Gasterophilus haemorrhoidalis

Gasterophilus haemorrhoidalis
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Clade:	Pancrustacea
Class:	Insecta
Order:	Diptera
Family:	Oestridae
Genus:	Gasterophilus
Species:	G. haemorrhoidalis
Binomial name
Gasterophilus haemorrhoidalis (Linnaeus, 1758)
Synonyms
Oestrus haemorrhoidalis Linnaeus 1758

Gasterophilus haemorrhoidalis (also called nose botfly or lip botfly) is a species of the genus Gasterophilus that lays eggs on the lips and around the mouth of horses, mules and donkeys. Their hatching is simulated by moisture from licking or feeding of hosts.

• First instar development: Penetrates epidermis of the lips of hosts and migrate into mouth.
• Second instar: Moves to stomach and duodenum of the small intestine
• Third instar: Larvae become detached after some time and then pass to the rectum and re-attach themselves.

Nose botflys appear with a postsutural scutum with ground color uniformly brown or black legs yellowish brown, with femora distinctly darkened; abdomen ground color dark brown or black, with reddish-yellow or orangish setae posteriorl. Males possess a surstylus that abruptly tapers distally, with short surstylar setae that reach at most halfway to the sagittal plane. Regarding egg description, the pedicel is long and slender, with a width/length ratio of approximately 1/6 in lateral view, comprising 2/5 of the total egg length.

Their eggs are pedicel long and slender, with width/length ratio around 1/6 in lateral view, accounting for 2/5 of the total egg length.

In Equidae, third-stage larvae attach to the stomach, but also to the rectum, sometimes in great numbers.¹ Heavy infestation can cause anal prolapse in foals and mules.

They do not parasitise humans.