Biology of the striped borer, Chilo zacconius Bleszynski (1970) (Lepidoptera: Crambidae) in Burkina Faso

---

Résumé

Chilo zacconius is one of the main rice stem borers in Burkina Faso. A study was conducted on its biology under controlled conditions of 25.46 ±1 °C temperature, 75.94 ±4% relative humidity, and a 12-hour photoperiod. To do this, immature populations of the insect were sampled in rice fields at Bama, western Burkina Faso for mass rearing of the insect pest
in the lab. Tavakilian food substrate was used to feed C. zacconius larvae till chrysalid stage, while adults were fed with
sugar water. Results showed that the insect had an average life cycle of 65.57±3.12 days, with egg incubation averaging
5.44±0.14 days. The larval phase was the longest one in the insect’s cycle, with an average duration of 48.71±2.46 days,
and comprised 7 larval instars. The average lifespan of pupae was 8.1±0.33 days. Average fecundity ranged from 80 to
309 eggs. The average fertility of the insect was 34±6 individuals, with a sex ratio of 1 male to 1.16 female. Average
insect longevity was 4.28 ±0.89 days for females and 2.25±0.96 days for males. Copulation occurred just a few moments
after emergence, and oviposition averaged 2 days. These results could be used for decision-making on the development of
control methods for this insect pest. Knowledge of the duration of the lifespan of C. zacconius particularly, its vulnerable
phases (eggs and the first two larval instars), could be useful in controlling it.

Mots-clés

Rice ,Artificial diet, Chilo zacconius , Life cycle, Burkina faso