Irrigated trap crops impact key hemipteran pests in organic pistachio orchard

Abstract

Using sown groundcovers as trap crops to protect a cash crop is a traditional pest management tool. Pistachio is a major crop in California’s Central Valley, where high summer temperatures and little to no precipitation between May and November lead to summer dry-down of annual groundcover. Hemipteran pests that consist of ‘small bugs’ and ‘large bugs’ are a major contributor to nut damage, especially in organic production. In this 2-year field study, we tested the use of irrigated trap crop mixtures, sown between tree rows, to reduce those hemipteran pests’ abundance or damage. Biweekly beat samples of the tree canopy and sweep samples of the sown groundcovers in trap crop plots and resident weedy vegetation in control plots were taken over two consecutive growing seasons. Arthropod richness and abundance were highest in the groundcover and tree canopy in the trap crop plots. Small and large bug pest populations were higher and lower, respectively, in the tree canopy in trap crop plots, indicating a mixed response of these hemipterans to the presence of the trap crops. Additionally, natural enemy populations were more abundant in the tree canopy in trap crop plots than in control plots. There was no difference in nut damage between plots with and without the trap crop. These findings suggest that populations of hemipteran pests and beneficials can be manipulated successfully with irrigated trap crops, but future studies will need to focus on doing so in a way that decreases hemipteran pistachio damage.

Grower assessment of profitability impact from Brown Marmorated Stink Bug, Halyomorpha halys (Stål), the value of management information sources, and use of potential management practices

“…Further, the repeated use of insecticides can lead to the development of insecticide resistance in BMSB populations, reducing the long‐term effectiveness of these control measures (Leskey et al., 2012). Besides insecticides, several other management strategies for the BMSB have been explored, including improved monitoring (Acebes‐Doria et al., 2018, 2019; Krawczyk et al., 2017), attract and kill (Morrison et al., 2019; Suckling et al., 2019), trap crops (Mathews et al., 2017; Nielsen et al., 2016; Stahl et al., 2021), repellents (Zhang et al., 2013), netting/barriers (Dobson et al., 2016; Kuhar et al., 2017), border sprays (Blaauw et al., 2014) and biocontrol tactics that conserve and promote natural enemies (Abram et al., 2017, 2020; Conti et al., 2021; Ogburn et al., 2021). Each of these strategies has its own advantages and disadvantages.…”

Reproductive biology of overwintering leaffooted bug Leptoglossus zonatus (Hemiptera: Coreidae) in California

“…In the Southeastern United States, L. zonatus was first reported around 2,000 (Henne et al 2003, Buss et al 2005) and in California's Central Valley it is now the dominant leaffooted bug in the affected crops such as almond, pistachio, and pomegranate (Joyce et al 2017). As part of a group of “large bugs” that otherwise consists of several pentatomid species (Daane et al 2016, Stahl et al 2021), L. zonatus feeding by adults and to a lesser extent nymphs damages developing fruits and nuts (Stahl et al 2020). They can cause nut drop, external and internal lesions, and deformities (Stahl et al 2020), lowering harvest quantity and quality, and have been implicated in the movement of pathogens such as Botryosphaeira fungi in pistachio (Michailides and Morgan 2016).…”

Volatiles of the trap crop sunflowers: Effects on the behaviour of adult female Conogethes punctiferalis moths

“…Plantings of highly preferred trap crops can arrest arriving insect herbivores thus preventing them from attacking economically valuable, nearby main crop species (Shelton & Badenes‐Perez, 2006). To date, trap crops have been used to reduce damage from some insect herbivores in fields of grain crops (Jindal et al, 2012; Sharma et al, 2019), orchards (Stahl et al, 2021; Tomaseto et al, 2019) and vegetable fields (Ayanava & Matthew, 2019; Balusu et al, 2021).…”