I would offer finely chopped greens of turnips, collards, mustard--- -grated carrots, bell pepper, squash, snow peas/ green beans, dandelions( greens & flowers). Also-- leaves & flowers of--- common sunflowers, ragweed ( a favorite food), Virginia Peppergrass, Gaillardia, Coreopsis, Helenium (Sneezeweed), several prostrate Euphorbias ( common sidewalk type of weeds), Clover. Really most anything in the families of-- sunflower / roses/ mallows& hibiscus/ honeysuckle/ Catalpa/ mustard/ gourd/ daylillies/ geranium/ waterleaf/mint( Salvias)/ legume/ four o'clock/evening primrose/figwort/ verain---- just about everything can be eaten by DI's. Some individuals refuse certain plants while others relish them ( no catsup ). In the wild they live off of fallen flowers from Palo Verde, Ocotillo, Globemallows, Bladderpods, Ambrosia( ragweed family), Rattlesnake Weed (Euphorbia) and damn near anything elso that blooms. Common desert weeds make up a large part of their diet.They also love bugs.
Where do you live?? Many of these plants can be grown in gardens or landscapes. Also--- remember when a lizard goes to eating-- the flower or leaf is still attached to the stem so it is anchored/ held steady. This allows for the liz to pull off small bite size pieces. Once you cut/ pull & toss a large flower or leaf in a cage with a DI---- he has to tear off pieces without it being held stable so it is harder for em to eat. They really do respond well to small flowers being tossed at em--- just like flowers falling off of a tree. Make sure the substrate & the flowers are dry --- if the flower is wet- sand/ dirt/ etc will stick to the foods & could cause impaction. Your temps sound ok--- maybe take it to 120 F from time to time on the hot spot but make sure there is good air exchange. Also-- the bigger the better on caging--- these guys run for miles in habitat so try to give em as much room as possible. They also love to tunnel so try to create a place for them to dig under STABLE rocks & sand.
Best of luck!!
David