Siphanta acuta (Walker, 1851)
Green planthopper, Torpedo Bug, Large green plant-hopper
Poeciloptera acuta Walker, 1851
Poeciloptera cupido Walker, 1851
Cromna elegans Costa, 1864
Phalainesthes schauinslandi Kirkaldy, 1899
Biostatus and distribution
This adventive plant hopper from Australia was first reported in New Zealand by Kirkaldy in 1909. It is now found in the North Island and parts of the South Island. It occurs on its herbaceous, shrub and tree host plants in city gardens and parks as well as native ecosystems.
Conservation status: Widespread, a minor pest on some garden plants.
Life stages and annual cycle
Nymphs and egg masses can be found on plants all year. Adults are commonest in Summer and Autumn. Many details of the annual cycle, life stages and behaviour of the Green planthopper are given by Myers in his informative 1922 paper on this insect.
Adults have green triangular wings that are normally folded to form a steep ‘roof’. The head and body are also green. There are two pairs of wings, three pairs of legs and one pair of antennae. The compound eyes are on the side of the head. A rostrum that holds the feeding stylets projects from the lower side of the head. The tip of the abdomen of females has an ovipositor for laying eggs.
After mating the female lays a flat oval cluster of eggs on a plant, usually on a leaf. There are 90-110 eggs in a batch, called an egg- cushion by Myers. The egg batch is initially white, but turns black due to a fungus that grows on the on the empty egg cases. After the nymphs hatch from the eggs, they usually stay near the egg mass for a short while before dispersing. Though they usually stay in small groups. The young nymphs are white and have a pair of white waxy filaments on each side of the sixth visible abdominal segment and two longer tufts at the tip of the abdomen. These wax tails are usually held close to the plant surface. The area around where they are living becomes lightly coated with wax. Like the adults the nymphs have a rostrum with the stylets for feeding, three pairs of legs and a pair of antennae. Nymphs go from one stage to the next by moulting. During moulting, the skin on the dorsal side splits and the next stage pulls itself out of the old skin. The second and third nymphal instars (stages) are increasingly green, while the fourth is green with some reddish markings. The fifth instar is white with pink markings. Older nymphs have wing buds. All nymphs have a white wax tail, with the wax mainly in two bundles. The tail is usually held flat against the plant, but can be lifted up and down. A little wax may be produced by other parts of the body.
Walking and flying
The nymphs and adults have three pairs of legs and when disturbed can jump. It is reported that the large nymphs can jump up to 60 centimetres, which is why they are called Torpedo Bugs in the USA.
The adults have two pairs of wings that are held over their body when not used for flying.
Like other Hemiptera, the green planthopper has piercing and sucking mouth parts. The long stylets, special shaped rods, are held in the rostrum. When it wishes to feed, the bug moves the tip of the rostrum to a suitable part of the plant. The stylets are then gradually pushed into the plant. The stylets form two tubes, one through which saliva is injected into the plant and a second through which plants juices are sucked up into the insect. The insects feed on the phloem, on of a plants two systems for distribution nutrients. Excess liquid is secreted at intervals. Myers in his 1922 paper describes in detail the way the insects jerk their abdomen while excreting a bead of honeydew that emerges from between the tufts of wax filaments on their tail. After its emergence it is flicked away.
The adult Green planthoppers are easy to distinguish from other insects by their bright green colour and shape of their wings that are held like a ‘steep roof’ and are sharply pointed at their tip. The most similar insect is the Grey planthopper, Anzora unicolor (Flatidae). It has a similar, though less angular shape and is blue-grey coloured.
The nymphs of the Green planthopper may be confused with those of the Grey plant hopper and the Passion vine hopper Scolypopa australis (Ricaniidae). Green planthopper nymphs have a pair of wax tails that are held close against the plant surface. There may be little wax on the plant around where they are living. Nymphs of the Grey planthopper produce a lot of wax from all over the body. The have long tails and ‘horns’ at the front. Nymphs of Passion vine hopper are red-brown with white markings. They also have a fluffy tail that is usually held upright.
Two parasitoids and one predator are associated with the Green planthopper. No pathogens are known from the active stages or eggs.
The Australian wasp, Green planthopper egg parasitoid, Aphanomerus pusillus (Platygasteridae) has been in New Zealand since the 1930’s according to a 1930 paper by Ted Gourley. The parasite was deliberately released into the USA to help control the green planthopper, which they call the Torpedo Bug, because of the long distnce that the nymphs can jump.
Planthopper parasitoid, Dryinus koebelei (Dryinidae) also comes from Australia and also parasitises the Grey planthopper. The larva may be seen on the planthopper nymphs where it is attched under one of the wing buds. The fully grown wasp larva leaves the now dead nymph and spins a cocoon in which it pupates. The adult female is very distinctive, the male less so.
The only recorded predator of the planthopper is the Steelblue ladybird, another insect of Australian origin. Myers in his 1922 paper reports that the ladybird devoured the eggs-cushions when placed in contact with them.
It is likely that the Green planthoppers are fed upon by other predatory insects, spiders and birds.
|Scientific Name||Common Name||Classification||Enemy Type||Reliability Index||Biostatus|
|Aphanomerus pusillus Perkins, 1905||(Wasp)||Hymenoptera: Platygasteridae||parasitoid||10||adventive|
|Dryinus koebelei (Perkins, 1905)||Planthopper parasitoid (Wasp)||Hymenoptera: Dryinidae||parasitoid||10||adventive|
|Halmus chalybeus (Boisduval, 1835)||Steelblue ladybird (Beetle)||Coleoptera: Coccinellidae||predator||10||adventive|
New Zealand host plants of the Green planthopper include native and adventive plants, including garden plants.
Feeding and plant damage
Like other Hemiptera, the green planthopper has piercing and sucking mouth parts. The long stylets, special shaped rods, are held in the rostrum. When it wishes to feed, the bug moves the tip of the rostrum to a suitable part of the plant. The stylets are then gradually pushed into the plant. The stylets form two tubes, one through which saliva is injected into the plant and a second through which plants juices are sucked up into the insect. The planthoppers feed on the plants phloem and secrete honeydew at intervals.
|Common Name(s)||Scientific Name||Family||Reliability Index||Biostatus|
|New Zealand celery, Sea celery, Shore celery, Tūtae kōau||Apium prostratum Labill. ex Vent.||Umbelliferae||10||indigenous, non-endemic|
|Cruel plant, Kapok vine, Moth plant, White bladder flower||Araujia horturum E.Fourn.||Apocynaceae||8||naturalised|
|Renga lily, Rock lily, Māikaika, Rengarenga||Arthropodium cirratum (G.Forst.) R.Br.||Asparagaceae||8||endemic|
|Bridal veil creeper, Smilax||Asparagus asparagoides (L.) Druce||Asparagaceae||10||naturalised|
|Taraire||Beilschmiedia tarairi (A.Cunn.) Benth. & Hook.f. ex Kirk||Lauraceae||10||endemic|
|Bushman's friend, Kōuaha, Pukapuka, Pukariao, Puke-rangiora, Rangiora, Raurākau, Raurēkau, Whārangi, Whārangi-tawhito||Brachyglottis repanda J.R.Forst. & G.Forst.||Compositae||10||endemic|
|New Zealand bitter cress, Panapana||Cardamine debilis Banks ex DC.||Cruciferae||10||endemic|
|Bitou bush, Boneseed, Higgin's curse, Jungle flower, Salt bush||Chrysanthemoides monilifera (L.) T. Norl. subsp. monilifera (L.) T. Norl.||Compositae||10||naturalised|
|Taupata||Coprosma repens A.Rich.||Rubiaceae||10||endemic|
|Twiggy Coprosma||Coprosma rhamnoides A.Cunn.||Rubiaceae||10||endemic|
|Tree tutu, Pūhou, Tāweku, Tūpākihi, Tutu||Coriaria arborea Linds.||Coriariaceae||10||endemic|
|Karaka nut, Karaka, Kōpī||Corynocarpus laevigatus J.R.Forst. & G.Forst.||Corynocarpaceae||10||endemic|
|Hawthorn, Neapolitan medlar, White hawthorn||Crataegus monogyna Jacq.||Rosaceae||10||naturalised|
|Dysoxylum sp. MARC||Meliaceae||9||cultivated|
|New Zealand mahogany, Kohe, Kohekohe, Koheriki, Kohepi (flowers), Kohepu (flowers), Māota (flowers)||Dysoxylum spectabile (G.Forst.) Hook.f.||Meliaceae||10||endemic|
|Eucalypt, Flowering gum, Gum, Stringybark||Eucalyptus sp.||Myrtaceae||7||unknown|
|Fuchsia, Ladies' eardrops||Fuchsia sp.||Onagraceae||7||unknown|
|New Zealand privet, Hangehange, Hengahenga, Pāhengahenga, Pāpā, Pāpāhenga, Pāpāuma, Whangewhange||Geniostoma ligustrifolium A.Cunn. var. ligustrifolium||Loganiaceae||8||endemic|
|Shrubby haloragis, Toatoa||Haloragis erecta (Banks ex Murray) Oken||Haloragaceae||9||endemic|
|Red hot poker, Torch lily, Tritoma||Kniphofia sp.||Asphodelaceae||7||unknown|
|Broadleaf privet, Tree privet||Ligustrum lucidum W.T.Aiton||Oleaceae||10||naturalised|
|Chinese privet, Small-leaf privet||Ligustrum sinense Lour.||Oleaceae||10||naturalised|
|Japanese honeysuckle||Lonicera japonica Thunb.||Caprifoliaceae||10||naturalised|
|Macadamia, Macadamia nut, Queensland nut||Macadamia sp.||Proteaceae||6||naturalised|
|Puka, Pukanui||Meryta sinclairii Hook. f.) Seem.||Araliaceae||10||endemic|
|Ngaio||Myoporum laetum G.Forst.||Scrophulariaceae||8||endemic|
|Red mapou, Red matipo, Māpau, Māpou, Mataira, Matipou, Takapou, Tāpau, Tīpau||Myrsine australis (A.Rich.) Allan||Primulaceae||9||endemic|
|New Zealand jasmine, Akakaikiore, Akakiore, Kaihua, Kaikū, Kaiwhiria, Poapoa, Tautauā, Tawhiwhi, Tūtae-kererū||Parsonsia heterophylla A. Cunningham||Apocynaceae||10||endemic|
|Banana passionfruit||Passiflora sp. 'banana passion fruit'||Passifloraceae||7||naturalised|
|Flax, Lowland flax, New Zealand flax, Swamp flax, Harakeke, Harareke, Kōrari||Phormium tenax J.R.Forst. & G.Forst.||Hemerocallidaceae||10||endemic|
|Pepper tree, Kawa, Kawakawa||Piper excelsum G.Forst.||Piperaceae||10||endemic|
|Kaikaro, Karo, Kīhihi||Pittosporum crassifolium Banks & Sol. ex A.Cunn.||Pittosporaceae||9||endemic|
|Lemonwood, Kīhihi, Tarata||Pittosporum eugenioides A.Cunn.||Pittosporaceae||10||endemic|
|Totara, Lowland totara, Amoka, Tōtara||Podocarpus totara G. Benn. ex D.Don||Podocarpaceae||9||endemic|
|Coastal five finger, Houmāpara, Houpara, Houparapara, Kokotai, Oho, Parapara, Whauwhau||Pseudopanax lessonii (DC.) K. Koch||Araliaceae||10||endemic|
|Fireweed, Pukatea||Senecio glomeratus Poir.||Compositae||10||indigenous, non-endemic|
|Fireweed, Shore groundsel, Variable groundsel||Senecio lautus G.Forst. ex Willd.||Compositae||10||indigenous, non-endemic|
|Flannel leaf, Kerosene plant, Tobacco weed, Wild tobacco tree, Woolly nightshade||Solanum mauritianum Scop.||Solanaceae||8||naturalised|
|Black nightshade, Blackberry nightshade, Garden huckleberry, Pōporo, Poroporo, Raupeti, Remuroa||Solanum nigrum L.||Solanaceae||10||naturalised|
|Small-flowered nightshade, Pōporo, Poroporo, Raupeti, Remuroa||Solanum nodiflorum Jacq.||Solanaceae||9||indigenous, non-endemic|
|Three Kings milk tree, Smith's milkwood||Streblus smithii (Cheeseman) Corner||Moraceae||10||endemic|
|Bushy starwort, Sea aster||Symphyotrichum subulatum (Michx.) G.L.Nesom||Compositae||10||naturalised|
|Wandering Jew, Wandering Willie||Tradescantia fluminensis Vell.||Commelinaceae||10||naturalised|
|Purple top, South American vervain, Tall verbena||Verbena bonariensis L.||Verbenaceae||10||naturalised|
|Hebe, Kōkōmuka||Veronica macrocarpa Vahl||Plantaginaceae||10||endemic|
|New Zealand oak, Kauere, Pūriri||Vitex lucens Kirk||Labiatae||10||endemic|
Green plant hoppers may be found on some garden plants and crops. If control is thought to be needed, commercial growers should contact their advisors and gardeners should contact a supplier of garden pesticides. If they are a problem in a garden, avoid growing very susceptible plants from where they can spread on to other plants.
Lariviere M-C, Fletcher MJ, Larochelle A. 2010. Auchenorrhyncha (Insecta: Hemiptera): catalogue. Fauna of New Zealand. 63: 1-228.
Myers,J.G. 1922: Life-history of (Walk.), the large green plant-hopper. New Zealand Journal of Science and Technology: 5:256-263.
Valentine EW. 1967. A list of the hosts of entomophagous insects of New Zealand. New Zealand Journal of Science. 10 (4): 1100-1210. This paper gives details of Gurley’s 1930 paper).
The New Zealand Plant & Food Research Institute Limited (Plant & Food Research) for permission to use photographs.
1 August 2018, NA Martin. Photo added of egg batch with parasitoid exit holes.