Biological control agent biotypes
Aeschlimann J.P. (1983).
Notes on the variability of Microctonus aethiopoides Loan (Hymenoptera: Braconidae: Euphorinae).
Contributions of the American Entomological Institute 20: 329-335.
The authory describes some characteristics of Mediterranean biotypes of the parasitoid Microctonus aethiopoides Loan. Laboratory experiments and field observations have shown that that there are several geographical as well as host-associated biotypes of the parasite.
Ash G.J., Chung Y.R., McKenzie C. and Cother E.J. (2008).
A phylogenetic and pathogenic comparison of potential biocontrol agents for weeds in the family Alismataceae from Australia and Korea.
Australasian Plant Pathology 37: 402-405
Plants in the family Alismataceae are weeds of rice in Australia and Korea. Research programs have investigated the use of inundative plant-pathogenic fungi for biological control of these weeds. Recent studies have shown a close phylogenetic relationship between the organisms under investigation in the two countries. A survey of Alismataceae weeds in southern South Korea was carried out and fungal isolations were made from the diseased specimens. The isolates overlapped between those previously described in Korea as Plectosporium tabacinum and the newly named P. alismatis. The host range testing on australian weeds in the glasshouse showed that the isolates from Korea were less pathogenic than the Australian isolates. Therefore, although the isolates were phylogenetically related, the isolates from Korea did not show greater virulence or a wider or different host range than the Australian isolates.
Chong J.-H. and Oetting R.D. (2007). Specificity of Anagyrus sp nov nr. sinope and Leptomastix dactylopii for six mealybug species. BioControl 52: 289-308
Clarke A.R. (1995).
"Strains" and the classical biological control of insect pests.
Canadian Journal of Zoology 73: 1777-1790
The strategy of introducing two or more populations of the same species of beneficial agent to increase the genetic diversity of that species is reviewed. From the literature literature, cases of multiple introductions of conspecific populations against insect targets were listed and the effect of subsequent introductions on the outcome of the project was recorded. The analysis suggested that introducing two or more populations of the same species is less likely to result in enhanced success than if other species of natural enemies are sought for "normal" classical biological control (historical success rate 12-16%). It was considered from a reveiw of genetic theory that there is also no theoretical support for the continued introduction of strains.
Gerard P.J., McNeill M.R., Barratt B.I.P. and Whiteman S.A. (2006). Rationale for release of the irish strain of Microctonus aethiopoides for biocontrol of clover root weevil. New Zealand Plant Protection 59: 285-289.
Goldson S.L., Phillips C.B., McNeill M.R. and Barlow N.D. (1997). The potential of parasitoid strains in biological control: observations to date on Microctonus spp. intraspecific variation in New Zealand. Agriculture, Ecosystems and Environment 64: 115-124.
Goolsby J.A., Makinson J.R., Hartley D.M., Zonneveld R. and Wright A.D. (2004).
Pre-release evaluation and host-range testing of Floracarus perrepae (Eriophyidae) genotypes for biological control of Old World climbing fern.
Proceedings of the XI International Symposium on Biological Control of Weeds: 113-116
As part of a biological control program for Lygodium microphyllum, an invasive climbing fern in Florida, surveys for natural enemies were conducted in the fern's native range (Australia, Asia and Oceania). Twenty-two herbivores were identified including an eriophyid mite, Floracarus perrepae Knihinicki & Boczek. Using molecular diagnostics a plant population from Cape York, Queensland was found to be an exact match with the invasive populations in Florida for the two chloroplast DNA sequences analyzed. Pre-release field impact studies revealed that F. perrepae caused more than 50% impact on L. microphyllum biomass production over a two-year period. Several genotypes of the mite were screened for their acceptance of the invasive Florida genotype, and the populations from Cape York and Thailand performed best and came from fern genotypes that were most closely related to the Florida genotype.
Hope K.J. and Olckers T. (2011). 2011. Gargaphia decoris (Hemiptera: Tingidae) from two South American provenances are equally safe for release against the invasive tree, Solanum mauritianum (Solanaceae). African Entomology 19: 106-112.
Hopper K.R., Farias A.M.I., Woolley J.B., Heraty J.M. and Britch S.C. (2005).
Genetics: relation of local populations to the whole "species" - implications for host range tests
Pp. 665-671 In: Second International Symposium on Biological Control of Arthropods, Davos, Switzerland, 12-16 September, 2005, M.S. Hoddle (Ed.) United States Department of Agriculture, Forest Service, Washington.
The literature on variation in host specificity among populations and sibling species of parasitoids is reviewed and the evolution and genetics of host specificity in Aphelinus varipes and A. albipodus (Hymenoptera: Aphelinidae) discussed. The take-home lessons for biological control are: parasitoids in what appears to be a single species, but collected from widely different geographical regions or from different host species, may differ greatly in host specificity and thus should be tested separately; and allopatric sibling species with different patterns of host use may introgress if placed in sympatry, which could lead to evolutionary changes in host use.
Mathenge, C.W., Holford, P., Hoffmann, J.H., Zimmermann, H.G., Spooner-Hart, R., Beattie, G.A.C. (2010). Determination of biotypes of Dactylopius tomentosus (Hemiptera: Dactylopiidae) and insights into the taxonomic relationships of their hosts, Cylindropuntia spp. Bulletin of Entomological Research 100: 3, 347-358
O'Hanlon P.C., Briese D.T. and Peakall R. (2000).
Know your enemy: the use of molecular ecology in the Onopordum biological control project.
Proceedings of the X International Symposium on Biological Control of Weeds: 281-288
Accurate identification of the target weed(s) for a biological control project is critical to the success of a biological control project, particularly where the weed may comprise different biotypes or be part of a species complex. Molecular ecology provides tools for resolving the identity of weeds. An example is given with a hybrid swarm of Onopordum spp. in Australia. Molecular markers can be used to better understand the phylogeny of plant groups containing the target weed(s).
Phillips C.B. (1996). Intraspecific variation in Microctonus hyperodae and M. aethiopoides (Hymenoptera: Braconidae); significance for their use as biological control agents. PhD Thesis, Department of Entomology, Lincoln University, Lincoln, New Zealand. 169 pp.
Phillips C.B., Cane R.P., Mee J., Chapman H.M., Hoelmer K.A. and Coutinot D. (2002).
Intraspecific variation in the ability of Microctonus aethiopoides (Hymenoptera: Braconidae) to parasitise Sitona lepidus (Coleoptera: Curculionidae).
New Zealand Journal of Agricultural Research 45: 295-303.
An experiment was conducted to compare the suitability of French and New Zealand Sitona lepidus (Coleoptera: Curculionidae) as hosts for a French biotype of Microctonus aethiopoides (Hymenoptera: Braconidae) Loan . This provided no evidence of S. lepidus intraspecific variation in host suitability for parasitism. However, amplification of inter simple sequence repeat (ISSR) regions of M. aethiopoides DNA demonstrated clear genetic differences between French and New Zealand M. aethiopoides. It was concluded that intraspecific variation in the ability of M. aethiopoides to evade the immune response of S. lepidus is the reason for the low levels of parasitism observed in New Zealand compared with Europe.
Phillips C.B., Iline I.L., Vink C.J., Winder L.M. and McNeill M.R. (2006). Methods to distinguish between the Microctonus aethiopoides strains that parasitise Sitona lepidus and Sitona discoideus. New Zealand Plant Protection 59: 1-6.
Phillips C.B., Vink C.J., Blanchet A. and Hoelmer K.A. (2008).
Hosts are more important than destinations: what genetic variation in Microctonus aethiopoides (Hymenoptera: Braconidae) means for foreign exploration for natural enemies.
Molecular Phylogenetics and Evolution 49: 467-476
Nucleotide sequence data were generated from the gene regions COI, 16S, and arginine kinase to assess genetic variation within the parasitoid, Microctonus aethiopoides, reared from Sitona discoideus, S. hispidulus, and Hypera posticafrom locations in France. The results combined with previously published data from 14 countries show that M. aethiopoides genetic variation is more strongly correlated with host taxon than with sampling location. The results suggested that success rates and environmental safety in biological control would be improved by ensuring that parasitoids collected in the native range are reared from the same host species as the one being targeted for control in the region of introduction.
Unruh T.R. and Messing R.H. (1993).
Intraspecific biodiversity in Hymenoptera: implications for conservation and biological control.
Pp. 27-52 In: Hymenoptera and Biodiversity, J. LaSalle and I. D. Gauld (Ed.) CAB International, Wallingford; UK.
Selected genetic and biological attributes of the Hymenoptera which differ from those of other insect groups are discussed in relation to modes of reproduction, sex determination and gender allocation and sex ratio. Genetic variation and population viability, single locus variation and quantitative variation are considered. Genetic load and inbreeding depression are discussed in relation to haplodiploidy and thelytoky. Intraspecific variation in response to abiotic factors, host suitability and in susceptibility to toxins is considered in the final section.
de Leon J.H., Neumann G., Follett P.A. and Hollingsworth R.G. (2010).
Molecular markers discriminate closely related species Encarsia diaspidicola and Encarsia berlesei (Hymenoptera: Aphelinidae): biocontrol candidate agents for white peach scale in Hawaii.
Journal of Economic Entomology 103: 3, 908-916.
The authors characterized Encarsia diapsidicola Silvestri and Encarsia berlesei Howard (Hymenoptera: Aphelinidae) by phylogenetic analysis of the cytochrome oxidase subunit I gene (COI) and intersimple sequence repeat-polymerase chain reaction (ISSR-PCR) DNA fingerprinting. These closely related parasitoids are candidate biological control agents for the white peach scale, Pseudaulacaspis pentagona Targioni-Tozetti (Hemiptera: Diaspididae), in Hawaii. Both molecular marker types successfully discriminated the two Encarsia spp., but the COI markers were considered useful to assess levels of parasitism in the field and to study competitive interactions between parasitoids.
Predatory biological control agents
Pre-release prediction of host range and non-target impacts