Insect Pests and their Direct Damage of Piliostigma reticulatum (D.C.) Hochst Flowers and Pods in North-Soudanian Region of Burkina Faso

Abstract

Aims: The objective of this work is to gain a better understanding of insect pests of flowers, fresh and ripe pods of P. reticultum in Burkina Faso.
 Study Design: The P. reticultum trees were selected randomly. Also, the collection of flowers and pods from these trees was done in the same way.
 Place and Duration of Study: Flowers, fresh pods and mature pods of P. reticulatum were collected in a village in the province of Bam called Yilou.
 The observations were conducted in the laboratory. The study was carried out between December 2020 and September 2021.
 Methodology: 120 flowers, 200 fresh pods and 2000 ripe pods of P. reticulatum were collected. Fresh flowers and pods were collected randomly from 20 trees and ripe pods from 100 trees. In the laboratory, fresh flowers and pods were dissected and insects were collected. Ripe pods were stored in the laboratory in polyethylene bags at room temperature for up to six months. When the bags were opened, all the insects observed were captured and placed in vials containing 70º alcohol. Insect damage to the pods was assessed using a score from 1 to 5. The pods were then dissected and the insects were collected again. All insects were identified under a binocular "stereomicroscope using identification keys.
 Results: The results showed that Thysanoptera (Thripidae) were the most important insects in the flowers followed by Hymenoptera (Formicidae) and Coleoptera (Curculionidae). The main pests on fresh pods were Lepidoptera larvae (Lepidochrysops quassi Karsch). The extent of damage on mature pods in storage was high with an average score of 4.68. The pests of these pods in stock are Caryedon serratus (Olivier) followed by Tribolium castaneum (Herbst).
 Conclusion: The study revealed that thrips, L. quassi and C. serratus are the main pests of P. reticulatum flowers, fresh pods and socked pods respectively.