Mediterranean Flour Moth Ephestia Kuehniella Research Articles

A semi-artificial rearing system for the specialist predatory ladybird Cryptolaemus montrouzieri

In the present study a semi-artificial rearing system for the Australian ladybird Cryptolaemusmontrouzieri Mulsant (Coleoptera: Coccinellidae), a specialist predator of mealybugs, was developed. In a first step, a rearing system using eggs of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) as a food and synthetic polyester wadding as an oviposition substrate was compared with a natural rearing system using the citrus mealybug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae), as to its effects on the predator’s developmental and reproductive parameters. In a second series of experiments the performance of C. montrouzieri on bee pollen or on a mixture of E.kuehniella eggs and bee pollen was assessed. E. kuehniella eggs proved to be a suitable food to support larval development of the predator. Ladybird larvae reared on flour moth eggs developed two days faster and weighed approximately 10 % more than their counterparts reared on mealybugs. Despite a prolongation of the preoviposition period with ca. eight days and a decrease in egg hatch by about 10 %, C. montrouzieri females fed moth eggs accepted the synthetic wadding as an oviposition substrate and deposited the same number of eggs their counterparts maintained on mealybugs. A mixture of E. kuehniella eggs with pollen yielded similar developmental and reproductive rates as E. kuehniella eggs alone, but a diet of bee pollen alone was not adequate for the predator. Our findings indicate the potential of a rearing system using E. kuehniella eggs as a factitious food and synthetic wadding as an artificial oviposition substrate for the mass production of C. montrouzieri.

Life history and fecundity rate of Ephestia kuehniella (Lepidoptera: Pyralidae) on different wheat flour varieties

The effect of different wheat flour varieties (Bahar, Zarin, Pishgham, Pishtaz, Sardari and Parsi) on the life history and fecundity of the Mediterranean flour moth Ephestia kuehniella (Lepidoptera: Pyralidae) was determined at 28 ± 2 °C, 65 ± 5% RH and a light: dark cycle of 14:10 h. The larval period ranged 38.60–49.60 days on Pishgham and Pishtaz, respectively. The longest development time was on Pishtaz (62.45 days) and the shortest was on Parsi (50.98 days). The highest total fecundity (284.60 eggs) and the lowest (219.93 eggs) was observed on Parsi and Zarin, respectively. Cluster analysis of the biological parameters of E. kuehniella on different wheat flour varieties demonstrated that Pishtaz was the partially resistant to E. kuehniella. Determining the suitable variety among wheat flour varieties would help us in improvement of natural enemy production using this pest as food on susceptible varieties of wheat flour.

Diet-dependent cannibalism in the omnivorous phytoseiid mite Amblydromalus limonicus

Amblydromalus limonicus (Garman & McGregor) (Acari: Phytoseiidae) is a commercially available predator of key pests in protected crops, particularly of thrips and whiteflies. Basic information on the developmental and reproductive performance of the predator as a function of food is largely lacking. In the present study, development, reproduction and growth rates were determined for A. limonicus on four economically important pests: Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae), broad mite, Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) and two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). The life history traits of females fed on these different target prey were compared with those of females offered Carpoglyphus lactis L. (Acari: Carpoglyphidae), which is the standard food source for mass-producing this predator. Additionally, three commercially available non-prey food sources with potential for use in the mass production or as supplementary food to sustain populations of the predator in the field were tested: the commercial pollen product Nutrimite (consisting of pollen of narrow-leaved cattail, Typha angustifolia L.), frozen eggs of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and frozen eggs of the Mediterranean fruit fly, Ceratitis capitata Wiedemann (Diptera: Tephritidae). Survival rates of immature A. limonicus were high (>94% survival) on all tested foods except on T. vaporariorum and T. urticae (76.0% and 17.1%, respectively). The fastest development was obtained when mites were fed on T. angustifolia, whereas the longest developmental times were obtained on T. urticae and T. vaporariorum. When females were offered P. latus, no reproduction was observed, despite a high prey consumption in both the juvenile and adult stages. The reproductive performance of A. limonicus fed on T. vaporariorum was significantly lower than that on F. occidentalis. Furthermore, no second generation could be obtained on a diet solely consisting of T. vaporariorum. Population growth rates were highest when A. limonicus was fed on Nutrimite, E. kuehniella or C. lactis, and exceeded those on a diet consisting of their natural prey, F. occidentalis. The phytoseiid showed cannibalistic behavior when maintained on E. kuehniella and C. capitata eggs and T. angustifolia pollen, with females consuming their own eggs. The rate of cannibalism was dependent on the food source offered, but always resulted in reduced population growth rates. This cannibalistic behavior should be taken into account when selecting food sources for mass rearing of A. limonicus or supporting its populations in the field.

Mediterranean flour moth Ephestia kuehniella eggs and larvae exposed to a static magnetic field and preference by Trichogramma embryophagum

This study investigated the effect of strong magnetic fields as insecticidal activity on Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) larvae and eggs at different stages of development and their preference by the egg parasitoid, Trichogramma embryophagum Hartig (Hymenoptera: Trichogrammatidae). Eggs ranging in age from 24-h to 48-h and 72-h-old and larvae (1 to 2 days) were exposed to 1.4 Tesla (T) magnetic fields from a DC power supply at 50 Hz for different time periods (3, 6, 12, 24, 48 and 72 h). Twelve hours of exposure at 1.4 T was toxic to 24-h-old eggs of E. kuehniella. The 72-h-old host eggs treated with 1.4 T for 6–72 h were not significantly preferred by T. embryophagum. The magnetic field was toxic to 24-h-old eggs of E. kuehniella exposed to 1.4 T for 12. The treatment of magnetic fields on the 72-h-old host egg with 1.4 T at 6–72 h was not significantly preferred by T. embryophagum. Magnetization of 24-h-old eggs of E. kuehniella for 3 h could be effectively used with T. embryophagum as sterilised host eggs. These eggs were markedly preferred by T. embryophagum. The LT50 and LT99 values of magnetic fields at different egg stages of E. kuehniella, and larvae were measured. A level of 1.4 T at 72 h completely prevented the development of the larvae. There was no significant effect on larval survival at 1.4 T at 48 and 72 h. Increasing magnetic fields exposure times for eggs that were 24-h, 48-h and 72-h-old prevented larval emergence and increased their mortality rate. Consequently, magnetic fields could be used in controlling stored-product pest eggs and larvae of E. kuehniella.

Magnetic field-induced oxidative stress and DNA damage in Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) larvae

Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) is cosmopolitan pest of stored products. The effect of strong magnetic fields (MFs) on DNA damage and oxidative stress on larvae stage of E. kuehniella was assessed. Antioxidant enzyme systems, which include superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and malondialdehyde (MDA), the end product of lipid peroxidation as a result of strong MF intoxication that might occur in the larvae tissue, were evaluated. A simple technique of single-cell gel electrophoresis (DNA comet assay) enabled a quick detection of MF treatment on larvae. The larvae were exposed in a 1.4-Tesla (T) MF from a DC power supply at 50 Hz for different time periods (3, 6, 12, 24, 48, and 72 h). MFs caused increasing DNA damage and demonstrated using the comet assay with its parameters including tail DNA%, tail length and tail moment. DNA damage at increasing exposure times were significantly larger than the control group (p < 0.05). These parameters were detected using BS 200 ProP with image analysis software. SOD, CAT, GPx, and GST activities decreased and MDA level increased in the MF-treated group in larvae tissue compared to control group for increasing exposure times at 1.4 T (p < 0.05). In our investigation, we showed that MFs caused oxidative stress and proved to be DNA damage as revealed by the comet assay. MFs may be used to determine potential toxic effects as a control agent against E. kuehniella larvae.

Potential of Photorhabdus temperata K122 bioinsecticide in protecting wheat flour against Ephestia kuehniella

The present study reports investigations on the insecticidal activity of the entomopathogenic bacterium Photorhabdus temperata K122 against the Mediterranean flour moth Ephestia kuehniella. Cultured in the optimized medium, P. temperata K122 cells aged 32 h exhibited 51% growth inhibition at a concentration of 9 × 108 cells/ml. However, culture must be prolonged up to 48 h incubation in the proteose peptone medium to reach only 28.6% inhibition. At the same concentration, no adult emergence was observed in the case of larvae feeding on wheat flour treated with the whole culture of P. temperata K122 after physical lysis. Interestingly, P. temperata K122 cells in the viable but non culturable (VBNC) state retained the same toxicity level as the culturable cells. At a high concentration of 12 × 108 cells/ml, 100% mortality of E. kuehniella larvae could be reached. Insect mortality is due to toxaemia as confirmed by the absence of Variants small colony (Vsm) or P. temperata colonies in E. kuehniella tissue. The investigation of the histopathological effect of P. temperata toxins on the gut of infected E. kuehniella larvae showed destruction of the gut epithelium, appearance of large cavities and cellular disintegration.

Assessment of the influence of magnetic fields on aspects of the biology of the adult Mediterranean flour moth Ephestia kuehniella Zeller, 1879 (Lepidoptera: Pyralidae)

All living systems are under the influence of magnetic fields (MFs) from various sources. In this study, experiments were performed to investigate the effect of MFs from a DC power supply on the longevity of adults, fecundity and daily egg laying pattern of female E. kuehniella. Adults of E. kuehniella (24 h old) were exposed to power supply generating MFs of different levels (0, 1.5, 3, 5, 7.5 and 10 mT) at 50 Hz for 24 h exposure time. Mortality increased with increasing MFs level and complete mortality was achieved at the level of 10 mT. Adult viability was highest in control (92%). Pest longevity was significantly reduced with increasing level of MFs (P<0.05). There was no significant difference in the longevity of males and females (P˃0.05). Exposing adults to increasing level of MFs significantly influenced daily egg laying patterns and fecundity of magnetized females. Larval emergence from these eggs was completely prevented at highest level of MFs. The LD50 and LD99 values of MFs against adult stages of E. kuehniella were measured as 5.23 mT and 12.81 mT, respectively. According to these results, 10 mT MFs for 24 h is sufficient to control adult survival and production of progeny in this pest

Insecticidal Effect of Labramin, a Lectin—Like Protein Isolated from Seeds of the Beach Apricot Tree,Labramia bojeri, on the Mediterranean Flour Moth,Ephestia kuehniella

The objective of this work was to study the insecticidal effect of labramin, a protein that shows lectin—like properties. Labramin was isolated from seeds of the Beach Apricot tree, Labramia bojeri A. DC ex Dubard (Ericales: Sapotaceae), and assessed against the development of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), an important pest of stored products such as corn, wheat, rice, and flour. Results showed that labramin caused 90% larval mortality when incorporated in an artificial diet at a level of 1% (w/w). The presence of 0.25% labramin in the diet affected the larval and pupal developmental periods and the percentage of emerging adults. Treatments resulted in elevated levels of trypsin activity in midgut and fecal materials, indicating that labramin may have affected enzyme—regulatory mechanisms by perturbing peritrophic membranes in the midgut of is. kuehniella larvae. The results of dietary experiments with E. kuehniella larvae showed a reduced efficiency for the conversion of ingested and digested food, and an increase in approximate digestibility and metabolic cost. These findings suggest that labramin may hold promise as a control agent to engineer crop plants for insect resistance.

Influence of predator density, diet and living substrate on developmental fitness of Orius laevigatus

Mass rearing of Orius laevigatus on non-insect foods could substantially increase the cost-effectiveness of the production of this biological control agent which is largely based on the use of expensive eggs of the Mediterranean flour moth Ephestia kuehniella. In this study, the effect of substrate quality and predator density on nymphal development of O. laevigatus fed on E. kuehniella eggs, honeybee pollen or an egg yolk based artificial diet was assessed using several types of substrates as shelter materials in the rearing containers (wax paper, bean pod or no extra substrate). In general, E. kuehniella eggs proved to be a nutritionally superior food compared to pollen and artificial diet. Pollen supported nymphal development of O. laevigatus better than the artificial diet. Overall, increasing nymphal density resulted in higher mortality, which may be due in part to cannibalism. The addition of a bean pod compensated for the nutritionally suboptimal artificial, but had a negative effect when O. laevigatus was fed on pollen. The non-insect foods tested could not adequately replace lepidopteran eggs as a food source for O. laevigatus but they may be useful as an alternative food or in a part of the rearing process.

The occurrence and phenology of moth pests in different granary of Borsod-Abaúj-Zemplén County

The aims of my studies were the followings: primarily to find correlation between the conditions of granary and the occurrence of moth pests. Secondly I studied the effect of disinfection on individual numbers in the population of moths. My studies were started in May 2009 in six different places of Borsod-Abaúj-Zemplén County. Indianmeal moth (Plodia interpunctella) and Mediterranean Flour Moth (Ephestia kuehniella) traps with pheromone were installed in four repetitions as well as Angoumois Grain Moth (Sitotroga cerealella) traps in also four repetitions. Control traps without attractant were also placed at every place.From my researches, it became clear that the disinfection alone is not enough to protect cereals from moths. As in the case of crop protection, we need to apply integrated pest management.We have to make differences between preventive protections from moth pests and the elimination of them by chemicals.Up to my opinion, the regular checking and cleaning of the granary are important as well as the prognosis of the possible occurrence of moths. The prognosis is considered important because the studied moths do not feed at the adult stage or only at a low level. However, the caterpillars coming from the eggs placed by females can cause a significant damage in the stored cereals.The studied sex pheromone traps are proved to be useful for the reduction of number of moths since the traps caught lots of them. These traps are relatively cheap because only the temporarily changes of pheromones increase the cost.

Composition and insecticidal activity of essential oil from Pistacia lentiscus L. against Ectomyelois ceratoniae Zeller and Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

This study reports investigations on the chemical constituents and fumigant toxicity of Pistacia lentiscus L. (Anacardiaceae) essential oil against two major stored-date insects, carob moth Ectomyelois ceratoniae Zeller and Mediterranean flour moth Ephestia kuehniella Zeller. Results showed that P. lentiscus essential oil contained terpinene-4-ol (23.32%), α-terpineol (7.12%) and β-caryophyllene (22.62%) as major compounds. Fumigant toxicity tests showed that P. lentiscus oil was more toxic to E. kuehniella (LC 50 = 1.84 μl/l, LC 95 = 5.14 μl/l) than E. ceratoniae (LC 50 = 3.29 μl/l, LC 95 = 14.24 μl/l). The fecundity and hatching rate of both insects decreased with increases in concentration or exposure time to the oil. At 136 μl/l air, fecundities and hatching rates were respectively 35 eggs/female and 42.86% for E. ceratoniae and 78 eggs/female and 29.49% for E. kuehniella.

Insecticidal Activity of the Essential Oils from Different Plants Against Three Stored-Product Insects

This study was conducted to determine the insecticidal activity of essential oils from oregano, Origanum onites L. (Lamiales: Lamiaceae), savory, Satureja thymbra L. (Lamiales: Lamiaceae), and myrtle, Myrtus communis L. (Rosales: Myrtaceae) against three stored-product insects. Essential oils from three species of plants were obtained by Clevenger-type water distillation. The major compounds in these essential oils were identified using gas chromatography-mass spectrometry and their insecticidal activity was tested against adults of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), the Indian meal moth Plodia interpunctella Hübner (Lepidoptera: Pyralidae) and the bean weevil Acanthoscelides obtectus Say (Coleoptera: Bruchidae). While the major compound found in oregano and savory was carvacrol, the main constituent of the myrtle was linalool. Among the tested insects, A. obtectus was the most tolerant species against the essential oils. However, the insecticidal activity of the myrtle oil was more pronounced than other oils tested against A. obtectus adults. The essential oils of oregano and savory were highly effective against P. interpunctella and E. kuehniella, with 100% mortality obtained after 24 h at 9 and 25 µl/l air for P. interpunctella and E. kuehniella, respectively. LC50 and LC99 values of each essential oil were estimated for each insect species.

Pollen as an alternative or supplementary food for the mirid predator Macrolophus pygmaeus

For the mass production of the mirid predator Macrolophus pygmaeus eggs of the Mediterranean flour moth Ephestia kuehniella are routinely used as an effective but expensive factitious food. In the current study, the potential of pollen as a supplementary food for M. pygmaeus was investigated. In a first experiment, the minimum amount of E. kuehniella eggs needed for optimal development and reproduction was determined to be 40 eggs per individual per 3 days. Then, different amounts of E. kuehniella eggs were offered to individual nymphs, supplemented or not with frozen moist honeybee pollen. Insects reared on only 10 E. kuehniella eggs per 3 days suffered higher mortality, developed slower and had lower adult weights and oocyte counts than insects reared on 40 E. kuehniella eggs or 10 eggs supplemented with pollen. When the nymphs were fed only pollen, survival rates and oocyte production were lower than when both pollen and flour moth eggs were provided. On pollen alone, ca. 80% of the nymphs successfully reached adulthood; their adult weights and oocyte counts were, respectively, 12% and 32% lower compared with individuals fed optimal amounts of flour moth eggs. When an egg yolk-based artificial diet was supplemented with bee pollen, development and fecundity were better than on the artificial diet alone. The practical implications of pollinivory for the mass production and the use of this beneficial insect in augmentative biological control programs are discussed.

Comparison of Short-term Preservation and Assay Methods for the Molecular Detection of Wolbachia in the Mediterranean Flour Moth Ephestia kuehniella

Comparison of Short-term Preservation and Assay Methods for the Molecular Detection of Wolbachia in the Mediterranean Flour Moth Ephestia kuehniella

Influence of larval density on biological fitness of &lt;i&gt;Ephestia kuehniela&lt;/i&gt; Zeler (Lepidoptera Pyralidae )

Mediterranean flour moth Ephestia kuehniella is a cosmopolitan pest of stored products and its eggs are widely used to rear parasitoids and predators for biological control programmes This experiment investigated how larval population density affected the survival rate and reproductive output of this species under four rearing densities (1 larva per 2 g food per vial; or 100 500 or 1000 larvae per 50 g food per jar) The survival rate and reproductive output significantly decreased (P

The effect of different temperatures and food densities on development of Blattisocius tarsalis (Berlese) (Acari: Ascidae) reared on Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

Blattisocius tarsalis (Berlese) (Acari: Ascidae) is an effective predatory mite species on eggs of Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). Mediterranean flour moth is an important pest of flour storages and mills in Turkey. The aim of this paper is to investigate the possibilities for the use of B. tarsalis as a biological control agent to control moth. The effect of different temperatures (15±1 oC and 25±1 oC) on development time of B. tarsalis at different food density levels (5, 10, 15 and 20 eggs densities) has been investigated. For 15 oC; the development times of immature stages were 5,53 (1-6); 4,86 (3-5); 4,53 (0-5) and 4,86 (1-6) days while adults life span were determined 52,00 (3-67); 42,77 (5-67); 29,85 (1-66) and 27,36 (7-39) days for 5, 10, 15 and 20 moth egg densities. For 25 oC the development times of immature stages were 5,00 (5-5) days at 10 prey eggs and 6,00 (6-6) days at the rest of prey densities, beside this life span of adults were determined 32,00 (20-39); 30,67 (15-40); 42,20 (10-64) and 38,67 (4-69) days at each food densities consequently.

Inherited sterility in Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae): Effect of gamma radiation on insect fecundity, fertility and developmental period

The effects of gamma radiation on the fecundity, fertility, longevity, development and level of inherited sterility in the Mediterranean flour moth Ephestia kuehniella were determined. Newly emerged virgin Mediterranean flour moth adults were irradiated with 100, 200, 400 and 600 Gy in a 60Co irradiator with a source strength of ca. 3811 Ci and a dose rate of ca. 1 Gy/min. Laboratory studies revealed that radiation did not effect the longevity of irradiated male and female adults. Inherited deleterious effects of gamma radiation were observed in the F 1 and F 2 generations. Fecundity and the daily egg laying pattern of irradiated and unirradiated females mated to irradiated males was not significantly different from untreated controls. Adverse effects of gamma radiation were observed in the percentage egg hatch and rate of development. Levels of sterility in the P 1, F 1 and F 2 generations were higher than that of untreated controls. The doses of radiation also had a significant effect on the time from oviposition to larval eclosion or adult emergence. Mortality increased with radiation dose. The incidence of larval and pupal mortality was higher in the F 2 than in the F 1 generation.

Nutritional value of brine shrimp cysts as a factitious food for Orius laevigatus (Heteroptera: Anthocoridae)

Decapsulated cysts of the brine shrimp Artemia franciscana were assessed as a factitious food for rearing the anthocorid predator Orius laevigatus. Developmental and reproductive traits of O. laevigatus reared for a single generation on A. franciscana from three geographical locations or on gamma-irradiated eggs of the Mediterranean flour moth Ephestia kuehniella were compared. There was no effect of diet on nymphal survival but nymphal period on E. kuehniella eggs (12.2 days) was 0.7–1.6 days shorter than on the Artemia diets. The predator developed 0.5–1 day faster on cysts from San Francisco Bay (USA) than on cysts from Great Salt Lake (USA) or Macau (Brazil). Fecundity on brine shrimp cysts from different locations was similar to that on flour moth eggs (142–187 eggs/female). The biochemical composition of decapsulated cysts from San Francisco Bay was compared with that of E. kuehniella eggs. Depending on the type of analysis, Artemia cysts contained higher or similar amounts of protein as compared with E. kuehniella eggs, but amino acid patterns were generally similar. Flour moth eggs were almost three times richer in fatty acids than brine shrimp cysts, with some marked differences in fatty acid profiles. Because nutrient imbalances in a diet may be expressed only after several generations of rearing, the predator was cultured for three consecutive generations on A. franciscana cysts from San Francisco Bay. In the third generation on brine shrimp cysts, nymphs took 18% longer to develop, and adults were shorted-lived and about 60% less fecund than those maintained on E. kuehniella eggs. Brine shrimp cysts may be used as a supplement in the mass production of O. laevigatus but may not be a suitable food for long-term culturing of the predator.

Transinfection reveals the crucial importance of Wolbachia genotypes in determining the type of reproductive alteration in the host

Wolbachia , a group of endosymbiotic bacteria in arthropods, alter the reproduction of their hosts in various ways. A Wolbachia strain (wSca) naturally infecting the adzuki bean borer moth Ostrinia scapulalis induces male killing, while another strain (wKue) infecting the Mediterranean flour moth Ephestia kuehniella induces cytoplasmic incompatibility (CI) in the resident host. Transinfection of Wolbachia can be a powerful tool to elucidate the relative importance of Wolbachia and the host in determining the type of reproductive alterations. Recently, male killing was shown to occur in E. kuehniella transinfected with w Sca. In the present study, we transferred w Kue to O. scapulalis by embryonic microinjection. In the O. scapulalis transinfected with wKue, CI, but not male killing occurred. Thus, in addition to wSca, wKue was shown to induce the same type of alteration in a foreign host as in its natural host. These results demonstrate the crucial role of the Wolbachia genotype in determining the type of reproductive alteration. However, the present study also revealed the involvement of host factors. First, the degree of incompatibility induced by wKue in O. scapulalis was stronger than that in E. kuehniella , indicating that host factors can affect the level of CI. Second, the vertical transmission rate of wKue in O. scapulalis was generally low, suggesting that the host affects the dynamics of Wolbachia transmission.

Interspecific transfer of Wolbachia between two lepidopteran insects expressing cytoplasmic incompatibility: a Wolbachia variant naturally infecting Cadra cautella causes male killing in Ephestia kuehniella.

Wolbachia is known as the causative agent of various reproductive alterations in arthropods. The almond moth Cadra cautella is doubly infected with A- and B-group Wolbachia and expresses complete cytoplasmic incompatibility (CI). The Mediterranean flour moth Ephestia kuehniella carries A-group Wolbachia and expresses partial CI. In the present study, the Wolbachia in C. cautella was transferred to E. kuehniella from which the original Wolbachia had been removed. We obtained transfected lines of three different infection states: single infection with A, single infection with B, and double infection with A and B. The doubly transfected lines and those transfected with only A produced exclusively female progeny. Two lines of evidence suggested that the sex ratio distortion was due to male killing. First, reduced egg hatch rate was observed. Second, removal of the Wolbachia from the transfected lines resulted in the recovery of a normal sex ratio of approximately 1:1. The occurrence of male killing following transfection showed that host factors influence the determination of the reproductive phenotype caused by Wolbachia. The transfected E. kuehniella males carrying exclusively B-group Wolbachia expressed partial incompatibility when crossed with the uninfected females. In addition, the transfected lines were bidirectionally incompatible with the naturally infected strain, which was the first demonstration of bidirectional CI in a lepidopteran.