Social insects make elaborate use of simple mechanisms to achieve seemingly complex behavior and may thus provide a unique resource to discover the basic cognitive elements required for culture, i.e., group-specific behaviors that spread from “innovators” to others in the group via social learning. We first explored whether bumblebees can learn a nonnatural object manipulation task by using string pulling to access a reward that was presented out of reach. Only a small minority “innovated” and solved the task spontaneously, but most bees were able to learn to pull a string when trained in a stepwise manner. In addition, naïve bees learnt the task by observing a trained demonstrator from a distance. Learning the behavior relied on a combination of simple associative mechanisms and trial-and-error learning and did not require “insight”: naïve bees failed a “coiled-string experiment,” in which they did not receive instant visual feedback of the target moving closer when tugging on the string. In cultural diffusion experiments, the skill spread rapidly from a single knowledgeable individual to the majority of a colony’s foragers. We observed that there were several sequential sets (“generations”) of learners, so that previously naïve observers could first acquire the technique by interacting with skilled individuals and, subsequently, themselves become demonstrators for the next “generation” of learners, so that the longevity of the skill in the population could outlast the lives of informed foragers. This suggests that, so long as animals have a basic toolkit of associative and motor learning processes, the key ingredients for the cultural spread of unusual skills are already in place and do not require sophisticated cognition.

Summary Mutualism between long corolla tubed plants and their potential pollinators, long‐tongued flies, is a classic example of coevolution, but to date, has only been reported from the regions of southern Africa. Many plant species from the Himalayas also show botanical characteristics that could be consistent with pollination by long‐tongued flies. Here, we seek the evidence of the “long‐tongued‐long tubed fly/flower” mutualism out of Africa, in a different continent and climatic region, the Himalayas.Floral traits of Himalayan region endemic alpine genus, Roscoea, indicate possible mutualism with long‐tongued flies for pollination success; however, effective pollinators of this genus are yet unknown. This study investigates whether long‐tongued flies and Roscoea purpurea in Nepal Himalayas show exclusive mutualism for their survival/reproduction.We made extensive observations of floral visitors of R. purpurea and food source of Philoliche longirostris across their wide ranges of populations in Nepal Himalayas for three consecutive years (2012–2014). To confirm the obligate reliance of R. purpurea upon P. longirostris for pollination success, manipulated pollination experiments were conducted at two populations for 2 years. Similarly foraging behavior, visitation frequency, and pollination efficiency of P. longirostris were assessed at two populations for 2 years, and its contribution for the reproductive success of R. purpurea was evaluated. Our results indicate that R. purpurea is self‐compatible but lacks autonomous selfing and obligatorily relies on P. longirostris for reproductive success. Across all populations, P. longirostris was observed as an exclusive and highly efficient pollinator of R. purpurea, while P. longirostris exclusively depends up on R. purpurea for food source.Out of Africa, this study provides the first evidence of long‐tongued fly pollination system and indicates the possibility of additional instances of such a rare phenomenon in the Himalayas. Finding of specialized pollinator of Roscoea only at its evolutionary center indicates that Roscoea species are originally pollinated by long‐tongued flies. Spatial mismatch with specialized pollinators may have induced the evolution of autonomous selfing in North Indochinese clades of Roscoea. This finding thus substantiates how geographic disjunction causes the shifting of pollination mechanism in closely related plant species.

The results for L. apertum are consistent with the 'size advantage hypothesis' developed for animal species with sex change. The theory predicts that when individuals are small they should exhibit the sex for which the costs of reproduction are less, and this usually involves the male phase. L. apertum provides an example of gender diphasy, a rare sexual system in flowering plants.