Post-harvest pests of almonds
Jo Holloway , NSW Department of Primary Industries , Wagga Wagga .
INFESTATIONS of orchard pests continue to cause kernel damage once almond crops are harvested and stockpiled . Further damage results from new infestations of stored product pests . In this article , Jo Holloway , a member of the research team for Hort Innovation Project AL16009 ‘ An Integrated Pest Management program for the Australian almond industry ’ discusses the main insect pests commonly found in almonds after harvest .
Pests of almond stockpiles The amount of damage caused to almond crops during storage depends on the insect species present and the extent and duration of infestation . Trapping studies were therefore included in the post-harvest research component of the Hort Innovation almond IPM project to determine the diversity of pests in stored almonds .
a . b .
Figure 1 . a ) Pitfall trap and b ) funnel trap used to catch crawling and flying insects in almond storages .
Our use of pitfall traps within almond stockpiles ( Figures 1 & 2 ) showed that a wide variety of insects colonise these habitats . Many of the species we identified are , however , incidental and not known to feed on , or cause damage to , almond kernels . Some , such as the hairy fungus beetle ( Typhaea stercorea ) and minute mould beetles ( Corticaria spp ) are likely attracted to micro-fungi and moulds that may be present . The rust-red flour beetle ( RRFB ; Tribolium castaneum , Fig . 3a ) is a stored product pest commonly found within almond stockpiles . This species is a major pest in cereal grains and processed products including almonds , and has been reported to damage in-shell Brazil nuts and shelled almonds in storage . RRFB can disperse over long distances and has been trapped several kilometres from grain storages . This species has also been found in almond mummies in trash heaps within orchards . The RRFB is highly responsive to volatile compounds released by fungi , and it is likely that it is attracted to micro-fungi and moulds present in almond stockpiles . Recent laboratory studies have confirmed that RFFB can initiate damage to intact in-hull almond kernels , as well as processed almond kernels . Of greater concern is the presence of the almond carpophilus beetle ( Carpophilus truncatus , Fig . 3b ) and carob moth ( Apomyelois ceratoniae , Fig . 3c ) in almond stockpiles . These are the most damaging insect pests of almonds in Australia and cause significant yield loss . Both species are known to be widely distributed throughout Australia ’ s major almond growing regions , and so may colonise stockpiles after harvest . Because these pests readily infest nuts on trees from hull split onwards , it is very likely that they are already present in nuts at the time of harvest . This is supported by the fact that we have trapped large numbers of carpophilus beetles from almonds that had been moved into sealed storages relatively soon after harvest .
Figure 2 . A stockpile of freshly harvested almonds in a storage shed , showing placement of a funnel trap on the ground and pitfall traps ( pink flags ) within the stockpile .
40 In A Nutshell - Winter 2022 Vol 23 Issue 2