Articles
Potential effects of insects on survival of Monilinia vaccinii-corymbosi pseudosclerotia
Article number
1357_39
Pages
273 – 280
Language
English
Abstract
Monilinia vaccinii-corymbosi (MVC) is a common fungal pathogen of lowbush blueberry (Vaccinium angustifolium) in Maine.
The fungus overwinters for one to multiple years as pseudosclerotia in the duff or litter layer in the field.
In prior field experiments, the number of pseudosclerotia placed in a field in the fall decreased by the spring.
The possible effects of other organisms, such as invertebrates and insects, on pseudosclerotia survival in the fall after harvest were examined.
In 2015 and 2016, field experiments investigating possible animal interactions with pseudosclerotia were set up to compare the loss of pseudosclerotia from treatments with no cages to the losses inside cages with varying sizes of mesh (ranging from 1, 4, 7 and 14 mm). In both years, there were greater numbers of pseudosclerotia remaining inside cages with the smallest mesh compared to larger mesh cages or treatments with no cages, and having a cage bottom had no effect on survival.
In 2016, there were the same proportion of loss of MVC pseudosclerotia in similar sized cages at the edge and middle of the field.
There was little effect of density of pseudosclerotia on proportion of loss.
The most common insects collected from pitfall traps in blueberry fields in September 2015 and 2016 were in the families, Gryllidae, Alydidae, Formicidae, Carabidae and Scarabidae. No-choice laboratory experiments using MVC pseudosclerotia and insect members of the most commonly collected families found most of the insects damaged pseudosclerotia, and some broke pseudosclerotia into small fragments.
The destruction of the pseudosclerotia may be due to their consumption or to the insects scavenging for blueberry tissue and seeds.
Insects present in lowbush blueberry fields may be affecting the overwintering of pseudosclerotia and result in a decrease in potential inoculum in subsequent years.
The fungus overwinters for one to multiple years as pseudosclerotia in the duff or litter layer in the field.
In prior field experiments, the number of pseudosclerotia placed in a field in the fall decreased by the spring.
The possible effects of other organisms, such as invertebrates and insects, on pseudosclerotia survival in the fall after harvest were examined.
In 2015 and 2016, field experiments investigating possible animal interactions with pseudosclerotia were set up to compare the loss of pseudosclerotia from treatments with no cages to the losses inside cages with varying sizes of mesh (ranging from 1, 4, 7 and 14 mm). In both years, there were greater numbers of pseudosclerotia remaining inside cages with the smallest mesh compared to larger mesh cages or treatments with no cages, and having a cage bottom had no effect on survival.
In 2016, there were the same proportion of loss of MVC pseudosclerotia in similar sized cages at the edge and middle of the field.
There was little effect of density of pseudosclerotia on proportion of loss.
The most common insects collected from pitfall traps in blueberry fields in September 2015 and 2016 were in the families, Gryllidae, Alydidae, Formicidae, Carabidae and Scarabidae. No-choice laboratory experiments using MVC pseudosclerotia and insect members of the most commonly collected families found most of the insects damaged pseudosclerotia, and some broke pseudosclerotia into small fragments.
The destruction of the pseudosclerotia may be due to their consumption or to the insects scavenging for blueberry tissue and seeds.
Insects present in lowbush blueberry fields may be affecting the overwintering of pseudosclerotia and result in a decrease in potential inoculum in subsequent years.
Publication
Authors
S.L. Annis, T. Case
Keywords
lowbush blueberry, Vaccinium angustifolium, Carabidae, Gryllidae, Scarabidae
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