Campus Access Only

All rights reserved. This publication is intended for use solely by faculty, students, and staff of University of the Pacific. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, now known or later developed, including but not limited to photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author or the publisher.

Date of Award


Document Type

Thesis - Pacific Access Restricted

Degree Name

Master of Science (M.S.)


Biological Sciences

First Advisor

Tara Thiemann

First Committee Member

Ryan Hill

Second Committee Member

Kirkwood Land


Filarial parasites are a type of nematode that requires arthropod vectors for transmission between hosts. Filarial parasites vary among species of vertebrate hosts and can cause varying symptoms in hosts, including death. The presence of filarial parasites can influence host populations and can be costly to infected areas. To evaluate the prevalence of filarial parasites in Lake County, CA, mosquitoes were collected in 2014 and analyzed for infection using polymerase chain reaction (PCR). Of 1,008 mosquito pools, six filarial parasite species were detected in 23 pools representing six mosquito species. The DNA of Dirofilaria immitis (n=6, MIR=0.26); Setaria yehi (n=9, MIR=1.44); Splendidofilaria sp. (n=4, MIR=0.20); unknown filarial parasites A (n=2, MIR=0.09), B (n=1, MIR=0.41), and C (n=1, MIR=0.05) were detected in Aedes increpitus, Aedes sierrensis, Anopheles franciscanus, Anopheles freeborni, Culex stigmatosoma, and Culex tarsalis mosquito pools. Due to the presence of D. immitis, which can lead to chronic illness and death in domestic dogs, in Lake County it is important to evaluate vector competency of D. immitis in mosquito species. Culex tarsalis was chosen due to the high abundance found in Lake County in 2014 (n=36,587). To evaluate vector competency of Cx. tarsalis in transmission of D. immitis, colony and field-caught Lake County (n=102, n=54 respectively) mosquitoes were analyzed for infectivity using decapitation. Fourteen days post feeding on infected blood, mosquitoes were decapitated to evaluate the presence of L 3 larvae; but no L 3 larvae were detected. The presence of D. immitis DNA was detected in eight colony (IR=7.8%) and fifteen field-caught (IR=23.1%) thoraces using PCR. Though no L 3 larvae were observed in decapitated mosquitoes, presence of D. immitis DNA in the thoraces of mosquitoes using PCR has previously been used as an indicator for vector competency. Thus it is probable that Cx. tarsalis is a competent vector for D. immitis.





To access this thesis/dissertation you must have a valid email address and log-in to Scholarly Commons.

Find in ProQuest



If you are the author and would like to grant permission to make your work openly accessible, please email


Rights Statement

Rights Statement

In Copyright. URI:
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).