro virus vector competence in Aedes aegypti. J Virol 97:e0069523 [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Markow TA, O’Grady P (2006) Drosophila. Academic Press, San Diego [Google Scholar]
  29. Perez-Leanos A, Loustalot-Laclette MR, Nazario-Yepiz N, Markow TA (2017) Ectoparasitic mites and their Drosophila hosts. Fly 11:10–18 [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Polak M (1996) Ectoparasitic effects on host survival and reproduction: the Drosophila-Macrocheles association. Ecology 77:1379–1389 [Google Scholar]
  31. Polak M (1998) Effects of ectoparasitism on host condition in the Drosophila-Macrocheles system. Ecology 79:1807 [Google Scholar]
  32. Polak M (2003) Heritability of resistance against ectoparasitism in the Drosophila-Macrocheles system. J Evol Biol 16:74–82 [DOI] [PubMed] [Google Scholar]
  33. Polak M, Markow TA (1995) Effect of ectoparasitic mites on sexual selection in a Sonoran desert fruit fly. Evolution 49:660–669 [DOI] [PubMed] [Google Scholar]
  34. Polak M, Starmer WT (1998) Parasite–induced risk of mortality elevates reproductive effort in male Drosophila. Proc R Soc Lond B 265:2197–2201 [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Polak M, Luong LT, Starmer WT (2007) Parasites physically block host copulation: a potent mechanism of parasite-mediated sexual selection. Behav Ecol 18:952–957 [Google Scholar]
  36. Polak M, Bose J, Benoit JB, Singh H (2023) Heritability and preadult survivorship costs of ectoparasite resistance in the naturally occurring Drosophila-Gamasodes mite system. Evolution 77:2068–2080 [DOI] [PubMed] [Google Scholar]
  37. Polak M, Das C, Schaefer P (2025) Drosophila melanotic lesions caused by ectoparasitic mites Gamasodes pachysetis from southern Thailand. figshare. 10.6084/M9.FIGSHARE.28216868.V1
  38. Polak M (2025) Personal observations
  39. Rosendale AJ, Romick-Rosendale LE, Watanabe M et al (2016) Mechanistic underpinnings of dehydration stress in the American dog tick revealed through RNA-Seq and metabolomics. J Exp Biol 219:1808–1819 [DOI] [PubMed] [Google Scholar]
  40. Rosendale AJ, Dunlevy ME, McCue MD, Benoit JB (2019) Progressive behavioural, physiological and transcriptomic shifts over the course of prolonged starvation in ticks. Mol Ecol 28:49–65 [DOI] [PubMed] [Google Scholar]
  41. San PP, Tuda M, Takagi M (2021) Impact of relative humidity and water availability on the life history of the predatory mite Amblyseius swirskii. Biocontrol (Dordrecht) 66:497–510 [Google Scholar]
  42. Su NY, Puche H. (2003) Tunneling activity of subterranean termites (Isoptera: Rhinotermitidae) in sand with moisture gradients. J Econ Entomol 96:88–93 [DOI] [PubMed]
  43. Walter DE, Proctor HC (2013) Mites and Biological Diversity. In: Walter DE, Proctor HC (eds) Mites: ecology, evolution & behaviour: life at a microscale. Springer, Dordrecht, pp 447–459 [Google Scholar]
  44. Webster AL, Polak M (2025) Priming for protection: inducible attachment-resistance to ectoparasitic mites in Drosophila. Parasitology 152:897–908 [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Windsor DA (1998) Controversies in parasitology, most of the species on Earth are parasites. Int J Parasitol 12:1939–1941 [DOI] [PubMed] [Google Scholar]
  46. Yao M-Y, Guo J-J, Michal P et al (2020) A new species and new record of Gamasodes (Mesostigmata: Parasitidae) from China. Syst Appl Acarol 25:1299–1318 [Google Scholar]
  47. Yoder JA, Hedges BZ, Benoit JB (2012) Water balance of the American dog tick, Dermacentor variabilis, throughout its development with comparative observations between field-collected and laboratory-reared ticks. Int J Acarology 38:334–343 [Google Scholar]

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