Science News
from research organizations

What's on the menu for young African sawflies?

March 17, 2015
Pensoft Publishers
Zoologists have been studying the habits of two species of widespread West African sawflies. Their caterpillar-like young stages were found to feed on unexpected plant species. One sawfly species eats leaves of grasses, including maize, the other feeds on day flowers, some of which are used as vegetables in Africa, or elsewhere are troublesome weeds.

This is an adult sawfly of the species Xenapates braunsi.
Credit: Dr. Georg Goergen; CC-BY 4.0

Sawflies belong to the same insect group as wasps, bees and ants. Unlike many of the latter, sawflies seldom make themselves conspicuous to humans, although the young stages (larvae) of some species, nearly all of which feed on plants, sometimes attract attention by damaging these.

In a reversal of the pattern found in most insect groups, a larger number of sawfly species occur in regions with a cooler climate, rather than in the tropics. On the other hand, many of the sawflies found in Africa south of the Sahara (the Afrotropical faunal region) belong to genera that occur nowhere else in the world.

In Europe much more is known about the habits of sawfly larvae than in most other parts of the world. This knowledge has been built up since the 18th Century, with a very significant contribution from amateur entomologists. By contrast, extremely little is known about the early stages of sawfly species in the Afrotropical region.

One of the distinctive and relatively species-rich groups of Afrotropical sawflies is the genus Xenapates, with 47 known species. Although two of the commonest and most widely distributed Xenapates species (X. braunsi and X. gaullei) were first described by the German amateur scientist Friedrich Wilhelm Konow in 1896, nothing was known until now about their early stages, seasonal occurrence (phenology), or even which plants these feed on.

Dr Georg Goergen (International Institute of Tropical Agriculture, Cotonou, Benin) discovered the early stages of X. braunsi and X. gaullei and in cooperation with Dr Frank Koch (Museum fuer Naturkunde, Berlin, Germany) and Andrew Liston (Senckenberg Deutsches Entomologisches Institut, Muencheberg, Germany) studied their morphology (physical appearance) and habits.

The results include information on the plant species fed on by the larvae. X. braunsi uses a number of grass species as hosts, some of which are of importance in African agriculture. One of these, but apparently not amongst the most frequently eaten, is maize. X. braunsi is so far the only sawfly known to feed on this important crop plant. Larvae of X. gaullei feed on a genus of plants called day flowers, related to the grasses. Some day flower species are invasive weeds in North America and Europe, and X. gaullei warrants further study as a possible agent in combatting these.

Story Source:

Materials provided by Pensoft Publishers. The original story is licensed under a Creative Commons License. Note: Content may be edited for style and length.

Journal Reference:

  1. Andrew Liston, Georg Goergen, Frank Koch. The immature stages and biology of two Xenapates species in West Africa (Hymenoptera, Tenthredinidae). Deutsche Entomologische Zeitschrift, 2015; 62 (1): 9 DOI: 10.3897/dez.62.8922

Cite This Page:

Pensoft Publishers. "What's on the menu for young African sawflies?." ScienceDaily. ScienceDaily, 17 March 2015. <>.
Pensoft Publishers. (2015, March 17). What's on the menu for young African sawflies?. ScienceDaily. Retrieved May 23, 2017 from
Pensoft Publishers. "What's on the menu for young African sawflies?." ScienceDaily. (accessed May 23, 2017).