The vital role of ‘unpopular’ pollinators

With growing knowledge about the importance of insect pollinators in ensuring effective crop production and global food security, and their high profile in biodiversity initiatives such as the work of 3Bee, it might be easy to imagine that they are all looked on relatively fondly by the public. Yet not all pollinators are perceived equal; while bees, and in particular honeybees and bumblebees, are the popular and ‘charismatic’ emblems among plant visitors, wasps are seen in an entirely different light.

It wouldn’t be too much to say, in fact, that bees are loved, and wasps are hated. This is despite the fact that wasps have multi-functional roles in ecosystems, pollinating plants while also serving as natural enemies of troublesome pests, either as predators or parasitoids, depending on the species. Part of the problem simply comes down to the fact there exists a tendency to lump all wasps in with the stinging, social wasps such as the ‘yellowjackets’ (which are great too, once you get to know them). The truth is that 99% of wasps don’t have a functional stinger at all, and the vast majority look nothing like the famous bright and stripey specimens.

While a lack of public knowledge is part of the negative perception, scientists can also bear some of the responsibility, with a comparatively low level of research effort exploring the ecosystem services provided by wasps. This relative lack of work seems to have resulted in science not fully appreciating the qualities of wasps. A study in the States has shown that assumptions about wasps’ role as pollinators are incorrect. In many aspects of pollination, such as interactions with specific flowers, they are comparable to bees, with the authors of the work suggesting that previous beliefs that this was not the case could be due to looking at specific species, rather than the pollinator community more broadly.

While it’s true that there are notable types of bees which are equipped to carry large amounts of pollen, such as Bombus bumblebees, there are several wasp families that carry more than some bees, and from the point of view of plants, quantity isn’t everything anyway. The researchers found wasp families that proved more ‘loyal’ to plants than certain families of bees, meaning that they are more likely to deliver pollen to the right places. They also revealed that wasps cover pollination niches that bees don’t, at vital points in the year.

Wasp families that are high-performance pollinators are one thing, but there are also many plants specialised for wasp pollination. Perhaps the most famous is the mutualistic relationship between figs and fig wasps, where fig species are served by specific types of wasp, the females of which die inside the fruit after laying the eggs of the next generation and pollinating the plant. Exclusively wasp-pollinated flowers tend to be visually drab, leading experts to suggest that chemical communication is pivotal. A good example of this is recent work in Germany looking at the African milkweed. Scientists found that the plant’s nectar contains toxins which have a more damaging effect on honeybees than social vespid wasps, while also releasing specific chemicals which elicit a response in wasp antennae.

Despite the abundant evidence on the vital work of wasps, take a scan of most of the mainstream media during any given summer and you will see largely tales of fear and loathing. From the threat of ‘plagues’ of “sugar-crazed” wasps invading gardens to treating the presence of wasps nests as a “horror” that necessitates little short of a war footing, there exists a general sense that wasps are something to be avoided or got rid of, by any means necessary. This is, naturally, something that those in the pest control industry are happy to encourage and amplify wherever possible.

Faced with swathes of anti-wasp material in the media, a committed cadre of experts have made it something of a mission to change perceptions, while conservation organisations and even farming commentators have also gone out of their way to make stirring cases for the defence. A survey has shown that even scientists working with wasps in the Southern Hemisphere, where there are more problems with invasive wasps causing ecological damage than in northern climes, are overwhelmingly positive about their study subjects, and more than happy to put this across when they get a chance.

The good news is that the views of the optimistic experts seem to be making something of a difference. In the same survey, 60% of scientists the researchers spoke to reported that their interactions with the media shifted stories in a more wasp-positive direction, with 10% believing that their influence on stories had been ‘enormous’. Offering some nuance to the media clearly works, but there also needs to be a broadening of research and direct public outreach about the diverse world of wasps. As it stands, there isn’t even much historical data on wasps, let alone great conservation concern. Yet there’s so much more than the stripes, stings and picnic panics which tend to dominate the media discourse.

A particularly notable part of the recent work debunking myths about wasp pollination was that in some habitat that is put in place specifically for conservation purposes in agricultural environments, such as prairie strips in US crop fields, wasps use similar plant communities to bees. On the other hand, for field margins mostly containing grasses and herbaceous flowering plants, the patterns differed between the two types of pollinators. This provides some food for thought when designing interventions to improve species’ prospects. Moves like 3Bee’s Biodiversity Oases, which aim to bring continuous biodiversity improvement to areas of different sizes through pollinator-friendly planting, may start with bees in mind but do much to help wasps, hoverflies and other invertebrates, too.

Ultimately, antipathy towards wasps can’t be seen in isolation — it has knock-on effects for other pollinators, given the fact that bees and hoverflies are often mistaken for wasps by the public. It also tends to towards dismissing the ‘point’ of some insects compared to others when all have a role in well-functioning ecosystems — a problem that even affects perceptions of some types of bee, to the neglect of others. All insects count, even the ones that can get a little irritating at certain points of the year. It’s time to support the pollinating, pest-controlling unsung heroes to thrive alongside us.