Search

A series of studies was conducted by exposing young and old eggs, nymphs, and adults of the psocids Liposcelis bostrychophila (Badonnel), L. paeta (Pearman), L. decolor (Pearman), and L. entomophila (Enderlein) to −18 °C for various time intervals. Survival was assessed as initial and final, at different times depending on the life stage. Young eggs of L. bostrychophila were the most tolerant life stage of any of the species, with scattered survival out to 120 h of exposure to −18 °C. Eggs were the most tolerant life stage for each species, requiring 24, 12, and 2 h of exposure for complete kill of L. paeta, L. decolor, and L. entomophila, respectively. Nymphs and adults of all species were far more susceptible than eggs, with no final survival after two hours of exposure. Results show the extreme variation between different psocid life stages and species to cold temperatures, and provide guidelines for using cold as a control strategy for psocids. Our results show that 24 h at −18 °C is sufficient to kill all life stages of the psocid species tested, except for young L. bostrychophila eggs which will require at least 128 h of exposure at −18 °C for complete mortality.

Rickettsia felis is a human pathogen transmitted by the cat flea, Ctenocephalides felis (Bouché) (str. LSU), as well as an obligate symbiont of the parthenogenic booklouse Liposcelis bostrychophila (Badonnel) (str. LSU-Lb). The influence of genetic variability in these two strains of R. felis on host specialization and fitness and possible resulting differences on infection and transmission kinetics in C. felis is unknown. Utilizing an artificial host system, cat fleas were exposed to a R. felis str. LSU-Lb-infected bloodmeal and monitored for infection at 7-d intervals for 28 d. Quantitative real-time PCR was used to determine rickettsial load and infection density in newly exposed cat fleas, and transmission frequency between cat fleas. The effect of persistent R. felis infection on cat flea F1 progeny was also assessed. At 7 d postexposure 76.7% of the cat fleas successfully acquired R. felis str. LSU-Lb. In R. felis str. LSU-Lb-exposed cat fleas, the mean infection load (6.15 × 106), infection density (0.76), and infection prevalence (91/114) were significantly greater than R. felis str. LSU infection load (3.09 × 106), infection density (0.68), and infection prevalence (76/113). A persistent R. felis str. LSU-Lb infection was detected for 28 d in adult cat fleas but neither female:male ratio distortion nor vertical transmission was observed in F1 progeny. While infection kinetics differed, with higher intensity associated with R. felis str. LSU-Lb, no distinct phenotype was observed in the F1 progeny.

Liposcelis bostrychophila (Psocoptera: Liposcelidae) is a widely distributed pest that can cause considerable economic losses and pose human health risks. Rapid development of insecticide resistance has made L. bostrychophila increasingly difficult to control. To obtain information potentially useful for pest management, genetic diversity and differentiation of L. bostrychophila from five geographic locations in China was studied using inter-simple sequence repeat (ISSR). A total of 104 loci were found by ISSR markers and amplified using 9 selected primers. The percentage of polymorphic bands (PPB) was 91.4%. Shannon’s information index (I) and Nei’s gene diversity (He) indicated high genetic diversity at the species level. Population differentiation (Gst = 0.484) was average in these populations. Analysis of molecular variation (AMOVA) indicated that genetic variation was mainly distributed within populations. Gene flow (Nm = 0.534) was moderate. Cluster analysis showed that genotypes isolated from the same locations displayed higher genetic similarity and permitted the grouping of isolates of L. bostrychophila into three distinct clusters. The correlation between genetic distance and geographic distance was not significant.

The repellent activities of one hot thermal-sense compound, vanillyl butyl ether (VBE), and two cool thermal-sense compounds, menthoxypropanediol (MPD) and (−)-isopulegol (IPG), against two stored product insects, Tribolium confusum and Liposcelis bostrychophila, were investigated. Such thermal-sense compounds affect mammals through transient receptor potential (TRP) channels, and both types of agonists (VBE and menthol) exhibited mutually inhibitory effects on mammalian TRPV1 and TRPM8 channels. Each compound exhibited repellent activity against both T. confusum and L. bostrychophila in a dose-dependent manner. Furthermore, synergistic effects were observed between VBE and MPD or IPG. The composition of TRP channels is different between mammals and insects. These results suggest that the use of thermal-sense compounds might serve as an alternative to essential oils in stored products protection.

Esterases (ESTs) play important roles in metabolizing various physiologically endogenous and exogenous compounds, and various environmental xenobiotics in insects. The psocid, Liposcelis bostrychophila is a major pest of stored products worldwide and rapidly develops resistance to commonly insecticides. However, the involvement of ESTs in insecticide metabolization and the application of RNAi approach in psocids have not been well elucidated. In this study, we characterized four LbEST genes and investigated the transcriptional levels of these genes at different developmental stages and under different insecticides exposures to assess their potential roles in response to insecticides. The four LbESTs contain a catalytic triad (Ser-His-Glu) linked to an oxyanion hole and acyl pocket involved in substrate stabilization during its hydrolysis. Synergism observed with the esterase-inhibitor DEF suggests the involvement of esterases in malathion detoxification. LbESTs were expressed during the whole of developmental stages, but predominant abundance in the first nymphal instar and adult stage. The mRNA level of three LbEST genes (except for LbEST4) was induced (1.29- to 5.60 fold) in response to malathion or deltamethrin exposures, indicating that these esterases are involved in the detoxification process. Silencing of LbEST1, LbEST2 or LbEST3 through dsRNA feeding led to a higher mortality of psocids upon the malathion treatment compared to controls (1.83 to 2.69-fold), demonstrating that these esterase genes play roles in malathion detoxification in L. bostrychophila. Our study provides new evidence for understanding of the function and regulation mechanism of esterases in L. bostrychophila in insecticide detoxification. The current study also suggests that the present RNAi method could be applied for gene functional studies in psocids.

The efficacy of low temperatures ranging from 0 to −15 °C was evaluated against all life stages of Tribolium confusum, adults of Oryzaephilus surinamensis and adults of Liposcelis bostrychophila. All species/life stages were exposed in empty vials or vials containing 5 g of flour, for time intervals of 2–7 d. Eggs and pupae were the least susceptible life stages of T. confusum, as these life stages had the highest survival at – 15 °C. Nevertheless, at this temperature, an exposure of 4 and 8 h for eggs and pupae, respectively, resulted in no survival. In most combinations, the presence of flour did not affect survival of T. confusum exposed to any temperature. There was no survival of O. surinamensis adults after exposure to −5 °C for 7 d or to −10 °C for 8 h, and the presence of flour had no effect on survival. Adults of L. bostrychophila were the most-cold tolerant among the species and life stages tested; at −10 °C, mortality was 100% only after 7 d of exposure. For this species, the presence of flour had some effect on adult survival, but results were not consistent with temperature. The results of this study can be utilized to develop control programs for using low temperatures as a disinfestation strategy for infested commodities.

In this work, the essential oils (EOs) of Alpinia zerumbet (Pers.) Burtt. et Smith were extracted from different organs (stems, leaves, flowers and fruits). The GC-MS analysis showed that two isomers m-cymene and o-cymene distributed totally diverse among different organs: m-cymene were relatively rich in the EOs from stems, flowers and fruits (7.1, 11.3 and 6.6%, respectively), but absent in the EO from leaves; o-cymene was predominant in the EO from leaves (14.9%), but missing in the EOs from other organs. A. zerumbet EOs from different organs, as well as seven characteristic compounds (m-cymene, o-cymene, camphene, eucalyptol, linalool, camphor, and borneol) showed varying degrees of insecticidal and repellent activities to Tribolium castaneum and Liposcelis bostrychophila. o-Cymene exhibited stronger fumigant and contact toxicity than m-cymene did to both insect species, suggesting that the relative position of methyl and isopropyl on benzene ring would influence the insecticidal activity. Positive correlation between relative content of camphor and LC50 value to T. castaneum was significant, while fumigant and contact toxicity of EOs appeared to be negatively correlated with the content of m-cymene.

Anatomy of the adult and the first-instar nymph of Liposcelis bostrychophila (Psocoptera, Liposcelididae) is described in detail for the first time based on series of sections and 3D computer reconstruction. Despite its tiny size, no strong structural simplification is observed in Liposcelis. The main features of the anatomy of this species associated with miniaturization are the merging of individual skeletal elements and simplification of the endoskeleton in the nymph, lack of the midgut muscles, simplification of the tracheal and circulatory systems, oligomerization and concentration of ganglia, asymmetry of the central nervous system in the nymph, and the absence of several muscles. Changes in the relative volumes of organs during the postembryonic development of Liposcelis are analyzed and compared with other minute insects.

In our screening program for new agrochemicals from wild plants and Chinese medicinal herbs, Teucrium quadrifarium aerial parts at flowering stage was found to possess strong insecticidal activity ...

A screening of Chinese medicinal herbs and wild plants for agrochemicals was carried out; the essential oil of Glycosmis lucida leaves was found to possess significant repellent activity against Tribolium castaneum and Liposcelis bostrychophila. It was found that the main components included elixene (19.81%), spathulenol (10.68%), anethole (12.05%), verbenone (10.32%) followed by β-caryophyllene (6.87%). The essential oil, anethole and verbenone were strongly repellent against T. castaneum (96, 86 and 94%, respectively, at 15.73 nL cm−2) and L. bostrychophila (100, 68 and 72%, respectively, at 31.58 nL cm−2) after a 2h treatment. The results indicate that anethole and verbenone had the potential to be developed as natural repellents for control of stored product insects.

Liposcelis bostrychophila is a globally important stored product pest that is adapted to many habitats and is difficult to control due to insecticide resistance. We evaluated effects of habitat fragmentation on the genetic diversity and differentiation of L. bostrychophila populations. These genetic data were collected in Wuhu city, China using inter-simple sequence repeat (ISSR). A total of 108 discernible DNA fragments were detected, 107 were polymorphic and the percentage of polymorphic bands (PPB) was 99.1%. Shannon’s information index ( I ) and Nei’s gene diversity ( He ) from four populations were ordered (high to low) as herbstore > flourmill > bedroom > library. Population differentiation ( Gst = 0.41) was average in these populations. Analysis of molecular variation (AMOVA) showed that variation existed mainly within populations (68.1%). At the same time, gene flow ( Nm = 0.72) was interpreted to be moderate. Cluster analysis showed a small degree of genetic distance among different isolates and permitted grouping the isolates of L . bostrychophila into three distinct clusters. The study demonstrated clear genetic effects of habitat fragmentation on L . bostrychophila populations. Genetic diversity decreased and genetic differentiation increased between remnant populations when habitats were fragmented. Gene flow is not impeded by habitat fragmentation due to the impact of human activities. These findings are of great use for the prevention and control of this pest.

During our screening program for new agrochemicals from the local wild plants and Chinese medicinal herbs, the essential oil of Cyperus rotundus rhizomes was found to possess strong insecticidal activities against the booklice, Liposcelis bostrychophila Badonnel. Essential oil of C. rotundus rhizomes was obtained by hydrodistillation and analyzed by Gas chromatography-Mass spectrometry. A total of 35 components of the essential oil of C. rotundus were identified. The main components of the essential oil were α-cyperone (29.38%), cyperene (13.97%), caryophyllene oxide (6.71%) and β-selinene (6.47%). Bioactivities-directed chromatographic separation on repeated silica gel columns led to the isolation of two compounds: cyperene and α-cyperone. α-Cyperone exhibited pronounced contact toxicity against L. bostrychophila (LC50 = 41.32 μg/cm2) and was more toxic than cyperene (LC50= 50.08 μg/cm2) while the essential oil acting against the booklice showed an LC50 value of 102.11 μg/cm2. These results sugge...

In this work, we investigated the chemical constituents of the essential oil extracted from the leaves of Rhododendron thymifolium and their insecticidal and repellent activities against Liposcelis bostrychophila and Tribolium castaneum. 14 chemical components were identified from the essential oil and included germacrone (20.83%), γ-elemene (11.10%), selina-3,7(11)-diene (6.18%), α-oxobisabolene (5.39%), β-sesquiphellandrene (2.44%), β-elemenone (35.17%), Z,Z,Z-1,5,9,9-tetramethyl-1,4,7,-cycloundecatriene (3.64%) and 1-(4-ethylphenyl)-3-methyl-pyrazol-(4H)-one (2.91%). Among them, the first five components were isolated and identified. The results showed that the essential oil and five pure compounds possessed the obvious repellent activity and various levels of contact activities against the two species of stored insects. The essential oil possessed the contact toxicity (LD50 = 19.63 μg/cm2) which was quite close to the toxicity of positive control pyrethrins (LD50 = 18.72 μg/cm2) against L. bostrychophila. The five pure compounds might individually or together effect the contact toxicity of the essential oil against L. bostrychophila. The essential oil possessed the contact toxicity (LD50 = 29.82 μg/adult) against T. castaneum, but only germacrone revealed strong contact toxicity (LD50 = 0.97 μg/adult), which was comparable with the toxicity of pyrethrins (LD50 = 0.24 μg/adult) among five compounds against T. castaneum. The existence of germacrone might be one of the key elements which affected the contact toxicity of R. thymifolium essential oil against T. castaneum. The insecticidal and repellent activities of essential oil and five compounds were evaluated, the results provide a basis of the development and utilization in the future for control of insects.

Psocids inhabit stored foods and cereals and cause serious problems with regard to food hygiene. They are a major target for pest control around the world, including Japan. Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelidae) is a representative species of household psocid that prefers to feed on fungi while also spreading fungi in the site it inhabits; it is therefore recognized as an indicator of fungal generation. The present study investigated the characteristics of fungi that influence the feeding behavior of this fungivorous insect using four fungus species (Aspergillus tubingensis, Aspergillus flavus, Penicillium chrysogenum, Cladosporium cladosporioides) that are representative fungi found in Japanese food factories and food storage facilities. The results of preference and feeding tests performed using an arena device (diameter: 9 cm) and a handmade olfactometer revealed that P. chrysogenum was the most attractive fungus for feeding. Based on the comparison of multiple characteristics of P. chrysogenum and the three other fungus species, the factors that were considered to evoke the feeding behavior of L. bostrychophila were a velvety appearance with hyphae that were shorter than the height of the insect as well as specific odors. The present study clarified the common characteristics of the fungi preferred by L. bostrychophila, which may be used to predict pest occurrence and develop agents for trapping and monitoring, thus leading to effective integrated pest management.

Phase-out, impending ban, and developing insect resistance to the commonly used insecticides for stored grains pose serious challenges to the scientific community and it is imperative to develop effective pest management strategies. Identification and testing of new compounds are potential options to deal with the growing threat. Ethylenesulphonyl fluoride (ESF), a new synthetic compound, is one of the most promising alternative fumigant insecticides that can be used to control the insect pests in stored-grains. However, limited evidence is available to support its efficacy to control the stored-product psocids. This study evaluates the ESF as a prospective control reagent to exterminate different life stages of the psocids Liposcelis bostrychophila Badonnel and L. entomophila (Enderlein). We conducted a 4 h toxicity trials and 12 h simulated efficacy trials with adults of the two species in wheat. Adults and nymphs were highly susceptible to ESF. Complete adult and nymph mortality (LD99) was also recorded at dosages ranged from 1.97 μL/L to 3.80 μL/L. Moreover, complete (LD99) egg mortality was recorded at dosages between 3.59 μL/L and 7.60 μL/L. Remarkably, the mortality of adults decreased with increasing depth of the grain bulk. Our study establishes ESF as a potential reagent that can be used effectively to control a variety of commonly known stored grain psocids.

The main objectives of the study were to establish an accurate multiplex PCR identification technique for five species of psocids from Chinese herbal medicines and to discuss the phylogenetic relationships among those species. Five species of booklice (Liposcelis bostrychophila, L. entomophila, L. tricolor, L. pearmani and L. rufa) were collected from Chinese herbal medicines. Genomic DNA of individual booklice was obtained via a nondestructive DNA extraction method. The internal transcribed spacer (ITS)1-5.8S-ITS2 gene sequences were obtained by PCR amplifying and sequencing. The primers were designed, and the phylogenetic trees were constructed using the NCBI website and MEGA software. In this research, a Multiplex PCR identification technique was established based on the ITS2 gene for the five species of booklice. The phylogenetic relationships among the five booklice species were analyzed and discussed based on the ITS gene sequences.

While typically a flea parasite and opportunistic human pathogen, the presence of Rickettsia felis (strain LSU-Lb) in the non-blood-feeding, parthenogenetically reproducing booklouse, Liposcelis bostrychophila, provides a system to ascertain factors governing not only host transitions but also obligate reproductive parasitism (RP). Analysis of plasmid pLbAR, unique to R. felis str. LSU-Lb, revealed a toxin–antitoxin module with similar features to prophage-encoded toxin–antitoxin modules utilized by parasitic Wolbachia strains to induce another form of RP, cytoplasmic incompatibility, in their arthropod hosts. Curiously, multiple deubiquitinase and nuclease domains of the large (3,841 aa) pLbAR toxin, as well the entire antitoxin, facilitated the detection of an assortment of related proteins from diverse intracellular bacteria, including other reproductive parasites. Our description of these remarkable components of the intracellular mobilome, including their presence in certain arthropod genomes, lends insight on the evolution of RP, while invigorating research on parasite-mediated biocontrol of arthropod-borne viral and bacterial pathogens.

The essential oil of Stachys riederi var. japonica (Family: Lamiaceae) was extracted by hydrodistillation and determined by GC and GC-MS. A total of 40 components were identified, representing 96.01% of the total oil composition. The major compounds in the essential oil were acetanisole (15.43%), anisole (9.43%), 1,8-cineole (8.07%), geraniol (7.89%), eugenol (4.54%), caryophyllene oxide (4.47%), caryophyllene (4.21%) and linalool (4.07%). Five active constituents (acetanisole, anisole, 1,8-cineole, eugenol and geraniol) were identified by bioactivity-directed fractionation. The essential oil possessed fumigant toxicity against maize weevils (Sitophilus zeamais) and booklice (Liposcelis bostrychophila), with LC50 values of 15.0 mg/L and 0.7 mg/L, respectively. Eugenol and anisole exhibited stronger fumigant toxicity than the oil against booklice. 1,8-Cineole showed stronger toxicity, and anisole as well as eugenol exhibited the same level of fumigant toxicity as the essential oil against maize weevils. The essential oil also exhibited contact toxicity against S. zeamais adults and L. bostrychophila, with LC50 values of 21.8 µg/adult and 287.0 µg/cm2, respectively. The results indicated that the essential oil of S. riederi var. japonica and its isolates show potential as fumigants, and for their contact toxicity against grain storage insects.

To develop natural product resources from the Clausena genus (Rutaceae), the essential oils (EOs) from four Clausena plants (Clausena excavata, C. lansium, C. emarginata, and C. dunniana) were analyzed by GC-MS. Their lethal (contact toxicity) and sublethal effects (repellency) against Liposcelis bostrychophila (LB) adults were also evaluated. Santalene sesquiterpene was the precursor substance of santalol, a valuable perfumery. It was found that plenty of α-santalol (31.7%) and α-santalane (19.5%) contained in C. lansium from Guangxi Province and α-santalene (1.5%) existed in C. emarginata. Contact toxicity of the four EOs was observed, especially C. dunniana (LD50 = 37.26 µg/cm2). Santalol (LD50 = 30.26 µg/cm2) and estragole (LD50 = 30.22 µg/cm2) were the two most toxic compounds. In repellency assays, C. excavate, C. lansium, and C. emarginata exhibited repellent effect at the dose of 63.17 nL/cm2 2 h after exposure (percentage repellencies were 100%, 98%, and 96%, respectively). Four Clausena EOs and santalol had an excellent potential for application in the management of LB. Clausena plants could be further developed to find more resources of natural products.

The psocid, Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae), is the most widespread psocid pest of stored products. Because L. bostrychophila has developed resistance to several chemical insecticides, it is important to investigate other integrated pest management (IPM) approaches, and a critical part of IPM programs is an effective monitoring program, Monitoring tools for psocids are limited, and few studies have been conducted on monitoring of psocids, with none on the attraction of lights for psocids. Therefore, we studied the response of L. bostrychophila adults to eight wavelengths of light-emitting diodes (LED) in paired-choice pitfall test. Among the LEDs evaluated, the strongest response by L. bostrychophila adults was to 351 nm UV. When LEDs were tested against brewer’s yeast (the most preferred attractant for L. bostrychophila among more than 20 potential attractants found in previous studies), the 351 nm UV wavelength was the only light that attracted more psocids than brewer’s yeast. These results suggest that the use of LEDs might be useful in psocid-monitoring programs for L. bostrychophila and other psocid species.

Fertility life table provides a comprehensive description of arthropod population dynamics by the estimation of parameters about arthropod population growth potential. It can also clarify the sublethal effects of chemicals on insects. Ethacrynic acid (EA), an inhibitor of glutathione S-transferases, is a diuretic compound that has been confirmed to modulate drug resistance in organisms. In this study, the effects of EA on growth and development of Liposcelis bostrychophila Badonnel were investigated in the laboratory to explore the potential possibilities of EA as an active agent to manage insecticide-resistant psocids. The treatment of psocids was obtained by feeding on the routine diet containing 3% EA for three successive generations, and psocids on routine diet served as control. The results indicated that EA possessed some negative effects on the life-table parameters of the psocid in F1 and F2 generations. The addition of EA to diet stunted psocids growth by lengthening development time and increasing mortality with a greater effect in the F2 generation. In the third generation of psocids on EA diet, it seemed there was a return to normal. Psocid fitness was influenced by addition of EA to standard diet. Using rm values, the fitness for EA diet in F1, F2, and F3 compared with the counterpart of routine diet was calculated as 0.80, 0.74, and 0.87, respectively.

Water-distilled essential oil from Clinopodium chinense (Labiatae) aerial parts at the flowering stage was analyzed by gas chromatography-mass spectrometry. Thirty-five compounds, accounting for 99.18% of the total oil, were identified, and the main components of the essential oil of C. chinense were spathulenol (18.54%), piperitone (18.9%), caryophyllene (12.04%), and bornyl acetate (8.14%). Based on bioactivity-directed fractionation, bornyl acetate, caryophyllene, and piperitone were identified from the essential oil. The essential oil possessed fumigant toxicity against booklice (Liposcelis bostrychophila) with a 50% lethal concentration (LC50) value of 423.39 μg/liter, while the isolated constituents, bornyl acetate and piperitone, had LC50 values of 351.69 and 311.12 μg/liter against booklice, respectively. The essential oil also exhibited contact toxicity against L. bostrychophila with an LC50 value of 215.25 μg/cm(2). Bornyl acetate, caryophyllene, and piperitone exhibited acute toxicity against booklice with LC50 values of 321.42, 275.00, and 139.74 μg/cm(2), respectively. The results indicated that the essential oil and its isolated constituents have potential for development into natural insecticides or fumigants for control of insects in stored grains.

The psocid species Liposcelis paeta Pearman, Liposcelis entomophila (Enderlein), Liposcelis decolor (Pearman), Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae), and Lepinotus reticulatus Enderlein (Psocoptera: Trogiidae) were evaluated in laboratory bioassays to determine their susceptibility to six concentrations of methyl bromide (0.027, 0.113, 0.280, 0.393, 0.452, and 0.616 g/m3) after 48 h of exposure at 27.5°C. The life stages that were evaluated were adults (for all species), nymphs (for all species except Lep. reticulatus), and eggs (for L. entomophila, L. decolor, and L. bostrychophila). Adults and nymphs were very susceptible, and complete mortality was recorded at concentrations between 0.027 and 0.280 g/m3. In contrast, eggs were by far more tolerant than adults and nymphs for all species tested. At 0.027 g/m3, mortality did not exceed 53%, while survival was high even at 0.113 g/m3. Complete (100%) egg mortality was recorded at 0.393 g/m3 for L. decolor and at 0.452 g/m3 for L. entomophila and L. bostrychophila; concentrations estimated to give 99% mortality for eggs of these three species were 0.710, 1.044, and 0.891 g/m3, respectively. These results show that stored-product psocids are susceptible to methyl bromide, but concentrations of ≥0.452 g/m3 should be used to control all life stages.

Water-distilled essential oil from Illicium henryi (Illiciaceae) root bark was analyzed by gas chromatography-mass spectrometry. Thirty-four compounds, accounting for 97.86% of the total oil, were identified. The main components of the essential oil of I. henryi root bark were safrole (46.12%), myristicin (20.39%), and 1,8-cineole (6.17%), followed by α-cadinol (3.784%) and linalool (3.22%). The essential oil had higher levels of phenylpropanoids (66.89%) than of monoterpenoids (14.83%) and sesquiternoids (16.14%). Three constituents were isolated from the oil based on bioactivity fractionation. The essential oil possessed fumigant toxicity against booklice (Liposcelis bostrychophila), with a 50% lethal concentration (LC50) of 380.39 μg/liter of air, while the two isolated constituents myristicin and safrole had LC50s of 121.95 and 322.54 μg/liter, respectively. Another constituent, 1,8-cineole, showed weaker toxicity, with an LC50 of 1,120.43 μg/liter. The essential oil also exhibited contact toxicity against L. bostrychophila, with an LC50 of 96.83 μg/cm(2). Myristicin (LC50, 18.74 μg/cm(2)) and safrole (LC50, 69.28 μg/cm(2)) exhibited stronger acute toxicity than 1,8-cineole (LC50, 1,049.41 μg/cm(2)) against the booklice. The results indicated that the essential oil and its constituent compounds have potential for development into natural insecticides for control of psocids in stored grains.

In order to find and develop new botanical pesticides against tobacco storage pests, bioactivity screening was performed. The essential oil obtained from the aerial parts of Liriope muscari was investigated by GC/MS and GC/FID. A total of 14 components representing 96.12% of the oil were identified and the main compounds in the oil were found to be methyl eugenol (42.15%) and safrole (17.15%), followed by myristicin (14.18%) and 3,5-dimethoxytoluene (10.60%). After screening, the essential oil exhibit potential insecticidal activity. In the progress of assay, it showed that the essential oil exhibited potent contact toxicity against Tribolium castaneum, Lasioderma serricorne and Liposcelis bostrychophila adults, with LD50 values of 13.36, 11.28 µg/adult and 21.37 µg/cm2, respectively. The essential oil also exhibited strong repellency against the three stored product insects. At the same concentrations, the essential oil was more repellent to T. castaneum than to L. serricorne adults. The results indicate that the essential oil of Liriope muscari has potential to be developed into a natural insecticide or repellent for controlling insects in stored tobacco and traditional Chinese medicinal materials.

The toxic and repellent activities of the essential oil extracted from the leaves of Atalantia guillauminii Swingle were evaluated against three stored product insects, red flour beetles (Tribolium castaneum), cigarette beetles (Lasioderma serricorne) and booklice (Liposcelis bostrychophila). The essential oil obtained by hydrodistillation was investigated by GC-MS. The main constituents of the essential oil were β-thujene (27.18%), elemicin (15.03%), eudesma-3, 7(11)-diene (9.64%), followed by (-)-4-terpeniol (6.70%) and spathulenol (5.25%). The crude oil showed remarkable contact toxicity against T. castaneum, L. serricorne adults and L. bostrychophila with LD50 values of 17.11, 24.07 µg/adult and 55.83 µg/cm(2) respectively and it also displayed strong fumigant toxicity against T. castaneum, L. serricorne adults with LC50 values of 17.60 and 12.06 mg/L respectively, while weak fumigant toxicity against L. bostrychophila with a LC50 value of 16.75 mg/L. Moreover, the essential oil also exhibited the same level repellency against the three stored product insects, relative to the positive control, DEET. At the same concentrations, the essential oil was more repellent to T. castaneum than to L. serricorne. Thus, the essential oil of A. guillauminii may be potential to be developed as a new natural fumigant/repellent in the control of stored product insects.

Amomum maximum Roxb. is a perennial herb distributed in South China and Southeast Asia. The objective of this work was to analyze the chemical constituents and assess insecticidal and repellent activities of the essential oil from Amomum maximum fruits against Tribolium castaneum (Herbst) and Liposcelis bostrychophila (Badonnel). The essential oil was obtained by hydrodistillation and analyzed by gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. The main components of the essential oil were identified to be β-pinene (23.39%), β-caryophyllene (16.43%), α-pinene (7.55%), sylvestrene (6.61%) and c-cadinene (4.19%). It was found that the essential oil of A. maximum fruits possessed contact and fumigant toxicities against T. castaneum adults (LD50 = 29.57 μg/adult and LC(50) = 23.09 mg/L air, respectively) and showed contact toxicity against L. bostrychophila (LD(50) = 67.46 μg/cm(2)). Repellency of the crude oil was also evaluated. After 2 h treatment, the essential oil possessed 100% repellency at 78.63 nL/cm(2) against T. castaneum and 84% repellency at 63.17 nL/cm(2) against L. bostrychophila. The results indicated that the essential oil of A. maximum fruits had the potential to be developed as a natural insecticide and repellent for control of T. castaneum and L. bostrychophila.

In this work, the essential oil (EO) was extracted from the fruits of Evodia lenticellata, and the fumigant toxicity, contact toxicity and repellency against three stored-product insect species were evaluated for the obtained EO and several of its chemical components. The target insects were the adults of Tribolium castaneum (Coleoptera: Tenebrionidae), Lasioderma serricorne (Coleoptera: Anobiidae) and Liposcelis bostrychophila (Psocoptera: Liposcelididae). The EO was obtained with hydrodistillation and its chemical components were analyzed with the gas chromatography-mass spectrometry (GC-MS). Twenty-seven compounds, accounting for 83.1% of the total amount of the oil, were identified from the EO sample. The main compounds included linalool (12.0%), β-pinene (11.5%), 3-carene (9.6%), caryophyllene oxide (8.7%) and β-caryophyllene (7.9%). Among them, the amounts of monoterpenes and sesquiterpenes were as high as 52.7% and 22.7% to the total amount of EO respectively. The results of bioactivity test showed that the EO and its testing compounds had interspecific toxicity and repellent activity. So that, it might be expected that the EO extracted from the fruits of E. lenticellata could be developed to a new type of eco-friendly natural insecticide or repellent for the control of stored-product insects.

The major chemical constituents of the essential oil extracted from Artemisia dubia wall. ex Bess. (Family: Asteraceae) were found as terpinolene (19.02%), limonene (17.40%), 2,5-etheno[4.2.2]propella-3,7,9-triene (11.29%), isoelemicin (11.05%) and p-cymene-8-ol (5.93%). Terpinolene and limonene were separated as main components from the essential oil. The essential oil showed fumigant toxicity against Tribolium castaneum and Liposcelis bostrychophila with LC50 values of 49.54 and 0.74 mg/L, respectively. The essential oil and isolated compounds of A. dubia showed repellency activities against both insects. Terpinolene and limonene showed the fumigant toxicity against T. castaneum. Terpinolene showed obvious fumigant toxicity against L. bostrychophila. The results indicated that the essential oil of A. dubia had potential to be developed into natural insecticides for controlling stored product pests.

Water-distilled essential oil from the dried bulbs of Allium chinense (Liliaceae) was analyzed by gas chromatography–mass spectrometry (GC–MS). Eighteen compounds, accounting for 98.4% of the total oil, were identified and the main components of the essential oil of A. chinense were methyl allyl trisulfide (30.7%), dimethyl trisulfide (24.1%), methyl propyl disulfide (12.8%) and dimethyl disulfide (9.6%) followed by methyl allyl disulfide (3.4%) and methyl propyl trisulfide (3.6%). The essential oil exhibited contact toxicity against the booklice ( Liposcelis bostrychophila ) with an LC 50 value of 441.8 μg/cm 2 while the two major constituents, dimethyl trisulfide and methyl propyl disulfide had LC 50 values of 153.0 μg/cm 2 and 738.0 μg/cm 2 against the booklice, respectively. The essential oil of A. chinense possessed strong fumigant toxicity against the booklice with an LC 50 value of 186.5 μg/l while methyl allyl trisulfide (LC 50 = 90.4 μg/l) and dimethyl trisulfide (LC 50 = 114.2 μg/l) exhibited stronger fumigant toxicity than methyl propyl disulfide (LC 50 = 243.4 μg/l) and dimethyl disulfide (LC 50 = 340.8 μg/l) against the booklice. The results indicated that the essential oil and its major constituents have potential for development into natural insecticides or fumigants for control of insects in stored grains.

Headspace from above either Liposcelis bostrychophila Badonnel reared on powdered food; insects without food or from powdered food only were collected on five occasions over a period of four weeks. Volatiles were analysed by thermal desorption gas chromatography-mass spectrometry (TD-GCMS) to look for ecologically significant volatile compounds. Hexanoic acid (HA) was the major compound in the insect only and diet only volatiles (insect 25.6 ± 1.6%, diet 32.9 ± 1.13%). Isobutyric acid was the main compound detected in the volatiles from both insects and diet (35.3 ± 6%). Butyric acid (BA) and acetoin (HB) were also present at >2% of the total peak areas. HB was not detected in the insect only volatiles. Bioassays showed that hexanoic acid was the most repellent chemical. Mixtures of compounds representing the proportions of HA, BA, IBA, and HB in the volatiles did not have any prolonged effect on settling or selection by booklice in a two choice bioassay. L. bostrychophila can avoid individual volatile chemicals but the effects can be masked when they are incorporated into mixtures. As some volatile compounds can be detected by booklice they may govern dispersal, but further work is required to clarify their significance.

Psocids can cause considerable economic losses to stored products by direct feeding, and they have become global pests during the last two decades. We studied the distribution of Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae), Liposcelis entomophila (Enderlein), and Liposcelis brunnea Motschulsky in different moisture gradients (11–12–13%, 11–13–15%, and 13–14–15%) and a control (13–13–13%) in wheat using a circular metal arena, which has a removable metal divider that partitioned it into three rings (outer, middle and inner). Lipsocelis bostrychophila and L. entomophila preferred grain with the highest moisture content in the different gradients evaluated. In general, populations of Liposcelis brunnea equally preferred grain with moisture contents greater than or equal to 13%. These results showed the moisture contents preferred for three of the main psocid pests of stored grains, and this could help in making better pest management decisions.

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Litsea cubeba fruits was found to possess strong contact toxicity against the cigarette beetle Lasioderma serricorne adults and the booklouse Liposcelis bostrychophila , with LD 50 values of 27.33 μg/adult and 71.56 μg/cm 2 , respectively, and also showed strong fumigant toxicity against the two stored product insects with LC 50 values of 22.97 and 0.73 mg/L, respectively. The essential oil obtained by hydrodistillation was investigated by GC MS. The main components of the essential oil were identified to be E-citral (geranial) (27.49%), Z-citral (neral) (23.57%) and d -limonene (18.82%) followed by β-thujene (3.34%), β-pinene (2.85%), α-pinene (2.57%), 6-methyl-5-hepten-2-one (2.40%) and linalool (2.36%). Citral (Z/E-citral), d -limonene, β-pinene, α-pinene and linalool were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. Citral and linalool showed strong contact toxicity against L. serricorne and L. bostrychophila (LD 50 = 11.76, 12.74 μg/adult and 20.15, 99.97 μg/cm 2 , respectively) and fumigant toxicity against L. serricorne and L. bostrychophila (16.54, 18.04 mg/L air and 0.14, 0.71 mg/L air, respectively). Otherwise, citral, d -limonene and linalool were strongly repellent against the cigarette beetle L. serricorne as the essential oil whereas β-pinene and α-pinene exhibited weaker repellency against the cigarette beetle compared with the positive control, DEET. Moreover, except α-pinene and linalool, the other three compounds as well as the essential oil exhibited comparable repellency against the booklouse relative to DEET.

The aim of this research was to determine chemical composition and repellent and insecticidal activities of the essential oil of Kaempferia galanga L. rhizomes against the booklouse, Liposcelis bostrychophila Badonnel, and to isolate insecticidal or repellent constituents from the oil. The essential oil was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. Twenty-eight components of the oil were identified. The major compounds in the oil were ethyl-rho-methoxycinnamate (38.6%), ethyl cinnamate (23.2%), 1,8-cineole (11.5%), trans-cinnamaldehyde (5.3%), and borneol (5.2%). Based on bioactivity-guided fractionation, four active constituents were isolated from the oil and identified as 1,8-cineole, ethyl cinnamate, ethyl rho-methoxycinnamate, and trans-cinnamaldehyde. The essential oil exhibited contact toxicity against the booklouse with an LC50 value of 68.6 microg/cm2. Ethyl cinnamate (LC50 = 21.4 microg/cm2) exhibited stronger contact toxicity than ethyl rho-methoxycinnamate and trans-cinnamaldehyde (LC50 = 44.6 and 43.4 microg/cm2, respectively) while 1,8-cineole showed weak acute toxicity. The essential oil also possessed fumigant toxicity against the booklouse with a LC50 value of 1.5 mg/liter air. 1,8-Cineole and trans-cinnamaldehyde (LC50 = 1.1 and 1.3 mg/liter, respectively) possessed stronger fumigant toxicity against the booklouse than ethyl cinnamate and ethyl rho-methoxycinnamate (LC50 = 10.2 and 10.2 mg/liter air, respectively). trans-Cinnamaldehyde was strongly repellent to booklice, whereas ethyl cinnamate and ethyl rho-methoxycinnamate were weakly repellent and 1,8-cineole did not repel booklice. The results indicate that the essential oil and its constituent compounds have potential for development into natural insecticides or fumigants and repellents for control of insects in stored grains.

The psocid, Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae), can cause significant damage to stored commodities, and its pest status in the United States has been increasing over the last decade. Because L. bostrychophila is difficult to control with conventional methods, it is critical to explore alternative approaches such as the use of attractants that can be incorporated into integrated pest management programs for monitoring psocids. The orientation response of several L. bostrychophila life stages (first and second instars, third and fourth instars, 0- to 7-d-old adults, 21- to 28-d-old adults, and adults of mixed ages) to a range of potential attractants (including whole and cracked grains, grain-based oils, wheat germ, brewer's yeast, and commercially available kairomone lures) was studied using a two-choice pitfall test to identify candidates for further development as lures in traps. Amongthe potential attractants evaluated, the strongest response by all stages of L. bostrychophila was to brewer's yeast. Other materials for which there was consistently a strong response were psocid diet, wheat germ, and wheat germ oil. These results show the potential for developing monitoring tools for integrated pest management programs for L. bostrychophila and other psocid species.

The aim of this research was to determine chemical composition and insecticidal activities of the essential oil ofAgeratum houstonianumMill. aerial parts against booklice,Liposcelis bostrychophilaBadonnel, and to isolate any insecticidal constituents from the oil. Essential oil ofA. houstonianumwas obtained by hydrodistillation and analyzed by GC-MS. A total of 35 components in the essential oil were identified. The major compounds were precocene II (62.68%), precocene I (13.21%), andβ-caryophyllene (7.92%). Based on bioactivity-guided fractionation, precocene II and precocene I were isolated and identified as the active constituents. The essential oil exhibited contact toxicity againstL. bostrychophilawith an LC50value of 50.8 μg/cm2. Precocene II (LC50= 30.4 μg/cm2) exhibited stronger acute toxicity than precocene I (LC50= 64.0 μg/cm2) against the booklice. The essential oil and the two isolated constituents also possessed strong repellent activity againstL. bostrychophila. The results indicated that the essential oil and its constituent compounds have potential for development into natural insecticides or repellents for control of insects in stored grains.

Spices are popular commodities with highly edible and medicinal values. At ancient times, people took advantage of spices to prevent insect infestation and mold erosion in stored-products. The Lauraceae family offers abundant raw materials as spices and plants from this family have widely biological activities. Here, the essential oils (EOs) of four spice plants from the Lauraceae, namely Cinnamomum burmannii, Cinnamomum migao, Litsea pungens and Laurus nobilis were analyzed for their chemical composition by GC–MS. The EOs and some of their individual components mainly monoterpenoids were evaluated for their bioactivities against stored-product insects. Three modes of action were selected: fumigant, contact toxicity and repellent activity. Target insects were adults of Tribolium castaneum and Liposcelis bostrychophila. Results of GC–MS analysis denoted that the chemical composition of EOs from these spice plants had certain similarity and diversity. All the EOs were rich in monoterpenoids, and the major components were limonene, sabinene, linalool, eucalyptol, borneol, α-terpineol, 4-terpinenol, α-terpinyl acetate, β-caryophyllene, spathulenol and 1,2,3,4-tetramethylbenzene. The results of bioassays indicated that all the EOs were toxic and repellent to T. castaneum and L. bostrychophila. Common monoterpenoids limonene, sabinene, linalool, eucalyptol, borneol, α-terpineol, 4-terpinenol and α-terpinyl acetate showed different levels of insecticidal or repellent activities against the two insect species. Among these monoterpenoids, borneol had no fumigant toxicity, but possessed contact toxicity and beneficial repellency at the concentration range of 63.17-2.53 nL/cm2 against L. bostrychophila. Sabinene and α-terpineol were significantly repellent to T. castaneum within the testing concentration range of 78.63-3.15 nL/cm2. Furthermore, β-caryophyllene (sesquiterpenoids) and 1,2,3,4-tetramethylbenzene (aromatics) were also assessed. β-caryophyllene exhibited contact toxicity and repellency against T. castaneum and L. bostrychophila. 1,2,3,4-tetramethylbenzene was toxic to these target insects in fumigant and contact assays. This work provides some evidence for explaining insecticidal and repellent activities of several spices from the Lauraceae based on individual active substances. It suggests that these spice EOs have promising potential to serve as bio-insecticides and green repellents for controlling pest damage in warehouses and grain stores.

For the sterile insect technique, and other related biological control methods where large numbers of the target mosquito are reared artificially, production efficiency is key for the economic viability of the technique. Rearing success begins with high quality eggs. Excess eggs are often stockpiled and stored for longer periods of time. Any pests that prey on these eggs are detrimental to stockpiles and need to be avoided. Psocids of the genus Liposcelis (Psocoptera, Liposcelididae) are common scavengers consuming various types of organic material that are distributed globally and thrive in warm damp environments, making insectaries ideal habitats. In this short report, we investigated the species that has been found scavenging stored mosquito eggs in our insectary and identified it to be Liposcelis bostrychophila Badonnel, 1931. Additional observations were made to determine whether these predators indeed feed on mosquito eggs, and to suggest simple, effective ways of avoiding infestation.Élevage de masse de moustiques : mais qui mange les œufs ?Pour la technique des insectes stériles et les autres méthodes de lutte biologique associées, dans lesquelles un grand nombre de moustiques cibles sont élevés artificiellement, l’efficacité de la production est essentielle pour la viabilité économique de la technique. Le succès de l’élevage commence par des œufs de bonne qualité. Les œufs excédentaires sont souvent stockés pendant de longues périodes. Tous les organismes nuisibles qui exploitent ces œufs nuisent à ces stocks et doivent être évités. Les psoques du genre Liposcelis (Psocoptera, Liposcelididae) sont des charognards répandus qui consomment diverses matières organiques, sont répartis dans le monde entier et prospèrent dans des environnements chauds et humides, ce qui rend les insectariums des habitats idéaux pour eux. Dans ce court rapport, nous avons étudié l’espèce qui mangeait des œufs de moustiques stockés dans notre insectarium et nous avons déterminé qu’il s’agissait de Liposcelis bostrychophila Badonnel, 1931. D’autres observations ont été faites pour déterminer si ces prédateurs se nourrissent effectivement des œufs de moustiques et suggérer des moyens simples et efficaces pour éviter l’infestation.

Psocids have become important pests of stored products during the last two decades, but little is known about their behavior or ecology. We examined distribution of Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae), Liposcelis entomophila (Enderlein), and Liposcelis paeta (Pearman), three of the main psocid pests of stored grain throughout the grain growing regions of the world, in temperature gradients of 20°–24 °C, 20°–30 °C, and 20°–42 °C in small bulks of wheat to determine their ecological preferences. Psocids consistently preferred the warmest regions of the gradients, except in the 20–42 °C gradients. Over 80 and 78% of psocids moved to the warmest region of the grain in the 20°–24° and 20°–30° gradients, respectively. Liposcelis bostrychophila females and both sexes of L. paeta preferred the warmer region of the grain in the 20°–42° gradient, while densities of L. entomophila males were higher in more moderate temperature regions of the grain and densities of L. entomophila females were evenly split between the warm and hot regions of the grain. Temperatures can be below 20 °C during much of the storage season for grains, so the current results help to explain why psocids move to warmer regions of the grain which occur toward the center of the grain mass as grain temperatures cool in the fall. This may allow psocid populations to continue to grow during the colder months.

The aim of this research was to determine the chemical composition and insecticidal and repellent activity of the essential oil of Artemisia rupestris L. aerial parts against the booklice Liposcelis bostrychophila Badonnel and isolation of insecticidal and repellent constituents from the essential oil. The essential oil of A. rupestris was obtained by hydrodistillation and analyzed by GC-MS. A total of 30 components of the essential oil of A. rupestris was identified and the principal compounds in the essential oil were α-terpinyl acetate (37.18%), spathulenol (10.65%), α-terpineol (10.09%), and linalool (7.56%), followed by 4-terpineol (3.92%) and patchoulol (3.05%). Based on bioactivity-guided fractionation, the four active constituents were isolated from the essential oil and identified as α-terpineol, α-terpinyl acetate, 4-terpineol and linalool. The essential oil of A. rupestris exhibited contact toxicity against L. bostrychophila with LD₅₀ value of 414.48 µg/cm². α-Terpinyl acetate (LD₅₀ = 92.59 µg/cm²) exhibited stronger contact toxicity against booklice than α-terpineol (LD₅₀ = 140.30 µg/cm²), 4-terpineol (LD₅₀ = 211.35 µg/cm²), and linalool (LD5₅₀ = 393.16 µg/cm²). The essential oil of A. rupestris (LC₅₀ = 6.67 mg/L air) also possessed fumigant toxicity against L. bostrychophila while the four constituents, 4-terpineol, α-terpineol, α-terpinyl acetate and linalool had LC₅₀ values of 0.34, 1.12, 1.26 and 1.96 mg/L air, respectively. α-Terpinol and α-terpinyl acetate showed strong repellency against L. bostrychophila, while linalool and 4-terpinol exhibited weak repellency. The results indicate that the essential oil of A. rupestris aerial parts and its constituent compounds have potential for development into natural insecticides or fumigants as well as repellents for control of insects in stored grains.

BACKGROUND Chlorantraniliprole belongs to the chemical group of anthranilic diamides. It has selectivity to beneficial arthropods and low mammalian toxicity. Laboratory bioassays were conducted to assess chlorantraniliprole as a potential grain protectant against Ephestia kuehniella Zeller larvae, Liposcelis bostrychophila Badonnel adults, Rhyzopertha dominica (F.) adults, Sitophilus oryzae (L.) adults and Tribolium confusum Jacquelin du Val adults and larvae. Factors such as dose (0.01, 0.1, 1 and 10 mg chlorantraniliprole kg−1 grain), exposure interval (7 and 14 days), formulation (chlorantraniliprole WG and chlorantraniliprole SC) and commodity (barley, maize, oats, peeled rice, whole rice and wheat) were evaluated for their impact on the insecticidal activity of chlorantraniliprole. Progeny production was assessed after 45 days of exposure in the case of L. bostrychophila adults and after 60 days of exposure in the case of R. dominica, S. oryzae and T. confusum adults. RESULTS For L. bostrychophila adults, after 7 days of exposure, mortality was lower in maize and whole rice in comparison with the other commodities. Increase in dose generally increased mortality. Similar trends were also noted after 14 days of exposure. Offspring emergence was higher in maize and whole rice in comparison with the other commodities. For E. kuehniella larvae, after 7 days of exposure, significant differences were noted among the tested commodities. Increase in dose only slightly increased mortality in all commodities. After 14 days of exposure, mortality was further increased, but did not reach 100%. For R. dominica adults, after 7 days of exposure, increase in dose increased mortality significantly. After 14 days of exposure, mortality in barley, maize, whole rice and wheat exceeded 92% at 10 mg chlorantraniliprole kg−1 grain. Offspring emergence was reduced, but 100% progeny suppression was not achieved. For S. oryzae adults, after 7 days of exposure, mortality was generally low at dose rates of ≤1 mg chlorantraniliprole kg−1 grain. After 14 days of exposure, 100% mortality was noted in whole rice. For T. confusum adults, after 7 days of exposure, mortality was low. After 14 days of exposure, mortality increased proportionately for all commodities. Most progeny production was noted in oats. For T. confusum larvae, after 7 days of exposure, mortality was generally higher in comparison with adults. After 14 days of exposure, mortality in maize was high. Generally, the two formulations performed alike for all the insects tested. CONCLUSIONS Based on the results of the present work, chlorantraniliprole is effective against major stored-product insect species. However, efficacy depends upon the type of commodity, the dose rate and the exposure interval. © 2013 Society of Chemical Industry

The insecticidal effect of Temprid, a formulation that contains beta-cyfluthrin and imidacloprid, was tested on concrete for control of seven stored-product insect species: the rusty grain beetle, Cryptolestes ferrugineus (Stephens); the sawtoothed grain beetle, Oryzaephilus surinamensis (L.); the red flour beetle, Tribolium castaneum (Herbst); the confused flour beetle, T. confusum Jacquelin du Val; the hide beetle, Dermestes maculatus (DeGeer); and the psocids Liposcelis bostrychophila Badonnel and L. paeta Pearman. Temprid, which contains 10.5% beta-cyfluthrin and 21% imidacloprid, was tested at the rate of 17.2 ml of formulation/4.1 liters of water/100 m2. Adults were exposed for 4, 8, 14, and 24 h, and then daily for 7 d, on untreated dishes or dishes treated with Temprid. In the untreated dishes, mortality of C. ferrugineus and O. surinamensis was lower when food was present, but food did not affect mortality of the other species. Presence of food did not affect mortality of any of the species tested in the treated dishes. C. ferrugineus, O. surinamensis, and the two psocid species were very susceptible to Temprid, with mortality of 97-100% after 7 d of exposure. In contrast, D. maculatus, T. castaneum, and T. confusum were tolerant to Temprid, as mortality did not exceed 57, 25, and 17%, respectively, at the 7-d exposure. A separate series of similar bioassays with Tempo, a formulation that contains 11.8% beta-cyfluthrin alone, which was applied at the same dose rate as Temprid, was conducted using O. surinamensis and T. castaneum as the target insect species, and results showed that Tempo was at least as effective as Temprid. Our results indicate that the simultaneous use of beta-cyfluthrin with imidacloprid is not more effective on concrete than beta-cyfluthrin alone, and efficacy of both formulations varies with the target species.

The screening for repellency against the booklouse, Liposcelis bostrychophila (Badonnel), and the red flour beetle, Tribolium castaneum (Herbst), from 14 Chinese medicinal herbs showed that the essential oils of Curcuma longa L., Epimedium pubescens Maximouwicz, Lindera aggregate (Sims) Kostermans, Nardostachys chinensis Battandier, Schizonepeta tenuifolia Briquet, Zanthoxylum schinifolium Sieber et Zuccarini, and Z. officinale Roscoe exhibited strong repellency against L. bostrychophila and T. castaneum. A total of 35 components of the essential oil of E. pubescens were identified by gas chromatography and gas chromatography-mass spectrometry. Beta-Eudesmol (14.89%), alpha-pinene (13.38%), borneol (9.56%), (R)-carvone (7.89%), and menthol (7.45%) were the main components of the essential oil of E. pubescens. From the essential oil of E. pubescens, four monoterpenoids and one sesquiterpenoid were isolated by bioassay-guided fractionation. The compounds were identified alpha-pinene, borneol, menthol, carvone, and beta-eudesmol. (R) -carvone, menthol, borneol, and beta-eudesmol were strongly repellent against L. bostrychophila at concentration of 8.5 nl/cm2 after 2 h exposure whereas alpha-pinene exhibited moderate repellency. (R)-carvone exhibited stronger repellency against the booklouse than the positive control, N, N-diethyl-3-methylbenzamide (DEET). Moreover, (R)-carvone also possessed stronger repellency against T. castaneum than DEET. The other four constituents, menthol, borneol, and beta-eudesmol also showed repellency against the red flour beetles but weaker than DEET at lower concentrations.