Field evaluation of the impact of Sahlbergella singularis Haglund infestations on the productivity of different Theobroma cacao L. genotypes in the Southern Cameroon
Mirids (Sahbergella singularis and/or Distantiella theobroma) are the major pests of cacao farms in Africa. Cocoa production losses due to these species have been widely documented in West Africa. However, their impact on cocoa production is unknown in Central Africa, especially in Cameroon. Moreover, no data are available on the threshold level of fruits tolerance to mirid attacks. For these reasons, we assessed the effect of S. singularis on the productivity of ten cacao genotypes as well as the threshold number of the lethal feeding punctures to fruits under a randomized experimental design. Observations were made on three categories of fruits (cherelle, immature and mature/ripe). A control trial was also set up per batch. The overall results showed that 68.0% and 0.4% of fruits aborted, respectively, in mirid and control trials. The percentages of aborted fruits were significantly (p < 5%) different between cacao genotypes and ranged from 20 to 100%. Bonferroni test revealed six homogenous groups for cacao genotypes susceptibility to mirid attacks; SNK52 proved to be most tolerant/resistant, whereas two genotypes (UPA138 and SNK67) revealed more sensitive. In contrast, six genotypes (SNK07, IMC60 × SNK417, T60/887 × PA7, T79/501 × SNK479, UPA143 × ICS84, UPA143 × NA33) displayed similar sensitivity to mirid attacks. ANOVA showed that the threshold tolerance of tested fruits, expressed by the mean numbers of lethal feeding punctures, to S. singularis attacks was comparable between cacao genotypes. This new quantitative database improves our knowledge on the (i) threshold tolerance of fruits to S. singularis attacks and (ii) economic impact of this pest on cocoa production in Cameroon.
KeywordsCacao genotypes Threshold tolerance Productivity Effect Infestations S. singularis
We thank the Institute of Agricultural Research for Development (IRAD)—Program of stimulating plants for providing financial via the investment public funds and logistic supports. Support from Audrey Valteri VOULA was especially valuable. We also thank the staff of IRAD, Nkoemvone, especially Damien EYENET and Irène NKOTTO for logistic and help for field data collections.
The manuscript has never been submitted to another journal for publication (partially or fully) in any other form or language. Our work was funded by the Agricultural Research Institute for Development (IRAD)—Through Stimulating Plants/Plant Protection using the National Public Investment Funds of Cameroon. In addition, our work presents no conflict of interests, both financially and scientifically.
Compliance with ethical standards
Conflict of interest
All authors agree that paper be published for the benefit of the scientific community and farmers and other stakeholders in the cocoa sector.
- Anikwe JC (2009) Evaluation of Field Damage and Chemical Control of Outbreak of Sahlbergella Singularis Haglund in a Cocoa Plantation in Ibadan, Nigeria. Am Eurasian J Sustain Agric 3:19–23Google Scholar
- Anikwe JC, Omoloye AA, Okelana FA (2010) The population dynamics of the brown cocoa mirid, Sahlbergella singularis Haglund in Ibadan, Nigeria. Afri J Food Agri Nutr Dev 10:2772–2783Google Scholar
- Babin R, Ten Hoopen M, Cilas C, Enjalric F, Yede, Gendre P, Lumaret JP (2010) The impact of shade on the spatial distribution of Sahlbergella singularis Hagl. (Hemiptera: Miridae) in traditional cocoa agroforests. Agric Forest Entomol 12:69–79. https://doi.org/10.1111/j.1461-9563.2009.00453.x CrossRefGoogle Scholar
- Bruneau de Miré P (1977) La dynamique des populations de Mirides et ses implications. In: Lavabre EM (ed) Les Mirides du Cacaoyer. Maisonneuve et Larose, Paris, pp 171–186Google Scholar
- Crowdy SH (1947) Observations on the pathogenicity of Calonectriarigidiuscula(Berk & Br.) Sacc. on Theobroma cacao L. Ann Appl Biol 34:45–59. https://doi.org/10.1111/j.1744-7348.1947.tb06342.x CrossRefGoogle Scholar
- Decazy B, Essono B (1979) Tests de contrôle d’infestation et traitements anti-mirides. Café Cacao Thé 23:35–42Google Scholar
- Entwistle PF (1972) Pests of cocoa. Longman Group Ltd, Harlow, p 779Google Scholar
- Idowu OL (1989) Control of economic Insect pests of cocoa. Progress in tree crop research, 2nd edn. CRIN, Ibadan, pp 152–165Google Scholar
- Lavabre EM (1970) Insectes nuisibles des cultures tropicales (cacaoyer, caféier, colatier, poivrier, théier). Edition G.P. Maisonneuve et Larose, Paris, p 276Google Scholar
- Lavabre EM (1977) Les mirides du cacaoyer. Edition G.P. Maisonneuve et Larose, Paris, p 366Google Scholar
- Lavabre EM, Decelle J, Debord P (1963) Etude de l’évolution régionale et saisonnière des populations de Mirides (Capsides) en Côte d’Ivoire. Café Cacao Thé 7:267–287Google Scholar
- Lotodé R (1969) Etude statistique de l’évolution d’une population de Mirides. Café Cacao Thé 13:216–220Google Scholar
- Mahob RJ, Ndoumbè-Nkeng M, Ten Hoopen GM, Dibog L, Nyassé S, Rutherford M, Mbenoun M, Babin R, Amang A, Mbang J, Yede, Bilong Bilong CF (2014) Pesticides use in cocoa sector in Cameroon: characterization of supply source, nature of actives ingredients, fashion and reasons for their utilization. Int J Biol Chem Sci 8:1976–1989. https://doi.org/10.4314/ijbcs.v8i5.3 CrossRefGoogle Scholar
- Mahob RJ, Baleba L, Yede Dibog L, Cilas C, Bilong Bilong CF, Babin R (2015) Spatial distribution of Sahlbergella singularis Hagl. (Hemiptera: Miridae) populations and their damage in unshaded young cacao-based agroforestry systems. Int J Plant Anim Environ Sci 5:121–131Google Scholar
- Mahob RJ, Nsoga Etam PB, Dibog L, Babin R, Voula AV, Begoude D, Fotso Toguem YG, Baleba L, Owona Ndongo PA, Bilong Bilong CF (2018) Assessment of the effect of cocoa mosquito mirid true bug, Helopeltis sp. (Hemiptera: Miridae) on the cocoa (Theobroma cocoa L.) production in Cameroon (Central Africa). Int J Biol Chem Sci 12:1865–1875. https://doi.org/10.4314/ijbcs.v12i4.27 CrossRefGoogle Scholar
- N’Guessan KF, Lachenaud Ph, Eskes AB (2010) Antixenosis as a mechanism of cocoa resistance to the cocoa mirid, Sahlbergella singularis (Hemiptera: Miridae). J Appl Biosci 36:2333–2339Google Scholar
- Nwana IE, Youdeowei A (1978) The spatial distribution of three species of heteroptera in a cocoa farm in Ibadan, Nigeria. Niger J Entomol 3:27–33Google Scholar
- Ojelade KTM, Anikwe JC, Idowu OL (2005) Comparative evaluation of the miridicidal efficacy of some insecticides for the control of the brown cocoa mirid, Sahlbergella singularis, in Nigeria. Appl Trop Agric 10:46–53Google Scholar
- Padi B (1997) Prospects for the control of cocoa capsids –alternatives to chemical control, pp. 28–36. In: Proceedings of the 1st international cocoa pests and diseases seminar. 6–10 November 1995, Accra, GhanaGoogle Scholar
- Padi B, Owusu GK (1998) Towards an integrated pest management for sustainable cocoa production in Ghana. In: Proceedings of the 1st sustainable Cocoa Workshop, Panama, pp 7–15Google Scholar
- Statistica 2011. StatisticaNeural Network Software (version 10.0). Inc.,Tulsa, Oklahoma: USAGoogle Scholar
- Varlet F, Berry D (1997) Réhabilitation de la protection phytosanitaire des cacaoyers et caféiers du Cameroun. Tome I : rapport principal. Cirad/Conseil interprofessionnel du cacao et du café. Douala, Cameroun, p 204Google Scholar
- Voula VA, Manga Essouma F, Messi Ambassa LM, Mahob RJ, Begoude BD (2018) Impact of mirids and fungal infestation on dieback of cocoa in Cameroon. J Entomol Zool Stud 6:240–245Google Scholar
- Wood GAR, Lass RA (eds) (1989) Cocoa: tropical agricultural series. Wiley, New York, pp 265–383Google Scholar
- Yede (2016) Diversité des peuplements des hémiptères dans les cacaoyères de la Région du Centre Cameroun: impact économique et essai de lute biologique. Thèse de Doctorat PhD, Université de Yaoundén I, Yaoundé, p 174Google Scholar