Mealworms are the larvae of the beetle Tenebrio molitor or Darkling Beetle LINK. They are 1.25-1.8 cm long and available in pet shops as feed for birds, chickens, reptiles, fish, etc. (below). They have also been used to lure migratory birds for photography LINK.
Aviculturist Lee Chiu San recommends that the mealworms be cut into bite-size and the head removed before feeding them to birds, especially baby birds. Why, you may ask? Fledglings have been known to die as the mealworms are capable of rupturing the crop as a result of chewing their way out – see comments from this LINK.
Giant Mealworms are mealworms treated with a hormone to prevent the larvae from pupating LINK. In other words, the larvae will continue to moult beyond their fixed number of times, thus growing larger. As with mealworms, it is advisable to also cut the worms into bite-size and remove the head before feeding them to birds.
Superworms are Zophobas morio larvae that grow naturally to a large size, 3.8-6.3 cm in length. They are a species of darkling beetle and used commonly to feed pet reptiles, amphibians, birds and koi LINK.
Once they reach adult size, the larvae pupate, and later emerge as large, black beetles. The larvae will not pupate if kept in a container with many other larvae and plentiful food, where they receive constant bodily contact. Keeping superworms this way is commonly used to hinder pupation. In order to mature the superworms into darkling beetles, they must therefore be kept away from their peers for about 7-10 days. They will then, upon maturation, emerge from their pupal stage as darkling beetles. Contrary to popular belief, the adult does not have fused elytra (modified, hardened forewings), as the beetle occasionally has been observed attempting to fly as an emergency measure against starvation.
YC Wee & Lee Chiu San
25th February 2017