Philippine Journal of Science
149 (S1): 175-181, Special Issue on Nuclear S&T
ISSN 0031 – 7683
Date Received: 13 Jun 2019

 

Effect of Gamma Irradiation on Coconut Leaf Beetle,
Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae)

 

Glenda B. Obra¹*, Mateo B. Zipagan², and Abigaile Mia V. Javier¹

 

¹Agriculture Research Section, Atomic Research Division
Department of Science and Technology – Philippine Nuclear Research Institute
(DOST-PNRI) Commonwealth Ave., Diliman, Quezon City 1101 Philippines

 

²Philippine Coconut Authority–Region V Rizal St., Old Albay District,
Sagpon, Legaspi City 4500 Philippines

 

*Corresponding author: gobra@pnri.dost.gov.ph

 

[Download]
Obra G et al. 2020. Effect of Gamma Irradiation on Coconut Leaf Beetle, Brontispa
longissima (Gestro) (Coleoptera: Chrysomelidae). Philipp J Sci 149(S1): 175–181.
https://doi.org/10.56899/149.S1.20

 

ABSTRACT

The effect of irradiation on the fecundity, egg hatchability, and longevity of the coconut leaf beetle (CLB) Brontispa longissima (Gestro) was studied using different doses of gamma radiation ranging from 20-50 Gy for pupa and adult males, and 20-40 Gy for adult females. The fecundity and fertility of adults decreased with irradiation dose. The pupae were more sensitive to irradiation than the adults based on LD values after 14 d. Adult females were more sensitive to irradiation than males based on fecundity and egg hatchability. No eggs were hatched at 40 Gy in irradiated females (IF) mated with unirradiated males (UM) and at 50 Gy in unirradiated females (UF) mated with irradiated males (IM), albeit with a significant effect on longevity at this dose. Using 45 Gy for mating competitiveness studies at a ratio of 1:15:1 (UF: IM: UM), wild females acceptance of IM was high based on the relative sterility index (RSI) value of 0.66.