Can pest management and biosecurity benefit from the surveillance and security industries

Selfreporting cameras have the potential to revolutionise the trapping networks utilised in pest management and biosecurity A study was carried out to determine whether commercially available selfreporting camera systems that use WiFi and GSM to transmit images to secure websites could be incorporated into trapping networks Of 45 systems initially examined one the RedEye security camera was laboratory tested Tests showed that the standard optics package was incapable of distinguishing between clover root weevil (Sitona lepidus) and Argentine stem weevil (Listronotus bonariensis) An upgrade of the cameras optics enabled it be used to successfully monitor porina (Wiseana spp) flight activity While this result was encouraging more research is needed before the technology can be incorporated into trapping networks In particular further thought is needed as to the level of image resolution that is required to ensure that the system is relevant to all pest management and biosecurity practitioners

Investigations into suitability of Trifolium occidentale as a host plant for two common pasture pests

Western clover (Trifolium occidentale) is a diploid perennial clover that is reported to be one of the progenitors of white clover (Trifolium repens) The ability to produce hybrids between T repens and T occidentale provides an opportunity to introduce factors to improve white clover tolerance to common stress factors A series of assays was undertaken to compare the feeding and performance of two contrasting pests on two T occidentale lines and two T repens cultivars Clover root weevil (Sitona lepidus) adults showed a preference for T repens but this diminished if weevils had been previously exposed to T occidentale Weevil longevity feeding levels and oviposition were comparable over 32 days indicating T occidentale is a host plant for adult S lepidus Clover flea (Sminthurus viridis) showed a strong preference for T repens over T occidentale in a choice test and higher feeding levels on T repens in the nochoice test

Effect of black legume aphid Aphis craccivora honeydew on survival of the parasitoid Microctonus aethiopoides

The introduced parasitoid Microctonus aethiopoides (Hymenoptera Braconidae) appears to be an effective biocontrol agent for clover root weevil Sitona lepidus Gyllenhal (Coleoptera Curculionidae) in New Zealand pastures As these pastures lack accessible nectar sources hemipteran honeydew may be the most readily available energy source for the parasitoid Experiments were undertaken to compare longevity of newly emerged M aethiopoides adults caged on white clover firstly with and without black legume aphid Aphis craccivora Kock (Hemiptera Aphididae) and then with additional water and sucrose solution treatments Parasitoids with access to aphid honeydew lived significantly longer (mean longevity 81 days) than those with water or no liquid (both 68 days) but not as long as those fed sucrose solution (109 days) Therefore the abundance of aphids commonly present on clovers may enhance M aethiopoides longevity and therefore efficacy in the field especially in mid spring when host availability is very low

A biochemical viability assay is compatible with molecular methods for species identification

A biochemical viability assay was recently developed to quickly and easily assess the viability of small immobile arthropods including eggs intercepted on plant products On finding a viable specimen species identification often becomes the next hurdle This paper demonstrates that amplifiable DNA is present in a used biochemical viability assay solution and can be used for making taxonomic identifications Cryptically labelled heattreated and untreated eggs of three weevil species (Listronotus bonariensis Sitona lepidus and S discoideus) were first tested for viability then a 1135 bp fragment of the cytochrome c oxidase I gene was amplified from each viability assay solution in the presence of a fluorescent dye SYBR Green Melt curve analysis of the amplicons (n36) revealed three distinct melt profiles that correctly corresponded to each of the three weevil species This shows that the biochemical viability assay is compatible with the application of subsequent molecular identification methods which will facilitate the appropriate management response

How fresh is that frass

Many insects inhabit concealed locations such as within timber but leave outward signs of their presence such as frass Deposits of fresh frass on the outside of infested material would indicate a high probability of live insects being present within A method for estimating the age of frass could therefore be useful for assessing treatment efficacy For example the success of termite eradication could be monitored by regularly checking for the presence of fresh frass near old colonies Similarly the presence of fresh frass in borer holes in fumigated timber would raise concerns that the fumigation had been ineffective This study examined whether the age of frass could be estimated from levels of esterase enzyme activity in frass of four species; the termites Stolotermes inopinus and Kalotermes brouni and the weevils Sitona lepidus and Listronotus bonariensis With the termites active esterases were found in 1dayold frass but not in 1monthold frass indicating clear potential for development of a test With the weevils esterase activity occurred both in 1dayold frass and in 1monthold frass so development of a method for these species requires a faster degrading enzyme

A simple PCRRFLP method to distinguish between species and strains of Microctonus parasitoids found in New Zealand

Two strains of the hymenopteran parasitoid Microctonus aethiopoides have been released in New Zealand for the biological control of Sitona weevil species One attacks Sitona discoideus a pest of lucerne and the other attacks Sitona lepidus a pest of clover Two other Microctonus species also attack weevils in pasture; M hyperodae was released for the biological control of Listronotus bonariensis and the native M zealandicus attacks Irenimus spp These Microctonus species can attack nontarget weevil hosts and the identification of the larvae of the different Microctonus species and the separation of adults of M aethiopoides strains can only be achieved by molecular methods This paper describes a simple polymerase chain reaction and restriction fragment length polymorphism (PCRRFLP) method for distinguishing between the two M aethiopoides strains M hyperodae and M zealandicus This PCRRFLP method requires minimal molecular equipment and is cheaper and/or faster than other molecular methods

Abundance and parasitism of clover root weevil (Sitona lepidus) and Argentine stem weevil (Listronotus bonariensis) in pastures

The period from 2006 to 2010 in the North Island encompasses the widespread establishment of Irish Microctonus aethiopoides for the biocontrol of clover root weevil (Sitona lepidus) and a severe drought in 2008 that greatly reduced host availability This parasitoid occupies the same pasture habitat as Microctonus hyperodae a parasitoid with a similar life cycle introduced to control Argentine stem weevil (Listronotus bonariensis) A retrospective study was carried out on L bonariensis data and stored samples collected during S lepidus studies It was found that at all four initial M aethiopoides release sites L bonariensis populations were lowest in 2007 and 2008 while S lepidus populations were lowest in 2008 and 2009 Microctonus hyperodae parasitism levels were lowest in 2009 with overall regional means ranging from 5 in Manawatu to 11 in Waikato whereas corresponding Irish M aethiopoides parasitism levels were 43 and 72 respectively

Status of clover root weevil and its biocontrol agent in the South Island after six years.

Clover root weevil was first discovered in the South Island in 2006. Since then its distribution has been monitored. Although not yet occurring throughout all the South Island, it is widespread and has become common in many regions. The first releases of a biocontrol agent, the Irish ecotype of the parasitoid wasp Microctonus aethiopoides, were also made in 2006, with more made as suitable weevil populations were detected. In all areas where the releases have been monitored the biocontrol agent has established and extensive natural spread has occurred from the earlier release sites. As a consequence it is now established extensively in the northern South Island. Targeted releases have established the agent in Canterbury, Otago and Southland. Keywords: Biocontrol, clover root weevil, Sitona lepidus, Microctonus aethiopoides