TITLE:
First Report on the Larval Development of Caryedon furcatus (Anton & Delobel), the Primary Pest of Senegalia macrostachya Reichenb. ex DC. (Kyal & Boatwr.) Seeds in Storage in Burkina Faso
AUTHORS:
Larissa Dioma, Marcellin Yamkoulga, Emmanuel Kaboré, Aboubakar Sanon, Antoine Sanon, Zakaria Ilboudo
KEYWORDS:
Caryedon furcatus, Development Time, Immature Stages, Oviposition, Biodemographic Parameters
JOURNAL NAME:
Advances in Entomology,
Vol.13 No.4,
September
29,
2025
ABSTRACT: Data on some biodemographic parameters of Caryedon furcatus (Anton & Delobel), a beetle belonging to the Chrysomelidae family and the primary pest of Senegalia macrostachya Reichenb. seeds, an edible wild legume in Burkina Faso, have been reported by some authors, but they do not include the development times of the immature stages or their descriptions. Our main objective was therefore to document this missing data on the biology of C. furcatus. We have therefore updated the biodemographic parameters of C. furcatus and identified larval stages which are currently unknown. For this purpose, Senegalia macrostachya seeds were exposed to C. furcatus adults for twenty-four hours and then incubated. Twenty seeds, each with no more than one egg, were selected and placed in a petri dish to form a seed batch that was stored in a freezer (−18˚C) until adults emerged from the incubated seeds. These seeds were then removed from the freezer and dissected after soaking in water. To determine biological parameters, forty pairs were isolated upon emergence and placed in Petri dishes containing 20 g of seeds. After twenty-four hours, the insects were transferred to new dishes, and this process was repeated daily until the females died. The eggs laid were observed until emergence of adults. The results showed that the average development time for each larval stage was 9 days for egg to first instar larva; 3.25 days for first instar larva to second instar larva; 4 days for second instar larva to third instar larva; 5.1 days for third instar larva to fourth instar larva; 6.07 days for fourth instar larva to pupa; and 10.2 days for pupa to adult. The results also showed that females live longer than males and the sex ratio was female-biased. Females laid during their lifetime an average of 25.4 eggs, of which an average of 21.95 hatched. The pre-oviposition period was approximately one day, and the peak of female oviposition occurred on the second and third day after emergence. The population of C. furcatus doubles every 9.63 days. These results will contribute to a better understanding of the biology of C. furcatus and hence provide cues for further studies towards effective control using parasitoids.