Effects of Larval Density on Plutella xylostella Resistance to Granulosis Virus
It has been reported that some phase-polyphenic insects from high-density conditions are more resistant to pathogens than those from low-density conditions. This phenomenon is termed "density-dependent prophylaxis" (DDP). However, whether non phase-polyphenic insects exhibit DDP has rarely...
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Published in | Insects (Basel, Switzerland) Vol. 11; no. 12; p. 857 |
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Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Switzerland
MDPI AG
02.12.2020
MDPI |
Subjects | |
Online Access | Get full text |
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Summary: | It has been reported that some phase-polyphenic insects from high-density conditions are more resistant to pathogens than those from low-density conditions. This phenomenon is termed "density-dependent prophylaxis" (DDP). However, whether non phase-polyphenic insects exhibit DDP has rarely been elucidated. The diamondback moth (DBM),
, one of the most destructive insect pests affecting cruciferous crops, is non phase-polyphenic. In this study, the resistance of DBM larvae to
granulosis virus (
GV) and their immune response to the virus when reared at densities of 1, 2, 5, 10, 15, and 20 larvae per Petri dish were investigated under laboratory conditions. Compared with larvae reared at lower densities, larvae reared at moderate density showed a significantly higher survival rate, but the survival rate significantly decreased with further increases in rearing density. Furthermore, the phenoloxidase, lysozyme and antibacterial activity and total hemocyte count in the hemolymph of the larvae, regardless of whether they were challenged with the virus, from different larval densities corresponded to the observed differences in resistance to
GV. These results demonstrated that
larvae exhibited DDP within a certain limited density. This study may help to elucidate the biocontrol effect of different density populations of
by granulosis virus and guide improvements in future management strategy. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2075-4450 2075-4450 |
DOI: | 10.3390/insects11120857 |