Squash bee (Peponapis pruinosa) is the canonical Cucurbita specialist pollinator — active at dawn before honeybees + bumblebees; delivers most cucurbit pollination across North America. Lifecycle is synchronized with cucurbit bloom; planting Cucurbita supports the species directly. Males sleep inside closed squash flowers in late afternoon — a magical wedge-relevant ecology observation visible to home gardeners.
The monoecious yellow cucurbit flowers need insect pollination to set fruit, and squash bees and other bees forage them; NC State Extension Gardener Plant Toolbox lists Cucumis melo as attracting bees and pollinators. Squash bees are cucurbit-flower foragers, so they are a plausible (not source-named) visitor of melon flowers.
Native squash bees (specialists on the gourd family, Cucurbitaceae) are efficient pollen vectors for cucurbit crops including watermelon, which depends on bee visitation to set fruit.