Larval diet prior to and following virus ingestion influences the efficacy of two nucleopolyhedroviruses in whitemarked tussock moth (Orgyia leucostigma) caterpillars

Abstract

Food quality can influence the performance of immature insects and their interactions with pathogens, such as viruses. In manipulative field studies, virus-free caterpillars of the whitemarked tussock moth (WMTM) (Orgyia leucostigma (Smith)) had higher survival, more female-biased sex ratios, and were larger when feeding on white birch (Betula papyrifera Marshall) versus balsam fir (Abies balsamea (Linnaeus) Miller) or red spruce (Picea rubens Sargent). Subsequent laboratory studies with two nucleopolyhedroviruses, derived from WMTMs and Douglas-fir tussock moths, indicated that caterpillars fed high quality food (i.e., artificial diet) prior to infection had less mortality associated with virus infection than those feeding on lower quality foliage (i.e., birch). In field studies, caterpillars fed birch following infection had significantly lower mortality than those feeding on relatively lower quality foliage (i.e., balsam fir). We postulate that higher nutritional quality in artificial diet relative to birch (previrus-ingestion nutrition) and in birch relative to balsam fir foliage (postvirus-ingestion nutrition) has a positive effect on the ability of tussock moth caterpillars to resist or recover from viral infections, although the specific mechanisms responsible for observed resistance remain unclear.

The Effect of Diet on Midgut and Resulting Changes in Infectiousness of AcMNPV Baculovirus in the Cabbage Looper, Trichoplusia ni

“…Once ingested, the alkaline pH of the larval midgut dissolves the viral occlusion body (OB), releasing the occlusion-derived virions (ODVs) that rapidly pass through the midgut peritrophic matrix (PM) and infect the microvilli of columnar midgut epithelium cells (Granados and Lawler, 1981 ). However, the infection process can be affected by the larval food source (Duffey et al, 1995 ; Cory and Hoover, 2006 ) as this shapes the environment of the gut (Keating et al, 1990 ; Brodersen et al, 2012 ). Secondary metabolites (phenolics, flavonoids, and tannins) affect the palatability of plant tissue and influence caterpillar growth, which in turn affects larval behavior and plant-pest interactions (Sarfraz et al, 2011 ).…”

Towards the Forest Virome: Next-Generation-Sequencing Drastically Expands our Understanding on Virosphere in Temperate Forest Ecosystems

“…In the present review, we have not addressed viruses of arthropods; however, it should be noted that baculoviruses of insect pests of temperate forest trees have been investigated for their biocontrol potential. The most prominent, that we mention here, are the nuclear polyhedrosis virus affecting Lymantria dispar on birches [173], oaks and poplars [174], the Condylorrhiza vestigialis multiple nucleopolyhedrovirus affecting Condylorrhiza vestigialis on poplars [175], the Orgyia leucostigma nucleopolyhedrovirus infesting Orgyia leucostigma on birches, firs and spruces [176,177] and the Neodiprion abietis nucleopolyhedrovirus (NeseSNPV) affecting Neodiprion abietis on conifers [178]. As part of the effort to control the sawfly, NeseSNPV was introduced from Sweden into Canada and spread rapidly through the cohort and ultimately the population resulting in long-term suppression of N. sertifer [179].…”

Towards the Forest Virome: High-Throughput Sequencing Drastically Expands Our Understanding on Virosphere in Temperate Forest Ecosystems

“…In the present review, we did not address viruses of arthropods; however, it should be noted that baculoviruses of insect pests of temperate forest trees have been investigated for their biocontrol potential. The most prominent, which we mention here, are the nuclear polyhedrosis virus affecting Lymantria dispar on birches [ 239 ], oaks and poplars [ 240 ]; the Condylorrhiza vestigialis multiple nucleopolyhedrovirus affecting Condylorrhiza vestigialis on poplars [ 241 ]; the Orgyia leucostigma nucleopolyhedrovirus infesting Orgyia leucostigma on birches, firs and spruces [ 242 , 243 ]; and the Neodiprion abietis nucleopolyhedrovirus (NeseSNPV) affecting Neodiprion abietis on conifers [ 244 ]. As part of the effort to control the sawfly, NeseSNPV was introduced from Sweden into Canada and spread rapidly through the cohort and ultimately the population, resulting in the long-term suppression of N. sertifer [ 245 ].…”