Which organisms is a secondary consumer in this food web?

In any food chain autotrophs are the producers which synthesizes food using solar energy. Autotrophs are green plants in terrestrial ecosystem. The herbivores which feed on plants are primary consumers and animals which feeds on herbivores are secondary consumer. These are carnivores or omnivores. For example, in forest ecosystem, trees are producers, deer is an primary consumer and lion is secondary or top consumer.    

the wires in the toaster turning red and the toast crisping and turning brown

allowed for the prediction of the properties of missing elements.