Anzora unicolor (Walker, 1862)
Massila unicolor Walker, 1862
Melicharia unicolor (Walker, 1862)
Sephena cinerea Kirkaldy, 1906
Biostatus and distribution
This adventive plant hopper from Australia is found in the North Island and the northern half of the South Island of New Zealand. It occurs on its herbaceous and shrub 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
Grey planthoppers can be found on plants from Spring to Autumn. Nymphs appear in a mass of white wax in the spring and adults may be found in midsummer. I have not found the eggs or any descriptions of them.
Adults have blue-grey wings that are normally folded to form a steep ‘roof’. The head and body are also grey. 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 it is assumed that the female lays a cluster of eggs on a plant. After the nymphs hatch from the eggs, they stay in small groups on plant stems. The young nymphs are white and covered in white fluffy wax and the area where they are living becomes 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. Older nymphs have wing buds. The white wax extends back to form a tail that is usually held close to the plant. At the front, wax on top may extend into horn-like structures.
Walking and flying
The nymphs and adults have three pairs of legs and when disturbed they can jump (hop). The adults have two pairs of wings held over their body.
Like other Hemiptera, the grey planthopper has piercing and sucking mouth parts. The long stylets, special shaped rods, are held in the rostrum. When it wishes to feed, the planthopper 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 Grey planthopper feeds on the phloem, one of the two systems for distributing nutrients in plants. The planthoppers excrete excess liquid as honeydew.
The adult Grey planthoppers are easy to distinguish from other insects by their blue-grey colour and the shape of their wings that are held like a ‘steep roof’ and are rounded at their tip. The most similar insect is the Green planthopper, Siphanta acuta (Flatidae). It has a similar shape but is green and the tip of the wings is sharply pointed.
The nymphs of the Grey planthopper may be confused with those of the Green planthopper and the Passion vine hopper Scolypopa australis (Ricaniidae). Nymphs of the Grey planthopper are typically covered in a mass of white wax, some of which forms a fluffy tail and ‘horns’ at the front. The wax on the nymphs of the Green planthopper is mainly restricted to two bundles on the tail that mainly lies flat. The body maybe white, white with reddish markings or green. Nymphs of Passion vine hopper are red-brown with white markings. They also have a fluffy tail that is usually held upright.
The only natural enemy reported is a parasitoid, but grey planthoppers are likely to be preyed upon by other insects, spiders and birds.
A wasp, Dryinus koebelei (Perkins, 1905) (Hymenoptera: Dryinidae) is an ectoparasitoid of the Grey planthopper. The wasp larva lives on the outside of the planthopper nymphs. Its head is under the nymph’s wing buds and it sucks nutrients from the nymph. When the wasp larva is fully grown it leaves the dying planthopper nymph and spins a long thin cocoon in which it pupates. When the adult wasp has emerged from its pupa and its body had hardened, it chews an exit hole in the cocoon.
Host plants include a fern, herbaceous plants, trees and shrubs. Colonies can be found on young green stems and woody stems. The plants include indigenous species as well naturalised species.
Adults and juveniles feed by inserting their stylets into the phloem of the plant. They excrete excess liquid as honeydew.
In 1925 it was demonstrated that Grey planthoppers were able to spread fire-blight, a disease of some fruit trees.
|Common Name(s)||Scientific Name||Family||Reliability Index||Biostatus|
|Austral bracken, Bracken, Bracken fern, Common fern, Manehu, rahurahu, Rārahu, Rarauhe, Rarauhe-mahuika, Tākaka||Pteridium esculentum (G.Forst.) Cockayne||Dennstaedtiaceae||10||indigenous, non-endemic|
|Asparagus||Asparagus officinalis L.||Asparagaceae||8||naturalised|
|Bitou bush, Boneseed, Higgin's curse, Jungle flower, Salt bush||Chrysanthemoides monilifera (L.) T. Norl. subsp. monilifera (L.) T. Norl.||Compositae||9||naturalised|
|Large seeded coprosma, Kākaramū, Kākarangū, Karamū, Kāramuramu, Karangū||Coprosma macrocarpa Cheeseman||Rubiaceae||10||endemic|
|Carrot, Wild carrot||Daucus carota L.||Umbelliferae||10||naturalised|
|tall willowherb||Epilobium tetragonum L.||Onagraceae||10||naturalised|
|Eucalypt, Flowering gum, Gum, Stringybark||Eucalyptus sp.||Myrtaceae||7||unknown|
|Fennel, Sweet fennel||Foeniculum vulgare Mill.||Umbelliferae||10||naturalised|
|Shrubby haloragis, Toatoa||Haloragis erecta (Banks ex Murray) Oken||Haloragaceae||10||endemic|
|White tea tree, Kānuka, Kōpuka, Manuea, Mānuka, Mānuka-rauriki, Mārū, Rauiri, Rauwiri||Kunzea ericoides s.l. (A.Rich.) Joy Thomps.||Myrtaceae||10||indigenous, non-endemic|
|Red tea tree, Tea tree, Kahikātoa, Kātoa, Mānuka, Pata, Rauiri, Rauwiri||Leptospermum scoparium J.R.Forst. & G.Forst.||Myrtaceae||10||indigenous, non-endemic|
|Moonah, Tea tree||Leptospermum sp.||Myrtaceae||7||unknown|
|Tall mingimingi, Hukihukiraho, Kaikaiatua, Mānuka-rauriki, Mikimiki, Mingi, Mingimingi, Ngohungohu, Tūmingi||Leucopogon fasciculatus (G.Forst.) A.Rich.||Ericaceae||10||endemic|
|Birdsfoot trefoil, Lotus||Lotus pedunculatus Cav.||Leguminosae||10||naturalised|
|King Island melilot, Small-flowered melilot||Melilotus indicus (L.) All.||Leguminosae||10||naturalised|
|Scrub pohuehue, Small-leaved pohuehue, Wire vine, Pōhue, Pōhuehue, Pōpōhue, Tororaro, Waekāhu||Muehlenbeckia complexa (A.Cunn.) Meissn.||Polygonaceae||10||indigenous, non-endemic|
|Ngaio||Myoporum laetum G.Forst.||Scrophulariaceae||10||endemic|
|Marsh ribbonwood, Salt marsh ribbonwood, Houi, Mākaka, Runa||Plagianthus divaricatus J.R.Forst. & G.Forst.||Malvaceae||10||endemic|
|Golden tainui, Gum-digger's soap, Kūmarahou, Kūmararaunui, Pāpapa||Pomaderris kumeraho A.Cunn.||Rhamnaceae||10||endemic|
|Coastal five finger, Houmāpara, Houpara, Houparapara, Kokotai, Oho, Parapara, Whauwhau||Pseudopanax lessonii (DC.) K. Koch||Araliaceae||10||endemic|
|Climbing dock, Rambling dock, Turkey rhubarb||Rumex sagittatus Thunb.||Polygonaceae||10||naturalised|
|Dock, Sorrel||Rumex sp.||Polygonaceae||7||unknown|
|Fireweed||Senecio esleri C.J.Webb||Compositae||8||naturalised|
|Fireweed||Senecio hispidulus A.Rich.||Compositae||10||indigenous, non-endemic|
|Upright hedge parsley||Torilis japonica (Houtt.) DC.||Umbelliferae||10||naturalised|
|New Zealand oak, Kauere, Pūriri||Vitex lucens Kirk||Labiatae||10||endemic|
Grey 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.
In 1925 it was demonstrated that Grey planthoppers were capable of being vectors of fire-blight, a disease of some fruit trees. It is not certain if this is still a problem.
Eggs of the Grey planthopper.
It appears that eggs of the Grey planthopper have not been seen and described. It would be useful to cage some adults in late summer with a selection of favoured plants and try and get them to lay eggs. Then describe the egg masses and record the places they are laid. This could be followed by trying to find eggs in the field and rearing them to see if they are parasitised.
Lariviere M-C, Fletcher MJ, Larochelle A. 2010. Auchenorrhyncha (Insecta: Hemiptera): catalogue. Fauna of New Zealand. 63: 1-228.
The New Zealand Plant & Food Research Institute Limited (Plant & Food Research) for permission to use photographs.