What Are the Best Pollinator Candidates for Camellia oleifera: Do Not Forget Hoverflies and Flies

Abstract

Camellia oleifera Abel. is an important woody oil plant, and its pollination success is essential for oil production. We conducted this study to select the best pollinator candidates for C. oleifera using principal component analysis and multi-attribute decision-making. Field observations of the flower-visiting characteristics of candidate pollinators were conducted at three sites. The insect species that visited flowers did not considerably differ between regions or time periods. However, the proportion of each species recorded did vary. We recorded eleven main candidates from two orders and six families at the three sites. The pollen amount carried by Apis mellifera was significantly higher than that of other insects. However, the visit frequency and body length of Apis mellifera were smaller than those of Vespa velutina. Statistical analysis showed that A. mellifera is the best candidate pollinator; Eristaliscerealis is a good candidate pollinator; Phytomia zonata, A. cerana, and V. velutina were ordinary candidate pollinators; and four fly species, Episyrphus balteatus, and Eristalinus arvorum were classified as inefficient candidate pollinators. Our study shows that flies and hoverflies play an important role in the pollination system. Given the global decline in bee populations, the role of flies should also be considered in C. oleifera seed production.

Pseudopollen in Camellia oleifera and its implications for pollination ecology and taxonomy

“…However, histochemical tests showed that C. oleifera pollen contained almost no protein, whereas its pseudopollen had significant amounts of protein. Furthermore, in our previous study, we found that the main visiting insects of C. oleifera were wasps and flies; additionally, pseudopollen was found in their intestines and pollen baskets, suggesting that they all collected pseudopollen ( Singer and Koehler, 2004 ; Pansarin et al, 2006 ; Pansarin and Maciel, 2017 ; Yuan et al, 2022a ). Therefore, we believe that pseudopollen in C. oleifera may be in the form of edible substances as a reward for visiting insects.…”

“…It did not differ significantly from normal pollen in the cross-sectional area and was ellipsoidal. Furthermore, it is transported along with pollen grains by pollinators ( Yuan et al., 2022 ). The pseudopollen of C. oleifera had almost identical morphology to that of real pollen; therefore, we speculated that the pseudopollen might convey deception signals to insects by simulating the morphology of normal pollen.…”

“…It has an important research value for species that use seeds as a source of production. Pseudopollen also exists in C. oleifera ( Hu and Gao, 2022 ; Yuan et al, 2022a ; Yuan et al, 2022b ). C. oleifera is a small evergreen tree species and produces seeds with edible oils rich in unsaturated fatty acids and vitamin E ( Xiong et al., 2019 ).…”

Unilateral cross-incompatibility between Camellia oleifera and C. yuhsienensis provides new insights for hybridization in Camellia spp

“…Pre-pollination barriers under natural conditions may be due to time, space, and availability of pollinators ( Moyle et al., 2014 ). One of the main differences between the C. oleifera and C. yuhsienensis is flowering phenology, which hinders genetic exchange, despite the similarity of their pollinators and geographical location ( Maekawa et al., 2022 ; Yuan et al., 2022 ). Artificial pollination overcame the flowering asynchronism between C. oleifera and C. yuhsienensis and facilitated the genetic exchange between them.…”