How many days can bedbugs survive without blood?

What are Bed Bugs?

Biology and Life Cycle

Bedbugs (Cimex lectularius) undergo a simple metamorphosis comprising five nymphal instars and an adult stage. Each instar requires a blood meal to molt to the next stage; without feeding, development halts. Adults also need blood for reproduction and maintenance, but they can persist for extended periods without it.

Starvation tolerance varies with developmental stage, temperature, and humidity. Research indicates:

First‑instar nymphs survive up to 5 days without a blood meal.
Second‑instar nymphs endure 8–10 days.
Third‑instar nymphs persist for 12–15 days.
Fourth‑instar nymphs remain viable for 20–30 days.
Fifth‑instar nymphs can last 35–45 days.
Adult bedbugs survive the longest, with documented cases of 100 days or more under optimal conditions (moderate temperature, high relative humidity).

Environmental conditions critically affect these limits. Lower temperatures slow metabolism, extending survival; however, extreme cold can be lethal. High humidity reduces desiccation risk, while dry environments accelerate water loss and shorten starvation periods.

Reproductive capacity declines sharply after prolonged fasting. Females that have not fed for more than two weeks produce few or no eggs, and any eggs laid after extended starvation exhibit reduced viability.

In summary, bedbugs possess a flexible biology that allows them to endure weeks to several months without a blood source, depending on their developmental stage and ambient conditions. This resilience contributes to their persistence in infested habitats.

Habitat and Behavior

Bedbugs (Cimex lectularius) inhabit human dwellings, favoring mattresses, box springs, bed frames, cracks in walls, and upholstered furniture. They thrive in environments that provide regular access to hosts, stable temperatures (20‑30 °C), and low humidity levels that prevent fungal growth. Their preference for concealed micro‑habitats reduces exposure to predators and facilitates rapid colonisation of new rooms.

Feeding behaviour is strictly hematophagous; adults and nymphs require blood to develop and reproduce. After a blood meal, a bedbug can enter a dormant state called diapause, during which metabolic activity declines sharply. In this state, the insect can endure prolonged periods without feeding, relying on stored lipids and proteins.

Key aspects of survival without a blood meal:

Metabolic slowdown: Energy consumption drops to less than 5 % of active rates.
Temperature dependence: Cooler ambient temperatures extend survival; at 15 °C, individuals may persist for several months, whereas at 30 °C the limit shortens to weeks.
Life stage variation: Adult females, possessing larger reserves, outlast nymphs and males under identical conditions.
Environmental humidity: Low humidity accelerates desiccation, reducing the starvation interval.

Understanding these habitat preferences and behavioural adaptations clarifies why bedbugs can remain viable for extended intervals between host contact, influencing control strategies that target their hiding places and exploit their limited starvation tolerance.

Factors Influencing Starvation Periods

Environmental Conditions

Bedbug longevity without a blood meal is governed primarily by ambient temperature and relative humidity.

At temperatures near 0 °C to 10 °C, metabolic activity slows dramatically; individuals can persist for several months, often entering a dormant state that reduces energy demands.
Between 15 °C and 20 °C, survival extends to roughly 30–45 days, reflecting a balance between reduced metabolism and occasional low‑level activity.
At 25 °C to 30 °C, the average lifespan without feeding contracts to 10–20 days, as higher metabolic rates accelerate depletion of stored reserves.
Temperatures exceeding 35 °C dramatically shorten survival, typically to less than a week, due to rapid exhaustion of energy stores and increased physiological stress.

Relative humidity also influences endurance.

Humidity levels above 80 % maintain cuticular water balance, supporting longer survival across temperature ranges.
Dry conditions below 40 % accelerate desiccation, cutting survival time by up to 50 % even at moderate temperatures.

Combined, optimal low‑temperature, high‑humidity environments enable the longest periods without a blood source, while warm, arid settings impose the shortest limits.

Temperature

Temperature strongly influences the length of time bed bugs can endure without a blood meal. At moderate room temperatures (20‑25 °C or 68‑77 °F), adults may survive 30‑45 days, with some reports of up to two months under optimal humidity. Cooler conditions extend survival:

15 °C (59 °F): survival often exceeds 60 days, occasionally reaching 90 days.
10 °C (50 °F) or lower: metabolic rates drop sharply; individuals can persist for several months, sometimes over 120 days.

Higher temperatures accelerate metabolism and reduce fasting endurance:

30 °C (86 °F): typical survival drops to 10‑20 days.
35 °C (95 °F) and above: most bed bugs die within a week without feeding.

Extreme cold (below 0 °C or 32 °F) is lethal within hours to days, depending on exposure length and life stage. Eggs are more vulnerable to low temperatures than nymphs or adults. Conversely, prolonged heat exposure (above 45 °C or 113 °F) also causes rapid mortality, a principle used in heat‑based extermination.

Thus, temperature defines a survival window: cooler environments prolong fasting periods, while warmer settings truncate them. Adjusting ambient temperature can therefore modify how long bed bugs persist without blood.

Humidity

Humidity directly influences the length of time bedbugs can endure without a blood meal. At low relative humidity (below 40 %), desiccation accelerates, limiting survival to roughly 10–14 days. Moderate humidity (50–70 %) slows water loss, allowing individuals to persist for 30–60 days. High humidity (above 80 %) further reduces dehydration, extending survival to 90 days or more, though excessive moisture can promote fungal infections that shorten lifespan.

< 40 % RH: 10–14 days, rapid weight loss, high mortality.
50–70 % RH: 30–60 days, balanced water retention, optimal for prolonged fasting.
 80 % RH: up to 90 days, minimal desiccation, increased risk of pathogen exposure.

Maintaining ambient humidity within the moderate range creates conditions under which bedbugs can survive the longest without feeding, while extreme dryness or excess moisture curtails their fasting period.

Age and Developmental Stage

Bedbug longevity without a blood meal is strongly linked to age and developmental stage. Younger individuals possess limited energy reserves, while mature adults can endure extended periods of starvation.

Eggs: hatch within 6–10 days; cannot survive without a host, mortality occurs within a few days if no blood is accessed.
First‑instar nymphs: rely on the nutrient load from the egg; typical survival without feeding ranges from 2 to 5 days.
Second‑ and third‑instar nymphs: accumulated reserves allow 5 to 10 days of sustenance without a meal.
Fourth‑instar nymphs: can persist for 10 to 14 days, reflecting increased body mass and stored lipids.
Fifth‑instar nymphs: approach adult capacity, surviving 14 to 30 days without blood.
Adults: exhibit the greatest resilience; documented starvation periods extend from 30 up to 180 days, contingent on temperature and humidity.

Temperature, humidity, and access to shelter modulate these intervals, but the hierarchy of survival capacity remains consistent across stages. Younger stages experience rapid decline once reserves are depleted, whereas adults maintain metabolic functions for months, enabling re‑infestation after prolonged absence of a host.

Nymphs vs. Adults

Bedbugs can endure extended periods without a blood meal, but survival limits differ markedly between immature stages and fully grown insects.

Nymphal stages, which consist of five molts before reaching adulthood, possess limited energy reserves. Their metabolic rate is higher relative to body mass, and they rely on frequent feeding to complete each molt. In laboratory conditions, first‑instar nymphs survive for approximately 10–14 days without blood, while later instars extend this window to 20–30 days. The final nymphal stage, just before the ultimate molt, can persist up to 40 days when temperatures remain moderate (20–25 °C).

Adult bedbugs store larger quantities of lipids and glycogen, enabling longer fasting periods. Under optimal ambient temperatures, adults have been recorded surviving 60–90 days without feeding. At lower temperatures (10–15 °C), metabolic demands drop, and some individuals remain viable for more than four months.

Key comparative points:

Energy reserves: adults > nymphs
Maximum fasting duration: adults ≈ 60–120 days; nymphs ≈ 10–40 days (stage‑dependent)
Temperature effect: cooler environments prolong survival for both groups, with adults showing the greatest extension

Understanding these differences is essential for estimating how long infestations can persist in vacant dwellings or during treatment interruptions.

Newly Hatched Bed Bugs

Newly hatched bed‑bug nymphs (first‑instar) can endure a limited period without a blood meal. Under optimal laboratory conditions—moderate temperature (20‑25 °C) and relative humidity around 70 %—survival without feeding typically ranges from five to seven days. In cooler environments (15 °C) the interval may extend to ten days, while higher temperatures (30 °C) reduce it to three‑four days. Dehydration accelerates mortality; humidity below 50 % shortens the fasting period dramatically.

Key variables influencing survival:

Temperature: lower temperatures slow metabolism, prolonging starvation tolerance.
Relative humidity: high humidity preserves water balance, extending life span.
Age of the nymph: first‑instar individuals have the least energy reserves; later instars survive longer without blood.
Genetic strain: some populations exhibit greater resilience to starvation.

If a first‑instar nymph fails to obtain a blood meal within the described window, mortality rates increase sharply, with most individuals dying before reaching the second instar. Consequently, prompt access to a host is essential for the development of newly emerged bed bugs.

Prior Feeding Status

Prior feeding history determines the length of time a bed bug can endure starvation. After a recent blood meal, metabolic reserves are at their peak, allowing the insect to survive for the longest period. In contrast, individuals that have not fed for several weeks possess depleted reserves and face rapid mortality.

Key observations:

Fully engorged adult – can remain viable for 100 – 150 days under moderate temperature (20‑25 °C) and low humidity.
Adult that fed within the past 7 days – survival typically extends 70 – 90 days.
Adult that fed 14‑21 days ago – survival decreases to 30 ‑ 45 days.
Nymph that has not fed for one molt cycle – survival limited to 15 ‑ 25 days.
Starved nymph or adult at the end of a molt – mortality often occurs within 5 ‑ 10 days.

These intervals reflect the balance between stored lipids, glycogen, and the insect’s ability to reduce metabolic rate. Temperature elevation accelerates depletion, shortening survival regardless of prior feeding. Conversely, cooler environments (15 °C) can prolong the periods listed above by up to 30 %. The data underscore that recent nourishment is the primary factor extending starvation endurance.

Typical Starvation Durations

General Estimates

Bed bugs can endure prolonged periods without a blood meal, but the exact duration varies with temperature, humidity, and developmental stage.

Adults at moderate room temperature (≈21 °C / 70 °F) typically survive 2–6 months without feeding.
Cooler environments (≈10 °C / 50 °F) extend adult survival up to 12 months.
Warm conditions (≈30 °C / 86 °F) reduce survival to 1–2 months.
Early‑instar nymphs survive shorter intervals, generally 1–2 months at room temperature and less than a month under heat stress.

These ranges represent general expectations; individual specimens may deviate based on microclimate and physiological condition.

Extreme Cases

Bedbugs can persist far beyond the average starvation period when environmental conditions are unusually favorable. Laboratory observations have recorded survival up to twelve months at temperatures near 10 °C (50 °F) with minimal humidity, a scenario far beyond typical indoor climates. In controlled settings where insects were kept at 5 °C (41 °F) and relative humidity below 30 %, individuals remained viable for 14 months, demonstrating that cold, dry environments dramatically extend fasting capacity.

Field reports from infested structures that experienced prolonged vacancy reveal similar extremes. Buildings left unoccupied for nine to eleven months, maintaining ambient temperatures between 12 °C and 18 °C (54 °F–64 °F) and low moisture levels, still yielded live bedbugs upon re‑inspection. These cases underscore that a lack of hosts does not guarantee eradication if the microclimate remains conducive to low metabolic rates.

Key factors influencing maximal survival without a blood meal:

Temperature: lower ranges slow metabolism, extending lifespan.
Humidity: reduced moisture limits water loss, preserving internal reserves.
Developmental stage: adult females possess larger fat bodies, surviving longer than nymphs.
Genetic variability: some populations exhibit innate tolerance to extended starvation.

Understanding these outlier conditions helps refine monitoring strategies, especially in seasonal properties or storage facilities where temperature and humidity may inadvertently create a sanctuary for dormant insects.

Why Bed Bugs Can Survive So Long

Metabolic Adaptations

Bedbugs (Cimex lectularius) can persist for extended periods without a blood meal due to several metabolic adaptations that minimize energy expenditure and protect vital functions.

Reduced metabolic rate: Basal respiration drops sharply after feeding, allowing the insect to consume only a fraction of its stored energy each day.
Energy reserves: Lipid droplets accumulated during the post‑prandial phase supply ATP through β‑oxidation; glycogen stores are tapped for short‑term needs.
Anaerobic pathways: When oxygen availability is limited, bedbugs shift to glycolytic metabolism, producing ATP without full oxidation, which conserves substrates.
Water balance mechanisms: Cuticular hydrocarbons limit transpiration; excretion is limited to uric acid, reducing water loss.
Behavioral quiescence: Activity ceases during starvation, decreasing muscular ATP demand and preventing unnecessary heat production.

These adaptations collectively enable the insect to survive for weeks without feeding. Under optimal laboratory conditions, individuals have remained viable for up to 300 days, while field observations typically report survival of 30–60 days before mortality rises sharply. The exact duration depends on ambient temperature, humidity, and the insect’s prior nutritional status.

Diapause and Dormancy

Bedbugs (Cimex lectularius) enter a state of diapause or dormancy when environmental conditions become unfavorable, markedly extending the period they can endure without a blood meal. Diapause is a hormonally regulated arrest of development triggered by photoperiod and temperature cues; dormancy encompasses a broader range of metabolic suppression that may occur at any life stage.

During diapause, metabolic rate drops to 10–20 % of that observed in actively feeding individuals. Energy reserves, primarily lipids stored in the fat body, are conserved, allowing nymphs and adults to survive for several weeks to months without nourishment. Studies report that adult bedbugs can remain viable for up to 150 days under optimal low‑temperature conditions (≈10 °C) when in diapause, whereas non‑diapausing insects typically survive no more than 30–45 days.

Factors influencing the duration of survival without blood include:

Ambient temperature: lower temperatures reduce metabolic demand and prolong diapause.
Photoperiod: short day lengths induce diapause in early instar nymphs.
Humidity: moderate relative humidity (≈70 %) prevents desiccation during prolonged inactivity.
Developmental stage: later instars possess larger lipid stores, extending survivorship compared to early nymphs.

When diapause terminates—often prompted by rising temperatures and longer daylight—bedbugs resume host‑seeking behavior, resume feeding, and resume reproduction. Understanding the physiological basis of diapause and dormancy clarifies why bedbugs can persist for extended periods in the absence of a blood source, complicating control efforts that rely solely on interrupting feeding opportunities.

Implications for Infestation Management

The Importance of Thorough Treatment

Bedbugs can remain viable for several weeks to months without a blood meal, depending on temperature and humidity. This physiological resilience means that any lapse in control measures allows a hidden population to rebound, rendering partial interventions ineffective.

A comprehensive eradication program must address every life stage and potential refuge. Typical components include:

Inspection of all sleeping areas, furniture, and wall voids to locate adults, nymphs, and eggs.
Application of insecticide formulations that penetrate deep cracks and reach concealed sites.
Use of heat treatment or steam to destroy eggs and nymphs that are tolerant to chemicals.
Installation of encasements on mattresses and box springs to prevent re‑infestation.
Follow‑up monitoring with passive traps and visual checks for at least two months after the initial treatment.

Thorough execution eliminates the possibility of survivors re‑establishing a colony during the extended fasting period. Incomplete coverage leaves a fraction of the population capable of surviving until conditions become favorable again, prolonging the infestation and increasing costs.

When to Re-treat

Bedbugs can endure several weeks without feeding, typically ranging from 30 to 45 days depending on temperature, humidity, and developmental stage. This survival capacity directly influences the timing of a secondary intervention after an initial treatment.

Re‑treatment should be scheduled before the longest possible starvation period expires, ensuring any survivors are exposed while still vulnerable.
Most professionals recommend a follow‑up application 2–3 weeks after the first treatment, aligning with the average time required for newly hatched nymphs to emerge and seek a blood meal.
In environments where temperatures are lower (below 15 °C), extend the interval to 4 weeks, as cooler conditions prolong starvation tolerance.
If initial treatment involved only chemical controls, combine the second round with non‑chemical methods—vacuuming, steam, and encasements—to target residual insects that may have hidden in cracks or furniture.
Monitor for continued activity using passive traps or visual inspections; evidence of bites or live insects after the first interval signals the need for an immediate additional treatment rather than waiting for the scheduled window.

Adhering to these timing guidelines maximizes the likelihood of eradicating the population before survivors can repopulate the site.

Preventing Reinfestation

Bed bugs can endure extended periods without a blood meal—often several months—making eradication efforts vulnerable to resurgence if any individuals survive. Effective reinfestation prevention therefore hinges on eliminating all viable insects and denying future access to hosts.

Conduct thorough inspections of mattresses, box springs, headboards, and furniture; use a flashlight and a fine-toothed comb to detect live bugs, eggs, or shed skins.
Reduce clutter that offers hiding places; seal cracks, crevices, and gaps around baseboards, electrical outlets, and wall voids with caulk or expandable foam.
Wash all bedding, curtains, and removable fabrics in hot water (≥ 60 °C) and dry on high heat for at least 30 minutes; treat non‑washable items with a steam cleaner reaching 100 °C.
Apply a certified residual insecticide to structural voids and potential harborages, following label directions and safety protocols.
Install interceptors under each leg of the bed and furniture to capture wandering bugs and monitor activity levels.

After treatment, maintain a schedule of weekly visual checks for at least three months. Replace or treat any newly identified items promptly. Limit the introduction of secondhand furniture unless it has been inspected, cleaned, and, when possible, heat‑treated. Consistent application of these measures blocks the survival window of any residual bed bugs, thereby preventing the colony from reestablishing.