Focus on Dasypoda visnaga, a wild bee specialized on Spanish oyster thistle

Published on: October 1, 2019, Submitted by Stefanie Christmann on: September 16, 2019

Learn more about a beautiful wild species we found in Morocco. Wild bees are the most important pollinators in natural and agricultural ecosystems worldwide. They are very diverse in terms of color and shape, but also in terms of nesting behavior and flower preferences. This might be useful to know for anyone loving nature and in particular for farmers. Here we describe the nesting behavior and flower preferences of the Hairy-Legged Mining Bee Dasypoda visnaga.

Female of Dasypoda visnaga at her nest entrance

During a field trip to Kenitra for the IKI project in May 2018, we had the chance to discover, close to the field of the farmer Tewil Laaoussi, a nest aggregation of a wild bee that has never been investigated before. This wild bee is a Hairy Legged Mining Bee called Dasypoda visnaga. It belongs to the genus Dasypoda of the family Melittidae. It is one of the smallest bee families in the world (201 species among ~19000 described bees).

The genus Dasypoda is common in the Palaearctic region from Morocco to Japan, but most species are west-palaearctic. Several researchers have studied the taxonomy, biogeography and floral choices of Dasypoda species, however their nesting behavior has been poorly investigated. We thus decided to come back to this aggregation the year to explore the nesting biology of D. visnaga.

Male of Dasypoda visnaga feeding on Spanish oyster thistle

Our observations began in mid-May 2019 in Douar Taleb near Kenitra. The first observations of these bees coincided with the blooming of the Spanish thistle Scolymus hispanicus, the plant commonly called by local people "Guernina".

Males of D. visnaga are attracted by this thorny yellow plant for its nectar but also use it as rendez-vous flower to mate with females. Females emerge few days after males, mate with a male and then start collecting pollen on the Spanish oyster thistle. They will then bring the pollen collected to the nest and make pollen balls used to feed their larvae.

Pollen ball with a single egg laid on top

Pollen ball with a single egg laid on top

Nests are built in sandy soil. The mount of soil at the entrance of the nest has a diameter of around 8 cm and a height of around 3 cm. The Female digs an oblique gallery of about 25 cm forming an angle of 45°. Then this gallery becomes vertical and can reach 60 cm deep.

Dasypoda visnaga is most probably a specialized bee. Our preliminary results show that 100% of pollen analyzed (pollen on scopa and pollen balls) comes from plants of the genus Scolymus sp.

Outside of Dasypoda visnaga, seven other species belonging to the genus Dasypoda are known in Morocco. Most of them have been poorly investigated and not much is known about their ecology. Specimens from two other species, Dasypoda maura and D. dusmeti, have also been observed in the field together with D. visnaga. We plan in the future to compare these 3 species to understand what are their differences in terms of nesting behavior and floral preferences.