Cotton being one of the plants most attacked by pests in Benin, this crop harbors a diverse range of predators. It is within this framework that this study aims to identify the main predators encountered on cotton plants in the phytosanitary zones of Benin, to determine their seasonal development and to assess their importance according to the stages of cotton development. Thus, the density of predators was assessed on 0.25 hectare of real fields. A factorial analysis of the correspondences was used to make the typology of predators. Their seasonal evolution was described using trend curves and then the Wilcoxon test was used to assess the density of predators according to the stages of cotton development. Thus, three groups of predators were identified according to the zones. We observed a first group consisting of spiders which are mainly distributed in zone 3. The second group is formed by ants, praying mantises and Phonoctonus spp. found in zone 2. The third group is composed of lacewings, syrphids and ladybirds found in zone 1. From the vegetative development stage of cotton to the fruiting development stage, the density of Syrphids varied from 1.80 ± 0.23 to 3.18 ± 0.27, while the density of lacewing varied from 2.37 ± 0.51 (vegetative stage) to 1.01 ± 0.25 (fruiting stage). The density of Syrphids significantly increased during the fruiting stage, unlike that of Chrysopes, which experienced a significant decrease. These results may contribute to a better understanding of the regulatory function of organic cotton predators on its pests and their importance in integrated pest management strategies.

The study on the efficacy of phytosanitary treatment programs based on neem extract or kaolin was undertaken in the center of Benin. The objective of the work was to identify a treatment program that is more effective than the outreach in the area. To achieve this goal, a Fisher block device with 6 treatments and 4 repetitions were set up on two sites. The treatments developed consisted of an untreated plot; of a treated plot to the program popularized (PP); of a plot treated exclusively in Kaolin 5%; of a plot receiving: 3 neem-2 emamectine/acetamipride-2 neem; of a plot receiving: 2 emamectine/acetamipride -2 neem-1 emamectine/acetamipride -2 neem and of a plot treated in the mixture of neem + emamectine/acetamipride on 7 applications. Ten applications were conducted with the kaolin used alone and 7 with the other objects. The results showed good control of endocarpiques larvae by programs N°4 and N°6, consisting respectively of 3neem-2 emamectine/acetamipride-2 neem and of 7 treatments in the neem mixture emamectine/acetamipride. The average number of larvae in the green bolls obtained on plots treated following these two programs has not been statistically different from that of the treated plots following the program popularized in the area. This average number of larvae was also reduced as compared to untreated parcels (p=0.0029). The program exclusive to the kaolin 5% has controlled the endocarpiques larvae, Pectinophora gossypiella and Thaumatotibia leucotreta as well as the popularized program. The number of plants attacked by pests of foliage, including Haritalodes derogata and Aphis gossypii has been reduced respectively by 34.7% and 47% against 95.6 and 82.4% on average by the other treatment programs. The program N°5, starting by two treatments to emamectine/acetamipride was in contrast less effective on the control of the endocarpiques larvae in the area. This study has shown that phytosanitary treatment program consisting of applications of neem extracts alternating or in mixture with an alternative product to pyrethroids can effectively control endocarpiques larvae on cotton, limiting resistance to insecticides and reduce The stress on environment due to chemicals.