The potato psyllid Bactericera cockerelli(Hemiptera:Triozidae)has recently emerged as a serious pest of potatoes and other solanaceous crops.It causes direct feeding damage and also vectors Candidatus Liberibacter sol...The potato psyllid Bactericera cockerelli(Hemiptera:Triozidae)has recently emerged as a serious pest of potatoes and other solanaceous crops.It causes direct feeding damage and also vectors Candidatus Liberibacter solanaceaerum(Lso),a pathogen that causes zebra chip disease in potatoes and which potentially costs growers millions of dollars each year.Such producers rely on frequent sprays of pesticides for psyllid control but the results are unsatisfactory and there are negative side effects.The psyllid has spread beyond its native range in southwest US and northern Mexico to Canada,El Salvador,Honduras,Guatemala and Nicaragua via medium to long range dispersal flights perhaps aided by wind currents,and through anthropogenic means.It was accidentally introduced into New Zealand in 2006 and most recently Australia,most likely through the importation of infested plant material.This review summarizes information from studies on the biology,impact and management of B.cockerelli,and highlights the imminent risk of this insect and its associated pathogen invading China,the world’s largest producer of fresh potatoes.Development of risk maps leading to increased surveillance,could prevent or delay an incursion and facilitate early detection or eradication should this occur.Long-term management with Lso-tolerant potato cultivars and psyllid control using the parasitic wasp Tamarixia triozae and other natural enemies should be pursued,rather than depending on synthetic pesticides.展开更多
Background:Flammability is a compound plant trait that can vary significantly across natural populations within species.Investigating intraspecific variation in flammability provides insights into the evolution of pla...Background:Flammability is a compound plant trait that can vary significantly across natural populations within species.Investigating intraspecific variation in flammability provides insights into the evolution of plant flam-mability and inform understanding of wildfire risk and behaviour in different habitats.Methods:We measured four flammability variables,representing ignitibility(time to ignition),sustainability(total burning time),combustibility(maximum temperature during burning)and consumability(percentage of biomass consumed by fire)to assess the shoot-level flammability of Dracophyllum rosmarinifolium(G.Forst.)(Ericaceae),a polymorphic endemic species distributed throughout New Zealand.We examined the relationship between flammability components and a suite of climatic and geographic variables(elevation,latitude,mean annual temperature(MAT),mean annual rainfall(MAR)of the sample locations,etc.).Results:We measured shoot-level flammability components of 62 individuals across eight populations.Burning time,maximum temperature and burnt biomass were positively correlated with each other,while ignition score was independent of other flammability components.All flammability components varied significantly across the eight populations.The habitat conditions we considered were not related to any of the shoot-level flammability components of D.rosmarinifolium.Conclusions:Intraspecific variation in flammability in D.rosmarinifolium may be a byproduct of selection on other functional traits,such as leaf size,shoot lipid content,indicating that plant flammability is an incidental result,rather than selected for,at least in ecosystems without fire as a selective force.展开更多
The efficacy of different combinations of undervine and inter-row treatments for managing a soil-dwelling orthopteran pest, weta （Hemiandrus sp.）, in vineyards was investigated over 2 seasons. This insect damages vi...The efficacy of different combinations of undervine and inter-row treatments for managing a soil-dwelling orthopteran pest, weta （Hemiandrus sp.）, in vineyards was investigated over 2 seasons. This insect damages vine buds, thus reducing subsequent grape yield. The undervine treatments comprised pea straw mulch, mussel shells, tick beans [Viciafaba Linn. var minor （Fab）], plastic sleeves on vine trunks （treated control） and control （no intervention）, while inter-rows contained either the existing vegetation or tick beans. Treatments were arranged in a randomized complete block design with 10 replicates. Data were collected on weta densities, damage to beans and components of yield. The latter were numbers of bud laid down per vine, shoots per bud, clusters per shoot, grape bunches per vine, bunch weight and yield. The undervine treatments significantly affected all variables except the number of shoots per bud. In contrast, none of the variables was significantly affected by the inter-row treatments or their interaction with undervine treatments, apart from weta density. At the end of the experiment, weta density in the shell treatment was about 58% lower than in the control. As a result, there was about 39% significant yield increase in that treatment compared to the control. Although the undervine beans and sleeves treatments increased yield, there were no reductions in weta density. With undervine beans, the insect fed on the bean plants instead of vine buds. Thus, yield in that treatment was approximately 28% higher than in the control. These results demonstrate that simple agroecological management approaches can reduce above-ground damage by soil-dwelling insects.展开更多
基金funded by the New Zealand Agricultural and Marketing Research and Development Trust (AGMARDT) Grant A17022
文摘The potato psyllid Bactericera cockerelli(Hemiptera:Triozidae)has recently emerged as a serious pest of potatoes and other solanaceous crops.It causes direct feeding damage and also vectors Candidatus Liberibacter solanaceaerum(Lso),a pathogen that causes zebra chip disease in potatoes and which potentially costs growers millions of dollars each year.Such producers rely on frequent sprays of pesticides for psyllid control but the results are unsatisfactory and there are negative side effects.The psyllid has spread beyond its native range in southwest US and northern Mexico to Canada,El Salvador,Honduras,Guatemala and Nicaragua via medium to long range dispersal flights perhaps aided by wind currents,and through anthropogenic means.It was accidentally introduced into New Zealand in 2006 and most recently Australia,most likely through the importation of infested plant material.This review summarizes information from studies on the biology,impact and management of B.cockerelli,and highlights the imminent risk of this insect and its associated pathogen invading China,the world’s largest producer of fresh potatoes.Development of risk maps leading to increased surveillance,could prevent or delay an incursion and facilitate early detection or eradication should this occur.Long-term management with Lso-tolerant potato cultivars and psyllid control using the parasitic wasp Tamarixia triozae and other natural enemies should be pursued,rather than depending on synthetic pesticides.
基金This work was supported by Lincoln University faculty funding(NO.3601-AGLS-45401-1128912).
文摘Background:Flammability is a compound plant trait that can vary significantly across natural populations within species.Investigating intraspecific variation in flammability provides insights into the evolution of plant flam-mability and inform understanding of wildfire risk and behaviour in different habitats.Methods:We measured four flammability variables,representing ignitibility(time to ignition),sustainability(total burning time),combustibility(maximum temperature during burning)and consumability(percentage of biomass consumed by fire)to assess the shoot-level flammability of Dracophyllum rosmarinifolium(G.Forst.)(Ericaceae),a polymorphic endemic species distributed throughout New Zealand.We examined the relationship between flammability components and a suite of climatic and geographic variables(elevation,latitude,mean annual temperature(MAT),mean annual rainfall(MAR)of the sample locations,etc.).Results:We measured shoot-level flammability components of 62 individuals across eight populations.Burning time,maximum temperature and burnt biomass were positively correlated with each other,while ignition score was independent of other flammability components.All flammability components varied significantly across the eight populations.The habitat conditions we considered were not related to any of the shoot-level flammability components of D.rosmarinifolium.Conclusions:Intraspecific variation in flammability in D.rosmarinifolium may be a byproduct of selection on other functional traits,such as leaf size,shoot lipid content,indicating that plant flammability is an incidental result,rather than selected for,at least in ecosystems without fire as a selective force.
文摘The efficacy of different combinations of undervine and inter-row treatments for managing a soil-dwelling orthopteran pest, weta （Hemiandrus sp.）, in vineyards was investigated over 2 seasons. This insect damages vine buds, thus reducing subsequent grape yield. The undervine treatments comprised pea straw mulch, mussel shells, tick beans [Viciafaba Linn. var minor （Fab）], plastic sleeves on vine trunks （treated control） and control （no intervention）, while inter-rows contained either the existing vegetation or tick beans. Treatments were arranged in a randomized complete block design with 10 replicates. Data were collected on weta densities, damage to beans and components of yield. The latter were numbers of bud laid down per vine, shoots per bud, clusters per shoot, grape bunches per vine, bunch weight and yield. The undervine treatments significantly affected all variables except the number of shoots per bud. In contrast, none of the variables was significantly affected by the inter-row treatments or their interaction with undervine treatments, apart from weta density. At the end of the experiment, weta density in the shell treatment was about 58% lower than in the control. As a result, there was about 39% significant yield increase in that treatment compared to the control. Although the undervine beans and sleeves treatments increased yield, there were no reductions in weta density. With undervine beans, the insect fed on the bean plants instead of vine buds. Thus, yield in that treatment was approximately 28% higher than in the control. These results demonstrate that simple agroecological management approaches can reduce above-ground damage by soil-dwelling insects.
