Open AccessOutbreak of armyworms in eastern Bay of Plenty
Author(s) -
P.J. Gerard,
P. J. Addison,
Pete E. Hedley,
N.L. Bell,
Cor J. Vink
Publication year - 2011
Publication title -
proceedings of the new zealand weed and pest control conference/new zealand plant protection/proceedings of the ... national weeds conference/proceedings of the new zealand weed control conference/proceedings of the new zealand plant protection conference
Language(s) - English
Resource type - Journals
eISSN - 0370-2804
pISSN - 0370-0968
DOI - 10.30843/nzpp.2011.64.5989
Subject(s) - outbreak , biology , bay , agronomy , mythimna separata , fall armyworm , subtropics , crop , pest analysis , pasture , ecology , geography , larva , botany , spodoptera , recombinant dna , biochemistry , archaeology , virology , gene
Tropical armyworm (Spodoptera litura) caused widespread serious damage to Bay of Plenty lucerne crops and clover plantain and chicory in pastures in April and early May 2011 reaching populations at high as 100/m2 This outbreak was preceded by an outbreak of cosmopolitan armyworm (Mythimna separata) attacking maize and grasses Tropical armyworm is a minor pest of subtropical crops such as kumara in Northland The last widespread outbreak was in autumn 1975 and resulted in serious pasture and crop damage in Northland and Auckland and minor damage in Bay of Plenty Taranaki and Manawatu The current outbreak in Bay of Plenty may be climate related with a mild and extremely wet winter in 2010 above average spring and summer temperatures and near record summer rainfall These conditions may have allowed tropical armyworm to complete four generations to build up to outbreak levels In addition dry spring soil conditions during maize establishment meant poor weed control a known factor to predispose problems with cosmopolitan armyworm which has a similar life cycle to tropical armyworm Similar weather patterns are expected to increase in frequency with climate change