Scaffolds 99 index

AUGUST LEAVES AND LEAVINGS

(Art Agnello ama4@nysaes.cornell.edu, Entomology, Geneva)

As you make plans for the final apple insect control sprays of the season, keep in mind that this is the time of year to be sure your blocks are not nursing a healthy and expanding infestation of woolly apple aphids.

Aerial colony of wingless adult female woolly apple aphids

These colonies show up predictably in some orchards, predominantly on unhealed pruning wounds, cankers, or water sprouts (which are not too numerous this year).

Apple twig cankers, a common site of aerial woolly apple aphid colonies;
gall plant parts, right, are caused by heavy infestations

Heavy infestations can cause honey dew and sooty mold on the fruit, and galls on different plant parts. Because woolly apple aphids are somewhat protected by a waxy covering, regular spray programs may not provide adequate control. Higher volume applications of recommended insecticides may be necessary to penetrate the wax.

Judge the severity of any infestations in your trees, plus the projected harvest dates, and if needed, select a suitable material keeping in mind the respective PHI: Penncap-M (14—21 days PHI), Thiodan (21 days), or Lorsban (28 days). Penncap-M and Lorsban will also control apple maggot. This is also prime time for an increase in nymphal populations of white apple leafhopper; an average of more than 2 per leaf can be addressed using Provado (7 days PHI), Sevin (1 day), the aforementioned Thiodan, Lannate (14 days), or Carzol (7 days). Provado and Lannate will also help out on any 3rd brood leafminers and green aphids, Sevin and Lannate will help control apple maggot, and of course Carzol is active against motile mites, although these should be packing it in on their own by now.

End of this issue: Scaffolds 1999 Index