<i>Yersinia</i> sp (MH96) a potential biopesticide of migratory locust <i>Locusta migratoria</i> L

Locusta migratoria L is a recognised global pest that feeds on a wide range of graminaceous crops and pasture The activity of the novel entomopathogenic bacterium Yersinia sp (MH96) against L migratoria was investigated in the laboratory Locusta migratoria were allowed to feed on ryegrass (Lolium multiflorum) carrying Y sp residues and mortality was observed daily for 5 days At constant temperatures of either 235 or 37C Y sp caused 100 mortality of 1st instar L migratoria after 72 h At constant temperatures of 235C mortality amongst 2nd3rd instar L migratoria after 48 h was ca 34 rising to 100 mortality after 5 days When 3rd instar L migratoria were exposed to Y sp cultured at either 25C or 37C mortality was higher in individuals maintained at 235C compared to 37C This result was attributed to the phenology of the bacterium at elevated temperatures These initial studies indicate that Y sp has promise as a biopesticide against L migratoria especially against early instars</jats:p

Development of a speciesspecific probe for detection of &lt;i&gt;Serratia entomophila&lt;/i&gt; in soil

Strains of the bacteria Serratia entomophila and S proteamaculans cause amber disease in the grass grub Costelytra zealandica (Coleoptera Scarabaeidae) an important pasture pest in New Zealand Strains of both Serratia species occur naturally in New Zealand pasture soils Serratia entomophila has been developed as a commercial biological control agent bioshield The persistence of the applied strain in soil is currently measured by enumeration of bacterial colonies on Serratiaselective agar and subsequent biochemical tests are carried out to differentiate between the two Serratia species on the basis of their ability to utilise itaconate as a sole carbon source A speciesspecific DNA probe has been developed as an alternative to these laborious biochemical tests Tests against a range of Serratia species in colony dot blots showed the probe could be used to differentiate between S entomophila and S protemaculans recovered from treated soil when assessing persistence of bioshield inoculum and efficacy of the product in the field</jats:p

Assessing the potential of &lt;i&gt;Yersinia entomophaga&lt;/i&gt; to control plantain moth in a laboratory assay

The recent increased use of the highquality droughttolerant forage plant plantain (Plantago lanceolata) (Plantaginaceae) has been associated with outbreaks of native geometrid caterpillars such as Scopula rubraria The outbreaks most often occur under warm climatic conditions and within plantain monocrops Pest populations can reach 11500 larvae/m2 Stands can be severely damaged with 90 of plants destroyed and stand life expectancy reduced by 23 years This study assessed the efficacy of the insecticidal bacterium Yersinia entomophaga against S rubraria under laboratory conditions using a leaf history of S rubraria and the pathobiology of Y entomophaga suggest the bacterium could be developed as a biopesticide for use against S rubraria</jats:p

Potential for biological control of porina (&lt;i&gt;Wiseana&lt;/i&gt; spp) with a novel insecticidal bacterium &lt;i&gt;Yersinia&lt;/i&gt; n sp (MH96) EN65 strain

Porina (Wiseana spp larvae) are endemic pests of pasture If detected early young larvae can be controlled with diflubenzuron but generally damage is not predicted and organophosphate insecticides (eg diazinon chlorpyrifos chlorfon) are required Yersinia n sp (MH96) cf entomophaga (EN65 strain) a novel bacterium with insecticidal properties is pathogenic to late instar Wiseana spp larvae in laboratory assays and has potential as a biopesticide This trial measured the effect of two formulations of EN65 and a commercial formulation of Bacillus thuringiensis var kurstaki (Btk) against late instar porina EN65 was formulated in a sprayable biopolymer and on to a kibbled wheat bait Both EN65 formulations caused significant mortality of porina larvae and reduced feeding damage on white clover; efficacy was superior to Btk Survival of the bacterium in the sprayable biopolymer formulation was enhanced compared to a nonformulated broth culture Bacterial survival on the kibbled wheat bait was better when stored at 4C compared to 20C over 3 months</jats:p

Survival of &lt;i&gt;Yersinia entomophaga&lt;/i&gt; MH96 in a pasture ecosystem and effects on pest and nontarget invertebrate populations

Yersinia entomophaga MH96 (Ye MH96) has shown activity against the pasture pest porina (Wiseana spp larvae) in laboratory bioassays In this field trial Ye MH96 was applied to pasture as three separate formulations The presence of viable Ye MH96 was detected in soil for 112 days following application but the number of bacteria decreased rapidly following heavy rainfall 4 days after treatment Porina numbers were reduced by all formulations of Ye MH96 at 5 and 17 weeks (3440 and 6172) and by fenitrothion an insecticide used to control porina (93 and 96 respectively) Other nontarget Lepidoptera were also reduced by Ye MH96 No effects of Ye MH96 were observed on the earthworms Aporrectodea caliginosa and Lumbricus rubellus the pasture pest Listronotus bonariensis or pasture inhabiting Staphylinidae The survival of Ye MH96 for long enough to affect the target insect despite the heavy rain suggests that a microbial alternative to conventional insecticide management of porina may be possible</jats:p

Laboratory bioassays of new synthetic and microbial insecticides to control Eucalyptus tortoise beetle &lt;i&gt;Paropsis charybdis&lt;/i&gt;

Paropsis charybdis or eucalyptus tortoise beetle is (one of) the most significant pests of eucalypts in New Zealand It severely defoliates Eucalyptus nitens and Eucalyptus globulus plantations leaving heavilydamaged trees with reduced growth and poor form Laboratory bioassays of new synthetic and microbial insecticides were undertaken to identify management options compatible with biological control The current insecticide used for operational control alphacypermethrin was a positive control Of the products tested spinetoram (Sparta) gave the most promising results (100 mortality after 14 days) for control of adult P charybdis Spinetoram and spinosad (Success Naturalyte) the microbial control agents Beauveria bassiana (F305 ex Botanigard) and Bacillus thuringiensis var tenebrionis and the enterobacterium Yersinia entomophaga all resulted in high mortality of larval P charybdis after 4 days Targeting larvae alone may not be economically viable leaving spinetoram as the only possible additional insecticide for managing P charybdis Potential barriers of cost application and nontarget impacts are yet to be addressed</jats:p