Control Of Stored Product Pests Research Articles

Surface application of diatomaceous earth, SilicoSec® are effective on Sitophilus granarius and Rhyzopertha dominica, but less against Tribolium confusum

Diatomaceous earth (DE) has a promising potential in the control of stored-product pests. Most of the studies on the insecticidal potential of DE products are based on their persistent effects or the mortality they lead to via mixing with the grain. However, the knowledge on the performance of DEs on a particular surface is limited. In the current study, the insecticidal efficacy of a DE product, SilicoSec® was investigated against adults of Sitophilus granarius, Rhyzopertha dominica, and Tribolium confusum by surface application at 2.5, 5.0, 10.0, and 20.0 g/m2 on a concrete surface that is commonly used in storage structures. In S. granarius experiment, the highest immediate mortalities (89.2-99.2%) were obtained by the 5-day exposure even at the lowest rate (2.5 g/m2), while the highest delayed mortalities were 92.5% and 85% at rates of 2.5 and 20 g/m2, respectively by the 3-day exposure. In R. dominica experiment, the highest immediate mortalities (92.5-98.3%) were obtained by the 3-day exposure even at the lowest rate, while the highest delayed mortalities were 90.1 and 98.3% at rates of 10 and 20 g/m2, respectively, by the 1-day exposure. In T. confusum experiment, the highest immediate mortalities (83.3-91.0%) were obtained by the 7-day exposure at 10 or 20 g/m2, while the highest delayed mortalities were obtained by the 7-day exposure, and were 90.0 and 95.9% at rates of 10 and 20 g/m2, respectively. In conclusion, the insecticidal effect of surface application of SilicoSec® was high, moderate, and low against S. granarius, R. dominica, and T. confusum, respectively at concrete surfaces. A rate of 2.5 g/m2 of SilicoSec® provided an efficient control for S. granarius and R. dominica by 3- and 5-day exposures, respectively, while comparable mortality was obtained at a higher rate (10 or 20 g/m2) and exposure time (7-day) for T. confusum.

Optimizing phosphine fumigation efficiency in hazelnut industry: Determining optimal exposure time for stored product pest control

Hazelnut, as with many other stored products, are susceptible to infestation by a variety of stored insect pests. Phosphine fumigation is a widely used method to control pests in stored products, including hazelnut kernels. This study aimed to determine the optimal exposure time for phosphine fumigation for management of stored product pests in hazelnuts. Four treatments with different exposure times (3, 4, 5, and 6 days) were conducted using various development stages of Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), Tribolium confusum Jaqcquelin du Val, (Coleoptera: Tenebrionidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), and Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) together with the control group. The trials were conducted in a commercial chamber of a hazelnut processing facility. The insects were placed in plastic containers within jute sacks filled with hazelnuts, fumigations were done under gas-proof sheet and the survival rate was assessed after treatments. The results showed that a 3-day exposure period was sufficient to fully eradicate the pupal and adult stages of O. surinamensis. For T. castaneum, 100% mortality was achieved in both larvae and adults from 3 days of exposure, but the pupal stage required at least 5 days. For T. confusum, all larvae and adults died in all exposure periods, but the pupal stage required at least 4 days. In the case of the moth species, a 100% mortality rate was achieved in the larval and pupal stages of both E. kuehniella and P. interpunctella at all exposure periods. The mortality rate of E. kuehniella eggs was 99% after 3 and 4 days of exposure, and a fumigation period of 5 days was required to control the entire population. However, only 67% of P. interpunctella eggs were controlled after 3 days of exposure. The time and stage factors were found to be significant in the egg stage of P. interpunctella. The results suggest that a 5-day exposure period is the most effective for controlling tested stored product pests in hazelnuts.

The Type of Grain Counts: Effectiveness of Three Essential Oil-Based Nanoemulsions against Sitophilus oryzae

Essential oil (EO)-based nanoemulsions (NEs) are promising grain protectants in the management of stored-product pests. However, the potential impact of the stored-grain species on the green insecticide effectiveness has been poorly studied. In this study, two concentrations of EO-based NEs from Carlina acaulis L., Mentha longifolia (L.) Huds., and Hazomalania voyronii (Jum.) Capuron were evaluated as insecticides against the major stored-product pest Sitophilus oryzae (L.) on barley, oats, and maize kernels. The C. acaulis EO-based NE applied at 1000 ppm on barley achieved the highest mortality, killing 94.4% of S. oryzae adults after a 7-day exposure, followed by 1000 ppm of H. voyronii EO-based NE (83.3%). The lowest mortality (1.1%) was recorded with 500 ppm of M. longifolia EO-based NE on maize after the same interval. All tested NEs exhibited elevated efficacy when applied on barley, while mortalities were lower on oats and maize. Furthermore, C. acaulis EO-based NE was the most effective when applied on all commodities, followed by H. voyronii and M. longifolia EO-based NEs. Overall, our results highlighted the significant impact of the stored cereal on the insecticidal effectiveness of EO-based NE used for stored-product pest control. Sitophilus oryzae adults on barley can be adequately controlled through the application of C. acaulis and H. voyronii EO-based NEs.

A potential role of nitric oxide in postharvest pest control: A review

Novel methods of stored-product pest control are essential to greater success against a wide variety of pest species worldwide, especially in tropical regions. Modern methods such as ozonation and organic pesticides have ensured grain preservation without loss of quality and without the accumulation of residues; these properties are considered fundamental to food safety. Thereby, nitric oxide (NO) is a newly discovered fumigant that has shown the potential to control stored product pests. It has also been described as a substitute for phosphine and sulfuryl fluoride. In this regard, NO has the potential to become an alternative method of postharvest pest control, primarily due to its high pest mortality rate from a broader range of pests and products. However, research is needed to reduce the impact of NO on food quality due to the high reactive power of NO. Potentially toxic residues, such as the primary forms of NO oxidation, NO2− and NO3−, can accumulate in treated products and damage consumers' health. Further research is needed into the possible use of NO fumigation as an alternative practice in controlling stored grain pests.

Transcriptomic analysis of Sitophilus zeamais in response to limonene fumigation.

Frequent application of chemical fumigants has contributed to the development of resistance in stored-product pests. Essential oils provide a novel and environmentally friendly alternative to conventional chemical pesticides. In this work, the fumigant activity of Taxodium 'zhongshansha' essential oil (TZEO) and main active components against Sitophilus zeamais were evaluated. In addition, the molecular mechanisms mediating the fumigant activity of limonene were assessed. TZEO showed strong fumigant activity against Sitophilus zeamais, with a 50% lethal concentration (LC50 ) of 22.90 μL L-1 air in 24 h. The main components of TZEO were identified using gas chromatography-mass spectrometry, the main active ingredient (limonene) showed an LC50 of 9.93 μL L-1 air in 24 h which had a serious dose-time-effect. The LC50 value of the positive control (aluminum phosphide) was 1.91 μL L-1 . In total, 3982 up-regulated and 3067 down-regulated genes were sequenced in limonene-fumigated Sitophilus zeamais, the genes related to metabolic detoxification were significantly enriched. The mortality rate of 7day-old Sitophilus zeamais adult mediated with knockdown of SzCYP6MS5 and SzCYP6MS6 raised up to 65.67% and 67.65% after fumigation with limonene in 24 h, respectively. The results showed that SzCYP6MS5 and SzCYP6MS6 are closely involved to the detoxification of limonene. In this study, candidate genes affected by limonene treatment in Sitophilus zeamais were identified. These findings provided insights into the systemic metabolic response of Sitophilus zeamais to limonene and established a basis for the development of limonene as a botanical pesticide for the control of stored-product pests. © 2022 Society of Chemical Industry.

Insecticidal potency of mixtures of plant powders and Actellic SuperTM (Pirimiphos-methyl + Permethrin) on Callosobruchus chinensis F. and Sitophilus zeamais Motch

Insect pests still cause substantial quantitative and qualitative grain loss ranging from 20 to 100% in small holder farming systems in tropical countries. Synthetic pesticides are recommended as stop gap measures for the management of stored product insect pests. However, their application has not been fully exploited in small scale farming due to environmental, health, and economic concerns. As a result, new researches have shifted focus to exploiting pesticidal plants as alternatives to synthetic pesticides. Therefore, the current study evaluated mixtures of plant powders and reduced amount of Actellic superTM (pirimiphos-methyl + permethrin) as alternative insecticide formulation against Callosobruchus chinensis and Sitophilus zeamais. Green grams and wheat grains were mixed with a mixture of plant powders in the ratios of 1:1, 1:3 and 1:9 to obtain four rates (0.0, 2.0, 6.0 and 10%w/w). Grains and plant powders were also mixed with reduced amount (10, 25, and 50 %) of recommended rate of Actellic SuperTM to obtain dosages as above. Twenty unsexed adults, 1-5 day old S. zeamais and C. chinensis were introduced into treated grains. The mixture of C. lusitanica: T. vogelii powders in the ratios of 1:1, 1:3 and 1:9 caused mortality in C. chinensis of 55, 95 and 85%, respectively. At the same ratio, E. saligna: L. camara mixture produced mortality in S. zeamais of 77, 82, and 85% respectively. In mixture of C. lusitanica and T. vogelii and reduced amount of Actellic SuperTM by 50% the mortality of C. chinensis was 85 and 80 % respectively. Similarly, E. saligna and L. camara and reduced amount of Actellic SuperTM by 50% caused a mortality of S. zeamais of 48 and 97% respectively. The application of plant powders and reduced amounts of synthetic insecticide has the potential to be applied in stored product pest control

Volatile Infochemicals from Rhyzopertha dominica Larvae and Larval Feces Involved in Theocolax elegans Host Habitat Location.

Simple SummaryFood protection is a key issue to guarantee food security. One of the major criticisms is related to insect pests, which can severely damage stored products. Control of stored product pests widely relies on synthetic pesticides, which are potentially harmful to human health and the environment. In this context, the application of chemicals during post-harvest should be limited, and natural enemies, like parasitoid wasps, might be useful for biologically based pest management programs. The effectiveness of this approach under field conditions is still uncertain, and more information about parasitoid biology and behavior can be valuable to improve mass rearing and control strategies. This study investigates the host habitat location behavior of Theocolax elegans, a generalist parasitoid attacking several stored product pests, including Rhyzopertha dominica, a key pest species of stored grains. Bioassays demonstrated that the parasitoid females were not attracted by intact kernels; indeed, the parasitoid females were strongly attracted by infested wheat and by the host feces, locating the suitable hosts through the characteristic volatile infochemicals emitted by these substrates. Results from the present research are encouraging and suggest that biological control agents might be used to reduce the amount of synthetic insecticides.The development of biologically based approaches for stored product pest control is needed to reduce chemical inputs. Bioassays were performed to investigate host habitat location in the trophic interaction durum wheat/Rhyzopertha dominica/Theocolax elegans. GC-MS analyses were carried out to identify some chemical compounds produced by the host-related substrates. Choice and no-choice experiments demonstrated that female parasitoids were poorly attracted to intact kernels with respect to the infested substrates. Furthermore, T. elegans females performed longer residence time on infested wheat, and they generally displayed a short-term like fidelity for this cue, remaining on it during the whole observation. Infested wheat emitted one chemical (fenchone), which is possibly linked to host larvae presence, while the feces produced by host larvae emitted some other characteristic compounds. Results demonstrated that the presence of host larvae is a key factor for T. elegans host habitat location, considering that the attractiveness of the undamaged wheat is irrelevant. Furthermore, parasitoid females tended to stay on attractive cues, limiting the risk of contamination of other commodities. Biological control tools may be useful to improve the efficiency of pest management programs, but their application should be carefully evaluated.

Evaluation of the efficacy of benzothiazole against the red flour beetle, Tribolium castaneum (Herbst).

In the context of the resistance development and health risks of currently used fumigants, it is urgent to seek more effective and ecofriendly compounds for stored-product pest control. The microbial volatile compound benzothiazole is known to have fungicidal and insecticidal activity; however, its detailed efficacy on storage pests is largely unknown. Benzothiazole was identified for its great ovicidal, larvicidal, pupicidal and adulticidal activity against Tribolium castaneum, and exhibited potent repellency against T. castaneum. The benzothiazole concentrations and developmental stage of T. castaneum were the key factors affecting the insecticidal effects. Adults of T. castaneum exposed to benzothiazole for as long as 168 h showed a decrease in progeny production. Based on 7 days of fumigation in the model food system, benzothiazole at 0.12 mg mL-1 provided an efficacy of 96% and completely inhibited the number of offspring. Safety profile assessment showed that benzothiazole did not affect the germination rate of wheat seeds but had a slight negative effect on seedling growth. However, sufficient ventilation and soil nutrients could relieve this adverse impact. Benzothiazole is a strong fumigant and repellent against T. castaneum. This study provides a good perspective of novel ways to control T. castaneum. © 2020 Society of Chemical Industry.

Biological activity of some essential oil constituents in four Nepeta L. species against Sitophilus oryzae L.

Amini S, Nohooji MG, Khani M, Labbafi MR, Khalighi-Sigaroodi f. 2019. Biological activity of some essential oil constituents in four Nepeta L. species against Sitophilus oryzae L.. Biodiversitas 20: 338-343. Recently, there has been a growing interest in research concerning the possible use of plant extracts as alternatives to synthetic insecticides. Essential oils are among the best-known natural substances with insecticidal properties. These compounds may act as fumigants, contact insecticides, repellents, antifeedants and may affect growth and development of the insects. In an attempt to find a natural and inexpensive method for the control of stored-product pests, contact toxicity of essential oils of Nepeta cataria, Nepeta pogonosperma, Nepeta glomerulosa. and Nepeta binaloudensis. were investigated on adult insects of Sitophilus oryzae L. (Coleoptera, Curculionidae) in vitro condition. Chemical Composition, repellency and fumigant toxicity of the essential oils were investigated. Chemical composition of the essential oils of above plants were identified by GC-MS. 4aα,7α,7aβ-nepetalactone (82.74 %) was major component of N. cataria and also different isomers of nepetalactone were among the major compounds in N. Pogonosperma and N. binaloudensis oils. In fumigants bioassay, N. glomerulosa (124.318μL/L air) showed the highest toxicity against S. oryzae adults, followed by N.pogonosperma (150.49μL/L air) and N. cataria (152.630μL/L air), respectively. Also, the S. oryzae was repelled by N. cataria (91.61%) and N. binaloudensis (91.50 %), respectively.

The potential of host-specific volatiles from Tribolium confusum larval faeces for luring the ectoparasitoid Holepyris sylvanidis : Presentation

The ectoparasitoid Holepyris sylvanidis (Bethylidae) attacks larvae of different stored product pest beetles. Previous studies on the olfactory host search of H. sylvanidis revealed that female parasitoids are strongly attracted to volatiles released from Tribolium confusum larval faeces, in particular to (E)-2-nonenal and 1-pentadecene. We suggested that these host-specific key compounds may serve the parasitoid as long-range attractants for host location. In this context, we propose that the attractive volatile blend could be used to establish a new approach within the biological control of stored product pests by guiding the parasitoid to its host and thus, increasing the host finding success. We investigated the potential of the identified host-indicating volatile cues to attract H. sylvanidis from a distance by offering the two key compounds to female parasitoids. Their walking behaviour and the covered distance were analysed on a Kramer sphere. Moreover, in semi-field trials both attractive volatiles were loaded onto rubber septa which were placed next to 4th instars of T. confusum at 1.5 m distance from the parasitoids. We studied the host finding success of H. sylvanidis by (i) measuring the mean time to locate and parasitise T. confusum larvae and (ii) counting the number of parasitised and unparasitised host larvae as well as the number of newly hatched parasitoids compared to the control without additional olfactory cues. First results showed that H. sylvanids females can locate the provided host larvae from a distance. Parasitistion of host larvae started four days after the release of parasitoids. No effect of the additionally offered hostspecific key volatiles ((E)-2-nonenal and 1-pentadecene) on the parasitoid´s host finding success was observed at the given conditions and used amounts of compounds. Further studies are required to determine the right odour blend and concentrations for attraction of parasitoids over a distance and finally to show that the addition of host-derived kairomones may support the host finding success of H. sylvanidis.

Susceptibility of the life stages of cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae) to ozone

The ban of methyl bromide and problems associated with the use of other stored-product pest control methods have demanded search for potential alternatives. Ozone, an oxidizing gas, is one of such potential alternatives. In this study, the susceptibility of life stages of the cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae) to ozone, was investigated. The concentration-mortality relationships for all life stages exposed to 100–400 ppm at 50 ppm increments for 1 h were determined. The time-mortality relationships for adult L. serricorne exposed to 100 ppm ozone concentration for 1–6 h were also determined. Mortality was recorded as percentages of eggs that failed to hatch 10 days after treatment (DAT), larvae or pupae that failed to develop into adults 28 or 15 DAT, respectively, and adults that died 2 DAT. The concentration-mortality estimates suggested that, generally, higher concentrations were required to kill 99% of insects when treated without food compared to when treated with food made of whole wheat flour and brewer's yeast. In the absence of food, larvae were the most tolerant and adults were the least tolerant to ozone treatment and required 15, 974 ppm and 3769 ppm to kill 99% of the individuals respectively. In the presence of food, eggs and pupae were the most and least tolerant respectively. An exposure time of 7.1 × 1030 h was required to kill 99% of adults treated in the presence of food and 99 h in the absence of food. When adult insects were exposed to 100 ppm ozone for 1–6 h in the absence of food, a weak relationship between survival rate and exposure duration observed initially became stronger in subsequent days. The present study suggests that ozone treatment could be a potential alternative for the management of all life stages of L. serricorne.

Evolution of Stored-Product Entomology: Protecting the World Food Supply

Traditional methods of stored-product pest control were initially passed from generation to generation. Ancient literature and archaeology reveal hermetic sealing, burning sulfur, desiccant dusts, and toxic botanicals as early control methods. Whereas traditional nonchemical methods were subsequently replaced by synthetic chemicals, other traditional methods were improved and integrated with key modern pesticides. Modern stored-product integrated pest management (IPM) makes decisions using knowledge of population dynamics and threshold insect densities. IPM programs are now being fine-tuned to meet regulatory and market standards. Better sampling methods and insights from life histories and ecological studies have been used to optimize the timing of pest management. Over the past 100 years, research on stored-product insects has shifted from being largely concentrated within 10 countries to being distributed across 65 countries. Although the components of IPM programs have been well researched, more research is needed on how these components can be combined to improve effectiveness and assure the security of postharvest food as the human population increases.

The Effect of Essential Oils from Laurus nobilis and Myrtus commonis on the Adults of Mediterranean Flour Moth, Ephestia kuehniella Zeller (Lep.: Pyralidae)

Today, to control of stored-product pests the gaseous chemical compound is usually used. These compounds do not have deleterious effects on non target organisms, environment pollutions, insect's resistance, toxicity to humans and other mammals. In recent years, plants essential oils have received much attention because of their insecticidal, oviposition deterency, repellent effects and antifeedant properties. This study was carried out to evaluate the repellent effects of essential oils from Laurus nobilis and Myrtus commonis against adults of Ephestia kuehniella Zeller (Lep: Pyralidae). Each essential oil consists of five concentrations and each concentration was repeated five times. Bioassays experiments were performed in 25°C, 65 ± 5 RH and in the dark period at the laboratory condition. The result showed that, repellency rate of this pest was significantly increased by essential oils. Repellency power of both essential oils was increased with increase of oil concentrations. Around 20.4 and 10.6 % repellency rates was observed at the lowest concentration (0.50 µl.L-1 air) of L. nobilis and M. commonis, respectively. Also at the highest concentration (2.00 µl.L-1 air) repellency rates were reached to 84.2 % by L. nobilis and 61.3 % related to M. commonis. As a result, it could be concluded that essential oils from L. nobilis and M. commonis have considerable repellent effects on E. kuehniella even at low concentrations.

Effect of diethyl maleate on the toxicity of essential oil from Citrus reticulata fruit peels to Tribolium castaneum Herbst under laboratory conditions

Certain compounds of plants, essential oils, with insecticidal properties have been considered as alternatives to chemical pesticides for pest control in recent years. In this study, the synergistic effect of diethyl maleate (DEM) on the toxicity of Citrus reticulata Blanco (Rutaceae) peel essential oil against a stored-product insect pest, i.e. red flour beetle, Tribolium castaneum Herbst (Tenebrionidae) adults was studied. DEM [one part], combined with acetone [two parts], was applied on T. castaneum adults. Five concentrations of essential oil from C. reticulata were tested. Three replicates and 30 adult insects/replicate/each concentration were used. LC50 values after 24 and 48 h of exposure were 33.8 and 28.2 μl/l air, respectively. Combination of the essential oil from C. reticulata with the synergist DEM after 24 and 48 h of exposure decreased the corresponding LC50 values to 18.1 and 12.2 μl/l air, respectively. These results revealed that DEM can considerably improve the potency of essential oil from C. reticulata and maybe applied successfully in the stored-product pest control programmes.

Essential oils nanoformulations for stored-product pest control – Characterization and biological properties

The lethal and sublethal activity of poly(ethylene glycol) (PEG) nanoparticles containing essential oils (EO), also the physicochemical characterization, were determined against Tribolium castaneum and Rhizopertha dominica. The 10% ratio EO-PEG nanoparticles showed an average diameter<235nm (PDI<0.280) and a loading efficacy>75%; after 6month of storage their size did not change significantly and the amount of the EOs decreased 25%, approximately. Furthermore, during this period, no chemical derivates were observed. The EOs nanoparticles produced a notable increase of the residual contact toxicity apparently due to the slow and persistent release of the active terpenes. In addition, the nanoformulation enhanced the EO contact toxicity and altered the nutritional physiology of both stored product pest. The results indicated that these novel systems could be used in integrated pest management program for T. castaneum and R. dominica control.

Protectability of nine Nigerian medicinal plants against cowpea beetle, Callosobruchus maculatus (Fab.) (Coleoptera: Bruchiidae) in storage

A study was conducted to examine the protectability of nine Nigerian medicinal plants against Callosobruchus maculatus at an ambient temperature of 28 ± 2 °C and relative humidity of 70 ± 5%. The nine plants used were dried and milled into fine powder before application. Among the nine plant powders used, Zanthoxylum zanthoxyloides effected highest mortality rate of 73.40 and 100% at 5% (wt/wt) concentration within two and three days of application, respectively. The effect of this plant at this level of concentration was significantly (p < 0.05) different from other plants. However, all the plant powders effected high mortality rate as they all achieved more than 50% beetle mortality within four days of application at 20% (wt/wt) concentration. Only the powder of Z. zanthoxyloides at 10% (wt/wt) concentration was able to achieve 0% adult emergence, 0% seed damage and 100% damage reduction. Moreover, powder of Z. zanthoxyloides, Aristolochia ringens and Colocasia esculenta at 20% (wt/wt) was also able to prevent the emergence of adult C. maculatus, prevent seed damage and achieve 100% damage reduction. All the powders had low weevil perforation index when compared to the control which had above 50% weevil perforation index. At all levels of concentration, the effect of the powders was significantly (p < 0.05) different from the control. However, Z. xanthoxyloides appeared to be the most effective; therefore, the effective utilisation of Z. xanthoxyloides as a botanical pesticide could minimise the use of hazardous chemicals in stored product pest control since it is of a botanical source.

Effect of diethyl maleate on the toxicity of garlic (Allium sativum L.) extract to Tribolium castaneum Herbst under laboratory conditions

The synergistic effect of diethyl maleate (DEM) on the toxicity of garlic (Allium sativum L.) extract against the stored-product pest, Tribolium castaneum Herbst was studied. DEM [one part] combined with acetone [two parts], was applied on T. castaneum adults. Five concentrations of garlic extract were tested. Three replicates and 30 adult insects/replicate/each concentration, were used. LC50 values after 24 and 48 h of exposure were 127.90 and 90.8 μL/L air, respectively. Combination of the garlic extract with the synergist DEM after 24 and 48 h of exposure decreased the corresponding LC50 values to 83.2 and 57.3 μL/L air, respectively. These results revealed that DEM can considerably improve the potency of garlic extract and maybe applied successfully in the stored-product pest control programmes.

Ionic liquids based stored product insect antifeedants

Ionic liquids are effective stored product insect antifeedants. Their activity depends on the type of cation and anion. A group of ionic liquids with inorganic (nitrate, nitrite, hydrogen sulphite, dihydrogen phosphate, thiocyanate, phosphate and tripolyphosphate) and organic (propionate, citrate, sorbate, undecylate, dodecylbenzenesulfonate, acesulfamate and saccharinate) anions was synthesized. Their physicochemical properties, microbial and deterrent activity against Tribolium confusum (larvae and beetles), Sitophilus granarius (beetles) and Trogoderma granarium (larvae) were determined. Ionic liquids with a didecyldimethylammonium cation demonstrated deterrent activity, exceeding the activity of the standard, azadirachtin. The compounds proved to be very effective against pathogenic bacteria and fungi. The appropriate selection of the cation and anion allows the design of economic and effective insect antifeedants. Ionic liquids based insect antifeedants provide novel examples of promising management tools in biorational approaches to stored product pest control.

Insecticidal effect of six entomopathogenic nematode strains against Lasioderma serricorne (F.) (Coleoptera: Anobiidae) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae)

The insecticidal effect of Heterorhabditis bacteriophora Poinar (Nematoda: Heterorhabditidae), Heterorhabditis megidis Poinar, Jackson and Klein (Nematoda: Heterorhabditidae) and two strains of Steinernema carpocapsae Weiser (Nematoda: Steinernematidae) and Steinernema feltiae Filipjev (Nematoda: Steinernematidae) against the cigarette beetle, Lasioderma serricorne (Fabricius) (Coleoptera: Anobiidae) and the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) was examined under laboratory conditions. The nematodes were applied at the following doses: 0 (control), 100, 1000, 5000, 10,000 and 20,000 infective juveniles (IJs) per ml, corresponding to 0, 10, 100, 500, 1000, and 2000 IJs per insect, and their infectivity was tested at 27 °C and 70% r.h. after 4 and 8 days of exposure. Adult emergence and progeny production was evaluated 4 and 8 weeks after the initiation of the bioassays. In the case of L. serricorne adults, one strain of S. carpocapsae caused 15.6 and 58.9% mortality after 4 and 8 days exposure, respectively, in semolina treated with 20,000 IJs per ml. On the other hand, larval mortality of L. serricorne did not exceed 19% in all treatments tested. Similarly, larval mortality of T. confusum was low, reaching 15.2 and 22.4% after 4 and 8 days exposure, respectively, at the highest dose tested. This is the first report on the effect of entomopathogenic nematodes against the cigarette beetle L. serricorne. Further experimental work is required to optimize the conditions under which these entomopathogenic nematodes could be used for the effective control of stored-product pests.

Advances in the use of pheromones for stored-product protection

Considerable progress has been made in the monitoring and control of stored-product pests, mainly Lepidoptera and Coleoptera, by pheromones, which are used in mass trapping, attracticide and mating disruption methods. In integrated pest management programmes of stored-product protection, the use of pheromones can lead to a reduction in chemical treatments, with economic advantages and the improvement of food-product quality. In this article, I report some promising results offering efficient detection and control of stored-product pests based on pheromones and line up a number of remaining questions to be answered to improve the reliability and competitiveness of the methods used.