Try to email this company katzbiotech ([email protected]), they usually can provide Episyrphus balteatus pupae within a couple of days

Thank you so much Malin! Much appreciated!

Dear Sarah Gabel

It's depend on the aim of research you conduct.

 You may contact the researcher working on Episyrphus balteatus (mentioned in the attached articles).

E. balteatus is the most wide-spread species of Syrphidae,The larvae preying on a wide range of aphid species on trees, shrubs and herbs, including cereal crops and cabbages or Vicia faba (especially in gardens), appears to prefer aphid colonies low down. Adults are usually seen visiting flowers or basking on sunlit foliage. They are very frequent in gardens, parks and waste ground including those in urban areas, sometimes in considerable numbers

Usually, for collecting predators or any insect we only mention the idea to school teachers to address homework or small seminar on the benefit of it and the pictures of it to students to collect it from garden or fields nearby with or without you. Baiting, is another useful methods of attracting insects, placing decaying fruit or a honey drops or sugar syrup  in an open area in your garden will often attract several adults , also Geranium attract insect adults

Pls. find the attached files

http://www.sciencedirect.com/science/article/pii/S0167880999000511

http://orbi.ulg.ac.be/bitstream/2268/180993/1/Francis.Eur.J.Entomol.2005.pdf

https://www.jstage.jst.go.jp/article/aez/42/2/42_2_167/_article

https://www.jstage.jst.go.jp/article/aez/42/2/42_2_167/_article

https://www.researchgate.net/publication/249887764_An_artificial_diet_for_aphidophagous_syrphids_Episyrphus_balteatus_de_Geer_and_Eupeodes_bucculatus_Rondani_Diptera_Syrphidae_using_drone_honeybee_brood_powder

http://link.springer.com/article/10.1023/A:1020925030522

https://www.deepdyve.com/lp/elsevier/attraction-and-retention-of-episyrphus-balteatus-degeer-diptera-92qMqZTKZz

https://www.ncbi.nlm.nih.gov/pubmed/24498730

https://www.researchgate.net/profile/Francois_Verheggen/publication/227503348_Role_of_terpenes_from_aphidinfested_potato_on_searching_and_oviposition_behavior_of_Episyrphus_balteatus/links/09e4150a536f1432fc000000.pdf

https://www.sussex.ac.uk/webteam/gateway/file.php?name=goulson-and-wright-1998-beh-ecol.pdf&site=411

https://www.videoblocks.com/video/a-marmalade-hoverfly-episyrphus-balteatus-and-other-smaller-flies-collecting-pollen-from-a-flower-htivcjg/

Hoping this will be helpful

Regards

Prof. Houda Kawas

Article An artificial diet for aphidophagous syrphids, Episyrphus ba...

Article Role of terpenes from aphid-infested potato on searching and...

Also

I agree with the above. Try http://www.katzbiotech.de/. It is quite straightforward to maintain a colony but it is labour intensive. I have done it by rearing dwarf broad bean plants, planting new seeds every two weeks.  You can then innoculate a couple of young plants with e.g. pea aphids and place these plants in a small net cage. Allow the aphid colony to multiply a little then introduce some adult flies or puparia to the cage. Soon you will have eggs, larvae then puparia and adults on these plants. These plants will start to get tired after a couple of weeks so you continue the cycle by putting some aphids on to new young plants. It might be desirable to remove puparia and place them in a small flight cage together with some bee pollen and dilute organic honey on cotton wool. This culture will provide many adults, but if you do not require so many, it can be easier to just buy puparia as and when required.

Good luck!

Thank you Houda and Matthew! Very helpful! I got in touch with Katz Biotech and they are still supplying hoverflies, so I will be ordering from them. Thanks everyone!

You most welcome

Houda