Which parasite forms warbles in cattle by larvae living in subcutaneous tissue?

Which parasite forms warbles in cattle by larvae living in subcutaneous tissue?

• A. Gasterophilus species
• B. Hypoderma species
• C. Oestrus species
• D. Cuterebra species

Answer: (B)

Warbles are caused by larvae of Hypoderma species, the cattle grubs. These larvae migrate into the subcutaneous tissue after the adult flies lay eggs on the cattle’s hair, forming firm swellings called warbles that have a breathing hole. The larvae remain under the skin for months, especially along the back, before dropping to the soil to pupate and emerge as adult flies. This pattern of subcutaneous development and the characteristic back lesions are what identify Hypoderma as the culprits. Other options describe parasites that inhabit different sites: Gasterophilus species end up in the stomach of horses; Oestrus species are nasal bots living in the nasal passages; Cuterebra infects various small mammals and causes subcutaneous lesions there, not the classic cattle warbles.

Warbles are caused by larvae of Hypoderma species, the cattle grubs. These larvae migrate into the subcutaneous tissue after the adult flies lay eggs on the cattle’s hair, forming firm swellings called warbles that have a breathing hole. The larvae remain under the skin for months, especially along the back, before dropping to the soil to pupate and emerge as adult flies. This pattern of subcutaneous development and the characteristic back lesions are what identify Hypoderma as the culprits.

Other options describe parasites that inhabit different sites: Gasterophilus species end up in the stomach of horses; Oestrus species are nasal bots living in the nasal passages; Cuterebra infects various small mammals and causes subcutaneous lesions there, not the classic cattle warbles.