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Aspects of the biology of Uropsylla tasmanica Rothschild (Siphonaptera)

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Pearse, Anne Maree (1981) Aspects of the biology of Uropsylla tasmanica Rothschild (Siphonaptera). Coursework Master thesis, University of Tasmania.

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Abstract

The flea Uropsylla tasmanica Rothschild is the only known flea
with a parasitic larval stage (Dunnet 1970). In Tasmania the most
commonly found host of U. tasmanica is the native cat Dasyurus viverrinus
(Dasyuridae Marsupialia).
The life cycle of U. tasmanica in relation to the annual cycle of
D. viverrinus is described. It was found that U. tasmanica adults and
parasitic larvae only occur on the hosts from March to September (Autumn
and Winter). Other species of fleas found on native cats decline in
numbers during this period. Reproduction in U. tasmanica coincides with
the reproductive period of its host.
Experimental work indicated that adult U. tasmanica emerge from
their cocoons in response to mechanical stimulation. "Readiness" to
emerge depends upon the amount of time spent in the cocoon as well as the
stage of desiccation of the fleas in the cocoons. (Fleas kept at 80% RH
took 10)4 -1-0.2 (n=10) days to emerge whilst those kept at 20% RH took
73-1- .19 (n=10) days to emerge from the beginning of the experiment.) After
emergence and in the absence of a host, fleas kept at high relative
humidities survived for longer periods than those kept at low relative
humidities (32±1.8 n=10 days at 80% RH compared with 13±3.25 n=10 days
at 20% RH). On emergence from the cocoons U. tasmanica are not sexually
mature and require a blood meal to complete sexual maturation. Newly
emerged fleas prefer to feed from sub-adult rather than mature native
cats during the host's non-reproductive phase. Experiments in which
prolactin and hydrocortisone were administered to some of the fleas
indicated that these mammalian hormones facilitated sexual maturation and
reproduction in. U. tasmanica.
The parasitic larvae of U. tasmanica undergo four larval stages
and are morphologically different from non-parasitic flea larvae. There
are some taxonomic features of U. tasmanica larvae which appear to
converge with the myiasis-producing Dipteran larvae. Fully developed
U. tasmanica larvae leave the host and build a cocoon in the litter of
the hosts den. The larvae do not always pupate immediately but may enter
a diapause the induction and duration of which appears to depend upon the
daily cycle of warmth and cold to which they are subject on emergence
from the host.
The phylogeny of U. tasmanica was investigated by comparing the
chromosomes of this species with those of Fygiopsylla hopZia and
Lycopsylla nova. U. tasmanica appears to have 2n = 14 chromosomes while
the other two species have 2n = 20 chromosomes.

Item Type: Thesis (Coursework Master)
Keywords: Fleas, Insects
Copyright Holders: The Author
Copyright Information:

Copyright 1981 the Author - The University is continuing to endeavour to trace the copyright
owner(s) and in the meantime this item has been reproduced here in good faith. We
would be pleased to hear from the copyright owner(s).

Additional Information:

Thesis (M.Sc.)--University of Tasmania, 1981. Bibliography: l. 185-195

Date Deposited: 03 Feb 2015 03:10
Last Modified: 11 Mar 2016 05:56
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