The temperature-dependent development of pupae and adults of strawberry
root weevil (SRW) Otiorhynchus ovatus (L.) was studied in strawberry (Fragaria x
ananassa Duch. var. 'Totem'). The development of pupae and adults was
investigated at constant temperatures from 3-33��C at 3��C intervals. Major
emphasis was on the development of a weighted linear temperature-based pupal
prediction model. The predictive ability of this weighted model was compared to a
traditional non-weighted linear degree-day model by relating predictions to the
observed occurrence of SRW lifestages determined by field sampling.
The upper thermal lethal limit for SRW pupae was between 30 and 33��C.
Pupae did not eclose below 6��C. Mean pupal duration was 127 d at 6��C and 7 d at
30��C. Rate of development (1/days) was greatest at 30��C. The weighted linear
pupal prediction model produced a developmental threshold of 4.3��C and a degree-day
requirement of 227.3. The non-weighted linear pupal prediction model
produced a developmental threshold of 6.2��C and a degree-day requirement of
163.9.
Adults fed at all temperatures from 3-33��C and oviposited at temperatures
between 18 and 30��C . The longest preoviposition period (32.8 d) and the least
total number of eggs (2.2) were observed at 18��C. The shortest preoviposition
period (15.1 d) and the greatest total number of eggs (282.5) were observed at
27��C. A temperature range of 21 to 27��C appeared to be optimum for oviposition;
i.e. relative to other temperatures, preoviposition time was short, mortality was low,
and total number of eggs laid was high. / Graduation date: 2000
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/33218 |
| Date | 02 June 1999 |
| Creators | Umble, Jon R. |
| Contributors | Fisher, James R., Berry, Ralph E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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