7 Nicholas Martin Ensign Scale, species (: Coccoidea: ) in New Zealand

Nicholas A. Martin Research Associate, Landcare Research, Private Bag 92170, Auckland 11072. Email: [email protected]

Have you heard of Ensign Scale (Ortheziidae)? Until two years ago I had no idea such strange insects existed. At the time I was looking at fungi on dead leaves and twigs, including dead leaves of New Zealand flax (Phorium tenax J. R. Forst. & G. Forst.). I found some strange mobile insects covered in white wax-like plates (Figs. 1-2). The insects appeared to be breeding on dead flax leaves, and they reminded me of scale insects but did not appear to be mealybugs or Margarodidiae.

Figure 1: Female Ensign scale , Newsteadia gullanae (Ortheziidae) on Kanuka (Kunzea sp.) bark. The Weta 53: 7-14 8

Figure 2: Underside of an Ensign scale nymph showing the short rostrum.

Ensign scales are readily distinguished by (i) possessing distinctive, well- developed legs and antennae, and (ii) having much of the body cloaked in bunches of white wax secretions (Szita et al 2015). In New Zealand, I imagine that only a few specialists of scale insects and avid identifiers of the contents of pitfall traps and of in litter samples have been aware of these fungal feeding scale insects. Yes, that’s right, some species of Ensign scale insects feed on fungi. There are two groups of Ensign scale. One group of species occur in leaf litter (feeding on roots and fungal mycelia), and lichens, while a second group of species feed on vascular plants (Szita el al 2015). Since discovering their existence, I have reared these scale insects, examined the slides in the NZAC collection at Landcare Research, Tamaki, and read some of the stories about them.

Until 2000 only one species was known from New Zealand, Newsteadia myersi Green, 1929 (Green 1929). After a revision of Newsteadia species of the Australian and Pacific regions (Kozár & Konczné Benedicty 2000), the late Rosa Henderson, Landcare Research, found that there were three species present in New Zealand (Macfarlane et al 2010, page 403). The comments on the genus made on page 268 (Macfarlane et al 2010) were written before the new information on species present in New Zealand was 9 Nicholas Martin available and mentions that N. myersi, which lives in litter and amongst mosses, was thought to be root feeding.

The three species found in New Zealand are N. myersi Green, 1929, Newsteadia caledoniensis Kozár & Konczné Benedicty, 2000 and Newsteadia gullanae Kozár & Konczné Benedicty, 2000. Newsteadia myersi is only known from New Zealand, while N. caledoniensis was first found in New Caledonia and N. gullanae was found in Tasmania, Southern Australia and possibly New Guinea (the two New Guinea specimens have slight differences from the Australian specimens) (Kozár & Konczné Benedicty 2000). The three species are widespread in New Zealand (Table 1).

Table 1: Distribution of Newsteadia species in New Zealand based on microscope slides in NZAC, Landcare Research, Tamaki. Regions are based on the codes devised by Crosby et al. (1998).

Regions N. caledoniensis N. gullanae N. myersi AK, Auckland X X CL, Coromandel X X BP, Bay of Plenty X X WO, Waikato X GB, Gisborne X X HB, Hawkes Bay X WN, Wellington X X X MB, Marlborough X X NN, Nelson X X BR, Buller X X X DN, Dunedin X OL, Otago lakes X FD, Fiordland X Chatham Isle X The Weta 53: 7-14 10 Mature females of the three species in New Zealand can easily be distinguished by the number of segments and kind of setae on the antennae (Table 2). So far I have only found live N. gullanae. It is usually possible to see the antennal segments and the hair-like setae. In their redescription of N. myersi Kozár & Konczné Benedicty (2000) were not able to see the anal ring, whereas slides in NZAC show that N. myersi has six large setae around the anal ring, like the other species illustrated in their paper. Like other scale insects N. gullanae has a winged male (Fig. 3).

Table 2: Some distinguishing characters of of Newsteadia species in New Zealand. Measurements based on Holotypes (Kozár & Konczné Benedicty 2000).

Characters N. caledoniensis N. gullanae N. myersi

Size of female 0.9 x 0.7 mm 2 x 1.1 mm 1.3 x 0.9 mm

Number of 4 segments 7 segments 5-6 segments antennae segments Type of antennal spine-like hair-like spine-like setae setae setae setae Length of apical 186 µm 217 µm 204 µm segment Antennae, Apical 74 µm 102 µm 70 µm seta

While all three species live in habitats on the ground, the data on the microscope slides reveals possible habitat preferences of the three species. For example, N. gullanae and N. myersi are both associated with perched and orchid mats and N. myersi was also found in perched litter on Kiekie (Freycinetia banksii A. Cunn. (Pandanaceae)). I have found N. gullanae in perched litter in Nikau Palms (Rhopalostylis sapida H. Wendl. & Drude (Palmae)), with invertebrate frass in the base of attached dead Nikau fronds, and under loose bark of Kanuka, Kunzea sp. (Myrtaceae). The microscope slide labels also indicate an association with grasses, grass roots and roots under a stone. The records of these plant associations are in the Internet Plant-SyNZ database, but do not necessarily mean that the Ensign scale insects were feeding on the plants. 11 Nicholas Martin

Figure 3: Male Ensign , Newsteadia gullanae (Ortheziidae). Note the eight wax tails.

One species, (De Geer, 1778), has been reared on dead leaves (Schumtterer 1952; Buchner 1965; in Kozár & Konczné Benedicty 2000, page 495). I have reared N. gullanae on dead leaves and observed them feeding on fungal hyphae, as well as inserting their stylets into moist dead leaf tissue. It is therefore likely that the three New Zealand species are fungal feeders.

A fascinating feature of Ensign scale insects is that the adult female has a special structure for carrying eggs, the marsupium. White wax abdominal secretions form a kind of basket with lid that carries the eggs (Fig. 4).

Until I accidentally discovered Ensign scale insects I had not thought much about the origins of scale insects or even Insecta. However, there appears to be some interesting debates about the origins of scale insects in which Ensign scale insects provide some revealing insights. A useful paper by Vea & Grimaldi (2012) has good drawings and photographs and describes The Weta 53: 7-14 12 species found in fossilised amber. The fossils show that Newsteadia species were present in the Eocene.

Figure 4: Female Ensign scale insect, Newsteadia gullanae (Ortheziidae). Note the ‘tray’ of the marsupium exposed by damage to the upper wax plates. The marsupium holds the eggs.

Another interesting paper is an essay by Koteja (1985) on the origins of Scale Insects. To me, it makes sense from an ecological perspective. Key elements of his proposal are:

1. Coccids remained in the primary habitat, the forest litter and retained the method of feeding by sucking liquids from the surface of the living and decaying plant tissues much longer than any other group of Homoptera

2. While living in litter, a habitat with lots of small and tight spaces, scale insects developed legs for digging (one claw, one-segmented tarsus, and functional tibiotarsal joint); the adult females lost their wings and became larviform; the adult males became non-feeding, dwarf-like, 13 Nicholas Martin dipterous and polymorphic and the last male nymphal instars became non-feeding resting stages that retained wing buds.

3. During the litter living stage, which was prior to the development of Angiosperms, the main groups of scale insects evolved. After the appearance of Angiosperms, the scale insects fed on live plants and most groups started to climb up the plants.

4. Evolution as plant feeders was limited by the absence of wings in females and the fragility of males. Specialization was directed towards a sessile life: the coccids developed a variety of protective systems with simultaneous reduction of locomotion ability. These systems involved major structural modifications of the female body (including diminution and hypertrophy), special glands in the integument and devices for ejecting honeydew.

The litter habitat and fungal feeding behaviour of some Ensign scales is believed to be the retention of features of the proto-scale insects.

My chance ‘discovery’ of these fascinating Ensign scales has led me to research a group of insects that I was previously unaware, and they may well become the subject of a future Landcare Research factsheet. I wonder what else I might find when I next turn over a leaf.

Acknowledgements

The author wishes to thank The New Zealand Institute for Plant & Food Research Limited for continuing to provide resources for taking photographs, and Peter Cameron for helpful comments on the manuscript.

References

Crosby, T. K., Dugdale, J. S., & Watt, J. C. 1998. Area codes for recording specimen localities in New Zealand subregion. New Zealand Journal of Zoology 25: 175-183. Green, E. E. 1929. Coccidae collected by J. G. Myers in New Zealand. Bulletin of Entomological Research 21: 377–389. Internet Factsheets: Interesting Insects and other Invertebrates http://nzacfactsheets.landcareresearch.co.nz/ Plant-SyNZ™: an invertebrate herbivore biodiversity assessment tool http://plant-synz.landcareresearch.co.nz/ The Weta 53: 7-14 14 Koteja J. 1985. Essay on the prehistory of the scale insects (Homoptera, Coccina). Annales Zoologici 38: 321-328. Kozár, F. & Benedicty, Z. K. 2000. Revision of Newsteadia of the Australian and Pacific Regions, with description of eleven new species (Homoptera: Coccoidea, Ortheziidae). Acta Zoologica Academiae Scientiarum Hungaricae 46: 197-229. Szita, E., Kaydan, M. B., Benedicty, Z. K., Tanaka, H., Fetykó, K., Kozár, F. 2015. The genus Arctorthezia Cockerell (Hemiptera, Ortheziidae) with the description of a new species. Zookeys 472: 59-75. Vea, I. & Grimaldi, D. A. 2012. Phylogeny of Ensign scale insects (Hemiptera: Coccoidea: Ortheziidae) based on the morphology of recent and fossil females. Systematic Entomology 37: 758–783.