Adrenal steroid, blocking agent, and social stress effects on northern fowl mite population development on Leghorn chickens and toxicological evaluation of selected acaricides (Acarina: <i>macronyssidae</i>)

Administration of adrenal steroids or blocking agents at optimum doses influenced northern fowl mite development on chickens. Corticosterone at 20 ppm or desoxycorticosterone at 30 ppm in feed were most effective in inhibiting mite infestations. High levels of social stress increased resistance of chickens to mites in a manner similar to but more effective than steroid administration. The mechanism of resistance was a decrease in capillary density at the skin surface. Commercial laying hens caged alone had lower plasma corticosterone levels and supported more mites than hens caged in groups. Stress-induced, steroid initiated, or inbred mite resistance was incompatible with maximum production from chickens. Resistant chickens produced poorer weight gains and testes mass than did susceptible birds. Sex hormones were shown to play a supplementary, and antibody a minor role in mite resistance. Carbaryl was shown to be the compound most toxic to northern fowl mites of those registered in Virginia for application to poultry. Malathien resistance was noted in mites from a commercial poultry house. The synthetic pyrethroid permethrin was effective against these mites.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Entomology

Department dc:contributor.department

Entomology

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1977

Author dc:creator

• Hall, Robert Dickinson

Chair dc:contributor.committeechair

• Turner, E. Craig Jr.

Committee members dc:contributor.committeemember

• Grayson, James McD.
• Robinson, William H.
• Gross, Walter B.

• poultry mites

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-07082010-020150

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/38708