Rothamsted suction trap information

The latest issues of the Rothamsted aphid bulletin and AHDB Aphid News have just been released: 2014webbulletin31.pdfahdb_aphid_news_20141107.pdf

Aphid flight into crops (primary infection)

Aphids reported in this week’s bulletin were caught during last week’s warm weather but aphid flight will have dropped considerably in the colder, wetter and windier conditions of this week. There is still the potential for a late trickle should good flying conditions return, the chance of which diminishes with time but, if there has been good control of aphids to this point and they can’t be found in crops, the danger is probably passed.

Aphid movement within crops (secondary spread)

The cold nights we had this week will have stopped aphid movement, reduced reproduction, but had little effect on survival. Thus, if warmer and drier conditions return before we’ve had a series of severe frosts there is still the possibility of virus spread if there are currently aphids in the crop. It’s hard to be precise about the level of frost needed, but three to five consecutive days with grass minima dropping below -6oC should cause high mortality.

Rosemary Collier : 07 Nov 2014 17:23 |  Comments (0) |  Report a problem