Yesterday, I took my throdama (143781), with which I explored two islands and lost two battles. Today, I explored two islands, won one battle and lost one battle. In the chart of tasks, needed for pheromone production, only visited islands are being counted, while battles, both won and lost, are not counted. 

The battles with monsters on islands do not count. Exploring gives experience for Scout and Harvester pheromones only. Warrior and Defender pheromones can be earned on Arena by fighting with other pets.