Which family of caddisflies is associated with the order Trichoptera?

Caddisflies belong to the order Trichoptera, which comprises a diverse range of families. The families mentioned in the options, Glossosomatidae and Hydropsychidae, are indeed part of this order.

Glossosomatidae, commonly known as the snout moths, are characterized by distinctive cases made from materials such as leaves and silk. They have a unique developmental cycle and are found in various freshwater habitats, typically preferring clean, flowing waters.

Hydropsychidae, on the other hand, are known as the net-spinning caddisflies. They construct intricate silk nets in freshwater environments, which they use to capture food, primarily small particles and microscopic organisms. Their presence is often an indicator of water quality, as they are typically found in clean, well-oxygenated waters.

The correct answer encompasses both families as they both belong to the order Trichoptera, confirming that both choices A and B are completely accurate representations of caddisfly families associated with this order.