Environmental Entomology (2009) 38, 121-128

Eun Young Yoon, Youngwoo Nam and Mun Il Ryoo (2009)
Effects of biological control of rice weevil by Anisopteromalus calandrae with a population of two Aspergillus spp.
Environmental Entomology 38 (1), 121-128
Abstract: In this study, we assessed the interaction occurring between the rice weevil and two storage molds (Aspergillus candidus Link and Aspergillus niger Van Tiegem) that prefer different moisture regimens under rice storage conditions. Rice weevil induced rapid population growth in both of the storage molds. The colony forming units (CFUs) of A. candidus and A. niger peaked at 10^9.00 ± 0.02 and 10^7.72 ± 0.03/g, respectively. All of the rice grains were infested with the molds and eventually deteriorated; in the jars infested with A. candidus, no living weevils were found after 135 d. Suppression of the rice weevil by its larval parasitoid, Anisopteromalus calandrae (Howard), significantly retarded the growth of A. candidus but completely halted the growth of A. niger, which was replaced by xerophyllic molds including Aspergillus penicilloides Spegazzini and Wallemia sebi (Fries). Regression analyses showed that the total number of weevils was a significant factor explaining grain moisture content, which was in turn a significant factor in the growth of both mold species. The growth of A. niger was dependent on the grain moisture content (r² = 0.52), thereby suggesting that the growth of A. niger was caused primarily by activity of the rice weevil and the resulting increased grain moisture content. However, 27% of the growth of A. candidus was explained by grain moisture contents, suggesting that a factor other than the grain moisture content may also affect its growth. Suppression of rice weevil by A. calandrae could induce an A. candidus- dominant molds community, which would be a factor for consideration in biological control program.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mun Il Ryoo

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Sitophilus oryzae	Stored grain	Korea-South
	Aspergillus niger	Stored grain	Korea-South
	Aspergillus candidus	Stored grain	Korea-South
Anisopteromalus calandrae (parasitoid)	Sitophilus oryzae	Stored grain	Korea-South