How long can bedbugs survive in a dormant state?

Understanding Bed Bug Dormancy

What is Dormancy?

Distinguishing Dormancy from Diapause

Bedbugs enter a non‑feeding, inactive phase when environmental conditions become unfavorable. This phase can be described using two distinct concepts: dormancy and diapause. Understanding the difference clarifies how long the insects can persist without a blood meal.

Dormancy refers to an immediate, reversible reduction in metabolic activity triggered by short‑term stressors such as temperature drops or lack of hosts. The insects remain alive but conserve energy, resuming normal activity as soon as conditions improve. The duration of dormancy is limited by the species’ physiological reserves and typically does not exceed several months under optimal shelter.

Diapause is a hormonally programmed state that prepares the insect for prolonged adverse periods. It is initiated by predictable seasonal cues—photoperiod, temperature trends, or humidity changes—and involves genetic regulation that suppresses development and feeding. Diapause can sustain the organism for many months, often up to a year, because metabolic suppression is deeper and internal resources are allocated for long‑term survival.

Key distinctions:

Trigger: dormancy – immediate environmental stress; diapause – seasonal cues.
Physiology: dormancy – rapid metabolic slowdown; diapause – hormonally mediated suppression.
Duration: dormancy – weeks to a few months; diapause – several months to a year.
Reversibility: dormancy – immediate upon favorable change; diapause – requires specific environmental signals to terminate.

For bedbugs, the non‑feeding period observed in infested dwellings usually reflects dormancy, allowing survival for a few months without a host. When populations experience consistent seasonal patterns, a proportion may enter diapause, extending survivability well beyond the typical dormancy limit. Recognizing these mechanisms informs control strategies that target the insects at the appropriate stage of inactivity.

Environmental Triggers for Dormancy

Bedbugs enter a dormant state when external conditions become unfavorable for feeding and development. The decision to suspend activity is governed by specific environmental cues that signal impending scarcity or stress.

Temperature exerts the strongest influence. When ambient temperatures drop below approximately 10 °C (50 °F), metabolic processes decelerate, and insects adopt a low‑energy mode to conserve resources. Conversely, prolonged exposure to temperatures above 30 °C (86 °F) can also trigger dormancy, as heat accelerates dehydration and reduces survivability without a blood meal.

Relative humidity affects water balance. Humidity levels under 30 % increase desiccation risk, prompting bedbugs to seek shelter and reduce activity. Higher humidity (above 70 %) can facilitate fungal growth, another factor that encourages a dormant response.

Host availability serves as a direct nutritional cue. Extended periods without a blood source—typically more than two weeks—activate a physiological shutdown that prolongs survival until a suitable host reappears.

Photoperiod and seasonal light cycles provide indirect information about environmental stability. Shortening daylight hours in autumn correlate with declining temperatures, reinforcing the onset of dormancy.

Key environmental triggers:

Low temperature (< 10 °C)
High temperature (> 30 °C)
Low relative humidity (< 30 %)
Extended host absence (> 14 days)
Decreasing daylight duration

These factors collectively determine when bedbugs cease feeding and development, extending their viable lifespan in a dormant condition.

Factors Influencing Dormancy Duration

Temperature

Impact of Cold Temperatures

Cold exposure forces bedbugs into a dormant phase characterized by sharply reduced metabolic activity. Temperatures near 0 °C trigger diapause‑like behavior, allowing insects to conserve energy while physiological processes continue at a minimal rate.

Metabolic suppression extends survival, but prolonged exposure below freezing compromises cellular integrity. At 4 °C, individuals can remain viable for several months; at 0 °C, viability declines after approximately 4–6 weeks; exposure to –5 °C or lower leads to mortality within 1–2 weeks.

Key observations from laboratory and field studies:

4 °C: up to 120 days of quiescence with >80 % survival.
0 °C: 30–45 days before significant loss of viability.
–5 °C: 7–14 days, rapid decline in survivorship.
–10 °C: mortality typically within 3–5 days.

Cold temperatures thus impose a time‑limited barrier to dormancy. Survival duration shortens as temperature drops, with a critical threshold around –5 °C beyond which bedbugs cannot maintain a dormant state for more than a fortnight.

Impact of Moderate Temperatures

Bedbugs enter a dormant state when environmental conditions become unfavorable, reducing metabolic activity to minimal levels. Moderate temperatures, typically ranging from 10 °C to 25 °C, create conditions where the insects can remain inactive for extended periods without the severe stress imposed by extreme cold or heat.

At 10 °C, metabolic processes slow dramatically, allowing individuals to survive several months in dormancy. As temperatures rise toward 20 °C, metabolic rate increases modestly, shortening the viable dormant period to a few weeks. Temperatures above 22 °C accelerate physiological functions enough that prolonged inactivity becomes unsustainable, leading to mortality within weeks.

Empirical observations support these patterns:

10 °C: up to 6 months of viable dormancy.
15 °C: 2–3 months before survival declines.
20 °C: 1–2 months of sustained inactivity.
22–25 °C: 2–4 weeks before significant mortality.

Laboratory studies demonstrate that bedbugs maintain a stable internal water balance at these moderate ranges, but gradual depletion of stored reserves sets the upper limit for survival. The absence of extreme temperature stress prevents rapid desiccation, yet the modest metabolic demand still consumes energy reserves over time.

For pest‑management professionals, understanding the relationship between moderate ambient temperature and dormant longevity informs monitoring schedules. In cooler indoor environments, inspections should be conducted at intervals of several weeks to detect reactivation, whereas warmer settings require more frequent checks due to the shorter dormant window.

Humidity

Role of Moisture in Survival

Moisture availability directly influences the length of bedbug dormancy. When ambient relative humidity falls below the insects’ tolerance threshold, cuticular water loss accelerates, leading to rapid desiccation and mortality. Conversely, environments that maintain moderate to high humidity slow dehydration, allowing individuals to persist for extended periods without feeding.

Experimental observations indicate that at 75 % relative humidity, adult bedbugs can remain viable for several months, whereas at 30 % relative humidity, survival typically declines to a few weeks. Temperature interacts with humidity; higher temperatures increase metabolic demands and exacerbate water loss, shortening the dormant interval even in moist conditions.

Bedbugs exploit microhabitats that retain moisture, such as seams of upholstered furniture, cracks in wall panels, and under baseboards. These niches provide localized humidity that can be markedly higher than room averages, creating refuges that extend survivorship.

Key moisture‑related factors affecting dormancy:

Ambient relative humidity level
Temperature‑humidity interaction
Access to microhabitats with elevated moisture
Frequency of ambient humidity fluctuations

Controlling indoor humidity, for example by maintaining relative humidity below 50 % and improving ventilation, reduces the capacity of bedbugs to endure prolonged inactivity and supports eradication efforts.

Food Availability

The Necessity of Blood Meals

Bedbugs require blood to complete each developmental stage. After hatching, nymphs must ingest a full blood meal before they can molt to the next instar. The protein and lipids in the blood provide the energy and building blocks for cuticle synthesis, hormone regulation, and metabolic processes that drive growth.

A single feeding also supplies the nutrients necessary for egg production in adult females. Without a recent blood source, ovarian development stalls, and fecundity declines sharply. Consequently, the timing of meals directly influences population expansion.

When a host is unavailable, bedbugs enter a state of dormancy known as diapause. During this period, metabolic activity drops to a fraction of the normal rate, allowing the insect to rely on stored reserves. These reserves are derived exclusively from previous blood meals; no alternative food sources exist. The length of survival without feeding is therefore limited by the quantity and quality of the last intake.

Key physiological functions supported by blood meals:

Energy provision for molting and locomotion
Synthesis of cuticular proteins for exoskeleton formation
Production of vitellogenin and other reproductive proteins
Restoration of glycogen and lipid stores used during dormancy

If a bedbug exhausts its reserves, it cannot maintain cellular homeostasis, leading to irreversible decline. The necessity of blood intake therefore determines both the duration of dormancy and the capacity for resurgence once a host becomes accessible again.

Life Stage

Dormancy in Nymphs

Bed bug nymphs enter a quiescent phase when environmental conditions become unfavorable. During this state, metabolic activity drops dramatically, allowing individuals to persist without feeding.

Under optimal shelter (stable temperature 15‑20 °C, relative humidity ≥70 %), nymphs can remain dormant for up to 12 months. Survival beyond a year is rare but documented in laboratory studies.
At lower temperatures (5‑10 °C), metabolic suppression extends viability; reports indicate survival for 18 months, though activity resumes only when temperatures rise above 13 °C.
Desiccating environments (relative humidity ≤30 %) reduce dormancy length sharply. Nymphs typically survive no more than 4 months before dehydration becomes lethal.
Food deprivation alone does not limit dormancy if moisture and temperature remain within tolerable ranges; nymphs can outlast adults by several weeks because they possess less developed exoskeletons and lower water loss rates.

Key physiological mechanisms include reduced respiration, accumulation of cryoprotectants, and cuticular lipid adjustments that minimize water loss. When conditions improve, nymphs resume feeding, molt, and progress to the next developmental stage.

Dormancy in Adults

Adult bedbugs can enter a prolonged dormant phase when environmental conditions become unfavorable. During dormancy, metabolic activity drops to less than 10 % of the active rate, allowing individuals to conserve energy and reduce water loss.

Key factors influencing survival time:

Temperature: At 20 °C, adults typically survive 100–150 days without feeding. At 10 °C, the survivorship extends to 250–300 days. Temperatures below 5 °C increase mortality due to cellular damage.
Relative humidity: Humidity above 70 % supports longer dormancy by limiting desiccation. Below 50 %, water loss accelerates death within weeks, even at low temperatures.
Food availability: Absence of a blood meal is the primary trigger for dormancy; once a host becomes accessible, reactivation occurs within hours.

Laboratory studies confirm that adult bedbugs retain viability for up to a year under optimal low‑temperature, high‑humidity conditions. Field observations show that infestations can persist for several months during winter, reemerging when temperatures rise and hosts are present.

Dormancy in Eggs

Bedbug eggs enter a dormant phase when environmental conditions are unfavorable, allowing the embryo to pause development until conditions improve. Viable eggs have been documented surviving for several months without hatching, with reports of persistence up to six months under typical household temperatures (20 °C–25 °C) and moderate humidity (45%–55%). In cooler, drier environments—temperatures near 10 °C and relative humidity below 30%—egg viability can extend beyond nine months, occasionally approaching a full year.

Key variables influencing the length of dormancy include:

Temperature: Lower temperatures decelerate metabolic processes, prolonging the dormant period; higher temperatures accelerate development and reduce survival time.
Humidity: Reduced moisture limits embryonic activity, enhancing longevity; excess moisture promotes fungal growth and egg mortality.
Light exposure: Darkness favors dormancy, while prolonged illumination can trigger premature development.
Chemical exposure: Sublethal insecticide residues may delay hatching but also increase mortality risk.

When conditions become optimal—temperatures above 22 °C, humidity around 50%–70%, and darkness—embryos resume development, typically completing the incubation cycle within 7–10 days. Consequently, the dormant capacity of bedbug eggs contributes significantly to the species’ ability to persist in infested dwellings despite periods of neglect or treatment.

Scientific Research and Observations

Laboratory Studies on Survival

Controlled Environment Experiments

Controlled environment studies provide the most reliable data on the maximum period bedbugs can remain viable without feeding. Researchers typically isolate adult and nymphal specimens in climate‑controlled chambers, adjusting temperature (5 °C to 30 °C) and relative humidity (30 % to 80 %). Each cohort is deprived of blood meals and monitored at regular intervals for movement, respiration, and response to tactile stimulation. Survival is recorded until no physiological activity can be detected for three consecutive assessments.

Key methodological elements include:

Temperature regimes: Low (5–10 °C), moderate (15–20 °C), high (25–30 °C).
Humidity levels: Dry (30–40 %), moderate (50–60 %), humid (70–80 %).
Specimen stage: Adult females, adult males, 3rd‑instar nymphs.
Assessment frequency: Daily for the first month, then weekly.
Endpoints: Loss of coordinated movement, failure to recover after a 5‑minute CO₂ stimulus, and absence of detectable metabolic heat.

Results consistently show that cooler temperatures and higher humidity extend dormancy viability. Under 5 °C and 80 % humidity, adults have been documented to survive up to 400 days, whereas at 25 °C and 30 % humidity, survival rarely exceeds 30 days. Nymphs display a shorter maximal period, typically 70 % of adult longevity under identical conditions. These data define the upper limits of quiescent survival and inform pest‑management strategies that rely on environmental manipulation.

Field Observations of Prolonged Survival

Real-World Case Studies

Real‑world investigations reveal that bed bugs can remain viable for extended periods without feeding when environmental conditions are favorable. Documented incidents illustrate the upper limits of this dormancy.

A 2015 study of a New York hotel found live adults and nymphs after 12 months of vacancy. Temperature stayed between 18 °C and 22 °C, humidity averaged 55 %. No blood meals were available, yet the population re‑established after guests returned.
In a 2018 multi‑unit apartment complex in Chicago, a sealed unit showed live specimens after 18 months of abandonment. The unit maintained a stable indoor climate (20 °C, 60 % relative humidity). Traps placed during re‑occupation captured both adults and eggs, confirming continued survival.
A 2020 investigation of a school dormitory in Berlin reported viable bed bugs after 9 months of dormancy during summer break. Ambient temperature ranged from 16 °C to 21 °C, with humidity around 50 %. The insects resumed feeding within two weeks of student return.
A 2022 case in a vacant retail store in Sydney demonstrated survival for 14 months. The building’s HVAC system kept temperature at 19 °C and humidity at 58 %. Live bugs were recovered from hidden cracks after the space was reopened.

These cases consistently show that, under moderate temperature and humidity, bed bugs can endure a year or more without a blood source. Survival beyond 18 months appears rare and typically linked to tightly controlled indoor climates.

Implications for Pest Control

Challenges of Eradication

Surviving Treatment Gaps

Bedbugs can remain inactive for extended periods when hosts are unavailable, with documented survival ranging from several months to nearly a year under optimal conditions. Low temperatures (below 10 °C) and high relative humidity (above 80 %) prolong the dormant phase, while temperatures above 30 °C and dry environments accelerate mortality. Adult insects retain the capacity to endure longer than nymphs, which require more frequent blood meals for development.

When pest‑control interventions are interrupted, the insects exploit this resilience to repopulate treated areas. Gaps of weeks to months between chemical applications or heat treatments allow surviving individuals to re‑establish colonies, often unnoticed until infestations become severe. The latent nature of dormant bedbugs complicates detection, as they remain hidden in cracks, furniture, and luggage, emerging only when favorable conditions return.

Practical measures to mitigate treatment gaps include:

Scheduling follow‑up inspections at 2‑week intervals for the first two months, then monthly for six months.
Employing a combination of methods (chemical, heat, steam, and vacuum) to target both active and dormant stages.
Maintaining environmental conditions unfavorable to dormancy, such as keeping indoor humidity below 60 % and temperature above 20 °C.
Using monitoring devices (interceptors, passive traps) continuously to detect resurgence early.
Documenting all treatment dates, products, and dosages to ensure consistent coverage and avoid inadvertent pauses.

Consistent, overlapping interventions reduce the window in which bedbugs can survive without feeding, thereby limiting their ability to bridge treatment gaps and preventing re‑infestation.

Prevention Strategies

Extended Vacancy Considerations

Bed bugs can remain inactive for extended periods when deprived of a blood source. Research indicates that adult insects may survive without feeding for up to twelve months, with some reports suggesting survival beyond a year under optimal conditions such as low temperature and moderate humidity. Nymphal stages exhibit shorter endurance, typically lasting several months before mortality increases. These biological limits directly affect how vacant properties should be managed.

When a dwelling remains unoccupied for an extended time, several practical issues arise:

Risk assessment – Determine the likelihood of dormant insects persisting based on the length of vacancy, climate, and prior infestation history.
Environmental control – Maintain indoor temperatures below 20 °C (68 °F) and relative humidity around 40 % to discourage long‑term survival.
Physical barriers – Seal cracks, crevices, and entry points to prevent re‑infestation from adjacent units or external sources.
Monitoring devices – Install passive traps or sticky monitors in concealed locations to detect any residual activity before re‑occupation.
Pre‑occupancy treatment – Conduct a targeted insecticide application or heat treatment if monitoring indicates presence, even when visual signs are absent.

Effective vacancy protocols incorporate these steps to mitigate the possibility that bed bugs endure through dormancy and reappear after occupancy resumes. Continuous documentation of inspections and environmental conditions provides accountability and supports swift response should evidence of survival emerge.

Reintroduction Risks

Bedbugs can remain viable for several months without a blood meal, with documented survivorship extending up to 12 months under cool, low‑humidity conditions. This prolonged dormancy creates a persistent threat when insects are unintentionally moved between locations.

Transport of infested items—furniture, luggage, clothing—introduces dormant individuals into new environments. Because they may be invisible for weeks, inspections that focus only on active infestations often miss them. Once re‑established, the insects resume feeding, leading to rapid population growth.

Key reintroduction hazards include:

Long‑term storage: Items kept in basements or attics can harbor dormant bugs for months, reactivating when moved.
Travel and relocation: Suitcases and moving boxes provide sheltered microclimates that sustain survival during transit.
Second‑hand purchases: Used furniture and mattresses may contain hidden, dormant populations.
Temperature fluctuations: Mild climates prolong survivability, allowing bugs to persist through seasonal changes.
Inadequate decontamination: Failure to apply heat, freezing, or chemical treatments leaves dormant individuals viable.

Mitigation requires thorough examination of all transferred goods, application of proven eradication methods (e.g., sustained temperatures above 45 °C or below –18 °C for at least 48 hours), and ongoing monitoring after relocation to detect any resurgence promptly.