As we approach the end of bloom, growers should consider the need for any post-bloom applications. The main pest targets for these applications are mainly Sparganothis fruitworm and spotted fireworm.

Sparganothis fruitworm (SPARG) – If your farm has high pheromone trap counts, you should consider managing this pest as soon as bees are removed. The timing for this 1st post-pollination spray is at 2 weeks after peak pheromone trap catches, which usually coincides with this time of the year.

Spotted fireworm (SFW) – SFW is one of the most important pests in New Jersey. Male SFW moth catches typically peak in the second through third week in June. Although trap catches give an indication of population size, these numbers not always correlate with numbers of egg masses. This insect becomes a problem in “weedy” beds because female moths lay their eggs predominantly on weeds. Thus, growers need to monitor for the presence of SFW egg masses on weeds (broadleaf species and grasses). Keeping beds clean from weeds will keep this insect under control. Egg masses should be hatching by now. SFW larvae from this generation feed on foliage as well as fruit.

Control Options – Insect Growth Regulators (IGRs) (e.g. Intrepid and Confirm) are effective against SPARG. Alternatively, if you have used IGRs intensively (e.g. last year and this year as a pre-bloom or bloom spray), and would like to rotate with other chemistries, you may want to use Altacor, Delegate, Exirel, or the broad-spectrum insecticides Diazinon or Lorsban. Broad-spectrum insecticides are also a choice if you have high blunt-nosed leafhopper populations because Intrepid, Delegate, and Altacor will have no effect against this insect. If you are an Ocean Spray (OS) grower please check restrictions on the use of these insecticides. Lorsban in particular can’t be used by OS growers after bloom due to MRLs for exporting cranberries. If you are an OS grower and want to use a post-bloom application to control SPARG then Delegate, Altacor, or Diazinon (no aerial application allowed) would be your options.

Blunt-nosed leafhoppers – The best timing for controlling blunt-nosed leafhoppers is before bloom when they are immatures. At this time

Table 1. Leafhopper control options

of the year, most of the population are adults and already laying eggs. If you did not spray before bloom and have a high leafhopper population, you may consider a post-bloom application to prevent from an increase in population size. You may also consider spraying next year to control for those immatures that will emerge from the already laid eggs. See Table for control options. Please check, especially for Ocean Spray growers, the restrictions based on maximum residue limits (MRLs).

Based on our degree-day (DD) model for Sparganothis fruitworm, peak flight and first eggs hatched events are expected at around 884 and

Sparganothis degree-day model benchmarks

895 DD, respectively (see chart). As of June 20, Sparganothis has accumulated 1022 DD (using March 1 as biofix) or 883 DD (using April 15 as biofix; a biofix more realistic to New Jersey practices). Based on the April 15 biofix, we are at peak flight activity and eggs should start hatching within the next few days. Larval injury to fruit usually begins after the eggs hatch. If treatment is required (based on pheromone trap counts), sprays should be applied two weeks after peak moth flight (i.e., 1st week in July) and/or earlier (i.e., next week) if populations are unusually high. When bees are present, your option is to use an insect growth regulator such as Intrepid. Our “standard” recommendation has been, however, to wait until bees are removed to apply an insecticide. Your post-bloom options include Diazinon, Altacor, Delegate, Exirel, or Intrepid. Timing of insecticide application is critical; so, if needed, do not wait longer than July 5 to manage this pest.