Characterization, mode of action, and efficacy of twelve silica-based acaricides against poultry red mite (Dermanyssus gallinae) in vitro

Morphological changes in plasma-exposed poultry red mites (Dermanyssus gallinae) using high-resolution video camera and optical coherence tomography (OCT)

Dermanyssus gallinae, the poultry red mite (PRM), is a hematophagous temporary ectoparasite that causes serious economic losses and animal health impairment on laying hen farms worldwide. Control is limited by the parasite's hidden lifestyle, restrictions on the use of chemical acaricides and the development of resistance against certain drug classes. As a result, research was conducted to explore alternative control methods. In recent years, atmospheric pressure plasma has been increasingly reported as an alternative to chemical acaricides for pest control. This physical method has also shown promising against PRM under laboratory conditions. However, the detailed mechanisms of action have not yet been elucidated. In the present study, the effects of cold atmospheric pressure plasma on PRM were investigated using digital videography and optical coherence tomography (OCT), an imaging technique that visualizes the topography of surfaces and internal structures. Digital videography showed that a redistribution of the contents of the intestinal tract and excretory organs (Malpighian tubules) occurred immediately after plasma exposure. The body fluids reached the distal leg segments of PRM and parts of the haemocoel showed whiter and denser clumps, indicating a coagulation of the haemocoel components. OCT showed a loss of the boundaries of the hollow organs in transverse and sagittal sectional images as well as in the three-dimensional image reconstruction. In addition, a dorso-ventral shrinkage of the idiosoma was observed in plasma-exposed mites, which had shrunk to 44.0% of its original height six minutes after plasma exposure.

Entomopathogenic fungi with biological control potential against poultry red mite (Dermanyssus gallinae, Arachnida: Dermanyssidae)

The poultry red mite, Dermanyssus gallinae (Arachnida: Dermanyssidae) is a pest that causes significant economic loss in laying hens for which control methods are limited. In this study, the effects of 20 indigenous fungal strains on poultry red mites in chicken farms were investigated. All experiments were conducted under laboratory condition at 28 ± 1 °C and 80 ± 5% humidity. A screening test showed that Metharizium flavoviride strain As-2 and Beauveria bassiana strain Pa4 had the greatest measured effect on D. gallinae at 1 × 107 conidia/ml 7 days after application. In a subsequent does-response experiment, these strains also caused 92.7% mortality at 1 × 109 conidia/ml within the same period. The LC50 of these strains was 5.5 × 104 (95% CI: 0.8-37.5) conidia/ml for As-2 and 3.2 × 104 (95% CI: 0.4-26.0) conidia/ml for Pa4, and their LT50 were 1.94 and 1.57 days, respectively. The commercial Metarhizium anisopliae bioinsecticide Bio-Storm 1.15% WP, used as a comparator, had LC50 and LT50 1 × 105 (95% CI: 0.1-7.9) conidia/ml and 3.03 (95% CI: 2.4-3.8) days, respectively. It is suggested that mycoacaricides could be developed using the best two fungal strains found in this study (As-2 and Pa4), providing potential for biological control of poultry red mites.

Efficacy and safety of geranium-oregano-thymol formulations to control of dog tick Rhipicephalus sanguineus sensu lato under laboratory and field conditions

The present study evaluated, in laboratory and field, the efficacy and safety of formulations of Pelargonium graveolens (geranium - G), Origanum majorana (oregano - O) commercial essential oils (EO) and thymol (T) to control of Rhipicephalus sanguineus sensu lato. In the laboratory, three formulas (A: 2% tween 80%, B: powder and C: nanoemulsion) by a mixture of these components (GOT) were prepared and evaluated, and the best one was used to assess its safety and field application against R. sanguineus s. l. on naturally infested dogs. Besides the major compounds of the EO used were identified. The results of the lab study showed that formula A (2.5 g of each G + O + T + 2% tween 80 to complete 100 mL) was significantly more effective than the other two formulas tested and exhibited highly effective adulticidal, larvicidal, and ovicidal activity against R. sanguineus s.l. Significant LC50 and LC90 values of GOT were evaluated (13.4 and 21.5 mg/mL, respectively) for the adulticidal activity, (2.81 and 4.46 mg/mL, respectively) for ovicidal activity and (2.44 and 4.45 mg/mL, respectively) for larvicidal activity. The safety of formula A has been proven by the absence of its cytotoxicity on a cell line of human epidermoid carcinoma. Citronella and carvacrol were the major compounds identified in the commercial essential oils of P. graveolens and O. majorana, respectively. Formula A was used in a field control trial for almost 8 months, during the tick infestation season (April to November, 2022). Fourteen naturally infested dogs were divided into two groups, each with seven dogs. One group received formula A spraying five times during an experiment that continued for 8 months, while the other group received treatment with commercially available malathion acaricide. The animals were sprayed on five occasions throughout the experiment (April, June, July, August, and September). The results showed a substantial percentage of effectiveness after the first application of formula A with a 99.3% reduction in tick count at day 28 post-application (PA). In the case of severe infestation 60 days after the first application of formula A (more than 180 ticks per dog), the second application was done, achieving an efficacy of 54.9% at day 3 PA, so an emergency spray was done at day 5 PA to combat the rest of the tick infestation, achieving efficacy of 99% after 3 days. Consequently, a regular spray (third, fourth, and fifth application) was done every 35 days. This regular spray revealed 100% effectiveness at 14 days PA. Biochemical parameters of treated dogs were evaluated to confirm the safety of formula A. Creatinine, ALT, and albumin of the dogs treated with formula A were within the normal range of dogs, while urea and AST were higher than the normal range. In conclusion, formula A can safely treat R. sanguineus s.l. infestations in dogs with regular application every 5 weeks.

Successful long-term control of poultry red mite (Dermanyssus gallinae) infestations in floor-kept laying hens via integrated pest management-a case report

This case report describes the successful control of poultry red mite [PRM] (Dermanyssus gallinae) infestations in an experimental laying hen house via a combined use of cleaning and disinfection measure, the preventive application of a synthetic silica-based acaricide and frequent mite monitoring. The high number of PRM in the laying hen house was reduced by 99.8% by treatment with fluralaner (Exzolt®, MSD Animal Health Unterschleißheim, Germany; 0.5 mg/kg body weight via drinking water twice, 7 days apart). After the laying hens were removed, the hen house was dry-cleaned, wet-cleaned and disinfected. After drying, synthetic amorphous silica (Fossil Shield® instant white, Bein GmbH, Eiterfeld, Germany) was applied as a preventive measure before the hen house was restocked with pullets for two housing periods of 58 and 52 weeks. Over these periods (i.e. more than 2 years), no PRM was detected during mite monitoring at two-week intervals via tube traps and visual monitoring. This result therefore suggests that the combined use of appropriate chemical and physical prevention measures within an integrated pest management regime can be successfully used for the long-term control of PRM. This could reduce the use of acaricidal drugs, thereby helping maintain their efficacy.

Advances in Non-Chemical Tools to Control Poultry Hematophagous Mites

The blood-sucking mites Dermanyssus gallinae ("red mite"), Ornithonyssus sylviarum ("northern fowl mite"), and Ornithonyssus bursa ("tropical fowl mite") stand out for causing infestations in commercial poultry farms worldwide, resulting in significant economic damage for producers. In addition to changes in production systems that include new concerns for animal welfare, global climate change in recent years has become a major challenge in the spread of ectoparasites around the world. This review includes information regarding the main form of controlling poultry mites through the use of commercially available chemicals. In addition, non-chemical measures against blood-sucking mites were discussed such as extracts and oils from plants and seeds, entomopathogenic fungi, semiochemicals, powder such as diatomaceous earth and silica-based products, and vaccine candidates. The control of poultry mites using chemical methods that are currently used to control or eliminate them are proving to be less effective as mites develop resistance. In contrast, the products based on plant oils and extracts, powders of plant origin, fungi, and new antigens aimed at developing transmission-blocking vaccines against poultry mites provide some encouraging options for the rational control of these ectoparasites.

Management of the poultry red mite Dermanyssus gallinae with physical control methods by inorganic material and future perspectives

Poultry red mite (PRM), the ectoparasitic mite Dermanyssus gallinae found in laying hen farms, is a significant threat to poultry production and human health worldwide. It is a suspected disease vector and attacks hosts' other than chickens, including humans, and its economic importance has increased greatly. Different strategies to control PRM have been widely tested and investigated. In principle, several synthetic pesticides have been applied to control PRM. However, recent alternative control methods to avoid the side effects of pesticides have been introduced, although many remain in the early stage of commercialization. In particular, advances in material science have made various materials more affordable as alternatives for controlling PRM through physical interactions between PRM. This review provides a summary of PRM infestation, and then includes a discussion and comparison of different conventional approaches: 1) organic substances, 2) biological approaches, and 3) physical inorganic material treatment. The advantages of inorganic materials are discussed in detail, including the classification of materials, as well as the physical mechanism-induced effect on PRM. In this review, we also consider the perspective of using several synthetic inorganic materials to suggest novel strategies for improved monitoring and better information regarding treatment interventions.

Poultry Mites: Ubiquitous, Spreading, and Still a Growing Threat

Poultry mites continue to be a major threat to poultry meat and egg production all over the world, with some species being blood-feeding arthropods that spend most of their time off-host and others burrowing under the bird's skin. Regardless of feeding strategy, these mites create welfare issues and production losses in poultry production systems in terms of bird growth, egg quality, and egg quantity. Furthermore, some species are able to transmit pathogens, introducing secondary infections that affect the birds' development and survival. Because of national restrictions on acaricide use and the development of mite resistance to available control products, the eradication of poultry mites is far from being achieved. However, new drugs and a better understanding of mite genetic and transcriptomic factors should aid the development of new control and treatment strategies. This review focuses on the main poultry mite species, their significance, and their current and future control.

Lethal Effects of Commercial Kaolin Dust and Silica Aerogel Dust With and Without Botanical Compounds on Horn Fly Eggs, Larvae, Pupae, and Adults in the Laboratory

The horn fly, Haematobia irritans irritans (L.) (Diptera: Muscidae), is an important bloodsucking ectoparasite of cattle throughout much of the world. The fly is mostly controlled using conventional synthetic insecticides but as concerns about resistance increase, alternative tactics have come under heightened scrutiny. Four desiccant dust products: Surround WP, a kaolin clay-based wettable powder; CimeXa, comprised of silica aerogel; Drione, silica aerogel + pyrethrins; and EcoVia, silica aerogel + thyme oil, were assessed for their lethal effects against horn fly eggs, larvae, pupae, and adults, under laboratory conditions. Although Surround WP and CimeXa did not prevent egg hatching and (when mixed with manure substrate) pupal development, the two products were associated with moderate reductions of emerged adults, and with complete adult contact mortality within 6 hr and 24 hr, respectively. Drione and EcoVia eliminated egg hatching, pupal development, and adults within 15 min to 1 hr, respectively, whether the flies were exposed to treated filter paper substrate or exposed by immersion in the dusts. Implications for horn fly control and advantages of inert desiccant dust formulations are discussed.

Possibilities for IPM Strategies in European Laying Hen Farms for Improved Control of the Poultry Red Mite (Dermanyssus gallinae): Details and State of Affairs

The Poultry Red Mite (PRM), Dermanyssus gallinae, is a major threat to the poultry industry worldwide, causing serious problems to animal health and welfare, and huge economic losses. Controlling PRM infestations is very challenging. Conventionally, D. gallinae is treated with synthetic acaricides, but the particular lifestyle of the mite (most of the time spent off the host) makes the efficacy of acaracide sprays often unsatisfactory, as sprays reach only a small part of the population. Moreover, many acaricides have been unlicensed due to human consumer and safety regulations and mites have become resistant to them. A promising course of action is Integrated Pest Management (IPM), which is sustainable for animals, humans and the environment. It combines eight different steps, in which prevention of introduction and monitoring of the pest are key. Further, it focusses on non-chemical treatments, with chemicals only being used as a last resort. Whereas IPM is already widely applied in horticulture, its application is still in its infancy to control D. gallinae in layer houses. This review presents the currently-available possibilities for control of D. gallinae in layer houses for each of the eight IPM steps, including monitoring techniques, established and emerging non-chemical treatments, and the strategic use of chemicals. As such, it provides a needed baseline for future development of specific IPM strategies, which will allow efficient and sustainable control of D. gallinae in poultry farms.

Lethal Effects of a Silica Gel + Pyrethrins (Drione) on Amblyomma americanum (Ixodida: Ixodidae) Larvae and Nymphs

Ixodids (hard ticks) ingest blood from host animals, and they can transmit pathogenic organisms that induce medical and veterinary diseases. As resistance to synthetic conventional acaricides becomes more common, alternative tactics are coming under heightened scrutiny. Laboratory bioassays were used to assess the efficacy of CimeXa, a commercially available silica gel desiccant dust product, and Drione, a commercial product containing silica gel + pyrethrins and a synergist, piperonyl butoxide, against lone star tick, Amblyomma americanum (L.) (Ixodida: Ixodidae), larvae and nymphs. Both life stages were completely killed by CimeXa by 24 h, and Drione caused total larval mortality within 1 h when they were briefly immersed in the dusts and when they crawled across dust-treated substrate; nymphs were completely killed by 4 h after the same kinds of exposure. Mortality of A. americanum larvae and nymphs occurred after the pests crawled across dried aqueous suspensions of the products, but this was not as efficient and fast-acting as when the immature life stages were exposed to dry dusts. Further, dried aqueous suspensions of Drione were not substantially more lethal than dried aqueous suspensions of CimeXa. CimeXa and Drione will provide prophylactic control on vegetation and animals for as long as the silica gel remains without being physically removed. Both of the dust-based products will likely also be effective against other problematic ixodid species. Advantages and disadvantages, and potential uses, of desiccant dust-based acaricides are discussed.

Management of the poultry red mite, Dermanyssus gallinae, using silica-based acaricides

Four silica-based acaricides were examined in laboratory tests for their effectiveness against poultry red mite, Dermanyssus gallinae. All acaricides resulted in 100% mite mortality. Two groups of active ingredients could be differentiated. The products Silicosec® and Ewazid®, based on naturally occurring diatomaceous earth (DE), killed 100% of adult D. gallinae within 48 h exposure time. The time to kill 50% of the mites (LT50) was calculated to be 31.7 and 34.9 h, respectively. The other two products, containing aggregates and agglomerates of pyrogenic synthetic amorphous silicon dioxide as active ingredients, killed the mites in a significantly shorter time: LT50 was 6.3 h for the liquid product Fossil Shield® Instant White and 11.8 h for the powdery product Fossil Shield 90.0 White. This is more remarkable as the quantities of active ingredients used for the DE treatments were several folds higher. The effectiveness of all tested products was also shown in practical tests. A professional company treated five chicken houses on one farm in the Berlin-Brandenburg region with the test products, three houses with Fossil Shield Instant White and one each with Ewazid and Silicosec. Over a period of 46 weeks after stocking, the mite development in the houses was assessed. Only in one of the houses, treated with Fossil Shield Instant White, the mite population remained permanently low. In two houses treated with Fossil Shield Instant White, small mite colonies appeared in week 36, which were controlled by a follow-up spot treatment in week 41. In the houses treated with DE, the first mite colonies appeared 12 weeks after stocking. The number increased continuously over the experimental period and in week 31 after stocking there were clearly visible colonies (2-3 cm diameter) and the first mites could also be detected on the chicken eggs. At this time both houses were treated again with a follow-up spot-treatment, which only led to a slight improvement in one house and to a stabilization of the infestation in the other house. In week 41, large mite colonies were detected in both houses. A spot treatment at this point was ineffective in reducing the infestation. The tests showed faster acaricidal action of the products with the synthetic active ingredients compared to the natural DE-based products. This matches the shorter killing times under laboratory conditions. The experiments in a commercial chicken farm showed that it is possible to control the mite population for a period of 46 weeks by using physically effective SiO2-based products. These products are therefore an effective alternative to the use of chemical acaricides.

Lethal Effects of a Silica Gel + Thyme Oil (EcoVia) Dust and Aqueous Suspensions on Amblyomma americanum (Ixodida: Ixodidae) Larvae and Nymphs

Ixodids suck blood from host animals and transmit pathogens that cause important medical and veterinary diseases. As synthetic conventional acaricide resistance becomes increasingly common, alternative tactics are likely to enhance control efforts. Laboratory bioassays assessed the lethality of CimeXa, a commercial silica gel desiccant dust, and EcoVia, a commercial product containing silica gel + thyme oil, against lone star tick, Amblyomma americanum (L.), larvae and nymphs. Both life stages were completely killed by CimeXa by 24 h, and EcoVia achieved total larval mortality within 1 h when they were initially immersed in the dusts and when they crawled across treated substrate. Larvae were killed faster than nymphs. Temporary immersion of A. americanum larvae and nymphs in aqueous suspensions of the dusts were less effective than exposure to the dusts applied dry. Larval and nymphal mortality associated with crawling on dried aqueous suspensions of the products was also not as strong as when the immature life stages crawled across substrate treated with dry dusts, and EcoVia was not more efficient than CimeXa. CimeXa and EcoVia can likely be used to protect cattle in a prophylactic context because silica gel does not degrade, and EcoVia might be effective at eliminating ticks that are feeding on cattle as well. We suggest that the two dust products be assessed for efficacy against other ixodid species, such as the southern cattle fever tick, Rhipicephalus microplus (Canestrini), which transmits the causal agents of babesiosis to cattle.

Association of mechanical cleaning and a liquid preparation of diatomaceous earth in the management of poultry red mite, Dermanyssus gallinae (Mesostigmata: Dermanyssidae)

The poultry red mite (PRM), Dermanyssus gallinae, is an ectoparasite of great importance related to poultry farms worldwide. Problems associated with its control have led to the search for alternative treatments, especially using inert dust, which has recently been introduced into liquid formulations. Therefore, the objective of this work was to evaluate the acaricidal activity of a liquid diatomaceous earth (DE) preparation in the laboratory and its association with mechanical cleaning (brushing) in the field. In the laboratory it was first determined that a concentration of 10% DE would be necessary for field applications. The field experiment was conducted in a commercial poultry house. The 10% DE liquid preparation was administered in three applications and associated to mechanical cleaning. Then, 42 days after the first DE application, a population reduction of 94.7% was observed in relation to the initial population of mites. These results confirm the efficiency of DE applications in association with mechanical cleaning already adopted in poultry houses as an alternative for the control of D. gallinae, which can also contribute to avoiding mite resistance to chemical acaricides.

Effects of Silica-Based CimeXa and Drione Dusts Against Lone Star Tick (Ixodida: Ixodidae) on Cattle

Ixodid ticks vector pathogens of humans, livestock, and wildlife, and occur in tropical and temperate regions worldwide. We used the lone star tick, Amblyomma americanum (L.) (Ixodida: Ixodidae), as a model for other ixodid species, including the southern cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini) (Ixodida: Ixodidae). We assessed the lethality of CimeXa, an inert silica-based desiccant dust, and Drione, a silica-based desiccant dust with pyrethrin and piperonyl butoxide (PBO), against A. americanum larvae and nymphs on calves. CimeXa was highly lethal to larvae released onto shaved calf skin 72-96 h previously, and moderately toxic to nymphs. It did not affect immature life stages treated after they began feeding because desiccation was offset by ingestion of blood. Being inert, CimeXa can protect cattle from infestation before feeding occurs for a potentially indefinite period of time. Drione killed immatures within 24 h when released on treated skin and when applied to feeding ixodids because of the pyrethrin and PBO (PBO will also reduce resistance to pyrethrin if it develops). When CimeXa was applied to calves with the hair intact, ≈90% and ≈70% of A. americanum larvae and nymphs, respectively, were killed within 24 h and Drione killed 100% of each life stage. Drione also prevented and drastically reduced egg production and hatching. While CimeXa protects against infestation by immatures, Drione will also control ticks that are feeding. When pyrethrin and PBO in Drione eventually degrade, the silica aerogel carrier can continue to protect against infestation indefinitely.

Lethal Effects of Silica Gel-Based CimeXa and Kaolin-Based Surround Dusts Against Ixodid (Acari: Ixodidae) Eggs, Larvae, and Nymphs

As tick resistance to conventional acaricides becomes more common, alternative control tactics are gaining attention. Insecticidal dusts CimeXa and Surround, based on silica gel and kaolin, respectively, were assessed against Amblyomma americanum (L.) (Ixodida: Ixodidae) eggs, larvae, and nymphs in the laboratory. Coverage by the dry dusts, particularly CimeXa, was strongly lethal to larvae and to a lesser extent to nymphs. Larval mortality was also high when larvae crawled across thin layers of CimeXa and, to a lesser extent, Surround dusts. CimeXa was more lethal to nymphs that crawled across a thin layer than Surround. Larval mortality after crawling on dried aqueous suspensions of the dusts for 30 min and for 48 h caused moderate mortality (<80%) regardless of a 10-fold difference in concentration; nymphal mortality was negligible. In a field experiment, CimeXa dust strongly reduced numbers of Gulf coast tick, Amblyomma maculatum (Koch) (Ixodida: Ixodidae), larvae and nymphs by 24 h. Possible application of CimeXa to control other species of ixodid ticks is discussed as well as advantages and disadvantages of using dusts for tick control under field conditions.

The acaricidal speed of kill of orally administered fluralaner against poultry red mites (Dermanyssus gallinae) on laying hens and its impact on mite reproduction

BACKGROUND

Dermanyssus gallinae, the poultry red mite, is a growing threat to chickens in poultry farms. This nocturnal hematophagous ectoparasite has a rapid rate of proliferation with a negative impact on the birds' health, welfare and productivity resulting in severe economic consequences for poultry farmers. A study was performed with fluralaner, a novel systemic ectoparasiticide, to evaluate its effect on mite vitality and reproduction after oral administration to laying hens.

METHODS

Sixteen healthy hens were randomly allocated to two study groups (n = 8). One group was orally treated with fluralaner by gavage at a dose of 0.5 mg/kg bodyweight twice 7 days apart. The negative control group received no treatment. Hens in each group were repeatedly infested with approximately 200 unfed adult D. gallinae at 1, 5, 8, 12, 15, 19, 22 and 26 days after the initial administration. After infestation and feeding for 2.5 h, 25 engorged mites per hen were collected and incubated in tubes. Mites were assessed for vitality (dead/live) at 4, 8, 12, and 24 h after each infestation. Tubes containing eggs and/or living mites were incubated another 8 days for assessment of mite reproductive capacity.

RESULTS

Fluralaner demonstrated a fast speed of kill in mites within 4 h post-infestation for 12 days after treatment initiation. An efficacy (mite mortality) of 98.7-100% was achieved. At 15 days after treatment initiation, 100% efficacy was achieved within 24 h post-infestation, and no mite oviposition occurred during this period. Nineteen days after treatment initiation, the mites' ability to generate nymphs was reduced by 90.8%, which decreased to < 24.1% at later infestations.

CONCLUSIONS

Fluralaner administered orally to hens twice, 7 days apart, provides efficacy against experimental poultry red mite infestation for at least 2 weeks. The demonstrated rapid speed of kill results in substantial depletion of the mites' oviposition and suggests that fluralaner can be an effective tool in the control of D. gallinae, one of the most urgent problems in poultry farms.

Repellent activity of desiccant dusts and conidia of the entomopathogenic fungus Beauveria bassiana when tested against poultry red mites (Dermanyssus gallinae) in laboratory experiments

Desiccant dusts and entomopathogenic fungi have previously been found to hold potential against the poultry red mite, which is an important pest in egg production and notoriously difficult to control. Both control agents may cause repellence in other arthropods and potentially also influence control levels adversely when used against the poultry red mite. Five desiccant dust products with good efficacy against the poultry red mite Dermanyssus gallinae caused avoidance behavior in mites when tested in bioassays. The repellent activity was correlated with efficacy, which was found to depend on both dose and relative humidity (RH). However, one desiccant dust was significantly less repellent compared to other dusts with similar levels of efficacy. Further, dry conidia of the fungus Beauveria bassiana were also shown to be repellent to poultry red mites, both when applied on its own and when admixed with a low dose of the desiccant dust Diamol. The pick-up of desiccant dust particles and fungus conidia from treated surfaces by mites did not differ depending on RH, whereas the overall efficacy of the two control agents were significantly higher at 75 than at 85 % RH. In addition, the combined effect of the two substances was synergistic when tested in a bioassay where mites could choose whether to cross a treated surface. This is the first time a member of Acari has been shown to be repelled by desiccant dusts and by conidia of an entomopathogenic fungus.

Understanding the biology and control of the poultry red mite Dermanyssus gallinae: a review

Dermanyssus gallinae, the poultry red mite (PRM), is a blood-feeding ectoparasite capable of causing pathology in birds, amongst other animals. It is an increasingly important pathogen in egg layers and is responsible for substantial economic losses to the poultry industry worldwide. Even though PRM poses a serious problem, very little is known about the basic biology of the mite. Here we review the current body of literature describing red mite biology and discuss how this has been, or could be, used to develop methods to control PRM infestations. We focus primarily on the PRM digestive system, salivary glands, nervous system and exoskeleton and also explore areas of PRM biology which have to date received little or no study but have the potential to offer new control targets.