Esteem (pyriproxyfen) - This insect growth regulator functions as a juvenile hormone mimic. It can be a highly selective insecticide providing control of leafroller and codling moth (not Lacanobia fruitworm) without disrupting activities of biological control agents. Esteem has low toxicity to mammals and has a short worker reentry period (12 hours), but a long pre-harvest period (45 days).
Lepidopteran pests
Codling moth – Esteem has activity against the codling moth egg,
acting as an ovicide. In order to be effective, the codling moth must deposit
eggs on top of Esteem residues. Therefore, Esteem should be applied prior
to the onset of oviposition (100 DD). In high pressure situations, especially
if reduced activity from organophosphates is expected, a second Esteem
application would likely be necessary at 14-21 days. This approach keeps
active Esteem residues during most of the egg laying period. Esteem can
only be considered a moderately effective codling moth tool, and can make
the difference in successfully implementing a “soft” pest management
program.
Leafrollers – Esteem seems to work equally well against the pandemis or obliquebanded leafroller. Esteem is thought to act primarily against the last larval stage of leafrollers. Esteem must be consumed by the leafroller larva to have any effect, therefore good coverage is very important. Once consumed by the leafroller larvae Esteem acts to disrupt the normal transition from larva to pupa or, in some cases, pupa to adult. Esteem may also have activity against leafroller eggs. Both leafroller species reach the last larval stage shortly after petal fall, which makes the 100DD timing for codling moth an ideal time to target leafrollers as well. Esteem efficacy against leafrollers is difficult to assess because the larvae do not immediately die and deformed larval-pupal intermediates or pupae that do not produce adults are difficult to locate. It is necessary to monitor the leafroller generation following the one treated to see the effect of the Esteem treatment.
Lacanobia fruitworm – We have no information on the efficacy of Esteem against Lacanobia. Because use of this product is probably going to be limited to the early season it probably does not have a fit for Lacanobia.
Indirect/secondary pests
Delayed dormant applications, and to a lesser extent early summer applications,
of Esteem have good activity against San Jose scale. Prelimary data indicate
Esteem may be active against rosy apple aphids. We have not tested Esteem
against other indirect pests.
Pear pests
In addition to being an effective management tool for control of codling
moth in pear, Esteem works well against pear psylla. Its juvenile hormone
mimic activity affects the insect much the same as Comply (fenoxycarb).
Esteem has been shown to act on eggs and first through third instar nymphs,
and may have sublethal effects on later instars (‘hardshells’)
and adults as well. The first generation of pear psylla is the best target
for Esteem applications, as the life stage distribution is the most synchronized
at this time. The use of delayed dormant oils, sulfurs, Thiodan, and
Surround greatly enhance this synchrony, further increasing the effectiveness
of Esteem. Applications against the first generation can be made from
delayed dormant (targeting early eggs) through 2 weeks post-petal fall
(targeting third instar nymphs). The optimal timing, however, is from
clusterbud to petal fall, when there is peak egg hatch. Results with
Esteem have been variable, in some cases being able to control high populations
while in others not controlling low populations. This may be a result
of a predisposition of some orchards to resistance. Orchards with some
degree of developing resistance to Comply may have reduced control effectiveness
with Esteem. Esteem does not appear to have significant effects against
grape mealybug.