Large bugs damage pistachio nuts most severely during midseason

Life History Parameters of <I>Chinavia hilaris</I> (Hemiptera: Pentatomidae), a Stink Bug Injurious to Pistachios in California

“…Furthermore, its combination of development, survivorship, and fecundity data from the same population provides a Þrm foundation for further development of models useful in pest management. Daane et al (2005) have shown that C. hilaris fourth and Þfth instars and adults are the stages responsible for the most costly damage to pistachio fruits. They have also pointed out that sampling of C. hilaris and other large bugs in the orchard at mid-season is not an efÞcient way to get reliable information on which to base management decisions, because good sampling methods for these bugs do not exist and damage may only become visible weeks after it was caused.…”

“…Seasonal changes in the population structure of C. hilaris in California pistachios, therefore, directly affect the amount of crop loss. The larger adults cause more damage than the smaller nymphs, with the amount of damage per bug a relationship between the bugÕs development stage and the maturation and shell-hardening of the pistachio crop (Michailides et al 1988, Daane et al 2005. Therefore, for pest management purposes, it is important to know the speciÞcs of the biology and seasonal development of C. hilaris that distinguish it from the other small and large bug pests attacking pistachio.…”

“…Although small bugs are often abundant and can cause damage early in the season (Purcell and Welter 1990), they pose little threat after shell hardening (Purcell and Welter 1991). Large bugs, including C. hilaris, have relatively larger and stronger mouthparts and, for this reason, can continue to penetrate the shell and damage kernels later into the season as shell hardening increases (Michailides et al 1987, Daane et al 2005.…”

“…The natural fruit drop of the pistachio tree from April to early May is thought to compensate for much of the fruit loss caused from this early season bug damage (Beede et al 1996). Later in the season, after the fruit load has been set, the damaged nut remains in the cluster, and the resulting epicarp lesion can stain the outer shell, lowering market value, and the pierced kernel can result in a necrotic spot on the nut meat (kernel necrosis), aborted nuts, or fungal contamination (stigmatomycosis; Michailides et al 1988, Daane et al 2005. Seasonal changes in the population structure of C. hilaris in California pistachios, therefore, directly affect the amount of crop loss.…”

Multiparasitism of stink bug eggs: competitive interactions between Ooencyrtus pityocampae and Trissolcus agriope

“…Feeding by B. signatum and other species of Pentatomidae on developing pistachio fruits causes significant direct damage in the form of epicarp lesions that can result in significant nut drop and quality issues (Daane et al 2005). The bug is also a vector of the pathogenic yeast Nematospora coryli, the causal agent of 'stigmatomycosis', a destructive disease of pistachio in many countries (Michailides et al 1990).…”