FNZ 8 - Calliphoridae (Insecta: Diptera) - Introduction
Dear, JP 1986. Calliphoridae (Insecta: Diptera). Fauna of New Zealand 8, 88 pages.
(
ISSN 0111-5383 (print),
;
no.
08.
ISBN 0-477-06764-6 (print),
).
Published 24 Feb 1986
ZooBank: http://zoobank.org/References/EC689DA4-9FFD-477E-B7BD-6126A8FE88A1
Introduction
The dipteran family Calliphoridae, to which belong the familiar blowflies, bluebottles, and greenbottles, is represented in New Zealand by 52 species. These are contained in 2 subfamilies comprising 7 genera. Six of the genera - Calliphora, Hemipyrellia, Lucilia, Pollenia, Ptilonesia, and Xenocalliphora - belong to the subfamily Calliphorinae. The seventh, Chrysomya, belongs to the Chrysomyinae, a group represented here by only two species. Two other subfamilies, the Ameniinae and Rhiniinae, have been recorded from New Zealand by early workers, but these records are based on erroneous locality data (see Miller 1950, pp. 138, 139, and 142).
In general appearance the New Zealand species of Calliphoridae are very much like the other members of this large and cosmopolitan family, which are mostly stout, large to moderate in size, and often metallic in appearance, at least on the abdomen. They can be distinguished from all other calyptrate flies in New Zealand by the presence of a row of hypopleural setae, an undeveloped post-scutellum, and a haired propleuron (if the propleuron is bare then the outer posthumeral seta is absent). However, in structural details some of the species differ from the normal calliphorid pattern. These anomalies are discussed below under the genera Pollenia, Ptilonesia, and Xenocalliphora.
There is a long history of work on New Zealand's calliphorids. The first species was described by Swederus (1787) from material collected during Cook's first voyage to New Zea1and. By the early twentieth century a few species had been described by European workers such as Macquart and Walker, and Hutton had recognised species endemic to the offshore islands. Subsequent workers such as Malloch (1924, 1927, 1930), Miller (1939b), and Murray (1954) continued to describe new species, and in general they had a good eye for valid species, although they often confused the nomenclature because of the inaccessibility of much type material in European museums at that time. Miller (1939b, p. 11) gave a very interesting account of the history of blowflies in New Zealand, including their significance in Māori lore. Hamson (1976, p. 147) has given a useful revision of the species from the southern islands.
Calliphorids are generally ubiquitous. They fly mainly by day, though a number of specimens I have examined were collected at light traps. Most species of Pollenia appear to be restricted to higher altitudes, whereas Ptilonesia and Xenocalliphora are often found at the seashore. Adults are often attracted to sweet liquids, and can be collected at flowers, where they feed on nectar. They also feed on the liquid products of organic decomposition, which provide the proteins essential to the female for egg maturation. Most species breed in carrion, but Pollenia may parasitise earthworms as it does in other geographical regions. Some of the species of Calliphora, Chrysomya, and Lucilia are of significant veterinary importance, causing the cutaneous myiasis of livestock known as 'fly strike', but the life history details of most New Zealand Calliphoridae are unknown.
This revision is based on almost 1400 specimens, from numerous sources. Virtually all type material has been examined.
Genus Calliphora
The genus Calliphora in New Zealand contains four species, two introduced from Australia and one from Europe, and the fourth endemic. The Australian species, Calliphora stygia and C. hilli, are two of the well known golden blowflies, or golden-haired blowflies. The first record of their appearance in New Zealand dates from 1841, when Dr A. Sinclair collected specimens of both (used in the type series of laemica White) in the Bay of Islands. In 1845 he made further collections of both species, and these are preserved in the BMNH collections. Colonel Bolton collected stygia in 1845 at the Auckland Islands [Note added T.K. Crosby: specimens collected by Bolton were from Auckland, North Island]. French expeditions visited New Zealand in 1824, 1827, and 1831, but when in Paris (MNHN) I found no golden blowflies collected on these expeditions. In his narrative of Cook's first voyage, Hawkesworth refers to "flesh flies" being like those of Europe (see Miller 1939b, p. 58); this probably refers to the endemic species, which has the appearance of European blowflies. Joseph Banks collected this species during Cook's voyage of 1768, and would surely have taken a golden blowfly had he seen one (he did while in Australia). During this voyage Cook was mapping the North and South islands, and Banks went ashore at every opportunity. It seems unlikely, then, that golden blowflies were in New Zealand at that time; or at best they were present only in very small numbers. It seems most probable that they were introduced from Australia between 1779 and 1841. J.S. Pollack in 1838 mentions a "gad fly" or oestrus depositing larvae on meat (see Miller 1939b, p. 61); this may refer to a golden blowfly. Hennig (1966, p. 10) accepts a passive dispersal from Australia in recent geological time, saying that man may not have been the agent.
The two golden blowflies C. hilli and C. stygia have been confused taxonomically by most authors. Hutton (1901, p. 64) mentions neither of them in his New Zealand synopsis. Malloch, in his Australian paper (1927, p. 309), discusses the confusion, keys the flies successfully, and also mentions that he has females of hilli from New Zealand, but he does not refer to them in his New Zealand work (1930, p. 313). Hardy (1937, p. 21) gives a rather confusing list of species and synonymies, including the names hilli, laemica, milleri, rufipes, and stygia. He does not mention stygia as occurring in New Zealand, but gives laemica and milleri as the two golden blowflies of New Zealand. He alludes to his new species milleri as the common New Zealand blowfly, and gives hilli as a synonym of rufipes (milleri is here referred to hilli). Miller (1939b, pp. 30 and 32) and Murray (1954, p. 719) both refer to hilli, as recognised here, as rufipes and to stygia as laemica. The name rufipes has in the past caused great confusion, as Macquart described both a Pollenia rufipes and a Calliphora rufipes, and both names have been applied to blowflies in New Zealand. Dr K.R. Norris (pers. comm.) has studied the type specimens of these species in conjunction with his work on Australian blowflies, and has found that the syntypes of P. rufipes are Calliphora stygia and that the holotype of C. rufipes is an Austro-Oriental Calliphora species. Kurahashi (1971, p. 158) placed C. stygia in his subgenus Neocalliphora (see below) and referred to C. hilli as C. (Paracalliphora) rufipes ssp. milleri, but I can find no justification for subspecific status for this species.
Calliphora quadrimaculata is an endemic species of striking appearance, being large, robust, and metallic. It is mentioned in Māori folklore, and was recorded by all the early authors, having been described by Swederus from material collected by Banks during Cook's first voyage. Malloch (1930, p. 316) unaccountably referred to this species as Calliphora sacra (Fabricius). Kurahashi (1971, p. 155) placed this species in his subgenus Neocalliphora along with five others, of which I find that only two, namely C. nigrithorax from Tasmania and C. ochracea from Australia, are closely related to quadrimaculata. These three species constitute a distinct group, and are probably living examples of something near to the ancestral stock of present-day Calliphora species. They have in common densely haired eyes, holoptic head in the male, very large thoracic spiracles, unicolorous undusted abdomen, and curved paralobes in the male genitalia. Calliphora testaceifacies is closely related to this group, but in having bare eyes and a dusted fifth tergite is reminiscent of the Australian Calliphora robusta group. It may be a relatively recent ofshoot from the ancestral line of the numerous species of the robusta group found in Australia today.
Similarly, C. stygia is closely related to the nigrithorax - ochracea group but has a golden-dusted abdomen, sparsely haired eyes, and straight paralobes. The thoracic spiracles are very large, and this is a characteristic feature of the ancestral group; enlargement is found to some degree in other golden blowfly species, but less strikingly so. It is probable that stygia is still quite close in its characters to the ancestral stock, and marks the first step in a morphological progression to the numerous golden blowfly species found in Australia today. C. quadrimaculata has been geographically and genetically isolated in New Zealand, and may form the stock for future speciation. Indeed, on Campbell Island and the Auckland Islands it differs from the mainland form in having the abdomen blue-green and metallic rather than violet. This subantarctic form was described by Hutton (1904, p. 155) as a distinct species, but I do not believe that it deserves this status. However, speciation appears to be rapid in the New Zealand subregion, with its many islands.
Calliphora vicina, accidentally introduced from Europe, was first recorded in New Zealand by G.V. Hudson in 1889, but under the name C. vomitoria, a misidentification. This species has now reached all geographical regions of the world, most probably dispersed passively by human agency in the days of sail.
Genus Hemipyrellia
This genus is very closely allied to Lucilia, and may at some time be considered synonymous. Like Lucilia, Hemipyrellia species breed in decaying animal matter, but adults are attracted to sweet-smelling substances.
In material received from Lincoln College I found a single specimen of Hemipyrellia ligurriens (Wiedemann), possibly incorrectly labelled. As with Chrysomya megacephala, this species is tropical and would probably not become established in New Zealand, but I have identified it amongst material collected at airports in New Zealand. The genus has been included in the key so that it may be identified should it turn up in imported cargo.
Genus Lucilia
The genus Lucilia is represented here by the well known, cosmopolitan sheep blowfly L. sericata Meigen, which was first recorded from New Zealand in 1872 by Hutton (1901, p. 63). Miller (1939b, p. 52) gave a key to three species, one sericata and the others called simply "A" and "B". His species B can be eliminated as it obviously did not originate in New Zealand, having a yellow third tergite; it fits the description of, and most likely is, the Australian species Hemipyrellia fergusoni Patton. Miller separates his species A from sericata using a poorly diagnostic colour character, but his genitalia drawings show quite marked differences. However, these may be artefacts due to distortion during slide mounting and to over-clearing of the aedeagus. I have not found a second species in the material I have examined. Material recently received from New Zealand airport authorities included a specimen of the tropical species L. cuprina Wiedemann. This is unlikely to become established in New Zealand, but I have included it in the key on p. 27 for the benefit of those identifying insects found in imported cargo.
Genus Pollenia
Pollenia has previously been considered a predominantly Palearctic genus, with one or two migrant species reaching North Africa, America, and north-western India. It is now clear that this is erroneous, and that Pollenia is substantially represented in the Southern Hemisphere. Many species await description from southern Australia, and new species are described here from New Zealand.
Apart from two recent introductions from the Northern Hemisphere, all New Zealand species are endemic. Pollenia is by far the largest - as well as the least known - genus of Calliphoridae in this country.
A few members of the tribe Polleniini were described from the Oriental and Austro-Oriental regions by early authors such as Francis Walker, but these have subsequently been transferred to other genera within the Calliphorinae and Rhiniinae. No Polleniini have been recorded from the Afrotropical and Neotropical regions. In North America the tribe is represented by two introduced species and the genus Melanodexia Williston, which is confined to river gullies in California and Idaho. There are, then, four distinct geographical groups of Polleniini: Palearctic Pollenia (30+ species); Nearctic Melanodexia (8+ species); Oriental and Austro-Oriental Pollenia (8+ species, including Xanthotryxus); and the Australian and New Zealand Pollenia (60+ species, including Anthracomyia). Basic external and genital morphology is identical in the four groups, head shape (Figure 12) and the bare prosternum and propleuron in particular distinguishing them from other Calliphoridae. The Oriental-Australasian genus Polleniopsis Townsend has a Pollenia-like head but a haired propleuron and prosternum, short, larviparous ovipositor, and Onesia-like aedeagus.
The question of origins and phylogenetic relationships of the Polleniini within the Calliphoridae is especially difficult, and its detailed resolution is outside the scope of this study. However, the existence of a large number of very similar species indicates that the Polleniini are a comparatively recent group, possibly originating in and dispersing from the Palearctic region. It is likely that this dispersal took place across the Bering land-bridge and along the island chains of South-west Asia to Australia and New Zealand. Whatever their origin, once established the groups would have been isolated by changes in sea level during Pleistocene interglacials and the post-Pleistocene period, and rapid speciation apparently took place in the more temperate areas. The distinct Oriental and Austro-Oriental group consists of the few species that were able to adapt to a subtropical climate.
In basic structure and general appearance the New Zealand Pollenia species resemble the Palearctic representatives, with only a few minor differences, and I regard the two groups as congeneric. New Zealand Pollenia do not have the facial carina that is present in most Palearctic species, nor such long, crinkled thoracic ground setulae. In some of them the abdomen is metallic blue or green, without distinct dusting, and often with pale ground colour to the thorax.
A few Palearctic species placed by some authors in a separate genus, Nitellia Robineau-Desvoidy, have shorter ground setulae and an undusted, metallic black abdomen. These are much more similar to the New Zealand species than they are to the rest of the Palearctic Pollenia (the rudis-group; see note on p. 47), which have long, crinkled, golden thoracic hairing and the abdomen densely dusted and olivaceous. The male genitalia of the New Zealand and Palearctic species are of very similar construction, but unlike any of the New Zealand species the rudis-group has a strongly sclerotised rod on the basal half of the hypophallus. In the Nitellia-group the marginal spines are confined to the dorsal portion of the hypophallus, and the lower portion is not produced forwards into a spine-like projection as in many of the New Zealand species. The aedeagus of Melanodexia resembles that of the Nitellia-group but has a broader, blunter paraphallus.
The Australian species are generally darker, and often have the thoracic hairing typical of the rudis-group. In structure of the aedeagus they are identical with the New Zealand species.
I wholeheartedly endorse the view of Mihalyi (1976) concerning the Hungarian Pollenia species: "Pollenia is the most difficult genus of the Calliphoridae". I have experienced considerable difficulty in producing useful taxonomic conclusions to the problems encountered while preparing a key to the New Zealand species of Pollenia, as with the Palearctic species. These problems have arisen mostly because of infraspecific variability, the general similarity of the species as regards external morphology, and the relative paucity of material available. Although infraspecific variability has been accounted for in the key, the figures of the male genitalia should always be used to confirm an identification.
A separate key to females has been given, and again variability has been accounted for, but as more material becomes available this key may prove unsatisfactory. Except where I have had reliably associated sexes, the females have not been assigned to species but left unnamed, and instead referred to as "species a" to "species q".
Hutton (1901) was the first to describe any New Zealand Pollenia species, but placed his new species demissum and fumosum in the genus Sepimentum. Malloch (1924) synonymised this genus with Pollenia and considered Hutton's two species to be conspecific. In a subsequent paper (1930), published after examination of more material, Malloch reversed his opinion and restored them as distinct species. He also described three new species, and two new varieties of demissa; these latter are discussed under P. demissa (p. 36).
Although unhappy about the validity of the generic characters of Huttonophasia as distinct from Pollenia, Malloch (1930) considered it a good genus. I consider it to be synonymous with Pollenia, as I can find no characters important enough to warrant its distinction (see Remarks under P. pernix).
Genus Ptilonesia
Ptilonesia is a very unusual calliphorid genus found only in New Zealand and two localities in Australia. It is monotypic, and in general appearance is very Onesia-like, with wide parafacials and jowls and the eyes reduced. It is also reminiscent of the endemic New Zealand genus Xenocalliphora, and was placed as a subgenus of it by Kurahashi (1971). I prefer to keep Ptilonesia as a distinct genus on the basis of its lack of ocellar and superior orbital setae, modifications to the fifth tergite, hairing on the parafacialia and squamae, facial shape, and male genitalia. The similarity to the Neotropical genus Toxotarsus I believe to be due to convergence, rather than an indication of any phylogenetic relationship, because both genera are seashore flies. Miller (1939b) says that the single species of Ptilonesia breeds in decaying seaweed. This may be a mistaken observation, and it may be that the flies were breeding in dead animals tangled in the seaweed masses.
Outside New Zealand Ptilonesia is apparently restricted to beaches north and south of Sydney Heads and at Seaford in Victoria (K. R. Norris, pers. comm). The question arises as to whether this disjunct and local distribution represents an introduction or is a relic of a previously wider distribution. Introduction on floating masses of seaweed is unlikely, as ocean currents run away from Australia throughout the year, and prevailing winds blow either towards New Zealand or northwards along the eastern coast of Australia. The other possibility is of dispersal by boats travelling between New Zealand and Australia, but it is strange that, once established, the individual colonies did not disperse rapidly, as is usual with other seashore Diptera. It seems most likely, therefore, that the Australian populations are a relic of a previously wider distribution.
Genus Xenocalliphora
This genus is endemic, and contains ten species, four of which are described here as new. Three species occur on the main islands, but the remaining seven are restricted to offshore islands.
Xenocalliphora is reminiscent of Onesia and Ptilonesia in general habitus, having dichoptic males, wide jowls and parafacialia, and in being larviparous. The species can be divided into two distinct groups which, however, are not distinguishable by their general appearance. The first group has two posterior ia setae, no pd setae on the fore tibia, and an aedeagus with a bifurcate harpes that is curved for its entire length (Figures 94 and 100). The second group has one posterior ia seta, a pd seta on the fore tibia, and a non-bifurcate aedeagus that is broad and curved at the tip (Figures 92 and 96). The first group is restricted to the North Island, northern South Island, and central offshore islands, and the second is found only in the southern islands - a distribution suggesting sister-group status. Unfortunately, Hennig (1966) does not mention this genus or any of its species in his work.
The phylogenetic relationships of Xenocalliphora within the Calliphoridae are not clear. Kurahashi (1971) suggests that the genus is derived from the same ancestral stock as the old Calliphora-group but has evolved in a way differing from modern Calliphora. Certainly it is of striking appearance when compared with other genera from the Southern Hemisphere. Kurahashi also suggests that it has affinities with some Holarctic genera such as Cynomya, Cyanus, Onesiomima, and Abago. This I find doubtful, and prefer to consider Xenocalliphora as a totally isolated group that is now found only in the New Zealand subregion, but which derives ultimately from the common ancestor of the Calliphora-group.
Malloch (1930) keyed four species correctly, using the name Xenocalliphora and describing one species as new. Miller (1939b) used Calliphora for all his blowfly species, including five Xenocalliphora species, two of which he described as new. Murray (1954) gave a very good key to all the species of Calliphora known to occur in New Zealand; this included six species of Xenocalliphora, one of which he described as new. Kurahashi (1971) included five species in his key to Xenocalliphora but did not see specimens of most of the species. Harrison (1976) gave a key to Calliphora species which included five Xenocalliphora species. In general, adequate keys have been given to the known species, but in many instances the nomenclature is incorrect, names being confused and assigned to the wrong species. Misidentifications are discussed under the relevant species.
Genus Chrysomya
This genus is represented in New Zealand by C. rufifacies (Macquart), which, like other Chrysomya species, is a tropical or subtropical blowfly adopting the ecological role of Lucilia in temperate regions. It is, however, unusual in being able to extend its geographical range to warm temperate regions (cf. C. albiceps in southern Europe). The male genitalia (Figure 19) are not typical of the Chrysomyinae, and the larva is unusual in having fleshy protuberances on the segments (see Figure 116).
The earliest recorded occurrence of rufifacies in New Zealand is 1911 (Miller 1939b, p. 56, and specimens in BMNH). Malloch (1930, p. 315) refers to this species as Chrysomya albiceps (Wiedemann), with which it may be conspecific (see Zumpt 1956, p. 192).
I have recently received from the Commonwealth Institute of Entomology two samples of Chrysomya megacephala (Fabricius) found aboard aircraft arriving in New Zealand from Australia. I also have a record of this species from rotting fruit at Springston, MC (possibly incorrectly labelled; R. A. Harrison, pers. comm.). This species is tropical, and is unlikely to become established in New Zealand, but I have included it in a key (p. 57) so that it can be identified should it turn up in seaports or at airports.