The pistachio green stink bug, Brachynema
signatum Jakovlev (Hemiptera: Pentatomidae), has great importance in
pistachio production due to the quantitative and qualitative damages it causes.
Serious infestation of pistachio nut by B. signatum makes it unpleasant
or unmarketable. Piercing of the soft-shelled pistachios by
the stylets of the stink bug and sucking the nutrients causes epicarp lesion on
the hull in the early season (13) and
kernel necrosis in the midseason as well as transmission of a fungal pathogen, Nematospora
coryli, in pistachio nuts (14). Due to the stink bug wide host-range,
adult dispersal habits, and diverse habitats this group of pistachio pests are
generally difficult to control. Injudicious use of pesticides can damage human
health and the environment. Given the concerns associated with pesticide use, using
natural enemies for biological pest control is a preferred approach to B.
signatum management (13). The egg parasitoids are considerable biocontrol
agents because they attack the host before it develops and inflicts feeding damage (13).
Field surveys have revealed the
existence of egg parasitoids of the green pistachio bug in Iran (17). Ooencyrtus
pityocampae (Mercet) (Hymenoptera: Encyrtidae) is a polyphagous egg
parasitoid that commonly attacks the pine processionary caterpillar, Thaumetopoea pityocampa (Denis and Schiffermfiller) (Lepidoptera:
Thaumetopoeidae), in southern Europe (12). It is also a parasitoid of B.
signatum eggs in Iran. This species is a synovigenic endoparasitoid that
benefits from a supply of carbohydrates to produce more eggs for a longer period
of time (2, 12, 19, 16).
Tiberi et al. (24) reported that
the augmentation of O. pityocampae has beneficial in controlling
processionary caterpillar, Thaumetopoea pityocampa (Denis and
Schiffermfiller) (Lepidoptera: Thaumetopoeidae) in young pine trees. Masutti et
al. (12) studied the rearing of O. pityocampae on artificial
eggs. Dulaurent et al. (4) assessed the response of O. pityocampae
and Baryscapus servadeii Domenichini to different trophic
resources, i.e. two types of honeydew produced by two aphid species feeding on
oak or pine trees. Tunca et al. (26) investigated the biological variables
that influence the parasitism of O. pityocampae on the new laboratory
host Philosamia ricini Danovan (Lepidoptera: Saturniidae).
So far, egg parasitoids have
proven to be successful biological control agents against several insect pests.
However, the biology of the majority of these effective parasitoids is not
fully understood. therefore, in this study, we investigated several biological
parameters of O. pityocampae on the green pistachio stink bug B.
signatum, including the development time, longevity, parasitism
percentage, and sex ratio.