We work with different aphid lines and to prevent aphids contamination or damages of aphids to not infested plants, we use pierced transparent plastic bags sealed around the plant's plastic pot using an elastic.

Dear Qi Liu 

It is preferable to follow the source of the insect (infestation), because Aphid will always search plant sourcefor feeding, preferably check the placement of nets on the ports and windows and ventilation outlets to prevent the entry of all types of insects can be put several types of traps, including small containers containing water and sugar with a small amount of liquid soap distributed in The perimeter and entrances of the plant growth rooms to attract the winged individuals.

Regards

Prof. Houda Kawas

Unforturnally, I have not seen any real effective method in controlling aphids in greenhouse except spreading chemicals/insecticide by far. During several years working at a USDA ARS facility, I have seen that the greenhouse rooms (dedicate to either Arabidopsis or tobacco) were spread periodically with chemicals to control aphids and other insects. And we have to follow all the directions to go in and out the rooms after they were spread.

Dear Yuan-Yeu Yau

You are right, but what do we do when we need plants that are not affected by the different chemicals, to use the plants in the experiments of infection by different insects such as whitefly and others, or even to test some insecticide effects, it is useful to set up traps, the insecticides must be not directed spray to the plants and protect the growing rooms well by double doors and nets..

Best regards

Houda

Dear Houda Kawas,

Thanks for your response. Yes, I agree with you. Methods which can completely control the insect other than using chemicals or herbicide application will be ideal. However, those 'greener' methods might only be able to control some population of the aphids, and usually not all of it. Once a small portion of the aphids reach the plants, they can live on and spread on the plants like wild fire. I have seen some tobacco leaves with hundreds (or even more) of them. Like the picture attached.

That is a good question--how would one perform insecticide effects experiments? I am not sure. Probably the researchers have to device a new strategy to perform their experiments.

This is a link about how the info of Aphids and how to control them: There are some products mentioned in the page. https://www.planetnatural.com/pest-problem-solver/lawn-pests/aphid-control/

These are some suggestions from the link:

• Pinch or prune off heavily infested leaves or other plant parts.
• Use the Bug Blaster to hose off plants with a strong stream of water and reduce pest numbers.
• Commercially available beneficial insects, such as ladybugs and lacewing are important natural predators. For best results, make releases when pest levels are low to medium. If populations are high, use a least-toxic, short-lived natural pesticide to establish control, then release predatory insects to maintain control.
• Apply food-grade Diatomaceous Earth for long-lasting protection. Made up of tiny fossilized aquatic organisms, that look like broken glass under the microscope, DE kills by scoring an insect’s outer layer as it crawls over the fine powder. Contains NO toxic poisons!
• Safer® Soap will work fast on heavy infestations. A short-lived natural pesticide, it works by damaging the outer layer of soft-bodied insect pests, causing dehydration and death within hours. Apply 2.5 oz/ gallon of water when insects are present, repeat every 7-10 day as needed.
• Horticultural oils should be applied early in the season or late in the fall to destroy overwintering eggs.
• Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
• Do not over water or over fertilize – aphids like plants with high nitrogen levels and soft new growth. Use organic fertilizers which release nutrients slowly.

For cotrolling aphids you have to use organophosphorus insecticides in the form of spray such as  Rogor or. Dichorovous. You can use neo-nicotinoids imidacloprid, thiacloprid . Pyrethroids like cypermethrin, permethrin, Deltamethrin can be used in a suitable concentrations in ppm.(250 to 500 ppm)dependig upon attack of aphids.

Dear Yuan-Yeu Yau:

Thanks for your answer. We have tried to kill aphids by use of imidacloprid and other chemical insecticide, but it's useless. On one hand, because aphids have high reproducibility, if there is only one aphids survived, hundreds of thousands of aphids will appear in a very short period. on the other hand, after we spray insecticide over plants, the plants may be stressed. The leaves are purpling and not normal. If your insecticide is useful, would you mind providing some detailed information about your insecticide?

Best wishes!

Dear Navaraj Upadhyaya:

Thanks! If I use beetles to biological prevention the aphids, will the beetles damage the plants? Have you tried this methods?

Maybe you can try "护花神"

Hi  Qi Liu,

Sorry for the late response.

I don't know the recipe of the insecticide they used because the whole Greenhouse complex was in charged by a manager. He took care of spreading the insecticide for our institute. But the spreading results were obviously very good. I have not seen any aphid outbreak in the Arabidopsis or tobacco rooms during the time I was there. I will try to find out their emails for you. You can contact them for possible ingredients of the insecticide.

By the way, from my experience on tobacco, I don't really think that using beetles is going to work because aphids are just spread too horribly fast.

Hi Qi

Several references on attachment 1

http://www.springer.com/cda/content/document/cda_downloaddocument/9781588293954-c2.pdf?SGWID=0-0-45-383624-p173728767

2

https://www.towergarden.com/blog.read.html/en/2016/9/aphids-indoor-plants.html

3

https://www.almanac.com/pest/aphids

4

https://www.thespruce.com/control-aphids-on-houseplants-1902889

5

http://www.canna-uk.com/aphids_in_detail

6

https://www.maximumyield.com/how-to-detect-and-treat-an-aphid-infestation-of-your-plants/2/2765

7

http://www.sandiegouniontribune.com/sdut-water-is-best-treatment-for-insects-on-citrus-2010nov12-story.html

8

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2259086/

9

https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html

10

https://www.todayshomeowner.com/how-to-control-aphids-in-your-garden/

11

https://cactiguide.com/cactipests/

12

https://www.alchimiaweb.com/blogen/combat-aphids-marijuana-plants/

13

https://www.aos.org/orchids/orchid-pests-diseases/home-remedies.aspx

14

http://www.just4growers.com/stream/pests-and-diseases/all-about-spider-mites.aspx

15

https://abrc.osu.edu/seed-handling

16

https://books.google.com/books?isbn=1601078420

17

https://www.royalqueenseeds.com/blog-how-to-spot-treat-and-prevent-aphids-on-cannabis-plants-n499

18

http://www.clemson.edu/extension/hgic/pests/plant_pests/flowers/hgic2101.html

19

http://homeguides.sfgate.com/aphid-control-zucchini-pumpkins-31131.html