Update on Rothamsted Suction Trap captures – week ending 10 July

A new edition of the Rothamsted Insect Survey Aphid Bulletin has been published (week ending 10th July). The latest edition of AHDB APHID News is here.

• Numbers of peach–potato aphid (Myzus persicae) and the potato aphid (Macrosiphum euphorbiae) remain very low this week.
• The numbers of willow ̶carrot aphid (Cavariella aegopodii) flying are now very low everywhere.
• Single currant-lettuce aphids (Nasonovia ribisnigri) were caught at Elgin and Starcross.
• Numbers of parsnip aphids, Cavariella pastinaceae (1 at Newcastle) and Cavariella theobaldi (1 at Wellesbourne) are also very low.
• Numbers of the black bean aphid (Aphis fabae) are conspicuously low, both for the time of year and compared to the large migrations seen in 2015. The threshold for black bean aphid (Aphis fabae) in field and broad beans is 10% colonisation at early flowering and 5% infested to prevent virus transmission. There have been no field reports of crops requiring treatment so far.
• Pea aphid (Acyrthosiphon pisum) numbers are low in trap catches compared to 10-year means for this time of year. Field reports indicate natural enemies are doing a good job, especially hoverfly larvae. Combining peas should be sprayed when around 20% of plants are infested and vining peas when 15% are infested. The vining pea harvest has already begun in Lincolnshire.

Rosemary Collier : 15 Jul 2016 15:10 |  Comments (0) |  Report a problem