Hoverflies have wide diversity between species. Several of them resemble bees or wasps in appearance (particularly large bodied species as they are more likely to be predated upon by birds)1. Hoverflies have been observed to imitate their stinging behaviour1 (pressing the tip of the abdomen against a threat, such as a human)1. Additionally, hoverflies can also imitate the buzzing noise that bumblebees make which are indistinguishable by computer based analysis1. A study that used pastry which was shaped and painted like hoverflies, found that birds only avoided attacking the pastries (which has similar nutrition as an insect) when the bumblebee sound was played1. Upon hearing the hoverfly recording, the birds ate the pastry, suggesting birds can make out the difference between bumblebees and hoverflies1.
Whilst Europe reimburse farmers to protect biodiversity, such as reducing chemical use or farming organically, Australia has no equivalent system in place2. This is an issue because it is estimated that ¾ of all food crops require pollinators, but little is known about what habitat requirements other non-bee pollinators need2. Australia is the second largest global exporter of Canola2, and in 2016 the Melangyna viridiceps hoverfly helped a farmer in Tasmania achieve a record yield of Canola (6.17 tonnes per hectare), acting both as a biological pest control agent and as a pollinator3. More focus on other pollinators such as hoverflies could increase the export earnings of the Australian agriculture industry, whilst simultaneously improve local biodiversity near managed crops.
It has been found that hoverflies and other pollinators such as bumblebees can transmit bee viruses4. It is thought that domestic infected honeybees infect wild flowers with the virus whilst feeding, which infects other pollinators such as hoverflies as they feed on the flower, spreading the infection4. This is a concern because one of the hoverfly species that harboured the bee virus undertakes annual migrations across Europe4, spreading the viruses to areas it may not have been present in before. As both honeybee and some hoverfly populations are decreasing4, preventing the spread of viruses is of paramount importance, with one suggestion being to plant more flowers that are pollinated exclusively by either bees or flies respectively4. This recent research highlights the effects of one species on others that interact with it.
References:
- Hassall C (2016). “To bee or not to bee – why some insects pretend to be dangerous”. The conversation, published September 21st, 2016. http://theconversation.com/to-bee-or-not-to-bee-why-some-insects-pretend-to-be-dangerous-65299
- Rader R, Saunders M and Cunningham S (2016). “Not just bees: the buzz on vital insect helpers”. The conversation, published January 26th, 2016 http://theconversation.com/not-just-bees-the-buzz-on-our-other-vital-insect-helpers-52373
- Kelly, M. (2017) “hoverfly migration helps record canola yield despite extreme season in Tasmania, ABC news, published 16th January 2017. Available from: http://www.abc.net.au/news/rural/2017-01-16/canola-record/8185568
- Bailes, E (2018). Embattled bees face yet another potential threat – virus carrying hoverflies. The conversation, published February 28th, 2018. Available from: https://theconversation.com/embattled-bees-face-yet-another-potential-threat-virus-carrying-hoverflies-92464