Various factors—embryology, host associations, and seasonal changes In eye worn populations—tending to promote the propagation of T. califomlensls were studied.

The early embryology closely parallels that of other nematode species.

The mature embryos remain alive in saline at 35°C as long as 5 days. Dead embryos can be distinguished from living ones by virtue of the rapid staining by methylene blue by the former. Parturient female thelazias release embryos into saline, and embryos are found regularly in tear secretions of infected laboratory rabbits.

Ovic embryos possess an enveloping egg membrane containing chitin. On this account, this eye worm species is oviparous. No ecdysis occurs before hatching from the ova. The egg membrane is susceptible to abrasive action, sodium hypochlorite, and pepsin. Ineffective are common mineral acids and alkalies. Evidence is presented to show the necessity of intermediate hosts for the development of embryos into juvenile stages.

Because of laboratory and field observations, flies belonging to the genus Fannia were suspected as intermediate hosts; therefore, a fly-rearing method was devised. Twelve generations of F. canicularis were reared with a decaying nutrient medium concisting of bran, alfalfa, malt and brewers yeast.

Early juvenile forms were seen in F. canicularis after Individually subjecting them to forced feeding of a saline suspension of ovic embryos. This was accomplished by fastening a fly to a tapered glass tube by means of suction. With a micromanipulator, the feeding pipette was maneuvered into contact with the fly's proboscis so that the fly was able to drink the suspension of ova.

P. benjamini is suggested for future intermediate host study on account of its affinity for the eyes of definitive host species. An analysis of treatment records of Southern California dogs, revealed that eye worm population size reaches its peak during the Fall of the year.

LLU Discipline





Graduate Studies

First Advisor

Edward D. Wagner

Second Advisor

Mervyn G. Hardinge

Third Advisor

Jack D. Zwemer

Fourth Advisor

U. D. Register

Fifth Advisor

Earl J. Thomas

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Spiruroidea; Eye Diseases



Page Count

vi; 77

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives