Agricultural production constitutes one of the important economic development factors that generates important incomes. Among many Insects, Acarina, Birds, Mammals and diseases that attack crops, the stinking locust, Zonocerus variegatus (Hyménoptère : Pygomorphidae) is a fearsome devastater of crops in the region. This study was conducted to study the population, the distribution of Zonocerus variegatus, its action modes in the field, and to identify its parasitoids in Kisangani. The study was carried out on food cultivation fields. Data were collected from July 2015 for six months, using a sweeping net. Two field works were conducted monthly. Stinking locusts were collected on fields and parasitoids around the fields (fallowland). Z. variegatus develops in 7 post-embryonic stages of which six larval and one adult stages. The data analysis showed abundance of larvae, from stage 1 to 6. Zonocerus variegatus larva appeared superior to the one of stage 7. We observed that larvae are more damaging than adults. 22.31% of Zonocerus variegatus specimens were collected on cassava fields while 5.03% were captured on maize and cassava fields. We collected more Zonocerus variegatus in March (32.6%). Their abundance also proves their aggressiveness to crops. In total, twenty families of parasitoids were collected and distributed into seven super-families. We captured more parasitoids in February (32.83%) than in other months. May is less rich with 4.60%. Scelionidae family largely dominates the others with 23.64% parasitoid specimens, followed by Bethylidae 20.08% and Platygastridae 16.70%. The poorest families are Charipidae (0.19%) and Tanaostigmatidae (0.19%).

This work aims to characterize the structure and diversity of the heterogeneous population of Yoko Forest Reserve. First, we considered (i) the floristic variability (specific richness and diversity), and (ii) the structural variability (in terms of density, ground surface and diametric structure) evaluated at the scale of a hectare. The second step consisted on the analysis of the spatial structure (i) generally and its comparison to the whole plot, and (ii) specific structure of the whole plot (only the spatial structure of the important species was analyzed). So, a systematic inventory of all trees of 10 cm dbh was conducted over five hectares. It should be also noted that the position of each foot has been taken according to the coordinate system (x, y). In total, 1,919 trees of 10 cm dbh were inventoried in five hectares. These individuals were distributed into 98 genera, 141 species and 31 families; with average density of 19.6 genera per hectare, 28.2 species per hectare, and 6.2 families per hectare. The resemblance or similarity degree among the plots (Hectares) showed clearly two coherent plant communities, with a low coefficient of similarity, and each consisting of more or less close plots. Although the density is dominated by Microdesmis yafungana species J. Léonard J. but Pericopsis elata Harms species and Fabaceae family dominated other quantitative parameters. As for the structural analysis, the individuals presented a shape with a significant decrease as we moved to the next class and the most significant densities were observed in classes of diameter 1, 2, 3 and 4. Therefore, a study on the structure and diversity of heterogeneous forest populations is very important because it gives information about the natural processes of trees (growth, regeneration, demographics) as well the anthropogenic action on the forest ecosystem.