Different Trap Types Depict Dissimilar Spatio-Temporal Distribution of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in Cotton Fields

Abstract

Pheromone-baited traps have been widely used for the monitoring of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), in order to time any control measures during the growing season. Different monitoring techniques may provide differential results regarding adult captures. However, studies on the comparative evaluation of the performance of different trap types on the captures of H. armigera are limited. To close this gap, in the present study, three different funnel traps (striped, green, and colored) were simultaneously evaluated in Central Greece, one of the main cotton-producing geographical zones in the European Union, in order to compare trap performance on the captures of H. armigera, as well as to depict the distribution of this species per trap in the study area. A differential performance of the different trap types tested, expressed as numbers of adults captured, was recorded. Specifically, the striped trap captured many more adult moths than the other two trap types. Given that the only difference among these traps was the color of the external trap surface, we hypothesize that trap color does matter in the case of H. armigera, and it is likely that brighter colors may be more attractive than darker ones.

Effect of Trap Type and Height on the Captures of the Pink Bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), in Pheromone-Baited Traps in Cotton

“…In fact, location is a critical parameter and should be taken into account when a trap-based monitoring protocol is planned. For instance, Karakantza et al [39] reported high variation in the total captures of H. armigera adults among twenty cotton fields. The differences found among the traps that had been placed at different heights, although less pronounced as compared with those of the different trap types, were considerable during the second half of the monitoring period, when P. gossypiella adult numbers were high.…”

Suitability of Satellite Imagery for Surveillance of Maize Ear Damage by Cotton Bollworm (Helicoverpa armigera) Larvae

“…Similarly, UV light traps are found to be the most effective for CBW adult monitoring at low intensity for both sexes [38]. Some studies indicate that trap color influences CBW adult captures since they have a preference for bright colors [39].…”

“…According to our review, there is no rapid, cost-and labor-effective CBW damage surveillance method for maize, despite the high economic impact of the CBW. Satellitederived surface reflectance provides insights into the visual characteristics and changes in maize [47,55,56,70] that play an important role in determining the oviposition preferences of CBW adults under maize field conditions [13,30,[33][34][35][36][37][38][39]75]. Our hypothesis is that models, based on satellite imagery, can be developed, that will improve CBW surveillance (including both monitoring and prediction) for maize crops, aligned with an optimal time period and maize phenology.…”