Surface‐applied insecticide treatments for quarantine control of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), larvae in field‐grown nursery plants

Abstract

July application was more consistent and effective than other timings, and higher rates (2x and 3 x) did not generally improve grub control. Overall, clothianidin, thiamethoxam and halofenozide (and dinotefuran applied in August) were equivalent to current DJHP standards. These insecticides may be suitable for DJHP Category 2 states, potentially lowering grower costs.

Preharvest Quarantine Treatments of Chlorantraniliprole, Clothianidin, and Imidacloprid-Based Insecticides for Control of Japanese Beetle (Coleoptera: Scarabaeidae) and Other Scarab Larvae in the Root Zone of Field-Grown Nursery Trees

“…August timings of neonicotinoids have not been consistent in other studies (Mannion et al 2001, Smitley et al 2006, Oliver et al 2009), likely owing to greater numbers of second and third instars, which are less sensitive to insecticides (Vittum et al 1999). Like Arena, another clothianidin product (Celero) was the most effective neonicotinoid tested in August in one other study (Oliver et al 2009). It appears Arena may have potential as both an early season (May to July) preventative insecticide and a late season (August) curative insecticide.…”

“…The DJHP allows for preharvest banding of insecticides from May through July (NPB 2011). The May through July timing is intended to target Þrst instars as a "preventative" treatment (Vittum et al 1999, Mannion et al 2001, Oliver et al 2009). Treatments applied after July mostly target older second and third instars (Fleming 1972a), which are more difÞcult to kill and require insecticides with more "curative" properties (Vittum et al 1999).…”

“…Mannion et al (2001) found a range of 83Ð100% Japanese beetle control for imidacloprid products (Merit 75 WP, Marathon 1G, and Marathon 60WSP) and 0 Ð100% for thiamethoxam products (CGA-293343 25 WG and 0.22G) during studies performed in Þeldgrown nurseries from 1996 to 1999. At labeled rates, Oliver et al (2009) found a range of 59 Ð100% for imidacloprid products (Marathon 60 WP and Discus SC), 75Ð100% for thiamethoxam (Flagship 25 WG and 0.22G), 13Ð 88% for dinotefuran (Safari 20SG), and 96 Ð100% for clothianidin (Celero 16WSG). Marathon 1G and 60 WP, Discus SC, and Flagship 0.22G and 25 WG are approved for use in the DJHP for Þeld-grown nursery stock shipments to category 2 states, despite the possible presence of Japanese beetle larvae in some of these treatments on occasion.…”

“…The Þrst method is a postharvest root ball immersion in chlorpyrifos or bifenthrin, and the second is a preharvest soil surface insecticide application between May and July banded 15 cm wider than the root ball diameter being harvested (Mannion et al 2000(Mannion et al , 2001Oliver et al 2007Oliver et al , 2009NPB 2011). Products approved for the preharvest treatment include imidacloprid (Marathon 1G or Marathon 60 WP), imidacloprid ϩ cyßuthrin (Dis-cus), or thiamethoxam (Flagship 0.22G or Flagship 25 WG) (NPB 2011).…”

“…The preharvest treatments are less labor intensive and hazardous to apply than the immersion treatment (Oliver et al 2007). However, preharvest treatments must be applied during summer months when susceptible Þrst and second instars are present, several months in advance of fall to early spring harvesting (Mannion et al 2001, Oliver et al 2009). Subsequently, if producers are unable to sell their plants, the summer preharvest treatments will have been unnecessary and costly.…”