小峰熊蜂访花偏爱性

传粉昆虫在访花时,通常会表现出对某一类型花的偏爱性。本研究利用人工制作的大小、颜色、形态和气味不同的9种类型的花来研究小峰熊蜂Bombus hypocrita的访花偏爱性。结果表明：当增加花的大小、形态、气味等附加特征数时,小峰熊蜂的偏爱性程度与花朵附加特征数有显著相关性（P<0.01）。当花朵颜色由2种增加到4种,熊蜂对紫色花的偏爱性程度降低,但花朵颜色的种类与小峰熊蜂的访花偏爱性没有相关性（P>0.05）,花颜色的种类对熊蜂访紫色花的偏爱性影响不大。大小为5 cm的紫花被访次数（108±9次）明显高于大小为3 cm的紫花被访次数（40±4次）（P<0.01）,说明熊蜂明显喜欢访大花瓣的紫花。完全盛开的紫花被访次数（129±13次）显著高于刚绽放的花被访次数（26±3次）（P<0.01）,说明熊蜂喜欢访盛开的紫花。柠檬味的紫花被访次数（63±8次）明显低于草莓味的紫色花被访次数（88±2次）（P<0.05）,说明熊蜂喜欢访草莓味的花朵。

Foraging preference of the bumblebee Bombus hypocrita (Hymenoptera: Apidae)

While foraging, insect pollinators often restrict their visits to one type of flower. We measured nine types of floral selectivity (preference) in the bumblebee Bombus hypocrita workers foraging on mixed arrays of artificial flower types differing in either colour only (variation in a single trait) or colour plus additional traits (variation in multiple traits). The results showed that there was a significant degree of preference as the number of flower traits (including size,morph and odour) was increased (P<0.01). There was a descreasing tendency for foraging rate as the number of flower colours was increased from two to four,and no significant relationship between the number of flower colours and preference（P>0.05）. The number (108±9) of 5 cm purple flowers visited by B. hypocrita was significantly higher than that (40±4) of 3 cm purple flowers (P<0.01),suggesting thatB. hypocrita has a preference for visiting 5 cm purple flower. The number (63±8) of purple flowers with lemony flavour visited by B. hypocrita was significantly lower than that (88±2) of purple flowers with strawberry flavour (P<0.05), suggesting that B. hypocrita had a preference for visiting the purple flowers with strawberry flavour.