These are very destructive parasites that attack valuable crops. Cluster-cups are orange-colored spores in little cup-like clusters.

Cluster-Cups on Barberry (Lower Side)

These are very destructive parasites that attack valuable crops. Cluster-cups are orange-colored spores…

The mite producing sheep scab.

Mite

The mite producing sheep scab.

Sacculina is a genus of barnacles that parasitize crabs. The female Sacculina larva finds a crab and walks on it until it finds a joint. It then molts, injecting its soft body into the crab while its shell falls off. The Sacculina grows in the crab, emerging as a sac, known as an externa, on the underside of the crab's rear thorax, where the crab's eggs would be incubated.

Crustacean Parasite

Sacculina is a genus of barnacles that parasitize crabs. The female Sacculina larva finds a crab and…

Sacculina is a genus of barnacles that parasitize crabs. The female Sacculina larva finds a crab and walks on it until it finds a joint. It then molts, injecting its soft body into the crab while its shell falls off. The Sacculina grows in the crab, emerging as a sac, known as an externa, on the underside of the crab's rear thorax, where the crab's eggs would be incubated. Here the parasite has been removed from the crab.

Crustacean Parasite

Sacculina is a genus of barnacles that parasitize crabs. The female Sacculina larva finds a crab and…

A parasite which feeds as larvae in rose-twigs or upon the leaves. Some species are confined to roses for their food, while others can also feed on other plants.

Larvae of Rose Sawfly

A parasite which feeds as larvae in rose-twigs or upon the leaves. Some species are confined to roses…

These are very destructive parasites that attack valuable crops. Rusty lines and dots appear on the leaves, which are masses of spores called summer spores.

Summer Spores (Uredospores) on wheat

These are very destructive parasites that attack valuable crops. Rusty lines and dots appear on the…

Trichina. 1) Female; 2) Male.

Trichina

Trichina. 1) Female; 2) Male.

These are very destructive parasites that attack valuable crops. Black lines and dots appear on the wheat forming masses of spores called winter spores.

Winter Spores (teleutospores) on wheat

These are very destructive parasites that attack valuable crops. Black lines and dots appear on the…