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Extracts from William Rae McLennan’s diary relating to the discovery of the moth Trysintopa scatophaga that nests with the Golden-shouldered Parrot

These notes were extracted from William Rae McLennan’s diary by Alfred Jefferis Turner. Turner transcribed the entries from the days that McLennan discovered and made observations on the moth Trysintopa scatophaga in the nests of the Golden-shouldered parrot near Coen, Cape York Peninsula, North Queensland. Turner’s notes are in the possession of Ted Edwards, CSIRO Entomology, Canberra.

Notes copied from Wm McLennan’s diary on observations made by him near Coen, Cape York peninsula, North Queensland, & dealing with the caterpillars and moths that he discovered living in the nests of the Golden-shouldered Parrot (Psephotus chrysopterygius), made in tall termitariums (13.8.22).

Male and Female Moth

Male (left) and female (right) moth, Trisyntopa scatophaga, from the nests of the Golden-shouldered Parrot

CSIRO Entomology , Canberra

[enlarge male]
[enlarge female]

6th May 1922. A pair of Psephotus seen, 100 yards away; found where these birds had recently started a nest in spire-shaped termitarium. A mile further on I saw another pair of Psephotus; search closely all around the spot, only old nests noted. Reach the place where I found the well feathered young on 1:5:22. Take a photo of termitarium [see The Emu, vol. 22, 1922: Plates XXX and XXI, opposite p. 98], then open the nest to get a photo of the young, found it contained 7 young, one of which was still in the downy stage with scarcely a feather showing. Could not make out what was the matter with the bottom of the nest, it was heaving and undulating in constant movement, little heads were flickering out and in through trapdoor like openings. At first I thought it was alive with maggots; a few seconds later a number of the insects came right out of the bottom of the nest and started to eat up the excreta which one of the young Psephotus had just voided. I then saw that the insects were caterpillars. In a couple of seconds the excreta were eaten up at the caterpillars at once disappeared into the bottom of the nest through the opening through which they emerged. I sat and watched them for some time; every now and again one or two caterpillars would come out & go exploring round the bottom and sides of the nest. The young birds were frequently voiding excreta and at times [it] would get all over their feet and tail feathers; instantly caterpillars would swarm out and devour it, eating up every scrap even off the feet & feathers of the young, thus the young birds were kept scrupulously clean. The young birds did not take any notice of the caterpillars. I took a photo of the nest and young; unfortunately they were all in shadow & may not show up too well. I took six of the young for the purpose of rearing them & noting their plumage changes. I now examine the bottom of the nest [.] The trap door like openings proved to be the mouths of cocoons in which the caterpillars lived, these cocoons were lightly bound or matted with web, the interstices between being filled with the excreta of the caterpillars and the fine chipped dirt in the bottom of the nest. Secure a number of the caterpillars, and also a portion of the bottom of the nest. Cut a piece out of another termitarium to repair hole made in the nesting chamber & replace the small young. Continue on, found a nest that had only just been started, 6 feet from ground in a big magnetic termitarium; it contained half-fledged young ones with the attendant colony of scavenger caterpillars. ‘Tommy’ found the next nest, 4 feet 6 inches from the ground in big magnetic termitarium; it contained one fully fledged young one which flew out and away when I went to look in the nest. ‘Tommy’ chased & caught it. Open up nest & examine it.

The caterpillars in this nest were just starting to pupate, a number of them had clustered their cocoons closely together & bored through the inside of the termitarium at the thinnest part of the side of the nesting chamber. Secure this cluster of cocoons. Further on I found an old nest, probably last season’s. The cocoons of the caterpillars were clustered together in the thinnest wall of the nest, but all the insects had emerged; secure cocoons.

Chunk of termite mound

As the anthill parrot nestlings near fledging, the larvae of their housekeeping moths move to the side of the nest cavity within the termite mound, build cocoons and begin to pupate. When the parrots return to nest the following season, the adult moths emerge from these cocoons to lay eggs and begin the cycle again. This chunk of termite mound came from the nest of a Golden-shouldered Parrot; its moth imbeds its pupal cocoon in the inner wall of the mound and emerges on the outside of the mound. The Hooded Parrot nests in thicker-walled, chaffy mounds, and its moth simply attaches its cocoon to the wall and the adult emerges inside the mound.

Photograph by Ederic Slater
Chunk of termite mound, formerly the wall of a Golden-shouldered Parrot nest, with embedded cocoons of Trysintopa scatophaga 2005
CSIRO Entomology, Canberra

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Another old nest had quite a large cluster of empty cocoons in thinnest wall of nest; secure them. I found another nest Psephotus, 2 feet from ground in a spire-shaped termitarium; small young just starting to get their feathers, with colony of scavenger caterpillars in bottom of nest.

7th May 1922. Flushed finch (P. nigrotecta) [north-eastern subspecies of Black-throated Finch Peophila cincta nigrotecta] from a fresh Psephotus nest in magnetic termitarium, in which it had built its nest of grass; it contained 6 eggs. Several old nests of Psephotus noted on this flat.

Further on I found a nest of Psephotus 7 feet from ground in a big magnetic termitarium; small young not long hatched, and attendant colony of scavenger caterpillars. About 100 yards further on I saw a female Psephtous flying towards the nest. A couple of miles further on I found a nest of Psephotus from which young had only just flown. The caterpillars were just starting to cluster together at the thinnest wall of the nest; no place to stow them, do not take them.

13th May 1922. Found several old nests of Psephotus with the clusters of empty cocoons of the caterpillars in each. Only one nest from which the young had flown this season, no sign of any caterpillars in this nest; the bottom of nest was literally caked with dried excreta of the young birds. A female Psephotus flushed from a nest while nearing camp, on looking in could plainly see 4 eggs. Four moths in the chamber, two of them coupling, evidently the moth responsible for the caterpillars. Secure & label them.

21st May 1922. Examine nest of Psephotus noted with young just hatched some days ago; it contained 4 young, two of them fairly well feathered, take these and leave the small ones. Colony of scavenger caterpillars in bottom of nest, secured them and put them in bottom of box in which I was carrying the young parrots. Go on to the second nest noted same day; this nest contained 5 young & the skeleton of a sixth. Red meat ants had raided this nest and were carrying off the scavenger caterpillars, but not interfering with the young birds. Go on to Psephotus nest noted with small young on 7:5:22; young now only just starting to get feathers; usual colony of caterpillars in bottom of nest. Go on to next Psephotus nest, from which birds flushed on 7:5:22, a finch (P. nigrotecta) flushed from its nest; open it up. The Finch’s nest contained 4 eggs. Nest of Psephotus in magnetic termitarium, young had only just gone; caterpillars had not started to pupate, so secure them.

Another nest of Psephotus in termitarium contained 4 almost full-fledged. Snap termitarium off level with nesting chamber, then take photos of young, & then photo of bottom of nest [to show] how clean it is kept by the caterpillars; [secure four] young, also the caterpillars.