Oviposition, Feeding Preferences and Distribution of Delia Species (Diptera: Anthomyiidae) in Eastern Canadian Onions

Abstract

Delia antiqua, Delia platura and Delia florilega are three root maggot species commonly considered pests in Eastern Canadian onions. The onion maggot, D. antiqua, is considered the primary root maggot pest in onion but it remains unclear whether the other two species are also causing damage. In order to develop updated management strategies for root maggot, we tested adult oviposition and feeding preference by Delia larvae on four growth stages of onion using bioassays and we determined the Delia species composition across the four major onion growing regions in eastern Canada. Delia species oviposit readily on onion at the 5–7 true leaf growth stage but damage on onions is not statistically different between Delia species in our zero-inflated models. The four eastern Canadian onion growing regions have different proportions of Delia species. Southern Ontario and Quebec were the only two regions where Delia antiqua was collected. The highest average numbers of Delia spp. were caught in Quebec and Nova Scotia. Our study shows that timing is important in implementation of management strategies for root maggot in Eastern Canadian onions.

Beheersing van bodemplaaginsecten via bodemgezondheidsmaatregelen : Een overzicht van de beschikbare kennis voor een selectie van akkerbouwgewassen met hun bijbehorende bodemplaaginsecten

“…De effectiviteit neemt af naarmate het areaal uien in een regio toeneemt en de afstanden tussen de percelen kleiner worden. Vluchtafstanden van 800 -1200 m van uienvliegen zijn waargenomen (Walters & Eckenrode, 1996;Mlynarek et al, 2020), maar ook afstanden van meer dan 2 km worden gerapporteerd (Berryman, 2008). Schade is direct gerelateerd aan nabij gelegen percelen met ui.…”

“…• Labonderzoek naar de effectiviteit van diverse Metarhizium anisopliae isolaten op de maden van de uienvlieg resulteerde in 50-90% afdoding en een Beauveria bassiana isolaat resulteerde in 100% afdoding van de adulte uienvliegen (Davidson & Chandler, 2005). Deze strategieën worden afzonderlijk en in combinatie gebruikt om de Delia-plaagdruk in Canada te verminderen (Mlynarek, 2020).…”

Utilization Clonal Selection Program to Improve Resistance Garlic (Allium sativum L.) Against Onion Maggot (Delia antiqua M.)

“…At different spots of field, four yellow sticky cards (15 cm x 15 cm) were placed facing into the field on the edge of the field. Where, sticky cards are the standard trapping method used to scout Delia populations and Delia antiqua is more attracted to yellow traps, rather than blue ones (Mlynarek et. al.…”

“…Additionally, identification of female Delia spp. relies on the number and position of bristles on the legs and thorax, which can be lost or damaged on sticky cards, leading to misidentifications (Mlynarek et. al.…”

Identification of morphologically challenging Delia (Diptera: Anthomyiidae) species from field vegetable crops using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP)

“…Field vegetables are subject to infestations by a complex of root maggot species in the genus Delia (Diptera: Anthomyiidae) (Finch 1989). Two Delia species, Delia antiqua (Meigen) and Delia radicum (Linnaeus), are known to be principle pest species of Canadian allium (Amaryllidaceae) and cruciferous (Brassicaceae) vegetables, respectively (Finch 1989;Howard et al 1996), but other Delia species, such as Delia platura (Meigen) and Delia florilega (Zetterstedt) (Mlynarek et al 2020), are commonly found in those same fields and have been observed to feed on decomposing or fresh crucifers, Allium, legumes, and even certain cereals (Griffiths 1993;Savage et al 2016). Without confirming or performing species identification, the presence of multiple Delia species where some might be secondary invaders can make it difficult to determine what control measures are necessary and to conduct research into new control measures (Mlynarek et al 2020).…”