When ladybugs are purchased for pest control, immediate release is often not the best strategy for their survival and retention. Factors such as high daytime temperatures, dryness, or an unsuitable time of day can cause the insects to quickly disperse. Temporary storage is necessary to keep the ladybugs in a quiescent state, conserving energy until environmental conditions are optimal for release.
Setting Up the Temporary Holding Container
The temporary enclosure must provide a safe, secure, and breathable environment for the dormant insects. Suitable containers include small cardboard boxes or plastic containers, but they must not be airtight. Adequate ventilation is secured by creating several small pinholes in the lid or by using a fine mesh screen over an opening.
The interior should not be completely smooth, as ladybugs require surfaces to cling to. Lining the container with a slightly crumpled piece of paper, a clean coffee filter, or a paper towel provides this necessary texture. This material also absorbs excess moisture and gives the ladybugs a place to hide. The container must be kept clean and free of any pesticide residue, which can be toxic to the insects.
Maintaining Cold Storage and Hydration
To keep the ladybugs in a state of dormancy, their metabolic rate must be significantly lowered through cold storage. The ideal temperature range for this process is typically between 35 and 40°F (2 and 4°C), which is usually the temperature of a standard refrigerator’s crisper drawer. Temperatures below this range risk freezing the insects, while warmer temperatures will cause them to become active prematurely, rapidly depleting their stored energy reserves.
A significant threat during cold storage is desiccation, especially in modern frost-free refrigerators that actively remove humidity. To prevent the ladybugs from drying out, a source of moisture must be included in the container. This hydration can be provided by lightly misting the inside of the container with water or by placing a small, damp piece of paper towel or cotton ball inside.
The hydration source should be moist but not soaking wet to prevent the insects from becoming waterlogged or drowning. If the storage period extends for more than a few days, the moisture source should be checked and lightly re-dampened as needed to maintain a slightly humid microclimate. The goal is to simulate a cool, moist hibernation environment without creating standing water.
Short-Term Feeding Requirements
Ladybugs kept consistently within the target cold temperature range remain largely dormant, relying on their internal fat reserves for energy. Because their metabolism is greatly slowed, feeding is generally not required for short-term storage lasting one to three days. Attempting to feed dormant insects can introduce unnecessary moisture or mold into the container, potentially causing more harm than good.
If the ladybugs must be stored for a longer period, such as four to seven days, a minimal food source should be offered to supplement their reserves. A simple solution of honey or sugar mixed with water can be applied sparingly to a cotton swab or a clean piece of paper towel placed in the container. The mixture should be diluted to prevent stickiness and applied as small droplets, ensuring the ladybugs cannot drown.
Another option is to provide a few pieces of soaked raisins, which offer both moisture and sugar without the risk of spillage. The food source should be small and easily accessible, and any uneaten portion must be removed after 24 hours to maintain sanitation and prevent mold or bacteria growth. Feeding is an exception and should only be considered when the storage duration necessitates it.
Releasing Ladybugs After Storage
The transition from cold storage to the garden environment must be done carefully to maximize the ladybugs’ likelihood of staying in the area. Before the actual release, the container should be removed from the refrigerator and allowed to warm up gradually at room temperature for approximately 30 to 60 minutes. This period allows the insects to slowly become active as their body temperature rises.
The optimal time for release is in the early evening or at dusk, as ladybugs are reluctant to fly in the dark and will be forced to settle in the garden overnight. This overnight acclimation encourages them to seek out food and water in the immediate area upon waking the next morning. It is also beneficial to lightly water the garden or target plants just before release, providing the thirsty insects with an immediate source of hydration.
To release the ladybugs, gently sprinkle them at the base of plants that are experiencing pest problems. Scattering them in multiple locations, rather than releasing them all at once, encourages wider distribution and colonization. The combination of cooler temperatures, immediate hydration, and a nearby food source helps ensure the ladybugs establish themselves in the garden.