All entries for November 2014

Update on Rothamsted suction trap captures

The latest issues of the Rothamsted aphid bulletin and AHDB Aphid News have just been released: 2014webbulletin34.pdfahdb_aphid_news_20141128.pdf.

The suction-traps are now emptied weekly. Today’s bulletin reports the last daily records for the year. Numbers of aphids flying are similar to the previous week, the generally warm weather extending the flight period.

APHID-BORNE VIRUSES - PARTICUARLY RELATING TO OILSEED RAPE (TuYV)

Aphid flight into crops (primary infection)

Numbers of peach–potato aphid are also a little above average. 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)

Conditions are still permitting aphid development, reproduction and movement within crops and, if aphids can be found easily, measures to control them (and hence reduce the risk of virus spread) remain justified. There is no sign in the forecast of the weather getting cold enough to kill aphids anywhere over the next ten days.

Rosemary Collier : 29 Nov 2014 06:59 |  Comments (0) |  Close comments |  Report a problem

Update from the Rothamsted Insect Survey

Rosemary Collier : 23 Nov 2014 20:24 |  Comments (0) |  Close comments |  Report a problem

Pest update from Wellesbourne

Between Tuesday (11th Nov) and Tuesday (18th Nov) we found:

• 21 carrot flies on traps in carrots (3 traps)
• We have stopped sampling for cabbage root fly eggs
• There were no turnip moths, no diamond-back moths and no silver Y moths (2 traps per species).

In 3 yellow water traps within our swede plot there were:

• No cabbage root fly
• 54 bean seed flies
• 1 flea beetle

Rosemary Collier : 20 Nov 2014 16:25 |  Comments (0) |  Close comments |  Report a problem

Update from Rothamsted Insect Survey

Rosemary Collier : 14 Nov 2014 17:46 |  Comments (0) |  Close comments |  Report a problem

Update from Wellesbourne

Between Tuesday (4th Nov) and Tuesday (11th Nov) we found:

• 10 carrot flies on traps in carrots (3 traps)
• We have stopped sampling for cabbage root fly eggs
• There were no turnip moths, no diamond-back moths and no silver Y moths (2 traps per species).

In 3 yellow water traps within our swede plot there were:

• No cabbage root fly
• 61 bean seed flies

Rosemary Collier : 11 Nov 2014 16:16 |  Comments (0) |  Close comments |  Report a problem

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) |  Close comments |  Report a problem

Update from Wellesbourne

Between Tuesday (29th Oct) and Tuesday (4th Nov) we found:

• 21 carrot flies on traps in carrots (3 traps)
• We have stopped sampling for cabbage root fly eggs
• There were 2 turnip moths, no diamond-back moths and 3 silver Y moths (2 traps per species).

In 3 yellow water traps within our swede plot there were:

• No cabbage root fly
• 93 bean seed flies
• 5 flea beetles

Rosemary Collier : 06 Nov 2014 14:59 |  Comments (0) |  Close comments |  Report a problem