Posted by Dr G. Bittar
The worldwide decline of pollinators is a major global disaster looming. It is thus worth of attention when a new study details the positive interaction between an introduced plant and local pollinators. A research carried in the Fiji islands shows that an invasive creeping daisy has a positive influence on a solitary bee pollinator species, thus benefitting crops and biodiversity on the islands. Contrary to the usual anti-invasive meme, flowering plants considered as invasive may have positive effects on insects, especially on nectar and pollen feeding species, and the presence of some exotic flowering plants may be of benefit by encouraging higher numbers of pollinating species to occur at a site.
The complete article
Factors influencing the foraging activity of the allodapine bee Braunsapis puangensis on creeping daisy (Sphagneticola trilobata) in Fiji
by Abhineshwar V. Prasad & Simon Hodge
Journal of Hymenoptera Research 35: 56–69, doi: 10.3897/JHR.35.6006
can be found on
Here’s the Introduction:
There is growing concern regarding the global decline of honey bee populations and the implications of this demise for the pollination of entomophilous crops (Potts et al. 2010, Groom and Schwarz 2011; Cornman et al. 2012). In the future we may rely on other insect species to perform crop pollination services, including naturally-occurring native or introduced species of bees (e.g. Rader et al. 2009). Pollination success of generalist plants tends to be positively related to pollinator diversity, so any habitat modifications that increase the number of pollinating species present at a site would tend to be of some inherent value (Hoehn et al. 2008, Albrecht et al. 2012). The deliberate sub-planting of crops, orchards or vineyards with flowering plants (such as buckwheat, Phacelia and Alyssum) is already employed as a means of attracting beneficial invertebrates by providing a nectar or pollen reward (Irvin et al. 2006). A similar process involves the leaving of field margins fallow to allow a higher diversity of flowering ‘weeds’ to grow, which again promotes a higher diversity of invertebrate predators and pollinators to occur (Cowgill et al. 1993).
The situations described above give the impression that the presence of some exotic flowering plants may be of benefit by encouraging higher numbers of pollinating species to occur at a site. Outside of agro-ecological systems, many studies have indicated that even flowering plants considered as invasive may have positive effects on insects, especially on nectar and pollen feeding species. For example, in Europe and North America, the exotic highly invasive Himalayan balsam (Impatiens glandulifera Royle) is visited by a high diversity of native pollinating insects, including bumble bees (Bombus spp), solitary bees, and domestic honey bees (Apis mellifera L.) (Showler 1989, Stary and Tkalcu 1998, Nienhuis et al. 2009).
Sphagneticola trilobata (L.) Pruski (Asteraceae) is an emerald-green creeping plant that has bright yellow daisy-like flowers. The plant is of Central/South American origin and is now found in many South Pacific island states, where it has become established on disturbed sites, such as waste land, road sides, riverbanks and the sea shore (Whistler 1995). The species is thought to have been introduced to Fiji sometime in the early 1970s as a garden ornamental near Suva Point, on the main island of Vitu Levu (Thaman 1999). A recent survey in the Suva area reported over 100 species of arthropods associated with road side patches of Sphagneticola trilobata, including Hymenoptera such as parasitoid wasps, honey bees and solitary bees (Prasad and Hodge in press). One species of solitary bee, Braunsapis puangensis (Cockerell, 1929) (Apidae: Allodapini) was locally abundant on patches of Sphagneticola trilobata in the Laucala Bay area of Suva. This bee species is probably of Indian origin and was most likely carried to Fiji by anthropogenic means (Groom and Schwarz 2011, Davies et al. in press). The genus Braunsapis is listed in the Fijian fauna provided by Evenhuis (2007), but does not appear in the older lists of Michener (1965), Fullaway (1957) and Turner (1919). Shenoy and Borges (2008) examined the diurnal activity patterns and pollination behaviour of this species in India and the phylogeny of the group has received some detailed attention (Bull et al. 2003, Schwarz et al. 2004, Fuller et al. 2005). The genus has also been studied in terms of its social parasite behaviour (Reyes and Sakagami 1990, Batra et al. 1993).
The aim of this study was to obtain empirical data on the activity and distribution of Braunsapis puangensis in the Suva area of Fiji and examine its association with Sphagneticola trilobata. We studied spatial patterns on a local scale by recording its presence or absence on patches of Sphagneticola trilobata along roadsides, and carried out long term sampling over 14 months to gain information on patterns in seasonal occurrence. A more detailed study was performed at a single site to investigate daily foraging patterns and examine the effects of environmental conditions on Braunsapis puangensis activity.
See also
Garden plants do not have to be native to help most pollinating insects — Garbuzov and Ratnieks 2013