Leek Moth Research Update2012-2015

Masanori SetoCornell University / New York State Agricultural Experiment Station

Allium School 2015Sept 14 & 15, 2015

Where are they?

LM distribution in North America

Plattsburgh, NYFirst detection

•1993 in Canada

•2009 in USA

What do they eat?

LM injury to leaves

(A) “Windowpane” damage (arrows) on onion; (B) Damage on leek; (C) Damage on garlic scape (arrow); (D) A damaged row of leeks

LM injury to leaves

(A) “Windowpane” damage (arrows) on onion; (B) Damage on leek; (C) Damage on garlic scape (arrow); (D) A damaged row of leeks

LM injury to bulbs

(A) Insect frass (arrow) indicates the entry of LM into onion bulb; (B) LM pupa (arrow) under the dry outer protective skin of onion bulb; (C) Insect frass (arrows) indicates the entries of LM into garlic bulbs.

Which Allium do they like?

How can we catch?

LM population monitoring

Pheromone trap with sticky card (three times a week)

Can we predict their emergence?

• Life-cycle model

After emergence it takes 4 days for adults to be ready for mating.

It takes about 3 days for oviposition (egg-laying)

LM complete their life cycle (egg to adult) for 443.85 degree-days

Life-cycle model to predict LM population

We can expect next generation emerges In 7 days + 443.85 degree-days

Num

ber o

f adu

lt m

ales

per

trap

/ Num

ber o

f lar

vae

per p

lant

Date

1st flight 3rd flight

2nd flight(B)7days + 443.85 ˚D apart

LM population fluctuation during growing season

How can I control?

Cultural control

Cultural control - Row cover

•Timing

•Affects yield

•Weeding

Biological control

Nematodes

• Steinernema feltiae is effective when used on leek.

• Not effective/reliable for onions.

• Plant architecture is the key.

S. feltiae

Diadromus pulchelus release in Canada

• D. pulchelus establishes and overwinters

• Parasitism rate ranges 10~20% in garlic fields

• Better control is expected as the population size grows.

Chemical control

Chemical control ~ Preventive control

(Olmstead & Shelton 2013)

Insecticide Labelrate/haa

2 DAT 4 DAT 8DAT

% mortality(± SE)b

% mortality(± SE)b

% mortality(± SE)b

lambda-cyhalothrin (Warrior® II) 0.140 L 96.3 ± 3.7 a 81.0 ± 9.9 a 66.7 ± 5.4 b

spinetoram (Radiant® SC) 0.730 L 92.6 ± 4.9 a 95.2 ± 4.8 a 91.7 ± 5.4 a

methomyl (Lannate® LV) 3.505 L 81.5 ± 8.1 ab 85.7 ± 6.7 a 83.4 ± 8.9 ab

chlorantraniliprole (Coragen®) 0.365 L 77.8 ± 7.8 ab 90.5 ± 6.1 a 91.7 ± 5.4 a

spinosad (Entrust®) 0.140 Kg 66.7 ± 7.8 b 71.4 ± 15.3 a 70.9 ± 9.8 ab

Bt aizawai (Agree® WG) 2.243 Kg 14.8 ± 8.1 c 9.5 ± 6.2 b 16.7 ± 6.3 c

azadirachitin (Neemix® 4.5) 0.511 L 11.1 ± 5.6 c 14.3 ± 6.7 b 12.5 ± 8.8 c

Bt kurstaki (Dipel® DF) 1.121 Kg 11.1 ± 5.6 c 14.3 ± 9.9 b 12.5 ± 6.1 c

untreated check - 14.8 ± 8.1 c 19.1 ± 9.9 b 16.7 ± 12.6 c

Chemical control ~ Curative control

How to combine LM and onion thrips managements

How to combine LM and onion thrips managements

One additional spray

Conclusion

• LM activity can be predicted by pheromone trap.

• Various effective control methods are available for different agricultural scenarios.

• More control options for organic farmers need to be explored.

Research support:Michael Bolton

Jordi Llorens CalverasAlyssa CollinsDevan GeorgeYanyan Guo

Tim Harvey-SamuelPaul Hetzler

Amy Ivy

Xiaowei LiDaniel OlmsteadLindsey Pashaw

Ensi ShaoJinda Wang

&Master gardeners

Acknowledgment

Special thanks to:Bittersweet Farm

Cross Island Farms

Kent Family GrowersRehoboth Homestead

Pest Management Alternatives Program Grant2013‐34381‐21310