I always believe variety in diet for any captive animals is one of the main key for success keeping and breeding that particular animals. White-rumped shama is mainly insect feeder so feeding the bird with variety insects (dead or alive) help to keep them in healthy state and avoid the synchrome of "picky eater." It is widely known in fish and reptile keeping that feeding the animals strictly his/her favorite live feeder food for a long time can lead to deficiency of certain vitamin (which can result in sickness or even death) and very hard to convert that animal to eat other less favorite live feeder food later on. No particular one kind of live feeder food can be sole staple in a diet. Variation of foods is the only way to provide our beloved animals complete nutrients required. Each live feeder food will offer a certain key ingredients to bring the shama or any animals in general to healthy state provided other factor such as housing, water, cleanness of aviary/cage are also in good condition. Cricket has good protein source and easiest way to "gutload" with multivitamin and calcium. Waxworm has lots of fat which can be a good food for quickly bring undernourishment bird back to health. Phoenix worm can provided good source of natural calcium. Small lizard, frog, or small fish can provide great source of calcium and protein. There are many live feeder food that can feed to the shama but those above are somewhat commonly available. Depend where you are locate, some live feeder insects are easily find than others. In some countries or states, and depends on the season you can catch wild live insects to give to the bird but make sure the wild caught insects are not sprayed with insecticide or carried parasites that can harmful to the bird. In my opinion, if feeding the bird your own wild caught live insects, it is better to either quarantine them for few weeks to a month before feeding to the bird or freeze them to kill off any internal parasites. Wild caught food is almost certainly has more complete nutrients than farm raise one, but farm raise insects have less risk of transmitting parasite than the wild counterpart. Minimealworm is rarely available in the State and expensive. All the shama love to eat them as they move very quickly unlike the cousin regular mealwormTenebrio molitor which is slow moving; however, in term of cost/nutrient/quantity per feed minimealworm is not a good choice to use to feed the shama. As the name suggest, minimealworm is very small so each shama can have easily 50 or so per feeding, not counting they are cost like three times more than regular mealworm. In conclusion, feed those minimealworm as treat once in a while is ok, but feeding those worms regularly will broke out pocket very soon! hehe.
Top view (the meter shows in reference is in cm)