Potential strategies to manage bronze beetle (<i>Eucolaspsis</i> sp) in organic apple orchards

Abstract

Bronze beetle (Eucolaspsis sp Coleoptera Chrysomelidae) threatens the viability of New Zealands organic pipfruit industry Small plot cultivation trials were conducted during spring to target immature beetles in the soil in a 25 m strip under apple trees A single cultivation treatment in October prevented 56 to 81 of the beetle population from emerging When plots were tilled every second week from October to December 79 to 95 failed to emerge The pattern and timing of bronze beetle emergence during 2006 was consistent between the four trial orchards and with the 2005 season A survey of 20 orchards during November 2006 was unable to link beetle damage levels with management practices and the physical environment New strategies to manage bronze beetle larvae are discussed

Population dynamics of bronze beetle <i>Eucolaspis</i> spp (Coleoptera Chrysomelidae) in relation to other soil macroinvertebrates in organic apple orchards in Hawkes Bay

“…The variation in bronze beetle populations found between the two selected groups of orchards corroborates with previous history (Rogers et al 2006;Rogers et al 2007) and growers' observations. Although High bronze beetle orchards had more sub-soil generalist predators (mostly centipedes), their soil also supported higher bronze beetle population densities, and much higher other herbivores living within the soil (Table 1) than Low bronze beetle orchards.…”

“…Bronze beetle damage has been shown to vary greatly between and within organic apple orchards in Hawke's Bay. This variation was not attributable to orchard management practices or site physical characteristics, and the population variations remained fairly consistent over 2 years of observation (Rogers et al 2006(Rogers et al , 2007. This suggests some other ecological factor may be influencing bronze beetle populations in different orchards.…”

“…Among these, four orchards had a history of high bronze beetle damage (will be referred to as "High bronze beetle orchards" from hereon) and the other four orchards had a history of low damage (will be referred to as "Low bronze beetle orchards"). The beetle damage histories were established through previous studies by Rogers et al (2006Rogers et al ( , 2007 and by talking to orchard owners.…”

“…Five soil samples per orchard were collected once a month for 4 months, starting from October 2007 to January 2008. Soil samples (18 × 18 cm, 14 cm deep) were obtained by digging with a spade beneath a branch within a 1 m radius from the five randomly selected apple tree trunks (Rogers et al 2007). The samples were transferred to the lab in clear plastic bags and stored at 4°C until processed for macro-invertebrates.…”

Effect of the bacterium <i>Yersinia entomophaga</i> on adult bronze beetle

“…Bronze beetle (Eucolaspis sp., Coleoptera: Chrysomelidae) is a serious pest in organic apple orchards, with feeding by adult beetles on fruit resulting in up to 50% of apples at harvest being damaged in the worst afected orchards (Rogers et al 2006(Rogers et al , 2007. Furthermore, expansion of the organic sector and associated higher premiums are limited by this pest.…”