Bot fly

Question 1

Latin name

Answer 1

Gasterophilus spp.

Question 2

Class

Answer 2

Insect

Question 3

Location in body

Answer 3

Stomach

Question 4

Life cycle

Answer 4

Adult fly - emerges mid-late summer - lives 7-10 days and lays up to 500 eggs (on lips, shoulder, and legs)

Fly eggs - on hair for 7-14 days

Bots (larvae) - inside stomach 8-12 months, from first frost till late spring

Pupal stage - on pasture 4-8 weeks - early summer

Frost kills bot fly so no reinfection till next season

Question 5

Management

Answer 5

Remove using bot fly knife

Fly spray as a preventative measure

Question 6

Prepatent period

Answer 6

8-12 months?

Question 7

Medicine

Answer 7

Fly spray as a preventative measure

Ivermectin, moxidectin

Question 8

Pathogenesis

Answer 8

Summer - adult flies emerge and lay eggs which are ingested into the stomach when grooming

colder months - adults killed by frost

Question 9

Clinical signs

Answer 9

gut irritation, colic, white/yellow eggs typically on legs or shoulder, unthrifteness, fear/agitation from noise

Question 10

Size

Answer 10

2cm

Question 11

Epidemiology

Answer 11

Adults present during summer
Larvae in stomach during winter
(The horse, 2012)