Establishment of in vitro soybean aphids, Aphis glycines (Hemiptera: Aphididae): a tool to facilitate studies of aphid symbionts, plant-insect interactions and insecticide efficacy.
BACKGROUND
Studies on plant-insect interactions of the soybean aphid, Aphis glycines (Matsumura), can be influenced by environmental fluctuations, status of the host plant and variability in microbial populations. Maintenance of aphids on in vitro-grown plants minimizes environmental fluctuations, provides uniform host materials and permits the selective elimination of aphid-associated microbes for more standardized controls in aphid research.


RESULTS
Aphids were reared on sterile, in vitro-grown soybean seedlings germinated on plant tissue culture media amended with a mixture of antimicrobials. For initiation and maintenance of in vitro aphid colonies, single aphids were inoculated onto single in vitro seedlings. After three rounds of transfer of 'clean' aphids to fresh in vitro seedlings, contamination was no longer observed, and aphids performed equally well when compared with those reared on detached leaves. The addition of the insecticides thiamethoxam and chlorantraniliprole to the culture medium confirmed uptake and caused significant mortality to the in vitro aphids. The use of the antimicrobial mixture removed the associated bacteria Arsenophonus but retained Buchnera and Wolbachia within the in vitro aphids.


CONCLUSIONS
The in vitro aphid system is a novel and highly useful tool to understand insecticidal efficacy and expand our knowledge of tritrophic interactions among plants, insects and symbionts. © 2016 Society of Chemical Industry.
Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA.
Andika
A
Gunadi
Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA.
Raman
R
Bansal
Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA.
John J
JJ
Finer
Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA.
Andy
A
Michel
D000818:Animals; D001042:Aphids / Q000187:drug effects / Q000382:microbiology / Q000502:physiology*; D020635:Buchnera; D004755:Enterobacteriaceae; D007306:Insecticides / Q000494:pharmacology*; D000073943:Neonicotinoids / Q000494:pharmacology; D009574:Nitro Compounds / Q000494:pharmacology; D010078:Oxazines / Q000494:pharmacology; D013025:Glycine max / Q000502:physiology*; D013559:Symbiosis; D000077922:Thiamethoxam; D013844:Thiazoles / Q000494:pharmacology; D020577:Wolbachia; D062367:ortho-Aminobenzoates / Q000494:pharmacology
D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010078:Oxazines; D013844:Thiazoles; D062367:ortho-Aminobenzoates; C517733:chlorantranilipole; D000077922:Thiamethoxam
Aphis glycines; antimicrobial; chlorantraniliprole; in vitro insect; symbiont; thiamethoxam