The New Zealand bat fly (''Mystacinobia zelandica'') is a small, wingless insect which lives in a
commensal relationship with the
New Zealand lesser short-tailed bat
The New Zealand lesser short-tailed bat (''Mystacina tuberculata'') is a small-sized omnivorous mammal endemic to the islands of New Zealand. It is one of two extant and three overall terrestrial mammal species unique to New Zealand. The NZ lesse ...
. It is a true fly, in the order
Diptera
Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...
, placed in its own genus, ''Mystacinobia'', and its own family, Mystacinobiidae. Although many other species of bat fly exist throughout the world, the New Zealand bat fly is
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to the islands of
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
.
[Gibbs, George. (2008). ''Ghosts of Gondwana''. Craig Potton Publishing: Auckland. p16] It appears to be the only insect, parasitic or otherwise, which lives with these bats (fleas, for example, which are common on many other species of bat, are unknown on the short-tailed bat).
Description
New Zealand bat flies are approximately 4–9 mm long,
[Ballance, A. and Morris R. (2008). ''Rare Wildlife of New Zealand''. Random House. p39] wingless in both sexes,
blind,
[Meads, Mike. (1990). ''Forgotten Fauna''. DSIR Publishing. p92] and have long, bristly, spider-like legs which end in specially adapted claws which are thought to help them "swim" through bat fur.
Males are larger than females
and look quite different; one Japanese expert when sent some of the first specimens collected for scientific study suggested that they were different species.
Discovery
''Mystacinobia'' was first discovered in 1958, and the first specimen was catalogued for analysis by zoologist P. D. Dwyer in 1962 after it dropped out of the fur of a short-tailed bat he was looking after.
In 1973 a 56 metre high
kauri tree in the
Omahuta Kauri Sanctuary in
Northland containing a large colony of short tailed bats collapsed. When inspected the following day a dead bat with three bat flies on it was found by a
New Zealand Forest Service
The New Zealand Forest Service was originally established in 1919 as the State Forest Service. The State Forest Service changed its name to the New Zealand Forest Service in 1949, at about the same time that the Forests Act of 1949 passed through ...
officer, who sent the insects to Auckland to be studied.
The opportunity to study live bat flies and learn about their behaviour and ecology was lost when the bats deserted their felled roost before a team of scientists from the
DSIR was assembled to investigate.
Two years later, on 14 March 1975, the kauri tree the bats had moved into was blown over, as
Cyclone Allison swept through Northland.
This time entomologists were able to collect a large number of bat flies for anatomical studies and to keep in captivity so that their behaviour could be studied and scientifically described and named.
Ecology
Unlike other bat flies such as those in the
Hippoboscidae, the New Zealand bat fly is not dependent on the blood of the bats with which it lives, instead feeding on
guano
Guano (Spanish from qu, wanu) is the accumulated excrement of seabirds or bats. As a manure, guano is a highly effective fertilizer due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. G ...
. It lives in colonies and the females lay their eggs in large shared nurseries of eggs and larvae, which require temperatures of over 30° C to develop.
The adult females will groom the larvae in the nurseries as well as each other and their other colony mates.
There also seems to be the beginning of a caste system, as some of the males live past their normal reproductive age and act as a "soldier caste" of colony guards.
These elderly males produce a high frequency buzz that seems to keep the bats from flying too close to the fly colony. As this species of bat is also an insect-eater, the flies would appear to be under constant threat of being eaten by their "hosts." The vibrations of these elderly males appears to be the mechanism by which the fly prevents itself from becoming prey.
[
To travel to other colonies, bat flies need to ride on their hosts; up to 10 flies can be found on the fur of a single bat when it leaves its roost.]
Taxonomy and naming
Entomologist Beverly Holloway named and described the bat fly as the sole member of its family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
(Mystacinobiidae) and genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
(''Mystacinobia''), making both of these monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...
.flesh flies
Sarcophagidae () are a family of flies commonly known as flesh flies. They differ from most flies in that they are ovoviviparous, opportunistically depositing hatched or hatching maggots instead of eggs on carrion, dung, decaying material, or o ...
and blow flies
The Calliphoridae (commonly known as blow flies, blow-flies, carrion flies, bluebottles, greenbottles, or cluster flies) are a family of insects in the order Diptera, with almost 1,900 known species. The maggot larvae, often used as fishing b ...
.Icarops
''Icarops'' is an extinct, possibly paraphyletic genus of mystacine bat with three described species. The genus is known from fossils found at Riversleigh, north-western Queensland, Bullock Creek, Northern Territory, and Lake Ngapakaldi to La ...
'', a Miocene bat which lived 20 million years ago) also lived in Australia, but it is not known whether the New Zealand bat fly evolved there or in New Zealand – it could have been transported across the Tasman Sea
The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abe ...
with its host, or arrived via a forested Antarctica.
References
External links
* New Zealand bat fly discussed on RNZ
Radio New Zealand ( mi, Te Reo Irirangi o Aotearoa), commonly known as Radio NZ or simply RNZ, is a New Zealand public-service radio broadcaster and Crown entity that was established under the Radio New Zealand Act 1995. It operates news and cu ...
'' Critter of the Week''
2 October 2015
{{Taxonbar, from=Q5685153
Oestroidea
Diptera of New Zealand
Insects described in 1976
Wingless Diptera