MPI is on high alert to keep out one nasty, stinky in­sect.

The Orchardist - - Contents - Story pro­vided by MPI

Pre­par­ing for emerg­ing pests and dis­eases that could af­fect New Zealand's en­vi­ron­ment and econ­omy is a key role for the Min­istry for Pri­mary In­dus­tries. The Min­istry has been keep­ing an eye on the brown mar­morated stink bug ( Ha­ly­omor­pha halys or BMSB) for a num­ber of years now and has stepped up its ef­forts to keep this pest out of New Zealand - or de­tect it early should it get here. This is in re­sponse to the in­sect emerg­ing as a se­ri­ous hor­ti­cul­tural pest in the United States.

BMSB is na­tive to Asia and has ag­gres­sively in­vaded the United States and has now been found in Canada, Switzer­land, Ger­many, Italy and France. At present it is re­garded by the New Zealand hor­ti­cul­ture in­dus­try as one of the top six pests of con­cern.

BMSB feeds on more than 300 hosts, pri­mar­ily fruit trees and woody or­na­men­tals but also field crops. Al­most any crop can be at risk, in­clud­ing: cit­rus; pipfruit; stone­fruit; berries and grapes; as­para­gus; soy­beans and maize; honey­suckle; maple; but­ter­fly bush; cy­press, hibis­cus; and roses. In its na­tive habi­tat of East Asia, BMSB is a pest of fruit trees and soy­beans. It feeds by suck­ing plant juices. Adults gen­er­ally feed on ma­ture and im­ma­ture fruit, while nymphs feed on leaves and stems as well as fruit. It se­verely dis­fig­ures fruit and ren­ders it un­mar­ketable, which re­sults in con­trol costs and pro­duc­tion losses. BMSB dam­age to woody or­na­men­tals and for­est trees has been re­ported as cos­metic only. In the US, BMSB has been pri­mar­ily re­ported as a house­hold nui­sance and or­na­men­tal pest, but it has also caused eco­nomic losses in tree fruit and soy­beans.

In a study of pop­u­la­tions at farms in New Jersey and Penn­syl­va­nia, BMSB caused about 25 per­cent pre­ma­ture fruit drop. Its pierc­ing/suck­ing ac­tion causes necrotic spots on fruit and leaf sur­faces that may then be com­pounded by sec­ondary in­fec­tion and scar­ring as the fruit ma­tures. In par­tic­u­lar, ap­ples are of­ten pit­ted and dis­coloured, and peaches fre­quently dis­play a dis­tinc­tive dis­tor­tion called ‘cat­fac­ing'.

About BMSB


Adults are about 15mm long with a dis­tinc­tive brown shield­shape. The un­der­side is white to tan and the legs are brown with white band­ing. Eggs are light green, bar­rel-shaped and found in clus­ters laid on the un­der­side of leaves.Young nymph stages are yel­low­ish brown, mot­tled with black and red. Older nymphs be­come darker and de­velop the band­ing pat­tern on the legs, an­ten­nae and sides of the ab­domen.


BMSB has only one gen­er­a­tion per year in the north­ern states of the US. How­ever, in the south­ern­most part of its na­tive range in south­ern China up to five gen­er­a­tions oc­cur each year. BMSB over­win­ters in the adult stage, mat­ing in spring about two weeks af­ter emerg­ing from the rest­ing phase. Soon the fe­males be­gin lay­ing egg masses at about weekly in­ter­vals on the un­der­side of leaves and oc­ca­sion­ally on stems and fruit.

Each fe­male lays up to 400 eggs in her life­time and the first-in­star nymphs emerge af­ter four to five days. There are five nymphal stages, each last­ing about a week de­pend­ing on tem­per­a­ture, and the adults be­come sex­u­ally ma­ture two weeks af­ter the fi­nal moult. In Penn­syl­va­nia, where fe­males have been seen lay­ing eggs from June to Septem­ber, all stages are of­ten seen si­mul­ta­ne­ously on the same host plant. The nymphs are soli­tary feed­ers but oc­ca­sion­ally ag­gre­gate be­tween over­lap­ping leaves or leaf folds. Adults are very ac­tive and drop from plants or fly when dis­turbed. The op­ti­mal tem­per­a­ture for BMSB de­vel­op­ment is 25ºC, while nymphs will not de­velop be­low 15ºC and eggs be­low 12ºC.

Ag­gre­ga­tions of adult BMSB over­win­ter­ing in build­ings and houses can be a nui­sance, as when dis­turbed or crushed they emit a char­ac­ter­is­tic, un­pleas­ant, long-last­ing odour (al­though this does not pose any health threat).

BMSB is a strong flier and highly mo­bile pest. Once es­tab­lished, it can spread quickly over long dis­tances through move­ment of host plants, goods and ve­hi­cles.

Es­tab­lish­ment of BMSB de­pends on favourable tem­per­a­tures for sur­vival at the time of in­tro­duc­tion of an egg mass, or males and fe­males, or even a sin­gle gravid fe­male.

Chem­i­cal treat­ments in the USA so far are lim­ited, but there has been good progress in re­search into trap-and-kill tech­niques. Con­tact with th­ese re­searchers is en­abling MPI to keep abreast of the best avail­able re­search.

BMSB is thought to have in­vaded the US in ship­ping con­tain­ers. Be­cause the adults hide in cracks and crevices dur­ing win­ter months, they can spread in all kinds of cargo, in­clud­ing per­sonal ef­fects and house­wares. Risk coun­tries of ori­gin in­clude the US, China, Ja­pan and Korea. BMSB is also as­so­ci­ated with im­ported dun­nage, wooden boxes or con­tain­ers.

Iden­ti­fi­ca­tion of BMSB by molec­u­lar and mor­pho­log­i­cal means is avail­able in New Zealand and any in­cur­sions are likely to be de­tected by the Min­istry for Pri­mary In­dus­tries' tar­geted High Risk Site Sur­veil­lance (HRSS) pro­gramme. Good phy­tosan­i­tary mea­sures are the best way to pre­vent in­tro­duc­tions, and early de­tec­tion through sur­veil­lance is the key to erad­i­ca­tion be­fore the pest can be­come es­tab­lished.

MPI is cur­rently tri­alling 50 traps in high risk ar­eas to de­ter­mine the fea­si­bil­ity of in­te­grat­ing pheromone lures for BMSB into its ex­ist­ing trap­ping pro­grammes. Bor­der and tran­si­tional fa­cil­i­ties have also been put on alert for BMSB. Strict biose­cu­rity re­quire­ments on im­ports, checks at the bor­der, sur­veil­lance pro­grammes, and ca­pa­bil­ity to re­spond to a pest in­cur­sion, all work to­gether to help pre­vent known pests such as the brown mar­morated stink bug es­tab­lish­ing in New Zealand. Al­though we can never have a 100 per­cent guar­an­tee or zero risk, this ap­proach has kept New Zealand free of many of the worlds' worst pest prob­lems.

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