Preliminary Data of Flyng Insects in Aquatic Ecosystem: Ngatsouéné and Yo in Djambala (Department of Plateaux, Congo Brazzaville)

Abstract

Insects represent an important taxon for the functioning of ecosystems. They also contribute to human and animal nutrition and are vector agents of several diseases. In Congo-Brazzaville the diversity of entomofauna is very little known. The present study aimed to investigate ponds. The inventory of insects was conducted in ponds Ngatsouéné and Yo, the first one was located in the center of Djambala and the last one was 2 km from the center of the city. The insects were caught with an entomological net from 23rd to 24th December 2012. The study identifies 37 species belonging to 17 families and 7 orders. This entomofauna study showed a high proportion of the Orthoptera order (27.20%). Family Mantidae has the largest species number (13.51%). Mantis sp is the most abundant species (13.51%). This is a database and therefore, should be extended to different aquatic ecosystems of the Department of Plateaux. The results obtained during this study will contribute to the development of a database for the management of entomofauna in Congo.

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Anthelme, T., Marcellin, M., Caelle, O.-O.D.B., Isabelle, M.-G.D. and Joseph, V. (2025) Preliminary Data of Flyng Insects in Aquatic Ecosystem: Ngatsouéné and Yo in Djambala (Department of Plateaux, Congo Brazzaville). Advances in Entomology, 13, 174-181. doi: 10.4236/ae.2025.131012.

1. Introduction

Insects represent the most important group because 4/5 of the animal species are currently known. However, the insects are the most well-known animal group on the planet. It is estimated that exist on earth over a million species of insects, while about 892,000 species have been described [1]. Insects are important in nature. They participate in the pollination of plants, humus soil formation, and material recycling. In the area of health, they are vectors of parasitic agents in humans and animals (trypanosomiasis, malaria, filariasis), and others spread foodborne pathogens. In agriculture, they cause havoc to crops. In food, insects are rich in protein, vitamins and minerals and are important sources of iron, and vitamin B [2]. Aquatic insects play an important role in the functioning of aquatic ecosystems [3].

Among aquatic ecosystems, the pond is a vital network for maintaining the metapopulation of many species and represents an essential medium for the preservation of protozoa, aquatic insects, mollusks, amphibians, fishes and aquatic reptiles [4]. In Congo Brazzaville, some fragmentary insect studies have focused particularly on terrestrial insects by various authors [5]-[10]. The study on aquatic insects was conducted on the macroinvertebrates of Djoumouna River [11]. Moreover, the implementation of important works during the accelerated municipalization in recent years in most departments of Congo Brazzaville will have many consequences on surrounding ecosystems. Indeed, major refurbishments in the country (construction of roads and bridges, airports, public buildings, stadiums) lead to the destruction of fauna and flora. The study of the entomofauna of two ponds (Ngatsouéné and Yo), located in the center of Djambala city in the Plateaux Department was completed. It aims to achieve the physicochemical study of water, inventory, and identification of insects.

2. Materials and Methods

2.1. Sampling Area

Identification of flying insects of aquatic plants was investigated in two ponds: Ngatsouéné and Yo. These ponds are located in the center of Djambala, at 02˚32'42.3" south latitude and 014˚45'6.59" E longitude. It shows two areas: a central area consisting of a grove and an exclusively savannah area in which the survey was conducted. Geographic references of: (location outskirts of center of Djambala, 02˚31'8.39'' South latitude and 014˚46'6.29'' East longitude). Both pools were separated by about 1 km (Figure 1), were characterized by the same vegetation, depth varies between 1m and 1.5 m.

2.2. Physico-Chemical Analysis of Surface Water

Physico-chemical parameters were measured using an apparatus multiparameter Hanna: the water temperature and the air temperature, the conductivity, the pH (potential of hydrogen), TDS (total dissolved solids). Insects were captured from 23 to 24 December 2012.

2.3. Capture Techniques and Species Identification

The flying insects located on the plants were collected by hand or using the entomological net. Captured insects were photographed and fixed in alcohol 70˚. These insects were identified using the keys proposed by different authors [12]-[15].

Figure 1. Location of the sampling area.

3. Results and Discussion

3.1. Physico-Chemical of Surface Water

The physico-chemical parameters of the water ranged between the two ponds. In the Yo pound, the pH was 6.1, the conductivity was equal to 29 μS/cm, TDS 14 ppm, the water temperature 28.23˚C and the air temperature 27.23˚C. Physico-chemical parameters values were measured in the Ngantsouéné indicate the following values: air temperature equal to 24.8˚C, water temperature equal to 24.9° C, a pH of 5.61, a conductivity of 18μS/cm, a TDS of 9ppm. The low conductivity of the water of Ngatsouéné and Yo indicates that these two ponds are poor in dissolved minerals. These results are similar to those found by [16] who found an acid pH (5.33) and a low conductivity (8.70 μS /m) in the Léfini River. By cons, in Nkéni River, they found almost the same value, an acidic pH (5.03) and low conductivity (8.68 μS/cm). Similar results were found in the Léfini River a pH of 5.6 and a conductivity of 7.9 [17]. The slight difference observed between pH, conductivity and turbidity values of the two ponds can be explained by the fact that in the Yo pond, is more frequented by populations who come from the fields and use soaps for cleaning their clothes and dishes.

3.2. Specific Composition of Insects Identified

The inventory of flying insects in two ponds Ngatsouéné and Yo, reported 37 species belonging to 17 families and 7 orders. The same species were found in both ponds; this implies that there is an interconnection between these two ponds. Each species is identified by its scientific name and common name in Téké language (Table 1). Some pictures of the insects collected are recorded in Figure 2.

Table 1. Specific composition.

Order

Family

Species

Name in Téké language

Odonata

Libellulidae

1-Orthetrum sp1

Momvimvi

2-Orthetrum sp

Mantoptera

Mantidae

3-Mantis sp1

Sonokoto

4-Mantis sp2

5-Mantis sp3

6-Mantis sp4

7-Mantis sp5

Orthoptera

Tetrigidae

8-Tetrix sp

Ampé

Acrididae

9-Schistocerca sp1

Ampé

10-Schistocerca sp2

11-Schistocerca sp3

12-Schistocerca sp4

Gryllidae

13-Gryllus sp1

Nzenze

14-Gryllus sp2

Pyrgomorphidae

15-Zonocerus variegatus

Ampé ntsoune

16-Zonocerus sp2

17-Zonocerus sp3

Diptera

Calliphoridae

18-Lucilia sp1

Nguingui

19-Lucilia sp2

Hymenoptera

Apidae

20-Apis sp1

Gnoun

21-Apis sp2

22-Melecta sp

Sphecidae

23-Sceliphron sp1

24-Sceliphron sp2

Formicidae

25-Formica sp1

Ingahien

26-Formica sp2

Megachilidae

27-Megachile sp

Coleoptera

Coccinellidae

28-Epilachna sp1

Ekoto ki manza

29-Epilachna sp2

30-Epilachna sp3

Lycidae

31-Calopteron sp1

32-Calopteron sp2

Meloïdae

33-Mylabris

Cerambycidae

34-Ceroplesis

Heteroptera

Coreidae

35-Amorbus sp

Ekoto

Pentatomidae

36-Biprorulus sp

Ekoto ki ntsoune ki manza

37-Gonopsis sp

7

17

37

Figure 2. Pictures of collected insects.

3.3. Spectrum of Insect Species Richness According to the Orders

The proportional distribution of species richness of insects according to the orders is shown in Figure 3. The order of Orthoptera is the most represented with 10 species or 27.02 %, followed by Hymenoptera (8 species or 21.62%), Coleoptera (7 species or 18.91%), Mantoptera (5 species or 13.51%), Heteroptera (cash or 08.10%). Diptera and Odonata are orders less represented each with 2 species (5.40%). These results differ from those obtained by [15] on the Djoumouna River that identified 34 families of insects belonging to seven orders. Diptera and Coleoptera are the largest orders. This difference may be explained by the fact that the studies were conducted in different ecosystems; Djambala being located on a plateau 789 m above sea level.

Figure 3. Distribution of the species richness of insects according to the orders.

3.4. Spectrum of Insect Species Richness According to the Families

Proportional representation of different families depending on the species richness (Figure 4).

In Yo and Ngatsouéné, family of Mantidae is the most abundant species with 5 (13.51%), followed by Acrididae (4 species; 10.81%), the Apidae, the Coccinellidae and Pyrgomorphidae (3 species; 8.10%), the Calliphoridae, the Formicidae, the Pentatomidae, the Gryllidae, the Libellulidae, the Lycidae and Sphecidae (2 species; 5.40%), finally Coreidae, the Meloidae, the Tetrigidae, the Cerambycidae and the Megachilidae each had one species (2.70%).

Figure 4. Distribution of the species richness of insects according to families.

4. Conclusion

The study aimed to inventory the aquatic insects of ponds Yo and Ngatsouéné located in Djambala center. The physicochemical analyses of the surface water of these pools show that the water is acidic, and the conductivity values indicate a low water mineralization. The entomofauna census showed a high proportion of the Orthoptera order, and the family of Mantidae has the largest species richness. Mantis sp is the most abundant species of these two ponds. This occasional entomological study of ponds Ngatsouéné and Yo constitutes a database which must be enriched by further studies on the aquatic entomofauna of the grove which is the center of the Ngatsouéné.pond. More inventories of other taxa (benthic macroinvertebrates, amphibians) must be made available in these ponds to better understand these ecosystems. It can also deepen this study by working for a longer time to learn about the pond’s entomofauna and extend it to all aquatic ecosystems of Djambala and the Department of Plateaux.

Acknowledgements

We thank Professor BANGA MBOKO Henri, Specialist of Animal Production, Superior School of Agronomy and Forestry, University Marien NGOUABI for the correction of the article English version.

Conflicts of Interest

The authors declare no conflicts of interest regarding the publication of this paper.

References

[1] Bameul, F. (1992) Revision of the Genus Psalitrus D’orchymont from Southern India and Sri Lanka (Coleoptera: Hydrophilidae: Omicrini). Systematic Entomology, 17, 1-20.
https://doi.org/10.1111/j.1365-3113.1992.tb00317.x
[2] van Huis, A. (2003) Insects as Food in Sub-Saharan Africa. International Journal of Tropical Insect Science, 23, 163-185.
https://doi.org/10.1017/s1742758400023572
[3] Dunbar, M.J., Warren, M., Extence, C., Baker, L., Cadman, D., Mould, D.J., et al. (2010) Interaction between Macroinvertebrates, Discharge and Physical Habitat in Upland Rivers. Aquatic Conservation: Marine and Freshwater Ecosystems, 20, S31-S44.
https://doi.org/10.1002/aqc.1089
[4] Association des Naturalistes de l’Ariège (2000) La mare: Un écosystème d’une grande diversité. Document pédagogique, Association des Naturalistes de l’Ariège, Cottes, 113 p.
[5] Nkouka, N., Onoré, G. and Fabres, G. (1981) Eléments d’un inventaire de l’entomofaune phytophage du manioc en vue de l’identification des insectes vecteurs de la bactériose vasculaire. Cahiers ORSTOM. Série Biologie: Phytopathologie et Zoologie Appliquée, 44, 9-10.
[6] Nkouka, E. (1987) Les insectes comestibles dans les sociétés d’Afrique centrale. Muntu: Revue scientifique et culturelle du CICIBA, 6, 171-178.
[7] Bani, G. (1990) Interactions Zonocerus variegatus (Orthoptères, Pyrgomorphidae)-Manioc au Congo: Bioecologie d’un ravageur vecteur de la bacteriose. Université de Rennes.
[8] Asseh, A. and Sitou, J.A. (1997) Inventaire des insectes comestibles dans le Département de Brazzaville. Mémoire de CAPES Option Sciences Naturelles UMNG.
[9] Matoko, J.D. and Kimbangui, C.G. (2001) Occupation de l’espace et utilisation du temps par les insectes: Cas des drosophiles. Mémoire de CAPES option Sciences Naturelles Ecole Normale Supérieure, Université Marien.
[10] Mikolo, B., Massamba, D., Matos, L., Lenga, A., Mbani, G. and Balounga, P. (2007) Conditions de stockage et revue de l’entomofaune des denrées stockées du Congo Brazzaville. Journal des Sciences, 7, 30-38.
[11] Batiabo Mikembi, L.A. (2013) Diversité et distribution spatiale des macroinvertébrés de la rivière Djoumouna au Sud-Ouest de Brazzaville. Mémoire de Master ès Sciences et Techniques Parcours Bioécologie Animale Faculté des Sciences et Techniques, Université Marien NGouabi.
[12] Roth, M. (1968) Initiation à la Systématique et à la Biologie des Insectes. Initiations Documentations Techniques.
https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2024-02/12174.pdf
[13] Durand, J.R. and Lévêque, C. (1980) Flore et faune aquatiques de l’Afrique Sahélo-Soudaniènne. Edition ORSTOM.
[14] Moisan, J. (2010) Guide d’identification des principaux macroinvertébrés benthiques d’eau douce du Québec. 2010: Surveillance volontaire des cours d’eau peu profonds. Direction du suivi de l’état de l’environnement, ministère du Développement durable, Environnement et parcs Québec. 89 p.
[15] Nowak, J. (2012) Clé d’identification: Les classes d’hexapodes et les ordres d’insectes.
[16] Moukolo, N., Laraque, A., Olivry, J.C. and Bricquet, J.P. (1993) Transport en solution et en suspension par le fleuve Congo (Zaïre) et ses principaux affluents de la rive droite. Hydrological Sciences Journal, 38, 133-145.
https://doi.org/10.1080/02626669309492651
[17] Ibala-Zamba A. (2010) Faune des poissons des rivières Luki et Léfini (Bassin du Congo): Diversité et Ecologie, Thèse de doctorat, Université de Leuven.

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