C. sulcicollis is the smallest member of the Cafius genus found on our sandy beaches, with a size range under 7.0mm. Their appearance is black with a reddish tint, noticeable under direct and sun light. They are less robust than C. luteipennis and the least common of all Cafius. They are only found on rare occasion but are more common farther north along the central coast. C. sulcicollis, like most sandy beach arthropods, can be found most commonly during spring to fall months, when temperatures are warmer. They consume fly larvae and scavenge dead flies along with free living mites underneath kelp wrack. This beetle is not likely to play a crucial role in the sandy beach ecosystem.