The crested gecko’s primary diet in captivity is a commercial powdered Crested Gecko Diet (CGD), which is formulated to be nutritionally complete. This staple food provides the necessary balance of protein, carbohydrates, vitamins, and minerals for daily maintenance. However, a diet consisting solely of CGD does not fully replicate the variety and complexity of a wild gecko’s intake. Live insects are a secondary but important component, offering a different source of nutrition and providing essential mental and physical stimulation. Incorporating a rotation of appropriate feeder insects ensures a gecko receives a well-rounded diet that promotes thriving health.
The Role of Live Insects in the Diet
Live insects provide a concentrated source of high-quality animal protein and essential fats that complement the fruit-based CGD. This protein is particularly beneficial for growth, helping juveniles develop strong muscle and bone structure.
Beyond the nutritional boost, live prey offers necessary enrichment by engaging the gecko’s natural hunting instincts. The act of stalking, chasing, and capturing a moving insect provides mental stimulation and physical exercise. For juveniles, insects should be offered approximately one to two times per week, while healthy adults typically benefit from an insect feeding once a week or less frequently.
Safe and Recommended Feeder Insects
A variety of insects should be rotated to ensure a broad spectrum of nutrients, focusing on those with a favorable calcium-to-phosphorus (Ca:P) ratio. The ideal ratio for reptiles is approximately 2:1, but most insects naturally contain more phosphorus than calcium. Crickets are a common staple, offering good protein, but they require diligent preparation to correct their poor Ca:P ratio.
Dubia roaches are often considered a superior staple feeder due to their higher protein content and lower fat levels compared to crickets. They possess a softer exoskeleton, which makes them easier for the gecko to digest and reduces the risk of impaction. Dubia roaches are also easier to keep as they do not jump, climb smooth surfaces, or produce the noise and odor associated with crickets.
Black Soldier Fly Larvae (BSFL) naturally contain an exceptionally high amount of calcium. Their Ca:P ratio is often close to the ideal 2:1, making them an excellent choice for bone health. These larvae are soft-bodied and easy to digest, making them a highly recommended part of the rotation.
Mealworms and superworms should be reserved as occasional treats rather than staples due to their high-fat content and tough, chitinous outer shell. The hard exoskeleton can be difficult for a crested gecko to process, potentially leading to digestive issues or impaction. If offered, they should be fed sparingly, perhaps once or twice a month, and only to larger, adult geckos.
Essential Preparation: Gut-Loading and Dusting
Feeder insects are only as nutritious as the food they consume, making proper preparation mandatory before feeding them to your gecko. Gut-loading is the process of feeding the insects a highly nutritious diet for at least 24 hours before they are offered. This ensures the gecko receives the benefit of the nutrients contained within the insect’s digestive tract.
Gut-Loading
Appropriate gut-load foods include commercial insect diets, fresh vegetables like collard greens, kale, and squash, and certain fruits. Foods high in protein or fat, such as dog or cat food, should be avoided as they can lead to health issues like hepatic lipidosis. Hydration is also important, and insects should be provided with water gels or fresh produce.
Dusting
Dusting is the second step, involving coating the insects with a calcium and vitamin supplement powder immediately before feeding. This powder adheres to the insect’s body, providing a direct source of calcium and Vitamin D3, which is necessary for absorption. For geckos not housed under a reptile-specific UVB light, a calcium supplement containing D3 should be used for most insect feedings. Juveniles require dusting on every insect meal, while adults can be dusted every other insect feeding.
Insects to Never Feed Your Crested Gecko
Certain insects pose a significant health risk and must never be offered to a crested gecko. Wild-caught insects should be strictly avoided because they can carry harmful pesticides, herbicides, or internal parasites. These contaminants can cause severe illness or death, making commercially raised feeders the only safe option.
Some insects are inherently toxic to reptiles, regardless of their source. Fireflies, also known as lightning bugs, contain lucibufagins, a class of defensive steroids that are highly poisonous and can be fatal even in small amounts. Any insect with a bright, unnatural warning coloration should be avoided entirely.
Insects that are too large also present a serious danger, as they can cause choking or intestinal impaction. The feeder insect should be no wider than the space between the gecko’s eyes. Furthermore, insects with hard, sharp spines or powerful mandibles, such as large superworms, should be avoided, as they can injure the gecko internally or bite the gecko.