Sorghum midge (Diptera: Cecidomyiidae) population distribution and survival on resistant sorghum /
Effects by resistance in sorghum, Sorghum bicolor (L.) Moench, on development of sorghum midge, Stenodiplosis sorghicola (Coquillett), were investigated. Sorghum midge- susceptible sorghum, Tx430, and resistant sorghums Tx2782 and Tx2767 were naturally infested by sorghum midge. Non preference was...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1995.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=742535071&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Effects by resistance in sorghum, Sorghum bicolor (L.) Moench, on development of sorghum midge, Stenodiplosis sorghicola (Coquillett), were investigated. Sorghum midge- susceptible sorghum, Tx430, and resistant sorghums Tx2782 and Tx2767 were naturally infested by sorghum midge. Non preference was detected before anthesis by means of sticky traps, which captured fewer ovipositing sorghum midges in plots of resistant sorghums; non-preference was confirmed by the fewer eggs laid in resistant sorghums. Most sorghum midge eggs in resistant sorghums were exposed to the environment or were laid in pedicellated spikelets, which do not produce kernels. Spatial distribution patterns for adult and immature sorghum midges failed to fit a Poisson distribution, and variance-to-mean relationship was properly described by Taylor's power law. Abundance of ovipositing sorghum midges in Tx430 was estimated with approximately 15- 20% precision by inspecting 48 sorghum panicles. Precision of abundance estimation was only 25% when 48 resistant sorghum panicles were sampled. Inspection of 96 spikelets enabled immature sorghum midge abundance to be estimated with 10% precision in Tx430 and 25% in the resistant sorghum lines. The proportion of sorghum midges dying before becoming adults was slightly higher in Tx430. Significant differences in vulnerability of sorghum midge life stages were observed among the sorghums. Most sorghum midges (48%) in Tx430 died as pupae, most (45%) in Tx2782 died as eggs, and most (35%) in Tx2767 died as larvae. Probability of sorghum midge eggs reaching diapause was higher than that of becoming adults in Tx430 or Tx2782, but was lower in Tx2767. Because of larval competition for resources, sorghum midge pupae in Tx430 were smaller than those in the resistant sorghum lines. However, 11 times more adults emerged from Tx430 than from either resistant sorghum line. The number of diapausing larvae in Tx430 was 12 times higher than in Tx2782 and 52 times higher than in Tx2767. From an ecological standpoint of persistence as a population, sorghum midges developing in susceptible sorghum had an advantage over those growing in resistant sorghum lines. |
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| Item Description: | Vita. "Major Subject: Entomology". |
| Physical Description: | xiii, 112 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |