56 Chapter 8 Columbia, General Technical Report NE-277. US Department of Agriculture, Forest Service, Northeastern Research Station, Newtown Square, Pennsylvania, pp. 65–73. Lyons, D.B., Kenis, M. and Bourchier, R.S. (2002) Acantholyda erythrocephala (L.), pine false webworm (Hymenoptera: Pamphiliidae). In: Mason, P. and Huber, J. (eds) Biological Control Programmes against Insects and Weeds in Canada 1981-2000. CAB International, New York, pp. 22–28. Mayfi eld III, A.E., Allen, D.C. and Briggs, R.D. (2005) Radial growth impact of pine false webworm defoliation on eastern white pine. Canadian Journal of Forest Research 35, 1071–1086. Mayfi eld III, A.E., Allen, D.C. and Briggs, R.D. (2007) Site and stand conditions associated with pine false webworm populations and damage in mature eastern white pine plantations. Northern Journal of Applied Forestry 24, 168–176. Moreau, G. and Lucarotti, C.J. (2007) A brief review of the past use of baculoviruses for the management of eruptive forest defoliators and recent developments on a sawfl y virus in Canada. The Forestry Chronicle 83, 105–112. Staples, J.K., Bartelt, R.J. and Cossé, A.A. (2009) Sex pheromone of the pine false webworm Acantholyda erythrocephala. Journal of Chemical Ecology 35, 1448–1460. Zahner, V., Lucarotti, C.J. and McIntosh, D. (2008) Application of 16S rDNA-DGGE and plate culture to characterization of bacterial communities associated with the sawfl y, Acantholyda erythrocephala (Hymenoptera, Pamphiliidae). Current Microbiology 57, 564–569. 8 Acrolepiopsis assectella (Zeller), Leek Moth (Lepidoptera: Acrolepiidae) Peter G. Mason,1 Wade H. Jenner,2,3 Andrea Brauner1, Ulrich Kuhlmann2 and Naomi Cappuccino3 1Agriculture and Agri-Food Canada, Ottawa, Ontario; 2CABI, Delémont, Switzerland; 3Carleton University, Ottawa, Ontario 8.1 Pest Status Prince Edward Island and is predicted to establish widely in eastern North America Leek moth, Acrolepiopsis assectella (Mason et al., 2011). Cultivated Allium (Zeller) (Lepidoptera: Acrolepiidae), native spp., particularly garlic, A. sativum L., to Europe, is an invasive alien pest of leek, A. porrum L. and onion, A. cepa L., Allium spp. (Amaryllidaceae) in North are the preferred hosts. However, nodding America. First reported in the Ottawa area onion, A. cernuum Roth, and prairie onion, in 1993 (Landry, 2007), A. assectella has A. stellatum Nutt. ex Ker Gawl., native to since spread throughout eastern Ontario North America, can support development and southern Quebec, is found in upper of A. assectella (Allison et al., 2007) and New York State, New Brunswick and are therefore potentially at risk of attack © Her Majesty the Queen in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada 2013 Chapter 8 57 from this pest. Damage is caused by the approach such as organic growers face larval stages, which feed on the aerial greater challenges. Biologically based growing tissues (Noyes, 1974). In eastern insecticides such as Bacillus thuringiensis Canada, damage is most severe in organic Berliner (Bacillaceae) and Spinosad® are production systems. In garlic, the scapes lethal to leek moth larvae (Mason et al., are destroyed early in the season and the 2006a; Allen et al., 2007; Allen and bulbs can be destroyed after harvest when Appleby, 2008), although to be effective, the crop is hung and larvae move down the they must be applied when 1st instar leek plant as it dries. Damage to leeks can be so moth are present on plant surfaces. Float- severe that plants are unmarketable and ing row covers provide the best protection, entire crops destroyed. particularly in organic production systems, Adult A. assectella overwinter and by preventing leek moth from ovipositing become active in spring when temperatures on the crop (Mason et al., 2006b). rise above 15°C (Abo-Ghalia and Thibout, Pino and Morton (2008) investigated the 1983). Females lay eggs singly on the leaf use of Steinernema feltiae (Filipjev) surfaces, and each female lays an average (Rhabditida: Steinernematidae) against A. of 100 eggs in fi eld conditions. Soon after assectella in leeks. They observed larval hatching, 1st instar larvae mine into the mortalities of 71.1–87.7% in experimental leaf tissue where they feed, completing 5 fi eld plots and concluded that S. feltiae instars. Mature larvae exit from the inner was effective because of the moist micro- plant tissues, spin a loosely woven cocoon habitat provided by the overlapping plant on external surfaces and develop through leaves and the tunnelling habit of A. prepupal and pupal stages. Adults emerge, assectella larvae. and, depending on the time of year, In the area of origin in Europe, a number produce a new generation or enter repro- of parasitoids are reported in the literature ductive diapause to overwinter. Repro- to attack A. assectella (Table 8.1). The ductive diapause (Thibout, 1981) is complex varies from generation to gener- induced when developing larvae are ation (Plaskota and Dabrowski, 1986) and exposed to daylengths shorter than 15 h many of the species have a broad host (Abo-Ghalia and Thibout, 1982). In eastern range (Jenner and Kuhlmann, 2004). Canada, development above a threshold of Although several predators have been 7°C takes 441.7 degree-days (DD) from egg reported, no comprehensive studies have to adult (Mason et al., 2010), similar to been conducted to provide information on requirements (450 DD above 6°C) in central incidence and impact. Europe (Bouchet, 1973) but signifi cantly Jenner (2008) studied A. assectella less than the 630 DD above 6°C required in populations in Switzerland. Four Hymen- Sweden (Åsman, 2001). In eastern Ontario, optera species were reared from A. three generations can occur, marked by assectella larval hosts: two Ichneu monidae, fl ight periods in early spring, mid- to late- Diadegma chrysostictos (Gmelin) and D. June and mid-July (Mason et al., 2010). A fenestrale Holmgren; and two Eulophidae, fourth generation is probable in south- Pnigalio soemius (Walker) and P. pectini- western Ontario (Mason et al., 2011) where cornis (L.). Acrolepiopsis assec tella pupae A. assectella will likely invade. were parasitized by two Ichneumonidae: Diadromus pulchellus Wesmael and Itoplectis maculator (Fabri cius). Among 8.2 Background these, D. pulchellus was the only species that appeared to be host-specifi c. There are Chemical insecticides such as Matador®/ no known records of this parasitoid emerg- Warrior® may provide some protection ing from hosts other than A. assectella in against A. assectella (Allen et al., 2007; the fi eld, whereas the other fi ve species Allen and Appleby, 2008). However, those have been associated with between 29 and using a reduced risk pest management 124 host species (Yu et al., 2009). 58 Chapter 8 Table 8.1. Parasitoids associated with Acrolepiopsis assectella in the European literature. Host stage European countriesa where Parasitoid species attacked found Reference Hymenoptera: Braconidae Apanteles impurus (Nees) ? AT, BE, BG, CZ, FR, DE, HU, Plaskota and Dabrowski IE, IT, LV, LT, MN, PL, RU, (1986); Yu et al. (2009) SE, CH, GB Aphaereta brevis Tobias ? BG, CZ, HU, RU, ES, RSPL Plaskota and Dabrowski (1986); Jenner and Kuhlmann (2004); Yu et al. (2009) Microchelonus blackburni larva ? Jenner and Kuhlmann (2004); (Cameron) Yu et al. (2009) Microgaster globata (L.) larva AL, AM, AT, AZ, BE, BG, CZ, Jenner and Kuhlmann (2004); FI, FR, GE, DE, GR, HU, IE, Yu et al. (2009) IT, KZ, LV, LT, MD, MN, NL, NO, PL, RO, RU, SK, SI, ES, SE, CH, TR, TM, UA, GB, RS Microgaster hospes Marshallb larva BG, CZ, FI, GE, DE, HU, IE, IT, Plaskota and Dabrowski LT, MD, MN, NL, PL, RU, (1986); Jenner and SK, CH, TR Kuhlmann (2004); Yu et al. (2009) Hymenoptera: Ichneumonidae Campoletis annulata ? AT, BE, BG, CZ, DK, FI, FR, DE, Yu et al. (2009) (Gravenhorst) HU, IE, IL, IT, LV, NL, PL, RO, RU, ES, SE, GB Diadegma fenestrale larva AT, AZ, BE, BG, CZ, DK, FI, FR, Plaskota and Dabrowski (Holmgren) DE, HU, IS, IE, IT, KZ, LV, LT, (1986); Jenner and MD, NL, NO, PL, PT, RO, Kuhlmann (2004) ; Yu et al. RU, ES, SE, CH, TR, TM, UA, (2009) GB, RS Diadromus collaris pupa AT, AZ, BE, BG, CZ, FR, DE, Jenner and Kuhlmann (2004); (Gravenhorst) GR, IT, MD, NL, PL, PT, RO, Yu et al. (2009) ES, SE, TR, TM, UA, GB, RS Diadromus pulchellus pupa BE, FI, DE, FR, PL, SE, GB Jenner and Kuhlmann (2004); Wesmael Yu et al. (2009) Diadromus varicolor ? AT, AZ, BE, BG, FI, FR, DE, HU, Jenner and Kuhlmann (2004); Wesmael NL, RO, RU, ES, SE, CH, GB Yu et al. (2009) Endromopoda nigricoxis ? PL Plaskota and Dabrowski (Ulbricht) (1986) Itoplectis europeator Aubert larva FR, HU, RO, CH, TR Yu et al. (2009) Itoplectis tunetana pupa AM, AT, AZ, BG, FR, GR, HU, Jenner and Kuhlmann (2004); (Schmiedeknecht) IT, KZ, KG, MK, MD, MN, Yu et al. (2009) PL, RO, RU, ES, CH, TR, TM, UA, UZ, RS, ME Tycherus impiger (Wesmael) pupa AT, BE, BG, CZ, FI, FR, DE, Plaskota and Dabrowski HU, IT, LI, NL, NO, PL, RO, (1986); Jenner and RU, SE, GB Kuhlmann (2004) Zaglyptus varipes larva AT, AZ, BY, CZ, DE, FI, FR, DE, Jenner and Kuhlmann (2004); (Gravenhorst)c HU, IT, LV, LT, MD, NL, NO, Yu et al. (2009) PL, RO, RU, ES, SE, TR, GB aISO 3166-1 Encoding list of countries (http://www.iso.org/iso/iso-3166-1_decoding_table); balso in USA; calso in Canada, USA; ?, no data available. Chapter 8 59 Furthermore, D. pulchellus was the most (2008) and Jenner et al. (2012) conducted abundant parasitoid on A. assectella, it was host specifi city testing and showed that in the only species found attacking A. the laboratory D. pulchellus would suc- assectella in all three generations and it cessfully develop in non-target species that was the sole species obtained from A.