The influence of moonlight and weather on catches of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in light and pheromone traps

Abstract

Records of hourly trap catches of Helicoverpa armigera (Hiibner) in a light trap and two pheromone traps in Andhra Pradesh, India, were used to assess the influence of moonlight and weather on trap performance. The environmental factors that were considered were mean hourly temperature, relative humidity, wind speed and maximum hourly percentage moon illuminance. The mean number of adults caught per hour reached a peak at 03.00 h in the light trap and at 02.00 h in one of the pheromone traps. The environmental factors were not sufficiently severe to produce any marked activity thresholds, although zero catches were recorded in the light and pheromone traps on occasions when the mean hourly temperature was 11°C. Despite there being obvious relationships between hourly light and pheromone trap catches with temperature, relative humidity and wind speed, it was not possible to determine whether these were causally related or merely coincidental relationships. Some of the observed relationships could not be explained in terms of known physiological or behavioural characteristics of the insect. It was evident that the light trap performance was influenced by the level of moon illuminance because this affected both the timing and size of the peak catch.

Effects of mobility on daily attraction to light traps: comparison between lepidopteran and coleopteran communities

“…, 1999). The effect of wind speed on captured Lepidoptera was not observed, in contrast to previous studies (Bowden, 1982; Dent & Pawar, 1988; Yela & Holyoak, 1997), because the wind was light during the sampling period. Relative humidity has been reported to have no effect on captures of Lepidoptera by light traps (Guedes et al.…”

“…Among the meteorological factors, the result that air temperature limited the trap captures of Lepidoptera is consistent with previous studies (Bowden, 1982; Dent & Pawar, 1988; Holyoak et al. , 1997; Yela & Holyoak, 1997; Butler et al.…”

“…, 1997; Yela & Holyoak, 1997). Trap efficiency for Lepidoptera is positively correlated with temperature and the thickness of cloud cover, and negatively correlated with wind speed, precipitation, and the fullness of the moon on the trap night (Bowden, 1982; Dent & Pawar, 1988; Yela & Holyoak, 1997; Butler et al. , 1999).…”

The relative performance of pheromone and light traps in monitoring the seasonal activity of both sexes of the eastern hemlock looper, Lambdina fiscellaria fiscellaria

“…Furthermore, the use of both types of traps simultaneously may help in interpreting pheromone trap catches because the reproductive state of the females caught in light traps may provide some insight into competition between pheromone traps and feral females (Gentry & Davis, 1973;Hendricks et al, 1973;Oloumi-Sadeghi et al, 1975;Fletcher-Howell et al, 1983;Dent & Pawar, 1988;Srivastava & Srivastava, 1989;Herbert et al, 1991;Campbell et al, 1992). However, using different trapping techniques simultaneously may also lead to additional sources of error in the interpretation of trap catches, because of potential interference between traps (Bucher & Bracken, 1979) or confounding effects of environmental conditions on insect activity patterns (Dent & Pawar, 1988). Jobin & Coulombe (1992) recently developed the Luminoc r trap, which is a miniaturized, portable insect light trap equipped with a 6 volt battery activated by a photocell and a time clock.…”

Biocontrol Potential and its Exploitation in Sustainable Agriculture

“…Besides these, environmental factors such as wind velocity, temperature and moonlight have a tremendous bearing on trap catches (Dent and Pawar, 1988). The highest catches of Helicoverpa armigera were recorded between 12 at midnight to 0200 h in the morning, while those of Spodoptera litura were highest between 2 to 4 o'clock in the morning.…”