Polia

Abstract: Sibling Polia grandis (Boisduval) larvae were reared at two constant temperatures on fresh foliage of quaking aspen (Populus tvemuloides Michx.). Female pupae developing at 25°C were 24% heavier than those developing at 30°C and corresponding males were 32% heavier. Duration of the larval period averaged 51 days at the former temperature and 41 days at the latter. Based on other Lepidoptera, a 24% change in pupal weight affects fecundity by 28 to 130 eggs per female. Fluctuations in larval temperature regime might induce size and fecundity variation in natural populations of grandis and other Lepidoptera.

Abstract: Electrophysiological analysis of olfactory hair sensilla in male P. pisi has revealed four different types of presumed pheromone receptor cells, maximally responsive to (Z)-11-tetradecenyl acetate (Z11-14:Ac), (Z)-9-tetradecenyl acetate (Z9-14:Ac), (Z)-11-hexadecenyl acetate (Z11-14:Ac) and (Z)-7-dodecenyl acetate (Z7-12: Ac), respectively. These four compounds were tested, singly and in various combinations, for efficacy in attracting P. pisi males in the field. High trap catches were obtained with mixtures of Z11-14: Ac/Z9-14: Ac in the ratio 100/100, whereas the 100/30 and 30/100 mixtures of the two compounds were only slightly attractive. No male P. pisi were captured by single chemicals or binary combinations of Z11-14: Ac/Z11-16: Ac, Z11-14:Ac/Z7-12:Ac, Z9-14:Ac/Z11-16:Ac, Z9-14:Ac/Z7-12:Ac, or Z11-16:Ac/Z7-12:Ac. Various compounds, including Z11-16: Ac and Z7-12:Ac, were tried as third chemicals in addition to 100 μg Z11-14: Ac + 100 μg Z9-14: Ac but none increased trap catches over the basic lure.