Probably too many at once. mealworms have very indigestible skins, so they need to be fed sparingly. Most insect exoskeletons are indigestible, but mealworms are known to cause blockages in the digestive tracts if fed in large quantities.
I'd recommend only ever feeding the freshly moulted mealworms or superworms that are still white and soft to reptiles, other than that, they make great bird food. This wild spangled drongo comes and takes them right out of my hand.