Ectoparasite Resistance

How is insecticide resistance different from anthelmintic resistance?

Resistance usually comes along with a fitness cost for the resistant insects

T/F ending the drug treatment helps resistance levels to go down for ectoparasites?

True

What are some factors that buffer insecticide resistance selection?

Infrequent applications

Refugia

Immigration from refugia

Fitness

Effect of short generation time on resistance for ectoparasites

Increase

Effect of few offspring per generation on resistance development

Decrease

Effect of isolated population on resistance development for ectoparasites?

Decrease

Effect of immigration from natural refugia on resistance population for ectoparasites

Decrease

Effect of a highly effective persistent residual insecticide on ectoparasite resistance

Increase

If an animal is not responding to one control measure what can you try before assuming resistance?

An additional control measure or switch to a different product

T/F rotational insecticide use is effective?

True

What is the treatment threshold for dairy cattle?

5 stable flies per leg causes a production loss

How can you control flies in feedlots and dairies?

Sanitation (remove manure)

Exclusion (screen doors)

Mechanical control (sticky traps)

Biological control (parasitoid wasps)

Chemical mixtures

What is the lifecycle of a lice?

All stages on a host

Why is lice resistance so bad?

All stages are on the lice so if there is resistance it is very likely to pass down

When does lice resistance get worse?

Winter-time when animals are crowded together

What is the source of lice infection?

Clinically normal carrier animals

What type of ticks have resistance most often?

1 host ticks like Rhipicephalus annulatus and R. microplus

What is the 1 3 host tick that has resistance?

Rhipicephalus sanguineus

Where does Rhipicephalus sanguineus have resistance?

Panama, Spain, Florida, Texas, Mexico, Yucatan

What are some common reasons for flea product failure?

Lack of understand of product performance attributes (speed and duration etc)

Inadequate control measures (not treating all pets, misadministration, etc)

Lack of knowledge on concerning parasite biology and epidemiology

What did the tampa flea studies find a decreased efficacy in?

Fipronil

Selamectin

Imidacloprid

What are the clinical implications of low levels flea resistance?

Decrease in residual speed of kill can increase C/S duration and if it take longer than 24 hours then you cannot break the life cycle

Less animals achieve full flea free status causing a decrease in % reduction in flea numbers

T/F integrated pest management is not feasible for fleas?

True

What are the things to remember for ectoparasite control?

Factors put high selection pressure on parasites drive resistance

Integrated pest management is with non-chemical control is effective for large animal control

Insecticide resistance comes with a fitness cost which is different from anthelmintic resistance

What effect does a highly host specific parasite do to horn fly resistance?

Increase

What does a short generation time do to horn fly resistance?

Increase

What does feed before mating do to horn fly resistance?

Increase

What does a high reproductive potential do to horn fly resistance?

Increase

What does a highly mobile pest do to horn fly resistance?

Decrease

What effect does a prolonged exposure to insecticides do to horn fly resistance?

Increase

What effect does a high insecticide selection pressure do to horn fly resistance?

Increase

What effect does 10 plus generations selected in one summer have on horn fly resistance?

Increase

What effect does selection occurring prior to mating have on horn fly resistance?

Increase

What does a high host specificity do to 1 host tick resistance?

Increase

What does a short generation time for 1 host ticks do to resistance?

Increase

What does feeding before mating do to 1 host tick resistance?

Increase

What does a high reproductive potential do to 1 host tick resistance?

Increas

What does exposure to a single insecticide do to a 1 host tick resistance?

Increase

What does having most hosts treated do to 1 host tick resistance?

Increase

What does having immature life stages treated do to 1 host tick resistance?

True

What does having no environmental life stages do to 1 host tick resistance?

Increase

What does having low host specificity do to 3 host tick resistance?

Decrease

What does having long generation times do to 3 host tick specificity?

Decrease

What does feeding before mating do to 3 host tick resistance?

Increase

What does having a high reproductive potential do to 3 host tick resistance?

Increase

What does exposure to multiple acaricides do to 3 host tick resistance?

Decrease

What does most host ticks are untreated do to 3 host tick resistance?

Decrease

What does immature life stages not treated do to 3 host tick resistance?

Decrease

What does environmental life stages do to 3 host tick resistance?

Decrease

What does having low host specific for fleas do to resistance?

Decrease

What does having a short generation time do to flea resistance?

Increase

What does feeding before mating do to flea resistance?

Increase

What does a high reproductive potential do to flea resistance?

Increase

What does using multiple insecticides within a practice do to flea resistance?

Decrease

What does using insect growth regulators/ovicides do to flea resistance?

Decrease

What does having many hosts untreated do to flea resistance?

Decrease

What does having persistent compounds do to flea resistance?

Increase