Area-Wide Pheromone Trapping of Helicoverpa zea and Heliothis phloxiphaga (Lepidoptera: Noctuidae) in the Sacramento and San Joaquin Valleys of California

Abstract

In 1986 and 1987, traps baited with the pheromone of Helicoverpa zea (Boddie) were operated adjacent to fields of processing tomatoes ( Lycopetsicon escutentum Miller) in the Sacramento and San Joaquin valleys of California to determine the seasonal flight patterns of male H. zea and Heliothis phloxiphaga Grote & Robinson. The latter species was attracted to the pheromone of H. zea and was commonly captured in traps. Results indicate there are at least two generations of H. zea per year in the Sacramento and San Joaquin valleys. In general, trap catches of H. zea increased rapidly starting in mid-August and peaked during late August or early September. Tile timing of trapping events, defined as first catch, first peak, initiation of late peak, and late peak, was similar among locations monitored. This indicated that regional monitoring of this pest may be feasible, although further effort is needed to define early-season events better. Males of H. phloxiphaga were captured at all locations; these were generally trapped in greatest numbers in May and usually exceeded the numbers of H. zea captured from February to June. The capture of H. phloxiphaga in traps intended for H. zea can make interpretation of trap catches difficult, especially early in the season. Moon phase did not appear to influence the timing of peaks in H. zea trap catch.