Diagnostic Molecular Markers for Phosphine Resistance in U.S. Populations of Tribolium castaneum and Rhyzopertha dominica (original) (raw)
Related papers
Genetics of Resistance to Phosphine in Rhyzopertha dominica (Coleoptera: Bostrichidae)
Journal of Economic Entomology, 2002
The inheritance of resistance to phosphine was studied in two strains of the lesser grain borer, Rhyzopertha dominica (F.), labeled ÔWeak-RÕ and ÔStrong-RÕ. These strains were puriÞed versions of Þeld-selected populations collected in Queensland, Australia. Weak-R and Strong-R were, respectively, 23.4 times (20-h exposure) and 600 times (48-h exposure) resistant to phosphine compared with a reference susceptible strain (S-strain). Each-R strain was crossed with the S-strain and the response to phosphine was measured in their respective F 1 , F 2 , and F 1-backcross (F 1-BC) progenies. Data from testing of reciprocal F 1 progeny indicated that resistance in Weak-R was autosomal and incompletely recessive with a degree of dominance-0.96. ModiÞed chi-square analysis and contingency analysis of the observed response to phosphine of F 1-BC and F 2 progenies rejected the hypothesis of single gene inheritance of resistance. Analysis of the response of the F 1 , F 2 , and F 1-BC progeny from the Strong-R x S-strain cross also rejected the null hypothesis for single gene resistance. Resistance in the Strong-R strain was autosomal and incompletely recessive with a degree of dominance of-0.64. The Weak-R and Strong-R strains were then crossed. Analysis of the F 1 and F 2 progenies of this reciprocal cross revealed that the strong resistance phenotype was coded by a combination of the genes already present in the Weak-R genotype plus an extra major, incompletely recessive gene. There was also evidence of a minor dominant gene present in Ϸ5% of Strong-R individuals.
Insects
Resistance to the fumigant phosphine in Tribolium castaneum occurs worldwide. This study evaluated tests based on adult knockdown time, the time for a beetle to become immobile, when exposed to a high concentration of phosphine. We recorded knockdown times of beetles that remained completely still for 30 s when exposed to 3000 ppm of phosphine in a large, gas-tight glass tube. Beetles were used from 12 populations, of which six were ‘susceptible’ to phosphine, three were ‘weakly resistant’, and three were ‘strongly resistant’. Knockdown times were determined for single beetles, as well as for groups of ten beetles for which the time to knockdown for either five beetles (KT50) or ten beetles (KT100) were recorded. Similar knockdown times occurred across susceptible and resistant populations. However, the KT100 tests generated conservative times for diagnosing strong vs. weak resistance. The strong resistant populations were all over 100 min with KT100, compared to 60 min or less for ...
Turkish Journal of Entomology, 2015
Fumigation with phosphine gas is the primary method of controlling stored grain pests. In Turkey, phosphine has been used extensively since the 1950's. Even though high levels of phosphine resistance have been detected in several key stored products pests across the world, it has never been studied in Turkey despite this long history of phosphine use. High-level phosphine resistance has been detected and genetically characterised previously in the rust red flour beetle, Tribolium castaneum in other countries. Since this pest is also a common problem in stored grain environment in Turkey, the current study was undertaken for the first time, to investigate the distribution and strength of phosphine resistance in T.castaneum. Four strains of T. castaneum were tested through bioassays for determining the weak and strong phosphine resistance phenotypes on the basis of the response of adults to discriminating phosphine concentrations of 0.03 mg/L and 0.25 mg/L, for 20 hour exposures respectively. Phenotype testing showed all strains exhibited some level of phosphine resistance with a maximum level of 196 fold. Sequencing and genetic testing of seven field-collected strains showed that all of them carried a strong resistance allele in at the rph2 locus similar to the one previously reported. Our results show that strong resistance to phosphine is common in Turkish strains of T. castaneum.
Julius-Kühn-Archiv, 2018
MThe lesser grain borer, Rhyzopertha dominica is one of the serious cosmopolitan stored grain pests worldwide. High phosphine resistant R. dominica has been reported in several countries. The evolution of strong phosphine resistance is a major challenge for continuous application of the fumigant. Rapid detection of phosphine resistance level is a prime key to implement an appropriate strategy for control the stored-product pests. Dihydrolipoamide dehydrogenase (DLD) is a key metabolic enzyme mediating the phosphine resistance in population of R. dominica, Tribolium castaneum and Caenorhabditis elegans. Analysis of the DLD sequences deposited in GenBank revealed that the P45/49S mutation was the most common one in many PH3-resistant stored-product pest insects. This information now enables direct detection of resistance using molecular diagnosis in field populations. We herein propose a method for rapid detection of phosphine resistance in R. dominica according to P49S point mutation...
Pest Management Science, 2012
BACKGROUND: The recent development of very high resistance to phosphine in rusty grain beetle, Cryptolestes ferrugineus (Stephens), seriously threatens stored-grain biosecurity. The aim was to characterise this resistance, to develop a rapid bioassay for its diagnosis to support pest management and to document the distribution of resistance in Australia in 2007-2011. RESULTS: Bioassays of purified laboratory reference strains and field-collected samples revealed three phenotypes: susceptible, weakly resistant and strongly resistant. With resistance factors of > 1000×, resistance to phosphine expressed by the strong resistance phenotype was higher than reported for any stored-product insect species. The new time-to-knockdown assay rapidly and accurately diagnosed each resistance phenotype within 6 h. Although less frequent in western Australia, weak resistance was detected throughout all grain production regions. Strong resistance occurred predominantly in central storages in eastern Australia. CONCLUSION: Resistance to phosphine in the rusty grain beetle is expressed through two identifiable phenotypes: weak and strong. Strong resistance requires urgent changes to current fumigation dosages. The development of a rapid assay for diagnosis of resistance enables the provision of same-day advice to expedite resistance management decisions.
Journal of Pest Science, 2012
In this article, we describe and compare two individual-based models constructed to investigate how genetic factors influence the development of phosphine resistance in lesser grain borer (R. dominica). One model is based on the simplifying assumption that resistance is conferred by alleles at a single locus, while the other is based on the more realistic assumption that resistance is conferred by alleles at two separate loci. We simulated the population dynamic of R. dominica in the absence of phosphine fumigation, and under high and low dose phosphine treatments, and found important differences between the predictions of the two models in all three cases. In the absence of fumigation, starting from the same initial frequencies of genotypes, the two models tended to different stable frequencies, although both reached Hardy-Weinberg equilibrium. The one-locus model exaggerated the equilibrium proportion of strongly resistant beetles by 3.6 times, compared to the aggregated predictions of the two-locus model. Under a low dose treatment the one-locus model overestimated the proportion of strongly resistant individuals within the population and underestimated the total population numbers compared to the two-locus model. These results show the importance of basing resistance evolution models on realistic genetics and that using oversimplified one-locus models to develop pest control strategies runs the risk of not correctly identifying tactics to minimise the incidence of pest infestation. Keywords Individual-based model Á One-locus Á Two-locus Á Phosphine resistance Á Lesser grain borer Communicated by C. G. Athanassiou.
Neotropical Entomology, 2010
The resistance to fumigant insecticides in stored-products insects is often recorded. Several factors influence the evolution of insecticide resistance. Among these, the frequency of applications and the migration of resistant populations are of primary importance for the stored-product insects. The aim of this study was to characterize the spectrum and investigate the status of phosphine resistance in Brazil, in 13 populations of the coleoptera Tribolium castaneum Herbst (Tenebrionidae), ten populations of Rhyzopertha dominica (Fabr.) (Bostrichidae), and eight populations of Oryzaephilus surinamensis (L.) (Silvanidae). The pattern of resistance dispersion in the populations of these species was also verified. The bioassays for the detection of phosphine resistance followed the FAO standard method. To test the influence of migration in the evolution of the phosphine resistance, the difference of mortality in the discriminating concentration and the geographical distance among each pair wise combination of collection sites were correlated. None of the populations exhibited mortality above 90% in the discriminating concentration, for the three species. Mortality in the discriminating concentration increased with the geographical distance for R. dominica and O. surinamensis. However, no significant linear response was observed among the variables for T. castaneum populations. These results suggest that the dispersion of insects and the local selection are relevant in the evolution of the phosphine resistance in populations of R. dominica and O. surinamensis. In contrast, grain trade and local selection are probably the factors that determine the evolution of the phosphine resistance in populations of T. castaneum.
Julius-Kühn-Archiv, 2018
Stored product beetles that are resistant to the fumigant phosphine (hydrogen phosphide) have been reported for more than 50 years in many places worldwide. The high levels of phosphine resistance in lesser grain borer Rhyzopertha dominica (F.) have been noted from several countries including Bangladesh. This study was designed to evaluate the status of resistance to phosphine in Bangladeshi R. dominica and to verify the possible comparison among other phosphine resistant strains from tropical countries viz. Burkina Faso and Malaysia. The data reported and summarized here showed varied levels of resistance compared to the laboratory phosphine susceptible strain (RDLAB). Rhyzopertha dominica strains originating from Bangladesh (RDBGD) and Burkina Faso (RDBKF) exhibited higher levels of resistance to phosphine compared to the Malaysian strains (RDMAL). Analysis of dose–response data indicated that the RDBGD and RDBKF strains were the most resistant to phosphine under different exposur...
The red flour beetle is a cosmopolitan pest of stored grain and stored grain products. The pest has developed resistance to phosphine, the primary chemical used for its control. The reproductive output of survivors from a phosphine treatment is an important element of resistance development but experimental data are lacking. We exposed mated resistant female beetles to 0.135 mg/L of phosphine for 48 h at 25uC. Following one week of recovery we provided two non-exposed males to half of the phosphine exposed females and to half of the non-exposed control females. Females that had been exposed produced significantly fewer offspring than non-exposed females. Females that remained isolated produced significantly fewer offspring than both exposed females with access to males and non-exposed controls (P,0.05). Some females were permanently damaged from exposure to phosphine and did not reproduce even when given access to males. We also examined the additional effects of starvation prior to phosphine exposure on offspring production. Non-exposed starved females experienced a small reduction in mean offspring production in the week following starvation, followed by a recovery in the second week. Females that were starved and exposed to phosphine demonstrated a very significant reduction in offspring production in the first week following exposure which remained significantly lower than that of starved non-exposed females (P,0.05). These results demonstrate a clear sublethal effect of phosphine acting on the female reproductive system and in some individuals this can lead to permanent reproductive damage. Pest population rebound after a fumigation may be slower than expected which may reduce the rate of phosphine resistance development. The results presented strongly suggest that phosphine resistance models should include sublethal effects.