scholarly journals Short communication. Mutual pheromone antagonism in two sympatric corn borers, Sesamia nonagrioides and Ostrinia nubilalis, under field conditions

2011 ◽  
Vol 9 (1) ◽  
pp. 308
Author(s):  
C. Lopez-Alonso ◽  
M. Eizaguirre ◽  
R. Albajes
Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 780
Author(s):  
María Arias-Martín ◽  
Miriam Haidukowski ◽  
Gema P. Farinós ◽  
Belén Patiño

Maize expressing Cry1Ab insecticidal toxin (Bt maize) is an effective method to control Sesamia nonagrioides and Ostrinia nubilalis, the most damaging corn borers of southern Europe. In this area, maize is prone to Fusarium infections, which can produce mycotoxins that pose a serious risk to human and animal health, causing significant economic losses in the agrifood industry. To investigate the influence of corn borer damage on the presence of Fusarium species and their mycotoxins, Bt maize ears and insect-damaged ears of non-Bt maize were collected from commercial fields in three Bt maize growing areas in Spain, and differences in contamination were assessed. Additionally, larvae of both borer species were collected to evaluate their role as vectors of these molds. Non-Bt maize ears showed significantly higher presence of F. verticillioides, F. proliferatum, and F. subglutinans than Bt maize ears. For the first time, Fusarium species have been isolated from larvae of the two species. The most frequently found mycotoxins in ears were fumonisins, with non-Bt ears being significantly more contaminated than those of Bt maize. High levels of fumonisins were shown to correlate with the occurrence of corn borers in the ear and the presence of F. verticillioides and F. proliferatum.


1987 ◽  
Vol 119 (4) ◽  
pp. 371-380 ◽  
Author(s):  
Dennis A. Lee ◽  
John R. Spence

AbstractTemperature effects on development were studied for two Alberta populations of Ostrinia nubilalis (Hübner), from the South Saskatchewan River valley and the surrounding plains. Lower developmental thresholds for all life stages of both Alberta populations were determined by linear regression. Thresholds for the egg stage were significantly less for plains borers (9.5°C) than for valley borers (10.8°C), and about 2°C lower than for corn borers from the United States. Thresholds in Alberta populations for the 4th (15.3°C) and 5th (14.0°C, plains) instars, and for post-diapause pupation (12.8°C), were much higher than in populations from the United States. Higher temperature thresholds delay development in Alberta populations, thus reducing midsummer pupation. Valley populations developed significantly faster than plains populations during egg development, during the prepupal period of the 5th instar, and during post-diapause pupation. These results explain why valley populations have a partial second generation in some years.


1978 ◽  
Vol 110 (12) ◽  
pp. 1351-1353 ◽  
Author(s):  
D. G. R. McLeod

AbstractGrowth rate, diapause incidence, and diapause intensity were different in two strains of corn borers found in southwestern Ontario. Crosses between these two strains demonstrated that growth rate was female sex linked while diapause incidence was male sex linked. The effect of these two characteristics on hybridization is discussed.


1987 ◽  
Vol 22 (4) ◽  
pp. 307-310 ◽  
Author(s):  
W. W. McMillian ◽  
N. W. Widstrom ◽  
D. M. Wilson

The use of plants that resist insects has been suggested as a potential means of reducing aflatoxin contamination in some crops. Dent corn, Zea mays L., germplasm possessing the characteristic of a relatively tight, complete husk cover and germplasm possessing the characteristic of a relatively loose, incomplete husk cover on the ear were evaluated for 3 years at Tifton, GA, for aflatoxin contamination. In two of the three test years, corn ears with tight, complete husk cover sustained significantly lower mean amounts of aflatoxin than ears with loose, incomplete husk cover following artificial inoculation with Aspergillus flavus Link spores. Ears hand-infested with maize weevils, Sitophilus zeamais (Motschulsky), sustained significantly higher amounts of aflatoxin (329 ng·g−1) than ears infested with fall armyworms, Spodoptera frugiperda (J. E. Smith), (80 ng·g−1), European corn borers, Ostrinia nubilalis (Hübner), (71 ng·g−1), or corn earworms Heliothis zea (Boddie) (60 ng·g−1). Overall, ears in the check (inoculated with A. flavus only) sustained significantly lower aflatoxin (37 ng·g−1) amounts than ears from plots supplemented with insects. Although insects were not applied in the check plots, some damage was observed on the ears.


2017 ◽  
Vol 53 (4) ◽  
pp. 346-348 ◽  
Author(s):  
M. I. Zhukovskaya ◽  
O. G. Selitskaya ◽  
A. V. Shchenikova ◽  
I. V. Grushevaya ◽  
Yu. M. Malysh ◽  
...  

2017 ◽  
Vol 15 (1) ◽  
pp. 44 ◽  
Author(s):  
Yuri S Tokarev ◽  
Mariya A Yudina ◽  
Julia M Malysh ◽  
Roman A Bykov ◽  
Andrei N Frolov ◽  
...  

Background. Endosymbiotic bacteria of the genus Wolbachia are widespread in arthropods and often cause reproductive abnormalities in lepidopteran insects, including corn borers of the genus Ostrinia. Wolbachia-Ostrinia is a promising model for studies of parasite-host interactions yet parasite prevalence in natural insect host populations remains unknown. Materials and Methods. Molecular genetic screening and statistical analysis is applied to evaluate prevalence rates of Wolbachia in sympatric populations of two corn borer species. Individual genomic DNA samples were extracted from last instar larvae collected in nature from different forage plants. For each sample of DNA showing positive signal with insect-specific primers the detection is performed using three diagnostic loci of Wolbachia: 16SrRNA, gatB and fbpA. Results. Wolbachia-positive signal is obtained for 13.5% larvae of Ostrinia nubilalis (N = 141) and 31.9% larvae of Ostrinia scapulalis (N = 138). In different localities the Wolbachia prevalence ranged from 2.9% (N = 34) to 65.8% (N = 38). Significantly higher rates of Wolbachia prevalence in insects from mugwort and hemp (O. scapulalis) as compared to those from corn (O. nubilalis) are revealed in three out of four localities. Conclusions. Endosymbiotic bacteria of the genus Wolbachia are revealed in natural populations of corn borers for the first time for Eastern Europe. The prevalence rates can be high and this should be taken into consideration when reproductive isolation is examined in population of these hosts as well as establishment of laboratory cultures is performed.


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