Phasmids Entomopathogenic Fungi

Entomopathogenic fungi represent a specialized group of fungal organisms that have evolved to infect, parasitize, and ultimately kill insects, making them among the most serious and deadly health threats facing captive phasmid populations. These fungi include species from several genera, most notably Beauveria, Metarhizium, and Cordyceps, which have developed sophisticated mechanisms to breach the insect exoskeleton, colonize internal tissues, and produce spores for transmission to new hosts. For stick insects and leaf insects, infection with entomopathogenic fungi typically represents a fatal condition with very limited treatment options, making prevention the essential focus of management.

Phasmids are susceptible to entomopathogenic fungi throughout their life cycle, from newly hatched nymphs to mature adults, though certain life stages and conditions increase vulnerability. These fungi are ubiquitous in natural environments where they serve as important population regulators for many insect species. While phasmids have evolved some resistance mechanisms, captive conditions can undermine natural defenses while simultaneously creating environments favorable for fungal proliferation. The combination of weakened host immunity and enhanced pathogen opportunity creates conditions where outbreaks can devastate entire collections.

The impact of entomopathogenic fungal infection on phasmid health is profound and typically fatal. Once fungal spores germinate on the cuticle and penetrate into the body cavity, the infection progresses inexorably as fungal hyphae consume internal tissues. The insect's hemolymph system becomes colonized, immune responses are overwhelmed, and vital organs are destroyed. Infected individuals typically die within one to two weeks of initial infection, depending on fungal species, inoculum load, and environmental conditions. Even before death, infected insects may display dramatic behavioral changes as the fungus manipulates host behavior to optimize spore dispersal.

Treatability of entomopathogenic fungal infections in phasmids is extremely limited to nonexistent with currently available methods. Unlike vertebrate animals, insects lack the complex adaptive immune systems that can clear systemic fungal infections, and no effective antifungal treatments have been established for invertebrate medicine. Some environmental manipulations may slow disease progression or reduce transmission, but once an individual shows overt signs of infection, recovery is highly unlikely. This reality underscores the critical importance of biosecurity measures, quarantine protocols, and environmental management in preventing introduction and spread of these devastating pathogens.

The primary cause of entomopathogenic fungal disease in phasmids is exposure to and penetration by specialized fungal spores adapted to exploit insect hosts. Several fungal species are responsible, with Beauveria bassiana and Metarhizium anisopliae being among the most common and well-studied. These fungi produce vast numbers of microscopic spores called conidia that can persist in the environment for extended periods. When spores contact the cuticle of a susceptible phasmid, they adhere through specialized structures and chemical processes, germinate, and penetrate the exoskeleton using a combination of enzymatic degradation and mechanical pressure from specialized penetration structures called appressoria.

Environmental factors play crucial roles in determining whether exposure to fungal spores leads to active infection. High humidity strongly favors germination and penetration of fungal spores, creating a paradox for phasmid keepers since many species require elevated humidity for successful molting. Temperatures between approximately twenty and thirty degrees Celsius generally favor the entomopathogenic fungi most common in captive settings. Poor ventilation that allows stagnant humid air creates ideal conditions for spore persistence and germination. Contaminated substrate, particularly organic substrates that have become wet and decomposing, can harbor tremendous fungal loads. Even food plants can carry fungal spores collected from the environment.

Husbandry-related causes frequently contribute to entomopathogenic fungal outbreaks in captive phasmid populations. Overcrowding increases both the stress that compromises immune function and the contact rates that facilitate transmission. Inadequate enclosure cleaning allows accumulation of frass and debris that can support fungal growth. Failure to quarantine new specimens introduces risk of bringing infected individuals or contaminated materials into established colonies. Poor food plant hygiene, including use of plants from areas where entomopathogenic fungi are applied as biopesticides, can directly introduce fungal spores. Cross-contamination through shared equipment, unwashed hands, or improper disposal of infected specimens spreads pathogens between enclosures.

Risk factors that increase susceptibility to entomopathogenic fungal infection include any condition that weakens the phasmid or compromises its cuticular defenses. Freshly molted insects are particularly vulnerable because their new cuticle has not yet fully hardened and may lack the complete chemical defenses present in mature exoskeleton. Insects stressed by inappropriate temperature, inadequate nutrition, or overcrowding mount weaker immune responses. Cuticular damage from handling, fighting, or previous molt problems creates direct entry points for fungal penetration. Wild-caught specimens may carry subclinical infections that activate under stress, and they may introduce novel pathogen strains to captive collections.

The disease mechanism of entomopathogenic fungi involves a sophisticated multi-stage process that has evolved over millions of years. After spore adhesion and germination on the cuticle, fungal hyphae penetrate through the exoskeleton by secreting a cocktail of enzymes including proteases, chitinases, and lipases that break down cuticular components. Once inside the body cavity, the fungus switches to a yeast-like growth phase that evades host immune cells, proliferating freely in the hemolymph. As fungal biomass increases, the insect's internal organs are consumed, and toxins produced by the fungus further damage tissues and suppress immune function. Eventually, the fungus kills the host and transitions to a sporulating phase, producing masses of new spores that typically erupt through the cuticle to disperse into the environment and infect new hosts.

Early warning signs of entomopathogenic fungal infection in phasmids can be subtle and easily missed, particularly in the initial days following spore penetration. Behavioral changes often appear before overt physical symptoms, with infected individuals showing reduced activity levels and decreased responsiveness to stimuli. Slight changes in posture may be noticeable, with insects appearing less firmly attached to perches or showing minor coordination difficulties. Appetite reduction commonly occurs early in infection as the fungus begins to consume host resources and produce metabolic toxins. These early signs are nonspecific and could indicate various health issues, making differential diagnosis challenging at this stage.

Physical symptoms of entomopathogenic fungal infection become increasingly apparent as the disease progresses. The exoskeleton may develop unusual discoloration, appearing duller, darker, or showing patches of abnormal color as fungal structures develop beneath or within the cuticle. Small spots or patches of white, green, or other colored material may become visible on the body surface, representing areas where fungal growth is beginning to penetrate outward. In some cases, the integument appears swollen or abnormally textured in localized areas. The distinctive fuzzy or powdery appearance of sporulating fungus typically appears only in advanced infection or post-mortem, but earlier stages may show subtle surface abnormalities detectable upon close examination.

Behavioral changes intensify as entomopathogenic fungal infection progresses. Affected phasmids often become increasingly lethargic, remaining motionless for extended periods and failing to exhibit normal nocturnal activity patterns. Movement when it occurs may appear uncoordinated or jerky, reflecting neurological effects of fungal toxins. Some infected individuals exhibit abnormal positioning behavior, climbing to elevated positions in the enclosure and gripping tightly in exposed locations, a phenomenon called summiting behavior that is induced by fungal manipulation of host behavior to optimize spore dispersal. Feeding typically ceases entirely in the later stages of infection, and the insect may become unresponsive to stimulation.

Molting-related symptoms can intersect with entomopathogenic fungal infection, as the molting period represents a time of heightened vulnerability. Fungal infection may trigger or complicate molting failure, with infected insects unable to complete ecdysis successfully. Alternatively, the stress and cuticle disruption of molting may allow previously subclinical infections to become active and progress rapidly. Post-molt insects are especially susceptible to new infection, and keepers may observe that newly molted individuals succumb to fungal disease while older, hardened individuals in the same enclosure remain unaffected initially.

Symptom progression in entomopathogenic fungal infection follows a relatively predictable course once established. After initial penetration and a variable incubation period typically lasting several days, behavioral and subtle physical symptoms emerge. Over the following days, the insect's condition deteriorates as fungal biomass increases and organ function is compromised. Activity decreases progressively, feeding ceases, and body condition visibly declines. The terminal phase involves the insect becoming nearly or completely immobile, often in an elevated position, followed by death. Post-mortem, the fungus completes its life cycle by producing sporulating structures that may extensively cover the body surface, creating a characteristic fuzzy, cotton-like appearance in many species.

Critical and emergency symptoms indicating advanced entomopathogenic fungal infection include any visible fungal growth on the body surface, complete cessation of movement and feeding, failure to respond to any stimulation, and the characteristic abnormal positioning associated with summiting behavior. An insect found dead in an elevated position with unusual body coloration should be assumed to have died from fungal infection until proven otherwise. The appearance of fuzzy white, green, or other colored fungal growth on a dead specimen confirms the diagnosis. Any observation of these signs necessitates immediate isolation of affected individuals, thorough evaluation of all other specimens in the enclosure, and implementation of aggressive decontamination protocols to prevent epidemic spread.

Visual examination is the primary diagnostic tool for entomopathogenic fungal infection in phasmids, though definitive identification typically requires microscopy or laboratory culture that is unavailable to most keepers. Initial assessment should carefully evaluate the entire body surface under good lighting, preferably with magnification, looking for any abnormal discoloration, texture changes, or visible fungal structures. The joints between body segments, the bases of legs, and areas around the head and mouthparts often show early signs of infection. Comparison with healthy individuals of the same species helps identify subtle abnormalities. The presence of visible sporulating fungus, appearing as fuzzy, powdery, or cotton-like growth, strongly supports diagnosis though this often appears only post-mortem.

Behavioral observation provides important diagnostic information that complements physical examination. Infected phasmids typically show progressive lethargy, reduced feeding, abnormal posture or positioning, and uncoordinated movement. The characteristic summiting behavior, where the insect climbs to an elevated exposed position and grips tightly, is highly suggestive of entomopathogenic fungal infection though not absolutely diagnostic. Tracking individual behavior over time helps identify the progressive decline characteristic of active infection. Sudden death in apparently healthy individuals should prompt careful examination for fungal evidence and consideration of subclinical infection.

Environmental parameter assessment is essential when entomopathogenic fungal infection is suspected, both for confirming conditions favorable to fungal pathogens and for identifying management changes to limit spread. High humidity combined with poor ventilation creates optimal conditions for these fungi. Temperature should be evaluated against the known optimal ranges for common entomopathogenic fungi. Substrate condition should be assessed for excessive moisture, organic debris accumulation, or visible mold growth. The history of any recent additions to the enclosure, including new insects, food plants, or substrate, should be investigated as potential sources of introduction.

Differential diagnosis for suspected entomopathogenic fungal infection should consider other conditions that may present similarly. Bacterial infections can cause lethargy, abnormal coloration, and death, though they typically lack the characteristic fungal growth seen post-mortem. Saprophytic fungi that grow on dead or dying insects can be confused with pathogenic species, though saprophytes typically colonize only after death rather than causing death. Viral infections, while less well documented in phasmids, could cause similar systemic disease. Natural senescence in aging adults may produce some similar symptoms though without the characteristic fungal signs. Toxin exposure from contaminated food plants can cause acute death without fungal involvement. Careful observation of symptom progression, examination of any deceased individuals, and evaluation of environmental conditions help distinguish among these possibilities.

Environmental correction is the primary management approach for entomopathogenic fungal infection, though it cannot cure established infections and serves mainly to limit spread and reduce conditions favorable to the pathogen. Reducing humidity while maintaining levels adequate for the phasmids' survival creates less favorable conditions for fungal spores. Improving ventilation helps prevent the stagnant humid microclimates where fungi thrive. Raising temperature slightly above optimal for common entomopathogenic fungi while staying within the safe range for the phasmids may slow fungal development. Thorough cleaning of enclosures, removal and replacement of contaminated substrates, and elimination of organic debris reduce environmental fungal loads.

Supportive care for phasmids with suspected or confirmed entomopathogenic fungal infection focuses on optimizing conditions to support whatever immune response the insect can mount while preventing transmission to others. Immediate isolation of affected individuals is essential, using a separate enclosure that can be disposed of or thoroughly decontaminated afterward. Maintaining temperature at the upper end of the species' preferred range may help stimulate immune function. Providing high-quality fresh food encourages feeding to maintain strength. However, keepers should have realistic expectations, as true supportive care options for systemic fungal infection in invertebrates are extremely limited.

Medical treatment options for entomopathogenic fungal infection in phasmids are essentially nonexistent with any proven efficacy. No antifungal medications have been established as safe and effective for insect use. Some keepers have experimented with treatments including dilute antifungal solutions applied topically, adjustment of environmental conditions, or transfer to sterile environments, but none of these approaches have demonstrated reliable curative effects once systemic infection is established. The fundamental biology of insect immunity, which lacks the adaptive immune responses of vertebrates, means that systemic infections cannot be cleared through host defenses even with supportive interventions. Treatment attempts should not be allowed to delay aggressive biosecurity measures needed to protect unaffected specimens.

Quarantine and containment protocols are critical components of managing entomopathogenic fungal outbreaks. Any suspected infected individual should be immediately isolated in a dedicated quarantine enclosure. Equipment used with infected specimens must not contact healthy colonies without thorough decontamination. Personal hygiene including handwashing and changing of clothing between handling infected and healthy groups reduces mechanical transmission. Quarantine enclosures should be maintained in a separate room if possible, or at minimum well away from healthy colonies with separate airflow. New acquisitions should undergo extended quarantine periods of at least thirty days before introduction to established populations.

Treatment monitoring during management of entomopathogenic fungal cases involves careful observation for disease progression in isolated individuals and surveillance for spread in exposed populations. Isolated infected individuals should be monitored for symptomatic progression to confirm the diagnosis and track disease course. All other individuals in the source enclosure should be considered exposed and monitored closely for signs of infection. Any additional cases should be immediately isolated. Environmental conditions should be monitored and maintained at levels less favorable for fungal development. Documentation of cases, including photographs and observations, helps track the outbreak and informs future prevention efforts.

Recognizing when treatment is not viable is essential given the extremely poor prognosis for entomopathogenic fungal infection. Once an individual shows clear signs of systemic infection including visible fungal growth, complete cessation of feeding, and advanced lethargy, recovery is essentially impossible with currently available methods. Continued housing of such individuals risks ongoing spore production and transmission to others. Humane euthanasia through freezing is appropriate for advanced cases. Dead specimens should be disposed of carefully, preferably by freezing followed by sealed disposal or incineration, to prevent spore dispersal. Enclosures, equipment, and materials that housed infected individuals should be discarded or subjected to rigorous decontamination before reuse.

Recovery timeline for entomopathogenic fungal infection in phasmids is extremely poor, with genuine recovery from established systemic infection essentially undocumented. If infections are detected and addressed at the very earliest stages, before significant fungal penetration and internal colonization has occurred, there is a theoretical possibility that environmental modification and the insect's own defenses might prevent progression. However, by the time symptoms are recognizable, infection has typically advanced beyond any realistic hope of cure. Survival following confirmed entomopathogenic fungal infection should be considered exceptional and may represent misdiagnosis rather than true recovery.

Post-outbreak care for surviving colony members focuses on preventing progression of subclinical infections and reducing the risk of new transmission. All survivors from an enclosure where entomopathogenic fungal infection occurred should be considered potentially exposed. Moving survivors to completely clean enclosures with new substrates and furnishings removes them from contaminated environments. Environmental conditions should be optimized while maintaining slightly reduced humidity that disfavors fungal development. Close observation for any symptoms should continue for several weeks. Some keepers advocate temporary isolation of all exposed individuals, though this may be impractical for larger colonies.

Prognosis factors for colony survival following an entomopathogenic fungal outbreak include the speed of detection and response, the extent of spread before containment, the thoroughness of decontamination efforts, and the susceptibility of the species being kept. Early detection of initial cases before widespread spore dispersal has occurred greatly improves the chance of containing the outbreak. Complete removal and replacement of contaminated materials reduces environmental pathogen load. Some phasmid species may have greater natural resistance than others, though this is not well documented. Prior colony health status may influence individual ability to resist infection.

Long-term considerations following entomopathogenic fungal outbreaks in phasmid collections include implementing improved biosecurity practices, considering changes to husbandry that reduce fungal risk, and potentially rebuilding colonies from verified clean stock. Learning from outbreaks to identify likely sources of introduction helps prevent recurrence. Modifying environmental management to reduce conditions favorable to pathogenic fungi while still meeting species needs requires careful balance. Thoroughly decontaminated or replaced enclosure equipment and substrates eliminate environmental reservoirs. In severe cases where contamination is extensive, complete depopulation followed by thorough facility decontamination and restocking with certified clean specimens may be the most effective approach to eliminating the pathogen.

Proper husbandry forms the foundation for preventing entomopathogenic fungal infections in phasmid collections. Maintaining clean enclosures with appropriate but not excessive humidity reduces fungal proliferation. Regular removal of frass, shed skins, and uneaten food prevents accumulation of organic material that can support fungal growth. Substrate management is particularly important, with many keepers preferring inert substrates or paper towels that can be frequently changed over organic materials that may harbor pathogens. Good enclosure ventilation prevents the stagnant humid conditions that favor fungal spores. Overall husbandry that promotes phasmid health helps maintain immune competence that provides first-line defense against infection.

Environmental control specifically targeting fungal risk involves managing the humidity paradox that many phasmids require high humidity for successful molting while high humidity also favors fungal pathogens. Strategies include providing humidity gradients within enclosures so insects can select microhabitats, timing misting to allow drying periods rather than maintaining constant wetness, using spot misting at molting sites rather than overall enclosure saturation, and ensuring excellent ventilation to prevent stagnant humid zones. Temperature management within species-appropriate ranges while avoiding conditions optimal for common entomopathogenic fungi provides some additional protection.

Quarantine protocols for new specimens are absolutely essential for preventing introduction of entomopathogenic fungi into established collections. All new acquisitions, regardless of source, should undergo quarantine for a minimum of thirty days before any contact with established colonies. Quarantine enclosures should be maintained in separate spaces using dedicated equipment. New animals should be carefully observed throughout quarantine for any signs of infection. Some keepers recommend even longer quarantine periods of sixty to ninety days for higher-value specimens or those from uncertain sources. Food plants should ideally be sourced separately for quarantine and main colonies until new specimens are cleared.

Stress reduction supports phasmid immune function and reduces susceptibility to opportunistic infections including fungal pathogens. Overcrowding should be avoided as it increases both stress and contact rates for disease transmission. Appropriate environmental conditions including suitable temperature, humidity, and lighting reduce physiological stress. Adequate food supply and appropriate diet support nutritional status and immune competence. Minimizing handling and disturbance reduces mechanical stress and prevents cuticular damage that could serve as entry points for pathogens. Stable conditions without frequent dramatic changes help insects maintain homeostasis.

Preventive monitoring enables early detection of potential fungal issues before they become epidemic. Regular close observation of all specimens allows identification of behavioral or physical changes that might indicate early infection. Any individuals showing suspicious symptoms should be immediately isolated for closer observation. Periodic thorough examination of enclosure conditions, including substrate, furnishings, and microclimates, helps identify developing problems. Mortality should be investigated rather than simply removed, with careful examination of dead specimens for fungal evidence. Environmental monitoring including humidity and temperature logging helps identify conditions that might favor pathogen development.

Enclosure maintenance takes on particular importance when managing entomopathogenic fungal risk in phasmid collections. Regular thorough cleaning removes organic material that could support fungal growth, but cleaning must be balanced against disturbance stress. Spot cleaning to remove frass and uneaten food can be done frequently with minimal disturbance, while more complete enclosure breakdowns for deep cleaning can occur periodically. All removed materials should be disposed of appropriately, particularly following any disease concerns. Cleaning equipment should ideally be dedicated to specific enclosures or thoroughly disinfected between uses. After any confirmed fungal infection, affected enclosures should either be discarded or subjected to rigorous disinfection with appropriate antifungal agents followed by thorough rinsing.

Environmental parameters in ongoing enclosure management should aim to provide appropriate conditions for the phasmids while minimizing fungal risk where possible. Humidity should be maintained at the lower end of the acceptable range for the species rather than maximizing it. Achieving this while ensuring successful molting may require strategic approaches like temporary humidity boosts during observed pre-molt periods followed by return to lower baseline levels. Temperature should stay within appropriate ranges for the species. Ventilation should be excellent, using enclosure designs that allow air movement without creating drafts. Light cycles should follow appropriate patterns for the species, as some evidence suggests UV exposure may have antimicrobial effects.

Feeding and nutrition practices impact both overall health and fungal disease risk. Fresh food plants should be provided regularly, with uneaten portions removed before they wilt and decompose. Food plant sources should be carefully considered, avoiding collection from areas where entomopathogenic fungi might be applied as biopesticides and avoiding plants that might harbor fungal spores. Some keepers rinse or briefly soak food plants before offering to remove surface contaminants, though this must be followed by drying to prevent introducing excess moisture. Adequate nutrition supports immune function that helps resist infection. Food plant containers should be managed to prevent drowning risk while avoiding water spillage that increases enclosure humidity.

Handling considerations in colonies at risk for entomopathogenic fungi emphasize biosecurity above all. Hands should be washed before and after handling any specimens. If managing multiple enclosures, work with healthy groups before moving to any quarantine or suspect groups, and wash thoroughly before returning to healthy animals. Equipment should be dedicated to specific enclosures or disinfected between uses. Any specimens showing potential disease symptoms should not be handled with bare hands. Gloves may be appropriate for working with suspect animals and should be discarded after single use. Minimizing overall handling reduces both stress and opportunities for mechanical pathogen transmission.

Long-term health monitoring in phasmid colonies should include ongoing surveillance for entomopathogenic fungal disease. Regular behavioral observation helps identify early changes that might indicate developing health problems. Mortality tracking including examination of dead specimens provides crucial information about colony health and potential disease presence. Environmental condition logging helps identify trends that might increase disease risk. Health records maintained over time enable recognition of patterns that might indicate emerging problems. Any specimens dying with fungal involvement should prompt heightened surveillance and possible prophylactic measures for remaining animals. Building relationships with entomologists or veterinarians familiar with invertebrates provides resources for consultation when health concerns arise.

High-risk species and groups for entomopathogenic fungal infection include phasmids with particularly high humidity requirements that create conditions favoring fungal pathogens. Tropical rainforest species from genera such as Phyllium, many Heteropteryx, and various New Guinean phasmids require elevated humidity that, if not carefully managed, can promote fungal proliferation. Large-bodied species have greater surface area for spore deposition and may be less able to groom effectively. Species with limited natural ranges may have reduced genetic diversity in immune function. Captive populations with limited genetic diversity due to small founder populations may similarly lack resilience to pathogen challenge.

Sensitivity to entomopathogenic fungi varies among phasmid species, with some proving more resilient than others under similar conditions. Hardy species that tolerate a range of environmental conditions, such as Carausius morosus and Sipyloidea sipylus, may show better resistance though they remain susceptible under heavy pathogen challenge. Species from seasonally variable habitats may have more robust immune responses adapted to fluctuating pathogen pressures. Individual variation within species also influences susceptibility, with stressed, injured, or nutritionally compromised individuals more vulnerable. Wild-caught specimens may carry novel pathogen strains or have compromised immune status from capture and transport stress.

Life stage considerations significantly influence vulnerability to entomopathogenic fungal infection. Freshly molted individuals are at highest risk, as the new cuticle has not yet fully hardened or developed complete chemical defenses, and the physical disruption of molting may damage existing cuticular barriers. Early instar nymphs with less developed immune systems and smaller body reserves may succumb more quickly to infection. Conversely, healthy adults with fully hardened cuticle may resist surface spore penetration more effectively. Stressed individuals at any life stage show reduced resistance. Gravid females under reproductive stress may be more susceptible. Understanding these life stage vulnerabilities helps target protective measures during highest-risk periods.

Commonly co-occurring conditions with entomopathogenic fungal infection include other opportunistic infections that take advantage of the immunocompromised state of affected insects. Secondary bacterial infections may develop at sites of fungal penetration or in insects weakened by fungal disease. Saprophytic fungi may colonize dying or dead insects, sometimes making it difficult to distinguish primary pathogens from secondary colonizers. Stress-related conditions including molt failure may co-occur, as the same husbandry problems that increase fungal risk also predispose to other health issues. Dehydration may accompany fungal infection as affected insects cease drinking.

Conditions with similar symptoms to entomopathogenic fungal infection include other causes of systemic illness in phasmids. Bacterial septicemia can cause lethargy, abnormal coloration, and death without the characteristic fungal sporulation, though it may present quite similarly before death. Viral infections, while poorly documented in phasmids, could theoretically cause similar systemic disease. Nutritional deficiencies severe enough to cause death may present with progressive weakness and reduced feeding. Toxin exposure from contaminated food plants can cause rapid decline. Natural senescence in aging adults produces lethargy and reduced feeding followed by death. Distinguishing features of entomopathogenic fungal infection include the characteristic post-mortem sporulation and, in some cases, the specific behavioral manipulation like summiting behavior.

Complications of entomopathogenic fungal infection extend beyond the individual affected insect to threaten entire collections. The enormous numbers of spores produced by sporulating fungi create heavy environmental contamination that persists for extended periods. Secondary transmission to cage mates is common when infected individuals are not promptly identified and isolated. Environmental contamination may persist in enclosures even after removal of infected individuals, requiring thorough decontamination. Equipment and materials can serve as fomites for transmission between enclosures. Stressed survivors may have reduced reproductive success even if they escape infection. Valuable breeding lines may be lost if infections spread through colonies. The potential for catastrophic collection loss underscores the importance of aggressive prevention and rapid response to suspected cases.