biology and management of phytomyza gymnostoma: a new invasive pest … · lancaster county, pa...
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Biology and management of Phytomyza
gymnostoma: a new invasive pest
of Allium crops in the eastern US
Entomological Society of America – Eastern Branch
March 19, 2018
Photo: Andre Megroz
Brian Nault1, Shelby, Fleischer3, Ethan Grundberg2,
Teresa Rusinek2, Dana Roberts2 and Timothy Elkner4
1Cornell University2Cornell Cooperative Extension3Penn State University4Penn State Cooperative Extension
American serpentine leafminer (Liriomyza trifolii)
Vegetable leafminer (Liriomyza sativae)
Leafminer pests (Diptera: Agromyzidae)
of Allium crops in U.S.
American serpentine leafminer (Liriomyza trifolii)
Vegetable leafminer (Liriomyza sativae)
*Allium leafminer (Phytomyza gymnostoma)
*New invasive Allium pest in North America detected in 2015
Leafminer pests (Diptera: Agromyzidae)
of Allium crops in U.S.
Outline
I. Origin and distribution
II. Identification and phylogeny
III. Host range and damage to
Allium spp.
IV. Biology and phenology
V. Detection and management
World distribution of P. gymnostoma
Origin – Poland (1858)
21 countries in Europe; 2 in Asia; 1 in North America
CABI Crop Protection Compendium (2018)
North American distribution of
Phytomyza gymnostoma
First detected in
Lancaster County, PA
(2015)
Confirmed in MD,
PA, NJ and NYas of 3/14/18
Phytomyza gymnostoma (Loew)
Adult
Photo: B. Nault
Photo: André Mégroz
Allium leafminer
Phytomyza gymnostoma (Loew)
Photo: E. Agallou and D. Collins
black body – 3.0 mm (2 to 3x larger than T. trifolli)
Yellow tips on distal end of femurs
large yellow frons
white haltere
Phytomyza gymnostoma (Loew)
MaleFemale
Solid black sternite Yellow “V” sternite
Photo: D. RobertsPhoto: D. Roberts
© The Author(s) 2018
Adults feed on exudates from large oviposition marks; some eggs laid
Phytomyza gymnostoma (Loew)
Photo: R. Donoval
Photo: T. Rusinek
Photo: E. Grundberg
Phytomyza gymnostoma (Loew)
Pupa3-4 mm
Larva (8 mm)
Photo: S. Spichiger
Photo: R. Donoval
Phylogeny of leaf-
mining flies:
(Diptera:
Agromyzidae)
Scheffer et al. (2007). Mol. Phylo. & Evol. 42(3): 756-775.
Phytomyzinae splits with Agromyzinae
Winkler et al. (2009). Systematic Entomology. 34, 260–292
Molecular phylogeny
of Phytomyza
*P. gymnostoma is the only Phytomyza spp. that utilizes Alliaceae
*
Common name Allium species Damage documented
Wild Onion Allium canadense Yes
Nodding Onion Allium cernuum Yes
Onion Allium cepa Yes
Scallion Allium fistulosum Yes
Giant Onion Allium gygantheum Yes
Field garlic Allium oleraceum -
Mediterranean Onion Allium paniculatum -
Leek Allium porrum Yes
Garlic Allium sativum Yes
Chive Allium schoenoparasum Yes
Round-headed leek Allium sphaerocephalon -
Ramps Allium tricoccum -
Garlic chives Allium tuberosum Yes
Wild garlic Allium vineale Yes
P. gymnostoma feeding damage detected
on following Allium spp.
Barringer et al. 2018. J. of Integ. Pest Mang. 9(1): 8.
Survey of P. gymnostoma detected in
Allium crops in NY in 2017
CropFarms
(n)
% plants
w/ marks
Avg. no.
marks/
plant
Avg. no.
larvae/
plant
Avg. no.
pupae/
plant
% plants
w/ active
mines
onion 3 16 13 0 0 0.3
scallion 11 28 16 0.06 0 0.4
leek 13 20 21 1.04 1.0 4.9
chive 6 24 15 0 0 0.2
Damage by Phytomyza gymnostoma
Twisting onion leavesLarval mining and bacterial rot in leek
Photo: R. Donoval
Photo: T. Rusinek
This type of damage does not occur with other leafminers Some onion and leek fields lost
Photo: E. Grundberg© The Author(s) 2018
Damage by Phytomyza gymnostoma
Oviposition marks cause cosmetic injury to scallions and chives
Biology of Phytomyza gymnostoma
© The Author(s) 2018
Adults live for up to two weeks; avg. 9 d in lab
Ovipositon marks peak 3 d after eclosion
Percentage of pupae to oviposition marks ~4%
Larvae (4 instars) feed within leaves and move toward
plant base to pupate or in surrounding soil
One generation is completed in 73 days @ 20° C
Two generations per year
Jan. Feb. March Apr. May June July Aug. Sept. Oct. Nov. Dec.
Summer
Pupae
Overwintering
Pupae
Adults Adults
Eggs & larvae Eggs
&
larvae
Spring Generation Fall Generation
Adapted from Shelby Fleischer, Penn State
Phenology of P. gymnostoma in U.S.
Adults
Eggs & larvae
Overwintering
Pupae
Overwintering
Pupae
Adults
Jan. Feb. March Apr. May June July Aug. Sept. Oct. Nov. Dec.
Spring Generation Fall Generation
Scallions and wild Allium spp.
transplanted onion
leek
seeded onion
Periods when Allium foliage is present
Jan. Feb. March Apr. May June July Aug. Sept. Oct. Nov. Dec.
leek
seeded onion
Periods when Allium foliage is available for ovipositing
Scallions and wild Allium spp.
transplanted onion
Fall GenerationSpring Generation
Detection of P. gymnostoma
Sticky cards are commonly used to monitor
leafminer adult activity, but this has been
largely ineffective for this P. gymnostoma
Photo: B. NaultPhoto: B. Nault
Detection of P. gymnostoma
Scout for oviposition marks on foliage
Flies and marks on foliage often
concentrated along field edges
Photo: B. Nault
Photo: B. NaultPhoto: B. Nault
Photo: B. Nault
Plant Resistance Chemical Control
Cultural Control Biological Control
Management possibilities for P. gymnostoma
on Allium crops
Plant Resistance Chemical Control
Cultural Control Biological Control
None known
ParasitoidsRow covers, delayed
planting, crop rotation, trap cropping?
Attract & kill?
Insecticides
Management possibilities for P. gymnostoma
on Allium crops
Summary
P. gymnostoma is expanding its range and/or
better documentation of its presence
Crops most vulnerable include scallions, leek
and transplanted onion
Monitoring approaches reliant on visual
inspection
Future Research
Develop a degree-day model that can help predict emergence and longevity of populations
Identify host plant preferences
Describe infestation patterns in fields
Monitor for parasitism
Evaluate efficacy of conventional and OMRI-listed products applied via foliar and drip systems
Identify how insecticides are managing this pest
Acknowledgements
Photo: Andre Megroz
Cornell UniversityMolly CappielloRiley HardingSouleymane Ouattara
GrowerMark Rogowski S&SO Produce
FundingNYS Ag and Markets