TY - JOUR
T1 - Intrastadial developmental resistance of third instar gypsy moths (Lymantria dispar L.) to L. dispar nucleopolyhedrovirus
AU - Grove, Michael J.
AU - Hoover, Kelli
N1 - Funding Information:
We thank Melody Conklin, Julie Reddinger, Mariana Amaral, Brianna Reed, Ryan Bissot, JoLynne Harenza, James McNeil, and Scott Geib for technical assistance. We thank Suzanne Thiem for the gifts of the LdMNPV occlusions and Ld652Y cells. Funding for this project was provided in part by the National Science Foundation, Ecology and Evolutionary Physiology Program (Award No. IBN-0077710).
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2007/3
Y1 - 2007/3
N2 - Gypsy moth larvae become increasingly resistant to lethal infection by the Lymantria dispar M nucleopolyhedrovirus (LdMNPV) as they age within the fourth instar. Newly molted larvae are most sensitive to infection, mid-instars are least sensitive, and late-instars display intermediate sensitivity. This resistance occurs whether the virus is delivered orally or intrahemocoelically. The present study reveals a nearly identical pattern of resistance in third instar larvae. An LD48 dose of polyhedra for newly molted third instars produced 18%, 10%, 8%, 25%, and 24% mortalities in larvae to which virus was orally administered at 12, 24, 48, 72, and 96 hours post-molt (hpm), respectively, which is a 6-fold reduction in mortality between newly molted larvae and mid-instars. An LD44 dose of budded virus for newly molted third instars produced 33%, 23%, 17%, 31%, and 31% mortalities when injected into larvae that were 12, 24, 48, 72, and 96 hpm, respectively, which is a 2.6-fold reduction in mortality between newly molted larvae and mid-instars, indicating that approximately half of this resistance is midgut-based and half is systemically based. Doubling the viral dose did not overcome developmental resistance whether the virus was delivered orally or intrahemocoelically. In addition, time to death was significantly affected by the time post-molt at which the insect was inoculated with the virus. We suggest that intrastadial developmental resistance may affect both the ecology and management of the gypsy moth.
AB - Gypsy moth larvae become increasingly resistant to lethal infection by the Lymantria dispar M nucleopolyhedrovirus (LdMNPV) as they age within the fourth instar. Newly molted larvae are most sensitive to infection, mid-instars are least sensitive, and late-instars display intermediate sensitivity. This resistance occurs whether the virus is delivered orally or intrahemocoelically. The present study reveals a nearly identical pattern of resistance in third instar larvae. An LD48 dose of polyhedra for newly molted third instars produced 18%, 10%, 8%, 25%, and 24% mortalities in larvae to which virus was orally administered at 12, 24, 48, 72, and 96 hours post-molt (hpm), respectively, which is a 6-fold reduction in mortality between newly molted larvae and mid-instars. An LD44 dose of budded virus for newly molted third instars produced 33%, 23%, 17%, 31%, and 31% mortalities when injected into larvae that were 12, 24, 48, 72, and 96 hpm, respectively, which is a 2.6-fold reduction in mortality between newly molted larvae and mid-instars, indicating that approximately half of this resistance is midgut-based and half is systemically based. Doubling the viral dose did not overcome developmental resistance whether the virus was delivered orally or intrahemocoelically. In addition, time to death was significantly affected by the time post-molt at which the insect was inoculated with the virus. We suggest that intrastadial developmental resistance may affect both the ecology and management of the gypsy moth.
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U2 - 10.1016/j.biocontrol.2006.12.003
DO - 10.1016/j.biocontrol.2006.12.003
M3 - Article
AN - SCOPUS:33846658070
SN - 1049-9644
VL - 40
SP - 355
EP - 361
JO - Biological Control
JF - Biological Control
IS - 3
ER -