APHIS FLIGHTS REVIEW

Press, Volume CVI, Issue 31107, 9 July 1966, Page 8

APHIS FLIGHTS REVIEW

Some districts have had their heaviest infestations of cereal aphides in the last four years during the current season.

The 10th report of the aphis and virus warning service says that there have been large increases in the number of winged aphides trapped at Timaru Waimate, and Oamaru this year. Most of this increase was in the first three weeks of May. “Trapping of cereal aphides ceased in all districts at the end of June and it is now possible to look over the figures and make comparisons between the different districts and with other years.” Average numbers of aphides trapped during May and June in various districts are:

•The figures for these districts are the average of several traps in that area, and represent numbers that would be found on a single trap. “Wheat crops in the Blenheim area are likely to be free of aphides because of the absence of winged aphides in that area throughout the trapping period. “From all the data, wheat crops which emerged before May 21 in all districts (other than Blenheim) will have had little chance of escaping a severe infestation of aphides and consequently are likely to suffer serious losses due to barley yellow dwarf virus. Treatment of these crops should be completed as soon as possible.

"Crops emerging before mid-June are likely to have •been infested and should be inspected. If aphides are found then these crops should be treated with a systemic insecticide.

“All crops emerging later than mid-June will have missed the aphis flights,” concludes the report.

’63 *64 ’65 ’66 Blenheim* 3 12 19 2 Rangiora* 0 2 52 39 Christchurch* 21 4 13 28

Ashburton* 18 0 27 27 Timaru* 5 1 7 19 Waimate 13 1 9 81 Oamaru 17 0 5 48 Mean 12 3 19 35