Impact of Host Plant Phenology on the Population Dynamics and Oviposition of Northern Corn Rootworms, Diabrotica barberi (Coleoptera: Chrysomelidae), in Field Corn

1988 ◽  
Vol 17 (3) ◽  
pp. 508-521 ◽  
Author(s):  
Steven E. Naranjo ◽  
Alan J. Sawyer
1987 ◽  
Vol 119 (6) ◽  
pp. 577-585 ◽  
Author(s):  
H.J. McAuslane ◽  
C.R. Ellis ◽  
O.B. Allen

AbstractThree sequential-sampling plans were developed for adult Diabrotica barberi Smith and Lawrence and D. virgifera virgifera LeConte in field corn in southern Ontario. The distribution of both species was well approximated by the negative binomial distribution and obeyed Taylor’s power law. Two plans, following the methods of Kuno (1969) and Green (1970), estimated populations with predetermined precision. The third plan, based on Wald’s (1947) sequential probability ratio test, categorized populations relative to an economic threshold. Different sequential-sampling plans were constructed for 1st-year fields and for all other fields because the parameter k, measuring the extent of aggregation of the beetles, differed between these two classes of fields. Decision equations for Wald’s plan in 1st-year fields were: D1 = 0.98n − 17.75 and D2 = 0.98n + 13.82. Decision equations for 2nd-year or older fields were: D1 = 0.99n − 13.42 and D2 = 0.99n + 10.45. The use of Wald’s plan reduced the required sample size by 55% in 1st-year fields, and by 48% in all other fields. The savings associated with the other sequential-sampling plans were not significant.


Ecology ◽  
2000 ◽  
Vol 81 (6) ◽  
pp. 1565-1576 ◽  
Author(s):  
Nora Underwood ◽  
Mark D. Rausher

2010 ◽  
Vol 24 (5) ◽  
pp. 1103-1109 ◽  
Author(s):  
Margriet van Asch ◽  
Riita Julkunen-Tiito ◽  
Marcel E. Visser

2019 ◽  
Vol 89 (3) ◽  
pp. 829-841
Author(s):  
Adam Ekholm ◽  
Ayco J. M. Tack ◽  
Pertti Pulkkinen ◽  
Tomas Roslin

2019 ◽  
Vol 112 (4) ◽  
pp. 1587-1597 ◽  
Author(s):  
Juan Pedro Raul Bouvet ◽  
Alberto Urbaneja ◽  
César Monzó

Abstract The Spirea citrus aphid, Aphis spiraecola Patch, and the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are key pests of clementine mandarines in the Mediterranean basin. Severity of aphid infestations is determined by environmental variables, host plant phenology patterns, and the biological control exerted by their associated natural enemies. However, there is no information about the role these limiting and regulating factors play. Aphid densities, citrus phenology, and associated predators that overwinter in the crop were monitored weekly throughout two flush growth periods (February to July) in four clementine mandarin groves; relationships between these parameters and environmental variables (temperature and precipitation) were studied. Our results show exponential increase in aphid infestation levels to coincide with citrus phenological stages B3 and B4; shoots offer more space and nutritional resources for colony growth at these stages. Duration of these phenological stages, which was mediated by mean temperature, seems to importantly determine the severity of aphid infestations in the groves. Among those studied, the micro-coccinellids, mostly Scymnus species, were the only group of predators with the ability to efficiently regulate aphid populations. These natural enemies had the highest temporal and spatial demographic stability. Aphid regulation success was only achieved through early presence of natural enemies in the grove, at the aphid colonization phase. Our results suggest that conservation strategies aimed at preserving and enhancing Scymnus sp. populations may make an important contribution to the future success of the biological control of these key citrus pests.


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