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

Abstract

The seasonal flight activity of both sexes of the eastern hemlock looper, Lambdina fiscellaria fiscellaria Guenée (Lepidoptera: Geometridae) was studied during two consecutive years in Quebec and Newfoundland, using light (L), pheromone (P) and combined light and pheromone (LP) traps. Moth density significantly affected the performance of the different traps, with P traps being more effective at low than high density. However, P trap catches decreased just prior to the onset of female captures, probably as a result of competition between traps and virgin calling females. Nearly all females caught in L and LP traps were already mated and even the first females caught had laid at least half of their egg complement. In Quebec under warm nights, the pattern of male activity occurred at different times, with peak P catches being later in the scotophase than those of L traps, but overall similar numbers of males were caught in both traps. In contrast, under cool nights, males were caught early in the night in both P and L traps, suggesting a strong competition effect between traps, although more males were caught in P than L traps overall. In Newfoundland, the pattern of male captures in L and P traps was similar at both high and low temperatures, so competition between trap types would always be high. Under these conditions P traps were more effective than L traps. Irrespective of the region, year or temperature, significantly more males were captured in LP, with the effect of L and P being additive. In both regions, females responded similarly to L and LP traps with peak activity occurring early in the night. Captures of females were lower than those of males under cool temperatures, suggesting that the temperature threshold for flight is higher for females. The use of L and P traps simultaneously and/or in combination is discussed in relation to integrated pest management programs and ecological considerations.

Monitoring autumn gum moth (Mnesampela privata): relationships between pheromone and light trap catches and oviposition in eucalypt plantations

“…Differences in catches from pheromone and light traps have not so far been satisfactorily explained by any author. Temporal differences in the efficacy of light and pheromone traps have also been reported previously (Srivastava and Srivastava 1989;Campbell et al 1992;Delisle et al 1998). It has been suggested that this occurs because at high moth populations, pheromone traps are 'out-competed' by calling females.…”

“…Pheromone traps can be used to monitor the temporal fluctuations, spatial distributions and abundances of insects of economic importance. Furthermore, because pheromone traps are species-specific, assessment of the abundance of the particular insect is less labour-intensive, which can make them a more cost-effective technique than light traps (Delisle et al 1998). In addition, pheromone traps can attract the target insect from considerable distances away (Ostrand and Anderbrant 2003).…”

Effect of simulated fall heat waves on cold hardiness and winter survival of hemlock looper, Lambdina fiscellaria (Lepidoptera: Geometridae)

“…However, it is a polyphagous herbivore, with larvae feeding on a variety of coniferous and deciduous trees (Carroll, 1956;Hébert et al, 2006;Berthiaume, 2007). Moths emerge from mid-August to late September and thus females lay eggs in late summer -early fall (Carroll, 1956;Delisle et al, 1998). Eggs are laid singly or in small groups of two or three on tree trunks or branches (Carroll, 1956) and they enter diapause for about 3 months (Delisle et al, 2009).…”

Wing wear and body size measurements of adult spruce budworms captured at light traps: inference on seasonal patterns related to reproduction

“…In these species, females rapidly lose weight after emergence as a result of egg-laying (Boggs 1997), and measurement of dry weight of field-collected specimens can be used to simulate the number and proportion of eggs laid by females relative to their potential fecundity (Lyons 1996). Equations describing the triangulation between potential fecundity (estimated using an indicator of body size), dry weight and realized fecundity (proportion of eggs laid by females at the time of sampling) are derived by rearing field-collected pupae to adulthood in the laboratory and allowing them to lay known numbers of eggs over different time intervals (Delisle et al 1998;Rosenheim et al 2008;Thomas 1978). The approach is depicted in Fig.…”