Canadian Forest Service Publications

Calling behaviour of the armyworm, Pseudaletia unipuncta. 1982. Turgeon, J.J.; McNeil, J.N. Entomologia experiementalis et applicata 31: 402-408.

Year: 1982

Issued by: Great Lakes Forestry Centre

Catalog ID: 22619

Language: English

Availability: PDF (request by e-mail)

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The calling behaviour of virgin female armyworms, Pseudaletia unipuncta (Haw.), was studied at 25° ± 0.5° and 65 ± 5% RH under a 16L: 8D photoperiod. The age at which females started calling following emergence varied from 2 to 10 days, with a mean of 3.9 days. Due to these differences comparisons of calling behaviour on successive days were made using the “calling” age rather than age from emergence. The calling pattern of individual females, observed every 10 min, changed on successive days of calling. Over 7 days, the mean onset calling time advanced from 396 to 301 min after the onset of the scotophase, the total time spent calling per day increased from 62 to 182 min. the number of calling bouts decreased from 1.8 to 1.4 while the duration of a calling bout increased from 34 to 125 min. Entrained females held under 56 hr of darkness exhibited an endogenous circadian rhythm of calling. Observations taken every 10 min significantly underestimated the number of calling bouts per day (1.8 instead of 16 on the first day of calling) and overestimated the duration of each bout (34 min instead of 2 min on the first day of calling) when compared with the data collected from continuous observations. Values for the mean onset calling time and the time spent calling each day did not differ significantly using the two observation schedules.