Study

Periods of artificial light stimulate egg-laying in buff-tailed bumblebee queens Bombus terrestris; laboratory experiments at the French National Institute for Agricultural Research (INRA), Poitou-Charentes, France.

  • Published source details (1994) Effect of different narcosis procedures on initiating oviposition of pre-diapausing Bombus terrestris queens. Entomologia experimentalis et applicata, 72, 273-279

Summary

Bumblebees Bombus spp. are declining in Europe, and captive rearing could be used to augment or re-establish populations. This study tests the effect of different rearing procedures on egg-laying in buff-tailed bumblebee queens Bombus terrestris, in a laboratory study at the French National Institute for Agricultural Research (INRA), Lusignan, Poitou-Charentes, France.

Five days after mating, 200 laboratory-reared B. terrestris queens (not hibernated) were cooled to 3-4°C, then anaesthetized in plastic boxes with 99.9% CO2 for two periods of 10 minutes, 24 hours apart. Between the periods of ‘narcosis’ queens were kept at 23-24°C.

After treatment, queens were introduced to wooden boxes (11.3 x 4.5 x 4.3 cm) with one B. terrestris worker. 73% sugar solution and freshly frozen pollen collected by honey bees Apis mellifera (renewed daily) were supplied, and a 3cm diameter plastic lid coated with beeswax.
 
Queens were kept in darkness at 28-29° C and 65% relative humidity, and observed daily under red light.
 
Experimental treatments varied the regime as follows: 44 queens were kept at 34°C for four to six days after narcosis, before rearing; 29 queens were given narcosis 30 days after mating instead of five; 103 queens were reared in eight hours light, 16 hours darkness; of these, 13 queens were given no narcosis; nine were given two five-minute periods; 36 were given the standard 10 minute periods of narcosis.

The only experimental treatment that increased the chances of a queen laying eggs, and made her lay more quickly, was eight hours of artificial light during rearing.

Queens exposed to light were more likely to survive and lay eggs (73%) than those kept in the dark (67%) and laid eggs more quickly (21.1 days on average, compared to 38.9 days to lay eggs in the dark).

 

A period of high temperature, narcosis at a greater age, or for a shorter time did not affect the percentage of queens that laid eggs (65-68%) or the amount of time before egg-laying (36-40 days), compared to the standard treatment.

 

Without narcosis, 7 of 13 queens (53%) survived and laid eggs, but took a similar amount of time to lay eggs as queens given 10 minutes of  narcosis (average 17.3 – 19.8 days). There was no significant difference between the proportion of queens surviving and the time taken to lay eggs, between the five and 10 minute narcosis treatments.

 

Note: If using or referring to this published study, please read and quote the original paper, the abstract of which is available at: http://www3.interscience.wiley.com/journal/117984720/home

Output references

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, terrestrial mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 18

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust