Arne van Aalst is soon to take up his position at Koppert Biological Systems. Van Aalst, who is now general director at the growers' association...
Aphidius matricariae takes off
10 May 2011
Several lab and cage experiments have shown that the aphid parasitoid Aphidius matricariae (Aphipar-M) performs better and faster as compared to Aphidius colemani on Myzus species. The tobacco aphid Myzus nicotianae, a major problem in sweet peppers, is easily controlled.
The tobacco aphid Myzus nicotianae is an important pest in sweet pepper and many other vegetables and ornamentals. The tendency to cluster in the top of the plant makes biocontrol difficult and causes growth reduction. In cooperation with Wageningen UR/Greenhouse Horticulture the commercially available Aphidius colemani was compared to Aphidius matricariae.
In a strictly controlled trial in a greenhouse the two wasp species were released separately in cages with aphid infested pepper plants. The ratio of female wasp:aphid at the start was approx. 1:20. Every week 24 leaves per cage were examined, for a total of 4 weeks.
One remarkable result was that Aphidius matricariae controlled the red Myzus consistently better than Aphidius colemani. Hardly any aphid colonies were formed and within several weeks the aphids were under control. Aphidius colemani on the other hand always showed an aphid peak in the first generation, before controlling the aphids in the second.
This picture was also confirmed by releases in commercial greenhouses. The exact explanation behind this feature is still under research. However, the current results of Aphidius matricariae are so promising that the wasp is a “must” in current Myzus control strategies. This spring season is the second year that Aphidius matricariae has been released commercially on a large scale by many growers and the results are very positive. Many growers and advisors have adopted A. matricariae as a vital tool in their aphid control program.