The purpose of this research is two fold. First to improve pest management of the
sciarid fly (Diptera: Sciaridae) by better defining its relation to mushroom production.
Secondly, to explore some of the factors and aspects of the biology of the fly which may
increase room to room dispersal rates of adults.
The effects of different generations of production room Lycoriella mali Fitch
infestations and seasons on yield were explored. In models regressing densities of
different generations to mushroom yield, significant negative slopes (p=.05) existed in
all models. However, flies did not account for as much yield variance as hypothesized
(16.43%). Yield is greatest during the winter months when insect pressure is lowest and
decreases in summer months when more insects are present. Diflubenzuron (Dimilin 25
WP, Uniroyal Co.) was tested for its effects on fly emergence and oviposition.
Diflubenzuron was effective in suppressing fly emergence and remained effective when
treated compost was exposed to phase II peak heating. In production room experiments
all fly generations had significantly fewer flies in rooms treated with diflubenzuron at fill.
L. mali showed a slight preference to oviposition in diflubenzuron treated compost,
indicating a possible attractant effect.
A criterion table was developed to estimate the age of L. mali. Both younger and
larger L. mali carried more ovarioles. The number of ovarioles that L. mali carry dropped
significantly after 48 h; this is likely the time the fly becomes parous.
The effects of ambient temperature and distance between production rooms on
dispersal were explored. The greatest number of dispersing flies were caught during the
summer months. As the daily median temperature increased, the number of dispersing
flies increased exponentially. Production room blocks on the perimeter of the farm
generally had fewer dispersing flies than centrally located production room blocks
indicating that it was unlikely that a reservoir population existed outside the farm.
Measurements of wing area and age of L. mali captured while dispersing and not
dispersing were compared. Dispersing flies had significantly smaller wings than non-dispersers
(p=.000). Wing area for dispersing flies decreased along a density gradient,
while wing area for non-dispersers did not. The mean age of dispersing flies was not
significantly different (p=.082) from non-dispersers, and neither changed along a density
gradient. / Graduation date: 1996
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/34683 |
| Date | 30 August 1995 |
| Creators | Mehelis, Christopher N. |
| Contributors | DeAngelis, Jack |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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