This datasheet on Plutella xylostella covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Environmental Requirements, Seedborne Aspects, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.
AbstractThe apple leaf midge,Dasineura mali(Kieffer) (Diptera: Cecidomyiidae), an invasive alien pest established for many years in Nova Scotia, Canada, has invaded Ontario and British Columbia, Canada apple (Malus domesticaBorkhausen; Rosaceae) orchards, damaging growing tips of trees. Molecular analysis indicated that Nova Scotia populations are genetically different from Ontario and British Columbia populations. Pheromone trap captures, oviposition on growing apple terminals, and the incidence of third instars indicate threeD. maligenerations in each province.Platygaster demadesWalker (Hymenoptera: Platygastridae), released in Nova Scotia in 1993, parasitised 34% of the third midge generation in that province and was reared fromD. malifor the first time in 2016 in the Fraser Valley of British Columbia.Lyrcus nigroaeneusAshmead (Hymenoptera: Pteromalidae) parasitised up to 21% ofD. maliin southwestern Ontario.Synopeas myles(Walker) (Hymenoptera: Platygastridae) was recorded fromD. malifor the first time, one specimen in each of Nova Scotia and Ontario, and was the most important parasitoid in British Columbia.Synopeas mylesparasitism in Okanagan and Similkameen, British Columbia orchards increased from 0% to a mean of 30% ofD. malilarvae from 2014 to 2016. Other minor parasitoids includedPlatygaster tuberosulaKieffer (Hymenoptera: Platygasteridae) in all three provinces andAphanogmus vicinusFörster (Hymenoptera: Ceraphronidae) in British Columbia.
The Nagoya Protocol is a supplementary agreement to the Convention on Biological Diversity that provides a framework for the effective implementation of the fair and equitable sharing of benefits arising out of the utilization of genetic resources, including invertebrate biological control agents. The Protocol came into force on 12 October 2014, and requires signatories and countries acceding to the Protocol to develop a legal framework to ensure access to genetic resources, benefit-sharing and compliance. The biological control community of practice needs to comply with access and benefit sharing regulations arising under the Protocol. The IOBC Global Commission on Biological Control and Access and Benefit Sharing has prepared this best practices guide for the use and exchange of invertebrate biological control genetic resources for the biological control community of practice to demonstrate due diligence in responding to access and benefit sharing requirements, and to reassure the international community that biological control is a very successful and environmentally safe pest management method based on the use of biological diversity. We propose that components of best practice include: collaborations to facilitate information exchange about what invertebrate biological control agents are available and where they may be obtained; knowledge sharing through freely available databases that document successes (and failures); cooperative research to develop capacity in source countries; and transfer of production technology to provide opportunities for small-scale economic activity. We also provide a model concept agreement that can be used for scientific research and non-commercial release into nature where access and benefit sharing regulations exist, and a model policy for provision of invertebrate biological control agents to other parties where access and benefit sharing regulations are not restrictive or do not exist.
The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is the most important pest of pepper (Capsicum Linnaeus; Solanaceae) crops in North America. Native to Mexico, the southern United States of America, and Central America, it is intercepted in Canada when peppers are imported to supplement domestic production. Given the proximity of greenhouse and field production to packing facilities, this pest poses a serious risk to the cultivation of peppers in Canada. Once established, it is difficult to control because immature stages of the weevil are protected within the pepper fruit. As such, chemical control targeting these life stages is not effective, and other strategies, including biological control, may prove useful. To explore the potential for biological control options to manage the pepper weevil in areas at risk in Canada, natural enemy surveys were conducted in southern Ontario following the reports of transient, localised field populations in 2016. Parasitoids belonging to three Hymenoptera families including Pteromalidae (Jaliscoa hunteri Crawford, Pteromalus anthonomi Ashmead), Eupelmidae (Eupelmus pulchriceps Cameron), and Braconidae (Nealiolus Mason species, Bracon Fabricius species) were reared from infested field-collected pepper fruits. Together, these new natural enemy records could facilitate the exploration and development of novel agents for the biological control of the pepper weevil.
Agriculture and Agri-Food Canada, Ottawa, Ontario, CANADA, Peter.Mason@agr.gc.ca, Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan, CANADA, Owen.Olfert@agr.gc.ca, CABI Switzerland, Delémont, Jura, SWITZERLAND, t.haye@cabi.org, Agriculture and Agri-Food Canada, London, Ontario, CANADA, Tara.Gariepy@agr.gc.ca, Agriculture and Agri-Food Canada, Agassiz, British Columbia, CANADA, Paul.Abram@canada.ca, gillespieroad@gmail.com
The pre-release risk assessment of parasitoids for classical biological control generally involves nontarget testing to define the agent's host range. To ensure that no suitable host species are falsely rejected in these tests, it has been suggested that the physiological and informational state of parasitoids be manipulated to enhance their "motivation to oviposit''. However, the effects of such factors on host acceptance are not consistent across parasitoid species, making it laborious to identify the conditions necessary to maximise host acceptance. Our objective was to determine whether changes in parasitoid state could alter host acceptance behaviour sufficiently to affect host range expression. In addition, we tested the assumption that a state-dependent shift in motivation to oviposit on the target host will translate to a similar change in responsiveness to lower-ranked host species. Three-day-old and 10-day-old females of the candidate classical biological control agent, Diadromus pulchellus, were offered 12 non-target species of varying relatedness to the target pest, Acrolepiopsis assectella, in a series of no-choice and choice oviposition trials. Younger D. pulchellus females had previously demonstrated greater motivation to oviposit in the target pest and were, therefore, predicted to express a broader host range than older females. Parasitoid age had a minor effect on host range expression that was contrary to expectations. Older females more readily attacked one of the non-target species in no-choice tests and inflicted higher mortality in one of the choice tests. Ultimately however, young and old parasitoids still attacked the same four non-target species and their offspring emerged from the same three. There was an interaction between the effects of parasitoid condition and experimental design on responsiveness to low-ranked hosts: increasing non-target density in choice tests significantly altered attack rates by 10-day-old, but not by 3-day-old, parasitoids. The implications of these findings for host specificity testing depend largely on the specific aims of a host range assessment. Parasitoid state influenced the frequency of non-target attack but did not affect which non-target species were attacked. (C) 2014 Elsevier Inc. All rights reserved.
We determined the host range of the parasitoid Trichomalus perfectus (Walker), a candidate for classical biological control of cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham), an important pest of canola in Canada. Studies were conducted in Europe and in North America. In laboratory experiments, the levels of parasitism (acceptance) of Ceutorhynchus turbatus Schultze, C. cardariae Korotyaev, C. omissus Fall and C. querceti (Gyllenhal) by T. perfectus were not significantly different than of the target host C. obstrictus. Although C. typhae (Herbst), C. pallidactylus (Marsham), C. americanus Buchanan, C. neglectus Blatchely and Ceutorhynchus sp. nr. nodipennis were parasitised by T. perfectus, the levels of parasitism were significantly lower on these species than on C. obstrictus. Ceutorhynchus peyerimhoffi Hustache, C. erysimi (Fabricius), C. alliariae H. Brisout, C. roberti Gyllenhal, Mogulones borraginis (Fabricius), Mononychus vulpeculus (Fabricius) and the leaf-mining fly Scaptomyza flava (Fallen) were not attacked. Ecological host range surveys in Europe corroborated the prediction that T. perfectus would attack C. cardariae at similar rates to C. obstrictus. In North America, the recent discovery of T. perfectus in a C. omissus population suggests that laboratory findings predicting that C. omissus is a preferred host may be the case in the field. We found that T. perfectus attacks larvae of some Ceutorhynchus spp. feeding on Brassicaceae and does not attack species outside of that host range. Thus, the parasitoid can be defined as narrowly oligophagous. These results demonstrate the value of ecological host range studies in the area of origin to validate hypotheses generated through laboratory host range experiments.
Surveys were conducted in Ontario and Quebec, Canada to determine the parasitoid communities associated with Ceutorhynchus Germar (Coleoptera: Curculionidae) weevil species that are potential nontarget hosts of candidate biological control agents of the cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham). New host plant associations are documented for Ceutorhynchus americanus Buchanan, Ceutorhynchus neglectus Blatchley, and Ceutorhynchus omissus Fall. More than 18 species of Chalcidoidea (Hymenoptera) were associated with six Ceutorhynchus species reared from siliques and stems of Brassicaceae plants. Silique-feeding Ceutorhynchus species supported a more diverse parasitoid community than stem-feeding or root crown-feeding species. The major components of the parasitoid assemblage of the native C. neglectus included Mesopolobus gemellus Baur and Muller, Mesopolobus moryoides Gibson, Trichomalus lucidus (Walker) (Hymenoptera: Pteromalidae) and a cryptic species complex previously reported as Necremnus tidius (Walker) (Hymenoptera: Eulophidae). These species, plus Trimeromicrus maculatus Gahan (Hymenoptera: Pteromalidae) were the main parasitoids attacking the native C. omissus. The major parasitoids associated with the accidently introduced Ceutorhynchus erysimi (Fabricius) and Ceutorhynchus typhae (Herbst) included T. maculatus, the N. tidius species complex, M. gemellus, and M. moryoides. Trichomalus perfectus (Walker) (Hymenoptera: Pteromalidae), a major parasitoid of C. obstrictus in Europe, is an accidental introduction first reared in Canada from that host in 2009 and first collected from C. omissus in 2011. Mesopolobus gemellus is shown to have a broad host range. These findings highlight the need for a cautious approach before introducing new biological control agents.
Biological control strategies capitalise on natural mechanisms such as predation and parasitism to reduce the need for chemical applications to control insect pests. In Canada, the parasitic wasp Diadromus pulchellus Wesmael (Hymenoptera: Ichneumonidae) is being investigated for its use in the biological control of an invasive crop pest, the leek moth, Acrolepiopsis assectella (Zeller) (Lepidoptera: Acrolepiidae). Large numbers of insects will be needed for releases to ensure that populations of D. pulchellus establish quickly and impact leek moth populations. Since the current culture is not producing the number of insects required for large-scale releases, the accumulation and storage of D. pulchellus might be a viable option to obtain ideal numbers. Currently, little is known about the optimal conditions for the long-term storage and release of D. pulchellus, which overwinter in nature as adults. Using insects from the active culture, the effect of intermittent, short-term warming on cold-stored adults was evaluated for survivorship and fecundity. In accordance with previous findings, females survived cold storage more readily than males. However, the warming regimes employed had no significant impacts on overall survivorship. Cold-stored females had reduced fecundity compared to females maintained in the culture, though no significant differences were noted between the treatments. In addition, the offspring sex-ratio for all treatments was male skewed. Thus, the warming procedures utilised provided no advantages over current techniques for the long-term storage of D. pulchellus intended for release.
Purple loosestrife, L. salicaria, is an invasive wetland perennial of Eurasian origin that occurs in all Canadian provinces. Biological control is an important strategy for its long-term management. This chapter presents information on the weed status in Canada, followed by a comprehensive background on previous studies, review of the application of biological control in these programmes, an evaluation of the biological control efforts and future needs in research or implementation activities.
The swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae) is an invasive gall midge of Eurasian origin that has recently become a pest of crucifer (Brassica oleracea L.) crops and canola (Brassica napus L.) in North America. In order to identify possible candidates for the classical biological control of this pest, we conducted an extensive survey of Europe to determine what species of parasitoids attack the swede midge. In addition, weekly monitoring of an oilseed rape plot in north western Switzerland allowed the observation of the seasonal phenological relationships between the swede midge and its parasitoids. Synopeas myles (Walker) (Hymenoptera: Platygastridae) and Macroglenes chalybeus (Haliday) (Hymenoptera: Pteromalidae) were found to be the two primary parasitoid species present throughout the surveyed range and, in Switzerland, attacking every generation of the swede midge. In the survey and the monitoring of the oilseed rape plot, total percent parasitism of samples ranged from 0% to 41%, but was typically quite low (<15%). Both S. myles and M. chalybeus have been reported to attack several other species of gall midges in Europe, casting doubt on their host specificity. However, before classical biological control of the swede midge in North America using its parasitoids from Europe can be ruled out, more research is needed to measure their importance as a mortality factor for natural swede midge populations and to properly assess their host specificity.
Synopeas myles (Walker) (Hymenoptera: Platygastridae) is a parasitoid of the swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), in Europe. We conducted the first thorough investigation of this parasitoid’s biology. Contrary to the biology reported for all platygastrids to date, exposure of late-instar host larvae to parasitism as opposed to eggs or early larvae yielded more S. myles offspring. Superparasitism was relatively common in the field and among groups of females in the laboratory, but was much less common among single females, providing preliminary evidence for self-discrimination. Observation of immature stages of S. myles inside living hosts revealed that supernumerary larvae in superparasitized hosts were probably eliminated by physical combat soon after hatching. With increasing levels of superparasitism, sex ratios of offspring became more female-biased and their mean development time increased. The probability that offspring would emerge from a host and the size of offspring were unaffected by increasing levels of superparasitism.
(Walker) (Hymenoptera: Platygastridae) is a parasitoid of the swede midge, (Kieffer) (Diptera: Cecidomyiidae), in Europe. We conducted the first thorough investigation of this parasitoid’s biology. Contrary to the biology reported for all platygastrids to date, exposure of late-instar host larvae to parasitism as opposed to eggs or early larvae yielded more offspring. Superparasitism was relatively common in the field and among groups of females in the laboratory, but was much less common among single females, providing preliminary evidence for self-discrimination. Observation of immature stages of inside living hosts revealed that supernumerary larvae in superparasitized hosts were probably eliminated by physical combat soon after hatching. With increasing levels of superparasitism, sex ratios of offspring became more female-biased and their mean development time increased. The probability that offspring would emerge from a host and the size of offspring were unaffected by increasing levels of superparasitism.
We report successful overwintering of Diadromus pulchellus in North America (Ontario) following introduction of this species from Europe to control the leek moth, Acrolepiopsis assectella, a recently established alien species. Field rearing revealed that the native Diadromus subtilicornis emerged only from diamondback moth, Plutella xylostella, whereas D. pulchellus was reared almost exclusively from leek moth. The single D. pulchellus reared from diamondback moth was anticipated because host range studies found this species could develop on both leek moth and diamondback moth in the laboratory, although, it had not been previously reported from diamondback moth in the field in Europe. DNA barcoding of specimens of both Diadromus spp. confirmed their species status and novel morphological characters are presented to distinguish D. pulchellus from D. subtilicornis. In addition, DNA from specimens of D. subtilicornis from Europe clustered with DNA from specimens across Canada, confirming that it is a single Holarctic species. Finally, a new host association for D. subtilicornis is recorded from the dame's rocket moth: Pseudoplutella porrectella.
Abstract Acrolepiopsis assectella (Zeller), leek moth, is a widespread and common pest of species of Allium L. (Liliaceae) in the western Palaearctic subregion. The establishment of A. assectella in eastern North America has resulted in economic losses to garlic (Allium sativum L.), leek (Allium porrum L.), and onion (Allium cepa L.) growers, especially to organic producers in eastern Ontario and southern Quebec. Acrolepiopsis assectella was first recorded in the Ottawa area in 1993. By 2010, A. assectella had expanded its range into eastern Ontario, southwestern Quebec, Prince Edward Island, and New York. A bioclimate model, using CLIMEX simulation software, was developed to produce mapped results that closely approximated known distributions for A. assectella in central Europe. This model was then validated with recorded distribution records in eastern Europe, Asia, and North America. Model output predicted that A. assectella will readily survive in southeastern Canada and the eastern United States of America. Other areas potentially suitable for A. assectella include coastal regions of the Pacific Northwest, the interior of southern British Columbia, and north-central Mexico. The continued range expansion of A. assectella into other Allium-growing areas of eastern North America appears to be inevitable. Establishment in these areas presents the risk of substantial production losses to Allium spp. producers.
Will the Convention on Biological Diversity put art end to biological control? Under the Convention on Biological Diversity countries have sovereign rights over their genetic resources. Agreements governing the access to these resources and the sharing of the benefits arising from their use need to be established between involved parties. This also applies to species collected for potential use in biological control. Recent applications of access and benefit sharing principles have already made it difficult or impossible to collect and export natural enemies for biological control research in several countries. If such an approach is widely applied it would impede this very successful and environmentally safe pest management method based on the use of biological diversity. The International Organization for Biological Control of Noxious Animals and Plants has, therefore, created the "Commission on Biological Control and Access and Benefit Sharing". This commission is carrying out national and international activities to make clear how a benefit sharing regime might seriously frustrate the future of biological control. In addition, the IOBC Commission members published information on current regulations and perceptions concerning exploration for natural enemies and drafted some 30 case studies selected to illustrate a variety of points relevant to access and benefit sharing. In this article, we summarize our concern about the effects of access and benefit sharing systems on the future of biological control.