Ostrinia nubilalis (Hb.) (Lep., Pyralidae) on sweet corn: relationship between adults caught in multibaited traps and ear damages

Abstract

Infestation with Ostrinia nubilalis "Hb[#\ the European corn borer "ECB# can be detected by using di}erent sampling techniques in the _eld and statistical models aimed to assess the development time of ECB larvae and crop damage[ An appropriate monitoring for this polyphagous species to show a relationship between the kind of sampling or a model and the subsequent damage in a particular crop\ is very di.cult[ Sex pheromone traps\ generally\ are also not reliable for monitoring ECB[ The possibility of employing new types of traps baited with a sex pheromone and a maize kairomone\ the phenylacetaldheyde "PAA# "multibaited traps# was investigated[ In sweet corn\ trapping experiments were conducted over a 1!year period with two kinds of cone traps "XLa and XLb# set up at the borders of _elds "four replicates#[ ECB attacks of _rst and second generation larvae were evaluated in the corn ears as a percentage of damage and using a damage index "DI#[ A correlation was found between the number of females caught per trap and either the percentage of damaged ears "r 9[62 for XLa^r 9[54 for XLb# and the DI "r 69 for XLa^r 9[59 for XLb#[ Conversely\ the number of males caught per trap was not correlated with ECB larval damage[ A linear model of multiple correlation _tted to the data of simultaneous captures of males and females showed that the coe.cients were not higher than simple correlation[ The correlation coe.cients obtained by _tting a curvilinear response surface were higher "r 9[70 for XLa and r 9[73 for XLb\ respectively\ related to percentage of damaged ears^r 9[68 for XLa and r 9[65 for XLb\ respectively\ related to DI# thus indicating that the simultaneous counting of males and females in cone traps can be an e.cient and simple monitoring tool[ U[ S[

Testing mating disruption of the horse chestnut leafminer Cameraria ohridella (Lepidoptera: Gracillariidae) in field tents

“…A lack of correlation between male captures in pheromone traps and damage levels in the crop to be protected has also been reported in other studies (Maini and Burgio 1999;Hillier et al 2004).…”

Field control of Fusarium ear rot, Ostrinia nubilalis (Hübner), and fumonisins in maize kernels

“…Indeed, only one spraying date is applicable on maize, and many factors interfere with the precise timing of the application. Such interfering factors are: low availability of self‐propelled sprayers with an adjustable working height allowing treatments above the crop stand; rain or irrigation, which impede sprayer access to the field, in many cases just after maize flowering; the coexistence of different ECB biotypes with different voltinism, which impedes the accurate detection of the threshold; monitoring difficulties: counting egg masses is time consuming and pheromone traps, in spite of many positive experiences,52, 53 did not show good efficacy in the situation considered (data not shown). …”

Monitoring and efficacy of selected insecticides for European corn borer (Ostrinia nubilalis Hubn., Lepidoptera: Crambidae) control

“…Despite considerable variability in the numbers of moths caught with pheromones at different sites throughout the years, the percentage of plants with damage and the intensity of the infestation in terms of larval density and galleries found on the untreated plots did not differ substantially over the years or among the sites. This shows that it is not possible to foretell the intensity of the attack by the catch on a pheromone trap, or to predict the intensity of the crop infestation, as stated by Maini and Burgio (1999). Bartels and Hutchison (1995) suggest using blacklight traps to monitor ECB flight.…”