First report of Nysius huttoni in the Netherlands and Belgium: addition to the EPPO Alert List
Dr Aukema (retired from the Dutch NPPO) attracted the attention of the EPPO Secretariat to the introduction of a new polyphagous pest, Nysius huttoni, in Europe and suggested that it could be added to the EPPO Alert List.
Nysius huttoni (Heteroptera: Lygaeidae – wheat bug)
Why: Dr Aukema (retired from the Dutch NPPO) attracted the attention of the EPPO Secretariat to the introduction of a new polyphagous bug in Europe. Since 2002, an unfamiliar species of Nysius was found at different localities in the extreme Southwest of the Netherlands (province of Zeeland) and the adjacent Northwestern part of Belgium (provinces of West-and Oost Vlaanderen and Brabant). The species was identified as Nysius huttoni, a species originating from New Zealand. So far, N. huttoni had not been reported outside New Zealand.
Where:
EPPO region: Belgium (Brabant, West-and Oost Vlaanderen), Netherlands (Zeeland).
Oceania: New Zealand (widespread in North and South Islands).
Pathways of introduction of N. huttoni into Europe are unknown, but as the international harbour of Antwerpen is close to the infested sites, it is suspected that it arrived accidentally with shipments from New Zealand.
On which plants: N. huttoni is a polyphagous species which feeds on a large number of weeds and crops. In New Zealand, it is mainly reported as a pest of wheat and Brassicaceae, but it can feed on many plant species. It can attack: Brassica spp., Medicago sativa (alfalfa), Trifolium dubium, T. pratense, T. repens (clovers), and Poaceae such as: Avena sativa (oat), Bromus, Hordeum sativum (barley), Lolium, Secale cereale (rye), Triticum aestivum (wheat). The following weeds have been reported as hosts: Anagallis arvensis, Calandrinia caulescens, Capsella bursa-pastoris, Cassinia leptophyla, Chenopodium album, Coronopus didymus, Hieracium, Polygonum aviculare, Rumex acetosella, Senecio inaequidens, Silene gallica, Soliva sessilis, Spergularia rubra, Stellaria media. It is also suggested that the presence of mosses (e.g. Ceratodon, Sphagnum, Polytrichum spp.) may be crucial for the overwintering period.
Damage: N. huttoni is a sap feeding insect which can attack many plant parts including seeds. Both adults and nymphs can cause damage. On wheat, damage is essentially observed when grains are attacked at the milk-ripe stage. The insect saliva contains an enzyme which affects the gluten proteins. This causes severe quality deterioration in baked products (sticky dough, poor loaf volume and poor bread texture). It is reported that during the worst outbreak recorded in New Zealand in 1970, about 10,000 tons of wheat were damaged by N. huttoni. On brassicas damage is observed when young plants are attacked. Feeding punctures are made around stems at ground level, often leading to plant wilting and collapse. For example during experiments, serious damage was observed on swede seedlings (B. napus var. napobrassica) with up to 70% of young plants being lost.
In New Zealand, N. huttoni has a wide ecological distribution from coastal locations to altitudes of over 1800 m. It is noted that N. huttoni usually feeds on weeds growing on waste lands or roadsides, often in the vicinity of crops, and only migrates to crops in dry years. In the Netherlands and Belgium, it was found in dry, warm waste grounds and roadsides with sparse vegetation (e.g. in Oost Vlaanderen, large numbers of N. huttoni were found in an abandoned wheat field). N. huttoni overwinters as adult and has 2 or 3 generations per year in New Zealand. Under European conditions, the situation is still unclear but related species have 1 to 2 generations per year.
Pictures of the pest can be viewed on Internet
http://www.hortnet.co.nz/key/stone/bugkey2a/wings/dblwing/clrwings/wbugad1.htm
Dissemination: Data is lacking on the natural spread of N. huttoni. Over long distances, movements of infested plants could theoretically transport the pest, but its major host plants (e.g. cereals) are not traded in this form. N. huttoni is reported as being a contaminating pest often found on apple fruit packages exported from New Zealand.
Pathway: Plants for planting? vegetables? Pathways are difficult to identify as it seems that the pest is mainly a hitchhiker.
Possible risks: In New Zealand, N. huttoni is reported as an economically important pest of wheat and brassicas. It is reported as a pest of other Poaceae (cereals and grasses) and of Fabaceae but more data is needed on type and extent of damage. Wheat and brassica crops are widely grown and economically important throughout the EPPO region. Control is difficult because N. huttoni usually feeds on weeds and only migrates to crops under certain circumstances. In New Zealand, no natural enemies are known (except starlings). Laboratory studies on thermal requirements of N. huttoni concluded that the pest was probably able to establish in regions with mild to warm climates. Its recorded presence in some parts of the EPPO region over several years showed that it can establish in Europe. More information is needed on its pathways of introduction. It may have to be recognised that it will be difficult to prevent its further spread, as N. huttoni is polyphagous, spreading naturally and is most likely a contaminant of many traded products.
EPPO RS 2006/030
Panel review date - Entry date 2006-02
Sources
Aukema B, Bruers JM, Viskens G (2005) A New Zealand endemic Nysius established in The Netherlands and Belgium (Heteroptera: Lygaeidae). Belgian Journal of Entomology 7, 37-43.
He XZ, Wang Q (1999) Laboratory assessment of damage to swede, Brassica napus rapifera, by wheat bug Nysius huttoni. Paper presented at the 52nd Conference of the New Zealand Plant Protection Society. Available on-line: http://www.hortnet.co.nz
Bejakovich D, Pearson WD, O’Donnell MR (1998) Nationwide survey of pests and diseases of cereal and grass seed crops in New Zealand. 1. Arthropods and molluscs. Paper presented at the 51st Conference of the New Zealand Plant Protection Society. Available on-line: http://www.hortnet.co.nz
Every D, Farrell JA, Stufkens MW, Wallace AR (1998) Wheat cultivar susceptibility to grain damage by the New Zealand wheat bug, Nysius huttoni, and cultivar susceptibility to the effects of bug proteinase on baking quality. Journals of Cereal Science 27(1), 37-46. (Abstact).
He XZ, Wang Q, Carpenter A (2003) Thermal requirements for the development and reproduction of Nysius huttoni White (Heteroptera: Lygaeidae). Journal of Economic Entomology 96(4), 1119-1125.