Plants-aphids-spiders-sparrows in this food chain the spiders are?

Spiders are the secondary consumers.

Explanation:

As you may already know, the food chain is formed by trophies. These trophies are: producers, primary consumers, secondary consumers, tertiary consumers and decomposers.

Producers are plants, primary consumers are herbivorous animals that feed on plants, secondary consumers are carnivorous animals that feed on herbivorous animals, tertiary consumers are carnivorous animals that feed on secondary consumers and decomposers are microorganisms.

As you can see in the food chain shown in the question above, spiders feed on aphids, which are herbivores and feed on plants. Therefore, spiders are secondary consumers.