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Corresponding author: Francesco Martoni ( francesco.martoni@agriculture.vic.gov.au ) Academic editor: James Zahniser
© 2018 Francesco Martoni, Samuel D. J. Brown.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Martoni F, Brown SDJ (2018) An annotated checklist of the Cook Islands psyllids with keys to the species and two new records (Hemiptera, Psylloidea). ZooKeys 811: 91-108. https://doi.org/10.3897/zookeys.811.28829
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An annotated checklist of the psyllids of the Cook Islands is presented. The presence of Syntomoza tahuata (Klyver, 1932) and Trioza alifumosa Klyver, 1932 in the archipelago, based on new material collected, is reported for the first time. This is the first record from these islands of the genus Syntomoza and the family Liviidae. An identification key to the psyllid species known from the Cook Islands is provided, and their origin and provenance are discussed in relation to their biogeographic implications.
Jumping plant lice, Pacific Islands, Polynesia, Rarotonga, Sternorrhyncha
The superfamily Psylloidea (Hemiptera: Sternorrhyncha) is composed of almost 4000 described species worldwide (
The first report on the psyllid fauna of the Cook Islands appears in Hodkinson’s checklist of the Austro-Oriental and Pacific area that listed three species: Mesohomotoma hibisci (Froggatt, 1901); Leptynoptera sulfurea Crawford, 1919; and Trioza vitiensis Kirkaldy, 1907 (
The geographical location of the Cook Islands puts them in a central position between French Polynesia and other countries such as Samoa, Tonga, Fiji, and New Zealand. This makes this small archipelago important for evaluating biogeographic hypotheses and testing theories of biological dispersal within the Pacific. Additionally, due to the high movement of people and produce between the Cook Islands, New Zealand and Australia, understanding the biodiversity of the Cook Islands allows evaluation of potential biosecurity risks for New Zealand or Australian agriculture.
For these reasons, recent field collections from the Cook Islands presented in this work have contributed to updating our knowledge of the psyllid biodiversity of the Islands, with the discovery of two additional taxa: Syntomoza tahuata (Klyver, 1932), and Trioza alifumosa Klyver, 1932, both originally described from French Polynesia (Marquesas) (
Specimens were collected by SDJB on the island of Rarotonga, Cook Islands, in March and April 2017. Collections were made by beating host foliage over a beating tray. Insects were stored in propylene glycol until morphological identification was performed. Photographs were taken using a Nikon DS-Ri2 camera connected to a Nikon SMZ25 microscope. Pictures presented in the plates are the result of stacking photographs using the software Nikon NIS-Elements D v4.5 resulting in a single image with an extended depth of field. Plates were prepared using GIMP version 2.8.14. For closer examination, two specimens of each species (male and female) were mounted on microscope slides following the protocol of
4 females, 10 males. This species was collected on two separate occasions on Rarotonga: on 15 April 2017 on Te Manga at elevations between 540 m and 560 m, collected from two host plants: from Weinmannia samoensis A.Gray (Cunionaceae) (five specimens) and from Freycinetia wilderi Martelli ex Wilder (Pandanaceae, plant specimens not collected) (two specimens), and on 17 April 2017 in the Avana Valley around 70 m elevation, from the foliage of a fallen Homalium acuminatum Cheeseman (Salicaceae) (seven specimens collected, with several more observed). Three additional specimens collected around Avatiu in November 1979 by NLH Krauss were located in the Bishop Museum.
Syntomoza tahuata. 1 lateral habitus of female 2 lateral habitus of male 3 dorsal habitus of female 4 dorsal habitus of male 5 head of female, dorsal view 6 head of male, dorsal view 7 wing of male 8 mesotibia of male 9 terminalia of female, lateral view of left side 10 terminalia of male, lateral view of left side. Abbreviation: par = paramere. Scale bars: 1 mm (1–7); 0.5 mm (8); 0.25 mm (9, 10).
Measurements are in mm (n = 3 ♂, 2 ♀ unless reported differently in brackets). Length of body (vertex to terminalia) ♂ 0.98–1.30 (n = 2), ♀ 1.17–1.53; length of body (vertex to apex of folded wings) ♂ 1.72–1.88 (n = 2), ♀ 2.21–2.22; width of head (HW) ♂ 0.53–0.60 (n = 2), ♀ 0.63–0.65; length of genal processes (GCL) ♂ 0.10 (n=1), ♀ 0.12; length of vertex (VL) ♂ 0.12–0.18 (n = 2), ♀ 0.18–0.19; width of vertex (VW) ♂ 0.30–0.35 (n = 2), ♀ 0.34–0.38; length of antenna (AL) ♂ 0.40–0.49 (n = 2), ♀ 0.44–0.57; length of fore wing ♂ 1.40–1.49, ♀ 1.71–1.77; width of fore wing ♂ 0.63–0.68, ♀ 0.75–0.85; length of vein Rs ♂ 0.82–0.87, ♀ 1.02–1.04; length of vein M (M) ♂ 0.44–0.46, ♀ 0.52–0.53; length of vein M1+2 (M1) ♂ 0.36–0.40, ♀ 0.48–0.51; marginal width of cell m1 ♂ 0.18–0.20, ♀ 0.26–0.27; marginal width of cell cu1 ♂ 0.50–0.54, ♀ 0.62–0.63; length of vein Cu1b ♂ 0.11–0.14, ♀ 0.13–0.16; length (height) of proctiger (PL) ♂ 0.21–0.24 (n = 2); length of paramere ♂ 0.17–0.19 (n = 2); length of proximal aedeagal segment ♂ 0.19 (n = 1); length of distal aedeagal segment ♂ 0.09 (n = 1); length of proctiger (PL) ♀ 0.44–0.52; length of circum-anal ring (CL) ♀ 0.16–0.20; length of subgenital plate (SL) ♀ 0.35–0.46.
The stout body shape, and the distinct dorsal patterning of orange stripes on a black background makes this psyllid readily recognised within the Cook Island fauna. This psyllid was identified using the original description (
11 females, 8 males. A single population of this species was collected on Rarotonga, on the summit of Raemaru at an elevation of 380 m. On 16 March 2017 all 19 individuals were collected from a single plant of Metrosideros collina (J.R.Forst. and G.Forst.) A.Gray.
Measurements are in mm (n = 2 ♂, 3 ♀ unless reported differently in brackets). Length of body (vertex to terminalia) ♂ 1.30–1.45, ♀ 1.60–1.78; length of body (vertex to apex of folded wings) ♂ 2.57–2.81, ♀ 2.86–3.10; width of head (HW) ♂ 0.50–0.53, ♀ 0.52–0.57 (n = 2); length of genal processes (GCL) ♂ 0.09–0.14 ♀ 0.10–0.13 (n = 2); length of vertex (VL) ♂ 0.21, ♀ 0.20–0.25 (n = 2); width of vertex (VW) ♂ 0.31–0.32, ♀ 0.32–0.33 (n = 2); length of antenna (AL) ♂ 0.78–0.79, ♀ 0.81–0.85 (n = 2); length of fore wing ♂ 2.27–2.28, ♀ 2.38–2.57 (n = 2); width of fore wing ♂ 0.83–0.86, ♀ 0.85–0.96 (n = 2); length of vein Rs ♂ 0.91–0.99, ♀ 1.00–1.08 (n = 2); length of vein M (M) ♂ 1.11–1.12, ♀ 1.15–1.24 (n = 2); length of vein M1+2 (M1) ♂ 0.44–0.48, ♀ 0.54–0.56 (n = 2); marginal width of cell m1 ♂ 0.28–0.32, ♀ 0.38 (n = 2); marginal width of cell cu1 ♂ 0.40–0.42, ♀ 0.42–0.44 (n = 2); length of vein Cu1b ♂ 0.23–0.25, ♀ 0.21–0.25 (n = 2); length (height) of proctiger (PL) ♂ 0.15–0.20; length of paramere ♂ 0.11–0.13; length of proximal aedeagal segment ♂ 0.17 (n = 1); length of distal aedeagal segment ♂ 0.16 (n = 1); length of proctiger (PL) ♀ 0.30–0.51; length of circum-anal ring (CL) ♀ 0.10–0.13; length of subgenital plate (SL) ♀ 0.29–0.34.
Trioza alifumosa. 11 lateral habitus of female 12 lateral habitus of male 13 dorsal habitus of male 14 dorsal habitus of female 15 head of female, dorsal view 16 head of male, dorsal view 17 wing of male 18 mesotibia of male 19 terminalia of female, lateral view of left side 20 terminalia of male, lateral view of left side. Abbreviations: aed = aedeagus, par = paramere, ptg = proctiger, sgp = subgenital plate. Scale bars: 1 mm (11–17); 0.5 mm (18); 0.25 mm (19, 20).
This psyllid can be identified by the following combination of characters: habitus as in Figures
The following checklist includes all species known to be present in the Cook Islands. Information on their taxonomy is reported together with their worldwide distribution and host plant associations. For species of socio-economic interest, such as pests, basic information on their biology is summarised.
Tyora hibisci Froggatt, 1901: 287.
Udamostigma hibisci (Froggatt); Enderlein 1910: 138.
Mesohomotoma hibisci (Froggatt); Crawford 1925: 32.
Reported on the Cook Islands by
Hibiscus species, especially H. tiliaceus L. (Malvaceae).
Hibiscus (woolly) psyllid (
the genus Mesohomotoma Kuwayama was reviewed by
Anomoterga tahuata Klyver, 1932: 94.
Syntomoza
tahuata
(Klyver);
Reported on the Cook Islands in the present study. Known only from Rarotonga. Other locations include: French Polynesia (Marquesas) (
No host plants have been previously proposed (
Heteropsylla cubana Crawford, 1914.
Reported on the Cook Islands by
Leucaena leucocephala (Lam.) de Wit (Fabaceae).
Leucaena psyllid (
Heterpsylla cubana is considered an agricultural pest both in the Asia-Pacific area and in Africa (
The biology and life cycle of H. cubana is reported here with the intent of summarising information (mostly from
Leptynoptera sulfurea Crawford, 1919: 147.
Reported on the Cook Islands by
Calophyllum inophyllum L. (Calophyllaceae).
Leptynoptera sulfurea forms galls along the leaf margins of Calophyllum inophyllum (
Trioza alifumosa Klyver, 1932: 96.
Reported on the Cook Islands in the present study. Known only from Rarotonga. Other locations include: French Polynesia (Marquesas, Fatu Hiva) (
Metrosideros collina (J.R. Forst. & G. Forst.) A. Gray (Myrtaceae).
Trioza vitiensis Kirkaldy, 1907: 103.
Megatrioza
vitiensis
(Kirkaldy);
Phyllopecta
vitiensis
(Kirkaldy);
Trioza
vitiensis
Kirkaldy, 1907 combinatio revivisco according to
Reported on the Cook Islands by
Syzygium malaccense (L.) Merr. & L.M.Perry, 1938 (Myrtaceae).
Reported on the Cook Islands by P.J. Dale (
Metrosideros collina (J.R. Forst. & G. Forst.) A. Gray (Myrtaceae).
no specimens of this psyllid were collected by the authors. Photographs provided by G McCormack were consistent with the morphology of T. zimmermani, with the greatest difference shown in the wings (Figures
Wings, schematic. 22 Leptynoptera sulfurea (after
1 | Forewing with vein R+M+Cu1 bi-furcating to form R and M+Cu1 (Figures |
2 |
– | Forewing with vein R+M+Cu1 tri-furcating to form R, M and Cu1 (Figures |
4 |
2 | Forewing with veins R and M+Cu1 equally long or M+Cu1 slightly longer than R (Figures |
Syntomoza tahuata (Klyver, 1932) |
– | Forewing with vein R longer than M+Cu1 (Figures |
3 |
3 | Forewing with vein Rs very short (♂ 0.91, ♀ 1.14), strongly bent towards margin at apex, with a transverse vein crossing from centre of Rs to the bi-furcation between M1+2 and M3+4 (Figure |
Mesohomotoma hibisci (Froggatt, 1901) |
– | Forewing with vein Rs not turning upward and no transverse vein crossing the wing (Figure |
Heteropsylla cubana Crawford, 1914 |
4 | Forewing with vein Cu1 not bi-furcating and therefore not forming cell cu1 (Figure |
Leptynoptera sulfurea Crawford, 1919 |
– | Cell cu1 present (Figures |
5 |
5 | Forewing with dark spot on cell c+sc (Figures |
Trioza alifumosa Klyver, 1932 |
– | Forewing with no spots (Figures |
6 |
6 | Male genitalia with parameres pointing forward at apex and proctiger bearing long setae on the apical part facing the parameres. Female genitalia extremely short, approximately ¼ of abdomen. Length of psyllid to tip of folded wings between 5 mm and 6 mm. Body colour brown, with tan patterning | Trioza vitiensis Kirkaldy, 1907 |
– | Male parameres pointing backward at apex, proctiger bearing short setae uniformly, female terminalia longer (half of the rest of abdomen). Length of the psyllid to tip of folded wings only 3.5mm. Body colour black with pale stripe at base of abdomen | Trioza cf. zimmermani Tuthill, 1942 |
Based on the similarity of the samples analysed with the description and the drawings provided by the literature, the presence of the psyllids Syntomoza tahuata and Trioza alifumosa is reported on the Cook Islands for the first time. Host plants for these two species in the Cook Islands are hypothesised to be Weinmannia samoensis or Homalium acuminatum and Metrosideros collina respectively, based on collection data. Percy’s collection of a large number of individuals of S. tahuata from Weinmannia parviflora suggests this genus could be a true host plant (Percy, personal communication). However, we consider that H. acuminatum should remain under consideration as a possible host. No specimens of W. samoensis were seen near the Avana Valley site where S. tahuata was collected from H. acuminatum, and the elevation of the site is well below the lower elevational limit of W. samoensis (
We consider these two species to be indigenous to the Cook Islands, despite their not having been recorded here previously. The Cook Islands are underexplored entomologically, with relatively little collecting having been done in indigenous vegetation in particular. Moreover, these species were found in areas of relatively intact vegetation, with little human modification, which tend to be more resistant to invasive species (
The psyllid fauna of the Cook Islands now includes seven psyllid taxa from five genera and four families. The addition of S. tahuata is not only the first report for the genus in the Cook Islands, but also for the family Liviidae.
Compared with the psyllid fauna of other nearby archipelagos, the Cook Islands appear to have a very similar psyllid biodiversity. In fact, the single taxon present in Niue (H. cubana) and three of the four taxa present in Tonga (H. cubana, M. hibisci, and L. sulfurea) are also present in the Cook Islands (
The authors would like to thank Gerald McCormack (Natural Heritage Trust, Cook Islands) for assistance, advice, and support in the Cook Islands. A special thank you to Dr Diana Percy, for reviewing the manuscript and providing important information regarding the host plant of S. tahuata. Ines Schoenberger and Mary Korver (Allan Herbarium, Manaaki Whenua Landcare Research, Lincoln) facilitated plant specimen collections and identification. Jim Boone and Neal Evenhuis (Bishop Museum, Honolulu, Hawaii) provided access to the type specimens of the psyllids of interest. Fieldwork in the Cook Islands was carried out under research permit 10/17, dated 21 April 2017, issued by Bredina Drollet through the Office of the Prime Minister. Thanks to John Marris and the Bio-Protection Research Centre (Lincoln University) for providing working space and equipment for sorting and imaging specimens. This research was supported by a Winston Churchill Memorial Fellowship awarded to SDJB, and Plant and Food Research Strategic Science Investment Funding (SSIF).