Grey planthopper - Anzora unicolor

By N A Martin (2017)

Caption:

Classification

Phylum

Arthropoda

Class

Insecta

Order

Hemiptera

Family

Flatidae

Scientific name

Anzora unicolor (Walker, 1862)

Common names

Grey planthopper

Synonyms

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.

Feeding

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.

Two adult Grey planthoppers, Anzora unicolor (Flatidae) on Haloragis erecta (Haloragaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5I]

Adult Grey planthopper, Anzora unicolor (Flatidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5L]

Underside of an adult Grey planthopper, Anzora unicolor (Flatidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5J]

Underside of an adult Grey planthopper, Anzora unicolor (Flatidae): note the rostrum that contains the stylets extending back from the head between the legs. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5K]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) on Marsh ribbonwood, Plagianthus divaricatus (Malvaceae): side view. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5M]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) on Marsh ribbonwood, Plagianthus divaricatus (Malvaceae): top view before fluffy wax has developed over the front of the body. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5N]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) on Marsh ribbonwood, Plagianthus divaricatus (Malvaceae): side view after fluffy wax has developed over the body. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5P]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) just after it has moulted: note the large wing buds and the moulted skin to the left of the nymph. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5Q]

Moulted skin of a nymph of Grey planthopper, Anzora unicolor (Flatidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5T]

Moulted skin of a nymph of Grey planthopper, Anzora unicolor (Flatidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5U]

Moulted skins of nymphs, nymphs and an adult of Grey planthopper, Anzora unicolor (Flatidae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M6F]

Colony of nymphs of Grey planthopper, Anzora unicolor (Flatidae) on Marsh ribbonwood, Plagianthus divaricatus (Malvaceae): note all the fluffy white wax. Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M5W]

Colony of adult Grey planthoppers, Anzora unicolor (Flatidae) on Haloragis erecta (Haloragaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M6G]

Recognition

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.

Adult Grey planthopper, Anzora unicolor (Flatidae) on Small-leaved pohuehue, Muehlenbeckia complexa (Polygonaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M5Y]

Adult Grey planthoppers, Anzora unicolor (Flatidae) on Haloragis erecta (Haloragaceae). An adult Passion vine hopper, Scolypopa australis (Ricaniidae) also present. Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M60]

Adult green planthopper, Siphanta acuta (Flatidae): note that descending from the head, the proboscis that guides the stylets used for feeding. Creator: Tim Holmes. © Plant & Food Research. [Image: 2M43]

Top view of an adult green planthopper, Siphanta acuta (Flatidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2M42]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) on Marsh ribbonwood, Plagianthus divaricatus (Malvaceae): side view showing the fluffy wax on the upper side of the body. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5R]

Two nymphs of Grey planthopper, Anzora unicolor (Flatidae) on Ngaio, Myoporum laetum (Scrophulariaceae). One nymph of the green planthopper, Siphanta acuta (Flatidae) is also on the leaf: note the green wax-free body and the fluffy tail held close to the surface of the leaf. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5E]

Nymphs of Grey planthopper, Anzora unicolor (Flatidae) on Willow herb, Epilobium sp. (Onagraceae). A nymph of Passion vine hopper, Scolypopa australis (Ricaniidae) is also present (white arrow): note the wax free body and the upright fluffy tail. Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M67]

Small nymphs of green planthopper, Siphanta acuta (Flatidae) and moulted skins on underside of a leaf of Coastal five-finger, Pseudopanax lessonii (Araliaceae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2M3V]

Nymph of green planthopper, Siphanta acuta (Flatidae) on leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2M4A]

Nymph of green planthopper, Siphanta acuta (Flatidae) on the underside of a leaf of Solanum nodiflorum (Solanaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M4J]

Side view of nymph of green planthopper, Siphanta acuta (Flatidae) on the underside of a leaf stalk of Solanum nodiflorum (Solanaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M4I]

Nymphs of Passion vine hoppers, Scolypopa australis (Hemiptera: Ricaniidae) on a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae): note the fluffy wax tails held upright. Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M8E]

Adult and nymphs of Passion vine hoppers, Scolypopa australis (Hemiptera: Ricaniidae) on a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae): note the nymphs with fluffy wax tails held upright. Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M8B]

Nymphs of the Passion vine hopper, Scolypopa australis (Hemiptera: Ricaniidae) on a leaf of Glossy karamu, Coprosma robusta (Rubiaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M8M]

Natural enemies

The only natural enemy reported is a parasitoid, but grey planthoppers are likely to be preyed upon by other insects, spiders and birds.

Parasitoids

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.

Nymph of Green planthopper, Siphanta acuta (Flatidae), with a larva of the ectoparasitoid Planthopper parasitoid, Dryinus koebelei (Dryinidae) that has its head inserted under the planthoppers wing bud. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M2B]

Nymph of Grey planthopper, Anzora unicolor (Flatidae), with a larva of the ectoparasitoid Planthopper parasitoid, Dryinus koebelei (Dryinidae) that has its head inserted under the planthoppers wing bud. Creator: Tim Holmes. © Plant & Food Research. [Image: 2M1T]

Cocoon of Planthopper parasitoid, Dryinus koebelei (Dryinidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2M1V]

Skin of a dead nymph of Grey planthopper, Anzora unicolor (Flatidae), after larva of the Planthopper parasitoid, Dryinus koebelei (Dryinidae) has left its host. Creator: Tim Holmes. © Plant & Food Research. [Image: 2M1W]

Cocoon of Planthopper parasitoid, Dryinus koebelei (Dryinidae) with exit hole made by adult wasp Creator: Tim Holmes. © Plant & Food Research. [Image: 2M1X]

Dead adult female Planthopper parasitoid, Dryinus koebelei (Dryinidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2M1Y]

Dead adult female Planthopper parasitoid, Dryinus koebelei (Dryinidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2M1Z]

Host plants

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.

Adult and nymph of the Grey planthopper, Anzora unicolor (Flatidae) on Ngaio, Myoporum laetum (Scrophulariaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5F]

Nymphs of the Grey planthopper, Anzora unicolor (Flatidae) on Ngaio, Myoporum laetum (Scrophulariaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2M5G]

Adult Grey planthoppers, Anzora unicolor (Flatidae) on Wild carrot, Daucus carota (Umbelliferae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M5X]

Nymphs of Grey planthoppers, Anzora unicolor (Flatidae) on Wild carrot, Daucus carota (Umbelliferae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M5Z]

Nymphs of Grey planthoppers, Anzora unicolor (Flatidae) on Dock, Rumex sp. (Polygonaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M61]

Adult Grey planthoppers, Anzora unicolor (Flatidae) on Fennel, Foeniculum vulgare (Umbelliferae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M62]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) on Climbing dock, Rumex sagittatus (Polygonaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M63]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) on Fireweed, Senecio hispidulus (Compositae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M64]

Adults and nymphs of Grey planthopper, Anzora unicolor (Flatidae) on Kanuka, Kunzea ericoides s.l. (Myrtaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M65]

Nymphs of Grey planthopper, Anzora unicolor (Flatidae) on Willow herb, Epilobium sp. (Onagraceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M66]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) on Manuka, Leptospermum scoparium (Myrtaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M68]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) on Manuka, Leptospermum scoparium (Myrtaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M69]

Adults of Grey planthopper, Anzora unicolor (Flatidae) on inflorescence of Coastal five finger, Pseudopanax lessonii (Araliaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M6A]

Nymph of Grey planthopper, Anzora unicolor (Flatidae) on Upright hedge parsley, Torilis japonica (Umbelliferae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M6C]

Nymphs of Grey planthopper, Anzora unicolor (Flatidae) on Coprosma macrocarpa (Rubiaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M6D]

Nymphs of Grey planthopper, Anzora unicolor (Flatidae) on Puriri, Vitex lucens (Labiatae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2M6E]

Table: Host plants of the Grey planthopper, *Anzora unicolor* (Hemiptera: Flatidae) from Plant-SyNZ database (9 September 2017). The reliability score shows the quality of evidence for the host association (1-10, 10=high).
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
	Chenopodium sp.	Amaranthaceae	7	unknown
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
Willowherb	Epilobium sp.	Onagraceae	7	unknown
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

Control

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.

Additional information

Research Project

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.

Information sources

Lariviere M-C, Fletcher MJ, Larochelle A. 2010. Auchenorrhyncha (Insecta: Hemiptera): catalogue. Fauna of New Zealand. 63: 1-228.

Acknowledgements

The New Zealand Plant & Food Research Institute Limited (Plant & Food Research) for permission to use photographs.

INTERESTING INSECTS

and other invertebrates