Journal of Pest Science (2018) 91:1165–1179
An assessment oftherisk ofBt‑cowpea tonon‑target organisms
MalickN.Ba1· JosephE.Huesing2· ManueleTamò3· ThomasJ.V.Higgins4· BarryR.Pittendrigh5· LarryL.Murdock6
Received: 21 April 2017 / Revised: 15 March 2018 / Accepted: 16 March 2018 / Published online: 10 April 2018
© Springer-Verlag GmbH Germany, part of Springer Nature 2018
Cowpea (Vigna unguiculata Walp.) is the most economically important legume crop in arid regions of sub-Saharan Africa.
Cowpea is grown primarily by subsistence farmers who consume the leaves, pods and grain on farm or sell grain in local
markets. Processed cowpea foods such as akara (a deep-fat fried fritter) are popular in the rapidly expanding urban areas.
Demand far exceeds production due, in part, to a variety of insect pests including, in particular, the lepidopteran legume pod
borer (LPB) Maruca vitrata. Genetically engineered Bt-cowpea, based on cry1Ab (Event 709) and cry2Ab transgenes, is
being developed for use in sub-Saharan Africa to address losses from the LBP. Before environmental release of transgenic
cowpeas, the Bt Cry proteins they express need to be assessed for potential eﬀects on non-target organisms, particularly
arthropods. Presented here is an assessment of the potential eﬀects of those Cry proteins expressed in cowpea for control
of LPB. Based on the history of safe use of Bt proteins, as well as the fauna associated with cultivated and wild cowpea in
sub-Saharan Africa results indicate negligible eﬀects on non-target organisms.
Keywords Cowpea· Maruca vitrata· Bt-cowpea· Non-target organisms· West Africa· Environmental risk· Assessment·
• Data on the environmental safety of Bacillus thuringien-
sis (Bt) Cry proteins, especially toward non-target arthro-
pods, are available for many genetically modiﬁed crops
but not in the contest of cowpea.
• Before environmental release of Bt-cowpea for control of
the legume pod borer, a major insect pest attacking cow-
pea, the potential eﬀects on non-target organisms (NTO),
particularly arthropods, need to be assessed.
• An assessment of the Bt Cry proteins, their history of safe
use, as well as the fauna associated with cultivated and
wild cowpea in sub-Saharan Africa indicates negligible
eﬀects on non-target organisms.
Cowpea (Vigna unguiculata Walp.) is the most economically
important legume crop in West Africa (Langyintuo etal.
2003). Nigeria, Niger and nations surrounding these two
countries are the most productive cowpea lands globally,
Communicated by N. Desneux.
* Barry R. Pittendrigh
1 International Crops Research Institute fortheSemi-Arid
Tropics, Niamey, Niger
2 United States Agency forInternational Development
(USAID), Washington, DC, USA
3 International Institute ofTropical Agriculture, Cotonou,
4 Commonwealth Scientiﬁc andIndustrial Research
Organisation (CSIRO), Agriculture andFood, Canberra,
5 Department ofEntomology, Michigan State University,
EastLansing, MI, USA
6 Department ofEntomology, Purdue University,
WestLafayette, IN, USA