ABSTRACT
Vernonia calvoana is a culture spread across the world and prized for its culinary and medicinal virtues. The data was collected in Yaoundé, Central Cameroon region through manual harvesting at two stations from 2017 to 2019. A total of 168 species or morphospecies belonging to 47 families and 12 orders from two phyla were collected. The most abundant phylum was Arthropoda which represented 99.96% of the total number of all species, while Mollusca represented the rest. Within arthropoda, insecta class was found the most dominant. In Insecta, Formicidae and Aphididae were the most frequent families. At Nkolbisson, Hymenoptera and Hemiptera are more abundant on the purple variety than on the white variety. However, both are less abundant compared to those at Nlong-mvolye. The species Uroleucon compositae (37.01%), Hilda cameroonensis (4.67%) and Sphaerocoris annulus (2.71%) were the most abundant species recorded in all the three variants. Depending on the preference with the host plant, some orders have a distribution according to the site, but also, the variety.
Key words: Manual harvest, insecta, hymenoptera, hemiptera, Nkolbisson, Nlong-mvolye.
Recent demographic studies predict that by 2050, the human population could reach a total of 9.7 billion people (Godfray et al., 2010). In addition, research suggests that such an increase in population would also be accompanied by various modifications of our planet such as the reduction of arable land characteristic of urban development, or, the increase of problems related to climate change such as food insecurity and health crises (Godfray et al., 2010; Pison, 2011).
Despite efforts to find alternative and sustainable solutions such as the implementation of increased global production and better management related to agricultural losses, the development of these strategies is slowed down by various challenges on a global or local scale. For example, many species of invertebrates are pests and vectors of diseases that hinder the development of sustainable agriculture (Liu and Sparks, 2001; Geering and Randles, 2012). This is especially in the countries of subtropical Africa. Invertebrates constitute about 80% of animal biomass. The most cited in the literature that causes the most crop damage are: Hemiptera, Orthoptera, Coleoptera and Lepidoptera.
The Asteraceae is one of the four most diverse families with over 1,500 genera and 23,000 species (Ehab, 2001). They are distributed throughout the world. Within the Asteraceae, the genus Vernonia is the most diverse with 1000 listed species (Keeley and Jones, 1979). Species of the genera Vernonia are prized either for their culinary or medicinal virtues. Its consumption is based on the belief that the plant is use in the management and cure of heart diseases, blindness, diabetes, malaria, stomach ache, as an anti-helminthic agent, and to prevent constipation. Preliminary pharmacological studies carried out on experimental models have validated the hypoglycemic and hypolipidemic (Iwara et al., 2015), antioxidant (Egbung et al., 2016; Iwara et al., 2017), antimicrobial (Ati et al., 2016), cardio-protective (Egbung et al., 2017), and anti-cancer properties of V. calvoana (Mbemi et al., 2020). In Cameroon, Vernonia amygdalina, Vernonia colorata and Vernonia calvoana are united under the name ‘ndolè’. According to Kahane et al. (2005), ‘ndolè’ is the sixth Cameroonian dish. In Cameroon V. amygdalina and V. calvoana are the most common species. Moreover, V. amygdalina can be substituted by V. calvoana (Grubben and Denton, 2004). Many studies have already focused on V. amygdalina while V. calvoana has been the subject of few studies. In order to contribute to integrated pest management, knowledge of the different groups of invertebrates associated with the culture of V. calvoana is necessary. This present work aims to determine the diversity of the invertebrate fauna associated with the culture of V. calvoana in the city of Yaoundé.
Study site
The study was conducted from August 2017 to April 2019 in two districts of the city of Yaoundé (Department of Mfoundi) (Figure 1). The city of Yaoundé is influenced by a Guinean-type equatorial climate with four seasons: a large dry season (from mid-November to mid-March); a small rainy season (from mid-March to the end of June); a small dry season (July to August); and a large rainy season (September to mid-November). Precipitation is in the range of 1400 to 1900 mm per year and temperatures vary from 18 to 35°C (Suchel, 1988).
Plant material
The plant material consists of the white and purple varieties of V. calvoana calvoana quite common in the Central region.
Experimental design
At the main station located in the Nkolbisson district, on an area of ??530 m2, three complete randomized blocks made up of eight experimental units of square shape and 16 m2 of surface each, spaced 0.8 m. Each experimental unit had five rows of 5 plants spaced 0.80 m each. At the peripheral station in Nlong-mvolye, on a surface of 412 m2, we placed plants of V. calvoana calvoana white variety in association with Abelmoschus esculentus, V. amygdalina, Solanum modiflorum, Amaranthus hybridus, Phaseolus vulgaris, and Talinum fruticosum.
The main station included the white (12 plots) and purple (12 plots) varieties of V. calvoana calvoana while the peripheral station only contains the white variety. The invertebrates were collected from August 2017 to September 2018 in Nkolbisson and from March 2018 to April 2019 in Nlong-mvolye.
Sampling method
Hand collection was the sampling technique used to collect invertebrate species to occur in each location. Two persons used either forceps or aspirator to collect species on aerial organs (leaf and stems) of plant for 5 min. Collections from V. calvoana calvoana plants were weekly, five plants randomly selected by plots. A total of 120 plants were sampled in Nkolbisson and 60 plants in Nlong-mvolye.
The collected invertebrates were stored in tubes containing 70% alcohol and identified using the appropriate dichotomous keys. The correct specimens were deposited in the reference collection in the Zoology Laboratory of the University of Yaoundé 1.
Data analysis
After identification, cumulative and relative abundances of invertebrates hosted by each plant species/varieties were computed. For further analysis, taxa (orders, the families and the species) with ≥ 5%; 5% < relative abundance ≥ 1% were considered dominant and less abundant, respectively. While those with abundance < 1%, were considered scarce during the study. We used the Excel software for the frequency calculation and the Past 3.12 software to generate the diversity indexes.
Diversity associated with V. calvoana calvoana
A total of 168 species of invertebrates belonging to two phyla, 12 orders and 47 families identified from 13,929 individuals were collected. The phylum of Arthropoda is more diverse (11 orders, 47 families and 167 species) and abundant (13,925 individuals or 99.96% of individuals collected) than the phylum of Mollusca (one order, one family and one species). The arthropods were grouped into 03 classes: the Arachnida (with an order, 6 families and 18 species), the Diplopoda (with an order, a family and a species), and the Insecta (with 9 orders 40 families and 149 species).
Diversity at the ordinal level
Among these invertebrates, four orders of insects are the most abundant in terms of specific richness (that is 99.25% of the total number of individuals collected). These orders include the Hymenoptera (3 families and 18 species), 6850 individuals or 49.32% of the individuals collected; Hemiptera (13 families and 41 species) 6,388 individuals, that is, 45.72% of the individuals collected; Coleoptera (7 families and 44 species) 401 individuals or 2.88% of individuals collected; and Orthoptera (8 families and 13 species) 185 individuals or 1.33% of individuals collected (Table 1).
Diversity at the family level of the most abundant orders
Without taking into account the location and the variety, 47 families were identified on V. calvoana calvoana, only two families belonging to Insecta have a frequency ≥ 5% (Table 2). This community is dominated by the Formicidae (49.31%) and Aphididae (37.01%) families. Also, four families, namely, Tettigometridae (4.67%), Pentatomidae (2.79%), Coccinellidae (2.07%), and Pyrgomorphidae (1.03%) were numerically significant with an abundance ≥ 1 (Table 2). The purple variety was the most diverse (Table 3). The activities of the species of these families contribute to weakening the growth and the yield of the plant.
Diversity at a specific level
The Hemiptera are the most diverse with 13 families and 41 species. The most abundant species are Uroleucon compositae (Theobalt, 1915), Hilda cameroonensis (Tamesse and Dogmo, 2016) and Sphaerocoris annulus (Fabricius, 1775) (Table 4).
U. compositae and H. cameroonensis have a regular distribution regardless of site and variety, while S. annulus seems to have a preference for the white variety in Nkolbisson (Table 4).
The order Hymenoptera is represented by three families and 18 species. The most abundant species are Pheidole megacephala (Fabricius, 1793), Diplomorium longipenne (Mayr, 1901), Camponotus acvapimensis (Mayr, 1862), Myrmicaria opaciventris (Emery, 1893), and Tetramorium acculeatum (Mayr, 1866) (Table 4).
The order Coleoptera is represented by seven families and 44 species, with the most abundant species being Coccinellidae species. The latter is being better represented in Nkolbisson regardless of the variety (Table 4).
The order Orthoptera is represented by eight families and 13 species, with the most abundant species being Zonocerus variegatus (Linnaeus, 1758) (Table 4). Z. variegatus is only distributed in Nkolbisson regardless of the variety (Table 4).
The present study showed that 168 species of invertebrates belonging to two phyla, 12 orders and 47 families were associated to V. calvoana calvoana. Our results are more diverse than the 31 families and 92 species obtained on Carthamus tinctorius (Asteraceae) by Saeidi et al. (2015) in Iran as well as the 30 and 36 families obtained, respectively on both Tithonia rotundifolia and Tithonia diversifolia Asteraceae by Donatti-Ricalde et al. (2018) in Brazil. This difference could be due to on one hand a much longer sampling period than theirs and to the other hand, the geographical variation of the sites. In addition, our results are less diverse than the 20 orders, 117 families and 412 species collected by Kakam et al. (2020) on 11 varieties of seven species of Curcubitaceae, in Minko’o in the South Cameroon region. This difference could be due to on one hand the number of varieties and species greater than that of our study. On the other hand, it could also be due to the fact that Curcubitaceae seems to attract more species than Asteraceae. The work also reveals the presence of Insecta, other classes like Diplopoda (Odontopygidae) and Gasteropoda.
The present results corroborate with those of Selim (1978) in Iraq and Campobasso et al. (1999) in India on C. tinctorius with regard to the dominance of Insecta over other invertebrate classes. This result would be because Insecta are the most abundant and diverse clade of the Invertebrate clade (Basset et al., 2012). In addition, the present results are different from theirs when it comes to composition. Indeed, their results revealed the dominance of Coleoptera, Diptera, Hemiptera, Lepidoptera and Thysanoptera as the most abundant orders. This difference could be due to climatic variations and the number of sampling methods but also the area of ??the fields. Indeed, Saeidi et al. (2015) used three sampling methods: sweep netting, yellow sticky trap, and pitfall trap. Also, the size of the farms was about 1000 m2 in the present work against 6000 m2. The present study does not reveal the presence of Thysanoptera.
This difference would be due to the mode of organization of Formicidae and Aphididae which live in colony on one hand and their great reproductive capacity on the other hand.
U. compositae has been reported as a pest of C. tinctorius. Ishaq et al. (2004) specified which is at the origin of crop losses ranging from 35 to 72%. In Cameroon, this is the first time that it has been reported on V. calvoana calvoana. H. cameroonensis was listed by Tamesse and Dogmo (2016) as a pest of V. amygdalina (Asteraceae). It is being reported for the first time on V. calvoana calvoana. Z. variegatus, polyphagous, which can develop on V. amygdalina is also reported on V. calvoana calvoana.
The present study shows that the invertebrate fauna of V. calvoana calvoana is diverse. It is grouped into 12 orders, 47 families and 168 species. The phytophagous species are concentrated in the order Hemiptera. The most abundant species are U. compositae, H. cameroonensis and S. annulus. There is little variation in diversity between varieties and sites.
For future work, the nature of the damage related to the invertebrate fauna present on V. calvoana calvoana will be investigated.
The authors have not declared any conflict of interests.
The authors thank NWATCHOK à ABOUEM Francis Honoré for the help with data input and advice on statistical analysis and MBENOUN MASSE Paul Serge for advice and review of an early draft of this paper.
REFERENCES
|
Ati BU, Iwara IA, Bassey AO, Igile GO, Duke EE, Ebong PE (2016). Antimicrobial Activity of Leaf Extract - Fractions of Vernonia calvoana against Selected Stock Cultures in Microbiology Laboratory , Cross River University of Technology , Calabar. International Journal of Current Microbiology and Applied Sciences 5(5): 512-520.
Crossref
|
|
|
|
Basset Y, Cizek L, Cuenoud P, Didham KR, Guilhaumon F (2012). Arthropod diversity in a tropical forest. Science 338:1481-1484.
Crossref
|
|
|
|
|
Campobasso G, Colonelli E, Knutson E, Terragitti L, Cristofaro M (1999). Wild plants and their cited insects in the region, primarily Europe and the Middle East. USDA-ARS 147:429.
Crossref
|
|
|
|
|
Donatti-Ricalde GM, Soussa WB, Ricalde MP, Silva AC, Abboud ACS (2018). Potencial atrativo de Tithonia diversifolia (Hemsl) A. Gray e Tithonia rotundifolia (Mill) S. F. Blake (Asteraceae) para utilização em controle biológico conservativo. Cadernos de Agroecologia 13(1).
|
|
|
|
|
Egbung EG, Atangwho IJ, Odey OD, Ndiodimma NV (2017). The Lipid Lowering and Cardioprotective Effects of Vernonia calvoana Ethanol Extract in Acetaminophen-Treated Rats. Medicines 4(90).
Crossref
|
|
|
|
|
Egbung GE, Atangwho IJ, Kiasira ZB, Iwara IA, Igile GO (2016). Antioxidant activity of the inflorescents of Vernonia calvoana growing in Yakurr Local Government Area of Cross River State, Nigeria. Global Journal of Pure and Applied Sciences 22:141-146. .
Crossref
|
|
|
|
|
Ehab A (2001). Chromosome counts and karyological studies on six taxa of the Egyptian Asteraceae. Compositae Newsletter 36: 81-92.
|
|
|
|
|
Geering ADW, Randles JW (2012). Virus Diseases of Tropical Crops. eLS:1-15.
Crossref
|
|
|
|
|
Godfray H, Beddington J, Crute I, Haddad L, Lawrence D, Muir JF, Pretty J, Robinson S, Thomas S, Toulmin C (2010). Food Security?: The Challenge of Feeding 9 Billion People. Science 327(February):812-818.
Crossref
|
|
|
|
|
Grubben GJH, Denton OA (2004). Plant resources of tropical Africa. 2nd Edition. 737 p. Backhuys Publishers, Wageningen, Pays-Bas.
|
|
|
|
|
Ishaq M, Usman M, Asif M, Khan IA (2004). Integrated pest management of mango against mealy bug and fruit fly. International Journal of Agriculture and Biology 63:452-455.
|
|
|
|
|
Iwara IA, Igile GO, Uboh FE, Eyong EU, Ebong PE (2015). Hypoglycemic and Hypolipidemic Potentials of Extract of Vernonia calvoana on Alloxan-Induced Diabetic Albino Wistar Rats. European Journal of Medicinal Plants 8(2):78-85.
Crossref
|
|
|
|
|
Iwara IA, Igile GO, Uboh FE, Elot KN, Mbeh UE (2017). Biochemical and antioxidants activity of crude , methanol and n-hexane fractions of Vernonia calvoana on streptozotocin induced diabetic rats. Journal of Pharmacognosy and Phytotherapy 9(3):24-34.
Crossref
|
|
|
|
|
Kahane R, Temple L, Brat P, De Bon H (2005). Leafy Vegetables From Tropical Countries: Diversity. Economic Wealth and Health Value In A Very Fragile Context pp. 1-9.
|
|
|
|
|
Kakam S, Mokam Didi G, Alene CD, Tadu Z, Fomekong Lontchi J, Tchoudjin LG, Massussi Anselme J, Djieto-Lordon C (2020). Biological diversity of invertebrate fauna circulating in some Cucurbit-based market gardening agrosystems at Minko'o (South Region, Cameroon). International Journal of Agriculture, Environment and Bioresearch 5(4):106-115.
Crossref
|
|
|
|
|
Keeley SC, Jones SB (1979). Distribution of pollen types in Vernonia (Vernonieae: Compositae). Systematic Botany 4 p.
Crossref
|
|
|
|
|
Liu T, A Sparks (2001). Aphids on Cruciferous Crops: Identification and Management. AgriLife Extension pp. 1-12.
|
|
|
|
|
Mbemi AT, Sims JN, Yedjou CG, Noubissi FK, Gomez CR, Tchounwou PB (2020). Vernonia calvoana Shows Promise towards the Treatment of Ovarian Cancer. International Journal of Molecular Sciences 21(4429).
Crossref
|
|
|
|
|
Pison G (2011). Sept milliards d'êtres humains aujourd'hui, combien demain? Population and Sociétés, 482:1-4.
|
|
|
|
|
Saeidi K, Mirfakhraei S, Mehrkhou F, Valizadegan O (2015). Biodiversity of insects associated with safflower (Carthamus tinctorius) crop in Gachsaran, Iran. Journal of Entomological and Acarological Research 47(1):26.
Crossref
|
|
|
|
|
Selim AA (1978). Insect pests of safflower (Carthamus tinctorius) in Musol, northern Iraq. Journal of Agriculture 12:75-78.
|
|
|
|
|
Suchel JB (1988). Les Climats du Cameroun. Université de Saint-Etienne, Tome III, pp. 902-940.
|
|
|
|
|
Tamesse JL, Dogmo LF (2016). Description of Hilda cameroonensis sp.n. (Hemiptera Tettigometridae) new species of Hildinae associated with Vernonia amygdalina Delile (Asteraceae) from Cameroon. Journal of Biodiversity and Environmental Sciences 9(2):156-164.
|
|
