Journal of Economic Entomology (1994) 87, 993-998

Bonnie B. Pendleton, George L. Teetes and Merry E. Makela (1994)
Predicting sorghum midge (Diptera: Cecidomyiidae) generations and abundance
Journal of Economic Entomology 87 (4), 993-998
Abstract: A total of 39,687 assessments of abundance of ovipositing sorghum midge, Contarinia sorghicola (Coquillett), and sorghum, Sorghum bicolor (L.) Moench, spikelets in flower were used to evaluate, refine, and validate a sorghum midge population dynamics simulation model. Number of spikelets per panicle was related positively to panicle length, with 42% of the variability in the number of spikelets attributable to length. Uniformly growing fields of sorghum were in flower <13 d. Most spikelets (388.2) per panicle were in flower the seventh day after flowering began in a field. The refined model was used to predict accurately time of sorghum midge emergence in all (mean R² = 0.83) but one field (R² = 0.59). However, predictions of sorghum midge abundance varied in accuracy (observed/predicted range of sorghum midges = 0.77-1.21). Predicted time of development of the F₁ to F₅ generations of sorghum midges ranged from 21.0 to 15.8 d. Abundance of ovipositing sorghum midges increased 2.5-, 3.7-, 24.6-, and 12.6-fold between the P-F₁, F₁-F₂, F₂-F₃, and F₃-F₄ generations, respectively, and then declined. Abundance was greatest (22.7 sorghum midges per panicle) in the F₄ generation. The economic-threshold level was exceeded during the last days of the F₃ generation.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Bonnie B. Pendleton

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Contarinia sorghicola	Sorghum (crop)