Greater number of pollen donors improves female reproductive success but not progeny vigour in Allium stellatum

By Yu & Muchhala

Animal pollinators are critical for the reproduction of most flowering plants. Because different animals may deposit more or less pollen on a flower based on their body size and how often they visit flowers, it is important to understand how these differences can affect plant reproduction. One important aspect of pollination is whether a pollinator deposits pollen from one or more fathers, because having more fathers to choose from can increase the likelihood of having more fit offspring. 

In our study, we test how the number of fathers donating pollen affects offspring growth rates by pollinating prairie onion flowers with pollen mixtures with either one, two, or three fathers. We found that pollen mixtures with a greater number of fathers led to a greater number of seeds that germinated into seedlings but also led to seedlings that grew more slowly. This is potentially explained with a trade-off between quality of seedling vs. number of seedlings. 

These effects indicate that the composition of pollen mixtures deposited by pollinators can have significant effects on plant populations and that understanding differences in animal pollination will help understand plant population patterns.

Read the scientific publication in JPE. 

 

Insect-flower interactions in the Mediterranean area: a Citizen Science dataset collated within the Life 4 Pollinators project

By Barberis, Bitonto et al.

 

Process of photographic record validation, from the upload to the final certification by the team of expert taxonomists and record display on the website map, where it becomes publicly available

The LIFE 4 Pollinators project (LIFE18/GIE/IT/000755) “Involving people to protect wild bees and other pollinators in the Mediterranean” aims to promote the conservation of pollinating insects and entomophilous plants across the Mediterranean region by fostering progressive changes in human practices that threaten wild pollinators. It’s well established that pollinators play a vital role in most terrestrial ecosystems, supporting wild plant communities and enhancing agricultural yields. However, despite their ecological and economic importance, they have been experiencing an alarming decline over the past decades, and many people still seem to be not fully aware of the consequences of such a loss. The Mediterranean region, in particular, is known for harboring highly diverse communities of plants and pollinators while being vulnerable due to intense anthropogenic pressures. In response to this urge to fill knowledge gaps and promote behavioral changes, in recent years growing attention has been directed toward the contribution that citizens can give in support of pollinator research by means of their engagement through Citizen Science. In addition to the implementation of several actions directed to raise awareness, the LIFE 4 Pollinators project launched a web platform to collect photographic records of flower–insect interaction from the public. The platform is expected to remain active for at least ten years, during which we encourage continuing record submissions by interested bodies. The dataset gathered so far is freely accessible to anyone, and it will be periodically updated with the new records collected.

Read the scientific publication in JPE 

Bumble bee colony health is diminished in a mesotunnel enclosure planted with a cucurbit monoculture crop

A bumble bee visiting a muskmelon flower.

By Gauger et al.

Vegetable growers commonly use forms of protective covers to help shield crops from insect pests, plant pathogens, and unfavorable climatic conditions. In particular, producers in the eastern and midwestern United States have adopted “mesotunnel” systems (a fine plastic mesh row-cover suspended over crop plants) for pest exclusion from cucurbits (melons, squashes, and pumpkins) and other crops. Cucurbit crops under the mesotunnel system require special management in order to achieve pollination, such as placing a commercial bumble bee colony into the mesotunnels, but little is known about how this environment affects bumble bee colonies’ health and reproduction.

Our primary goal for this study was to document initial evidence about commercial bumble bee colonies’ health outcomes in a cucurbit monoculture mesotunnel system. In the summers of 2022 and 2023, we planted large mesotunnels with cucurbit crops (muskmelon or acorn squash) and allowed Koppert Bombus impatiens colonies to forage within them for ~4 weeks. We dissected these colonies and compared them to colonies that did not forage at all, and colonies that foraged freely on the 100-acre organic research farm. We found that in 2023, colonies from the cucurbit mesotunnel had worse reproductive and overall health than free-foraging colonies, and in some measurements, performed no better than colonies that did not forage at all. This indicates that something about the cucurbit mesotunnel system is constraining bumble bee colonies’ growth and health.

Read the scientific publication in JPE