Infestation of stored medicinal plants and herbal tea by insects and mites

The effectiveness of the neonicotinoid insecticide imidacloprid was evaluated against four psocid pests of stored grain. This research was undertaken because of the growing importance of psocids in stored grain and the need to identify methods for their control. The mortality and reproduction of adults of Liposcelis bostrychophila Badonnel, L. entomophila (Enderlein), L. decolor (Pearman) and L. paeta Pearman in wheat treated with imidacloprid were determined. There were five application rates (0.5, 1, 2, 5 and 10 mg AI kg−1 grain) and an untreated control. There were significant effects of application rate on both adult mortality and reproduction for all four species, but the effect of imidacloprid was sometimes more pronounced on reproduction. Imidacloprid was most effective against L. bostrychophila, with 100% adult mortality after 7 d at 5 mg AI kg−1, 14 d at 2 mg AI kg−1 and 28 d at 0.5 and 1 mg AI kg−1. No live progeny were produced at 2 mg AI kg−1. For L. decolor, there was 100% adult mortality after 28 d at 10 mg AI kg−1 and no live progeny were produced at 2 mg AI kg−1. For L. entomophila, there was 100% adult mortality after 14 d at 10 mg AI kg−1 and 28 d at 2 and 5 mg AI kg−1. No live progeny were produced at 10 mg AI kg−1. At 10 mg AI kg−1 there was 100% mortality of L. paeta adults after 28 d exposure and no live progeny developed. Because reproduction at some application rates occurred only in the first 14 d of exposure, it is concluded that the application rate leading to population extinction was 1 mg AI kg−1 for L. bostrychophila, 2 mg AI kg−1 for L. decolor and L. entomophila and 5 mg AI kg−1 for L. paeta. This study shows that imidacloprid has potential as a grain protectant to control all four Liposcelis species in stored grain. Copyright © 2006 Society of Chemical Industry

Section: Introductionmentioning

confidence: 99%

Potential of imidacloprid to control four species of psocids (Psocoptera: Liposcelididae) infesting stored grain

Nayak¹,

Daglish²

2006

“…The cosmopolitan psocid, Liposcelis bostrychophila Badonnel, is a serious pest of stored commodities in several tropical and sub‐tropical countries in Asia,1–5 Europe6–10 and Africa,11–13 and has emerged as a major pest of stored grain in Australia during the last decade 14, 15. This insect's parthenogenic mode of reproduction coupled with its short life cycle in favourable conditions16–19 make it particularly troublesome, as it can rapidly infest susceptible commodities.…”

Section: Introductionmentioning

confidence: 99%

Inhibition of egg development by phosphine in the cosmopolitan pest of stored products Liposcelis bostrychophila (Psocoptera: Liposcelididae)

Nayak

Collins

Pavic

et al. 2003

104

Phosphine-induced delay in development of eggs was investigated as a mechanism of resistance to this fumigant in Liposcelis bostrychophila Badonnel. One-day-old eggs of a susceptible and a strongly resistant strain of L bostrychophila were exposed to a range of phosphine concentrations for 6days at 30 (+/- 1) degrees C and 70 (+/- 2)% RH. Delay in mean hatching period occurred in both susceptible and resistant eggs, although it was more pronounced in the latter. A maximum delay of 2.65 days was recorded for eggs of the susceptible strain at 0.01 mg litre(-1) (the highest concentration at which eggs survived) and 13.39 days for the resistant strain at 1 mg litre(-1) (the highest concentration tested). Delay in egg development time was positively correlated with increasing phosphine concentration. Our results reveal that the most successful strategy to control resistant L bostrychophila is to apply relatively low concentrations of phosphine for extended exposure times (eg 0.05 mg litre(-1) for 16 days) that allow all eggs to hatch to the much less tolerant nymph stage.

“…Psocids belonging to genus Liposcelis are serious pests of stored commodities in several countries in Asia,1–5 Europe6–8 and Africa,9–11 and have emerged as major pest of stored grain in Australia during the last decade 12. Information on the effectiveness of various protectant chemicals and structural treatments against three liposcelidid psocids, L bostrychophila Badonnel, L entomophila (Enderlein) and L paeta Pearman, has been reported earlier 2.…”

Section: Introductionmentioning

confidence: 99%

Long‐term effectiveness of grain protectants and structural treatments against Liposcelis decolor (Pearman) (Psocoptera: Liposcelididae), a pest of stored products

Nayak

Collins

Pavic

2002

Numerous strains of the psocid pest, Liposcelis decolor (Pearman) were collected from farms and central storages and interbred to form three representative strains from three major grain-growing states of Australia: Queensland, South Australia and New South Wales. These were tested against the grain protectants and structural treatments currently registered for use in Australia. Recently, L decolor has become an important pest of stored grain in Australia, particularly in the eastern and southern parts. There is no published information available on management of this pest and the current pest-management strategy, based predominantly on phosphine fumigation, has failed to control infestations of this pest in numerous grain storages in Australia. Alternative methods of control such as use of contact insecticides were explored in the present work to supplement phosphine fumigation to manage this new pest. From eight grain protectants tested as admixtures, only chlorpyrifos-methyl, bioresmethrin plus piperonyl butoxide, and fenitrothion were found to provide long term (3-9 months) protection against all three strains of L decolor. Chlorpyrifos-methyl gave the best protection, providing a minimum of 7.5 to a maximum of 9 months protection, depending on the strains tested. Three structural treatments, azamethiphos, azamethiphos plus carbaryl and permethrin provided long-term control (8-9 months) of all three strains of L decolor on galvanised steel surfaces, with permethrin delivering 9 months protection against all strains. However, all of these treatments failed to provide long-term control of any strains on concrete surfaces. We conclude that chlorpyrifos-methyl as a grain admixture can be incorporated into fumigation strategies to optimise the control of L decolor infestations. Structural treatments, such as permethrin can be used to support a fumigation strategy in storages made of galvanised steel.