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Trichogramma spp. (Hymenoptera: Trichogrammatidae) parasitoids have been commonly used as biological control agents in insect pest management. Host quality is believed to influence parasitism, host preference, and suitability for parasitoids. To date, limited studies have compared the parasitism of Trichogramma parasitoids on fertilized, unfertilized, and sterilized host eggs. Hence, we studied the performance of three Trichogramma egg parasitoids, Trichogramma japonicum Ashmead, Trichogramma chilonis Ishii, and Trichogramma leucaniae Pang & Chen, on fertilized, unfertilized, and ultraviolet (UV)-irradiated fertilized (UVF) eggs of rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae). In a no-choice test, T. japonicum and T. leucaniae parasitized significantly more fertilized or UVF than unfertilized hosts, and T. chilonis parasitized significantly more UVF than either fertilized or unfertilized hosts. In a choice test, all three Trichogramma parasitoids parasitized UVF hosts the most, and unfertilized hosts the least. There were similar percentages of adult emergence and female progeny among fertilized, unfertilized, and UVF hosts for all three Trichogramma parasitoids, except that T. japonicum had significantly lower adult emergence on fertilized hosts. We also found that all three Trichogramma parasitoids developed slower on unfertilized hosts. Regardless of host treatments, T. leucaniae had the longest developmental time and T. chilonis had the shortest. We conclude that Trichogramma parasitoids prefer parasitizing UVF eggs of C. cephalonica without negative effects on their emergence and sex allocation.

Wolbachia are a group of maternally inherited bacteria frequently found in arthropods and filarial nematodes. They have recently attracted attention for their ecological roles in manipulating host reproduction, their potential use in biological control of pest insects and medical significance. Classification of Wolbachia strains is currently solely based on molecular methods. However, the strains even with identical sequence types may induce different host phenotypes. Here we isolated a Wolbachia strain from the rice moth Corcyra cephalonica (designated as wCcep_B_BJ), which was shown to share multilocus sequence typing and Wolbachia surface protein hypervariable region profiles with a cytoplasmic incompatibility (CI)-inducing strain in supergroup B, but the phenotype wCcep_B_BJ may induce needs to be determined. We thus transinfected it into the whitefly Bemisia tabaci harbouring an A-Wolbachia through nymphal microinjection. Fluorescent in situ hybridization demonstrated that wCcep_B_BJ was successfully transinfected into B. tabaci and transmitted to offspring through host eggs. Reciprocal cross showed that wCcep_B_BJ induced a strong bidirectional CI in the transinfected host without imposing a significant cost on female fecundity. Our results suggest that wCcep_B_BJ may be a promising strain for biocontrol of B. tabaci, an important agricultural pest insect.

Vitellogenin (Vg) is a precursor of the major yolk protein, an essential nutrient for the embryonic development of oviparous animals including insects. Here, the gene(CceVg [Corcyra cephalonica Vg] ) encoding the Vg (CceVg of moth, C. cephalonica, was cloned and sequenced. The gene sequence was 6,721-bp long and contained 5five introns and six exons that together formed a 5,382-bp open reading frame. The deduced protein (CceVg) consisted of 1,793 amino acid residues, including a 16-amino-acid signal peptide. The putative molecular weight of the primary Vg protein was 202.46 kDa. The CceVg contained all conserved domains and motifs that were commonly found in most insect Vgs except the presence of a polyserine tract at the C-terminal region, which had not been reported in other lepidopteran Vgs. The expression pattern showed that CceVg was first transcribed at a very low level in the early larval stage but disappeared in later stage larva. In female, the CceVg mRNA was detected in early pupal stage and throughout adult stage. Interestingly, the CceVg mRNA was detected only in mated males at low levels, not in the virgin ones. Injection of CceVg double-stranded RNA into early-emergent females caused severely abnormal ovaries.

A laboratory study was made on the development of two strains, T originating from Tchad and C from the Cameroon, of Corcyra cephalonica (Stainton) (Lep. Galleriinae) on millet and sorghum at 28 °C and different R.H.'s. The moisture contents of the grains in equilibrium with the R.H.'s tested were as follows: Millet 70% R.H. (12.98%), 30% R.H. (8.11%), 20% R.H. (6.62%) and 10% R.H. (5.53%); Sorghum 70% R.H. (12.17%), 30% R.H. (8.27%) and 20% R.H. (6.80%). The following mean developmental periods in days (egg-hatch-adult) were obtained: T-strain on millet, 70% R.H. (♀ 33.28, ♂ 33.64), 30% R.H. (♀ 55.71, ♂ 53.11), 20% R.H. (♀ 69.70, ♂ 57.68), 10% R.H. (♀ 100.77, ♂ 87.25); T-strain on sorghum, 70% R.H. (♀ 46.00, ♂ 46.88), 30% R.H. (♀ 70.00, ♂ 64.75), 20% R.H. (♀ 74.50, ♂ 65.93); C-strain on millet, 70% R.H. (♀ 41.00, ♂ 40.94), 30% R.H. (♀ 55.71, ♂ 53.11), 20% R.H. (♀ 79.00, ♂ 69.73), 10% R.H. (100% mortality); C-strain on sorghum, 70% R.H. (♀ 58.33, ♂ 51.50), 30% R.H. (♀ 68.25, ♂ 62.17), 20% R.H. (♀ 96.00, ♂ 141.00), 95.9% mortality. Adult weight and fore wing length decreased gradually at lower R.H., but the mean adult weight and fore wing length of the T-strain was greater than that of the C-strain under all conditions. The T-strain originating from the Sahel is considered better adapted for development under dry conditions than the C-strain which came from the humid african west coast. Females had in general one instar more than males bred at the same R.H. The number of instars increased at lower R.H. At 70% R.H. there were 7 instars in the female and 6 in the male, at 30% R.H. resp. 10 and 9, at 20% R.H. resp. 11 and 10 and at 10% R.H. resp. 12 and 11. In certain cultures exceptionally large numbers of instars were produced. The number of eggs laid by adult females ranged from 18 to 467 and was correlated with body weight, the heaviest adults laying the most eggs. Unfertilized females produced as many eggs at 70% R.H. as fertilized females but at 30% R.H. egg production of unfertilized females was considerably lower. No drinking of water was observed in females, even under dry conditions. The T-strain performed as well at 35 °C and 70% R.H. as at 28 °C. Fertility of males does not seem to become impaired by the high temperature. The results obtained in this study are discussed in relation to control of C. cephalonica. Zusammenfassung Laboruntersuchungen uber die Entwicklung von Corcyra cephalonica (Stainton) (Lep. Galleriinae) auf Hirse und Sorghum bei 28°C und bei verschiedenen relativen Feuchtigkeiten Es betrug der Feuchtigkeitsgehalt von: Hirse 70% r.F. (12,98%); 30% r.F. (8,11%); 20% r.F. (6,62%) und 10% (5,53%). Sorghum 70% r.F. (12,17%); 30% r.F. (8,27%) und 20% r.F. (6,80%). Die Untersuchung erfolgte mit 2 Stammen von C. cephalonica, die aus Tschad und Kamerun stammten; Hirse und Sorghum stammten aus Tschad. Bei allen relativen Feuchtigkeiten entwikkelte der Stamm aus Tschad sich gut auf Hirse und Sorghum. Die Entwicklungsdauer (Larve-Imago) nahm bei abnehmender relativen Feuchtigkeit allmahlich zu. Bei 10% r.F. entwickelte der Stamm aus Kamerun sich nicht auf Hirse, wahrend bei 20% r.F. nur einige Larven auf Sorghum zur Entwicklung gelangten. Die Entwicklungsgeschwindigkeit war bei allen relativen Feuchtigkeiten bei beiden Stammen groser auf Hirse als auf Sorghum. Der Stamm aus Tschad entwickelte sich in allen Fallen schneller als der Stamm aus Kamerun, auch waren im Durchschnitt die Adulten schwerer und ihr rechter Flugel groser. Im allgemeinen hatten die weiblichen Larven ein Stadium mehr als die mannlichen Larven. Die Zahl der Larvenstadien nahm bei geringerer Feuchtigkeit zu. Die Zahl der abgelegten Eier war positiv mit dem Korpergewicht korreliert; die schwersten Motten legten die meisten Eier. Bei 70% r.F. legten befruchtete Weibchen ebenso viele Eier wie nicht befruchtete, jedoch war bei 30% r.F. die Zahl der Eier befruchteter Weibchen bedeutend geringer. Auch bei niedriger rel. Feuchtigkeit tranken Motten kein Wasser. Der Stamm aus Tschad entwickelte sich sowohl bei 35 °C/70% r.F. als auch bei 28 °C/70% r.F. Die erzielten Ergebnisse werden in bezug auf die Bekampfung von C. cephalonica diskutiert.

The hemolymph protein HP19 of the rice moth, Corcyra cephalonica, mediates the 20-hydroxyecdysone (20E)-dependent acid phosphatase (ACP) activity at a nongenomic level. Affinity-purified polyclonal antibody against HP19 (αHP19-IgG) was used in the present study to understand the role of HP19 during the postembryonic development of Corcyra. In the in vitro studies, HP19 action was blocked either by immuno-precipitation using αHP19-IgG, prior to its addition to the fat body culture or by the addition of the antibody directly to the culture, along with 20E and hemolymph containing HP19. The αHP19-IgG blocked the HP19-mediated 20E-dependent ACP activation. In the in vivo studies, the αHP19-IgG was injected into the fully developed last (final/Vth) instar larvae of Corcyra, to complex the HP19 in vivo, in order to block the action of HP19. The injection of αHP19-IgG resulted in defective development of larvae, which grew either into non-viable larvae or larval-pupal/pupal-adult intermediates relative to the effect of pre-immune IgG injected controls. The present study shows that HP19 plays an important role in controlling the metamorphosis of Corcyra by regulating the 20E-dependent ACP activity. Coupled with the earlier findings, the ecdysteroid hormone regulates this action at a nongenomic level. Arch. Insect Biochem. Physiol. 66:32–44, 2007. © 2007 Wiley-Liss, Inc.

Field control failures with pirimiphos-methyl against the rice moth, Corcyra cephalonica (Stainton), in Weslaco, Texas, USA, led us to investigate the susceptibility of this particular strain to pirimiphos-methyl, spinosad, pyrethrins synergized with piperonyl butoxide, and pirimiphos-methyl combined with synergized pyrethrins. In laboratory bioassays, 50 eggs of C cephalonica were exposed to untreated and insecticide-treated corn and sunflower seeds to determine larval survival after 21 days, egg-to-adult emergence after 49 days, and larval damage to seeds at both exposure periods. Pirimiphos-methyl at both 4 and 8 mg kg(-1) did not prevent larval survival or egg-to-adult emergence of C cephalonica on either corn or sunflower seeds, and seed damage was evident at both rates. The C cephalonica strain was highly susceptible to spinosad at 0.5 and 1 mg kg(-1). At both spinosad rates, reduction in larval survival, egg-to-adult emergence, and seed damage relative to the control treatment was > or = 93% on both corn and sunflower seeds. Pirimiphos-methyl and spinosad were generally more effective against C cephalonica on corn than sunflower seeds. The C cephalonica strain was completely controlled on corn treated with 1.5 mg kg(-1) of pyrethrins synergized with 15 mg kg(-1) of piperonyl butoxide. Many larvae survived and became adults on corn treated with synergized pyrethrins at or = 95%, egg-to-adult emergence by > or = 97%, and seed damage by > or = 94%. Our results suggest that the C cephalonica strain can be controlled on corn by combining pirimiphos-methyl with synergized pyrethrins or with synergized pyrethrins at the labeled rate. Although spinosad is not currently labeled for use on stored corn and sunflower seeds, it appears to be effective against C cephalonica on both commodities at very low rates.

The rice moth Corcyra cephalonica was reared at 30°C and 65–70% R.H. on wheat flour. Eggs, larvae, pupae and 24 hours old moths were exposed to gamma rays from Cobalt 60 at dose levels of 2000, 4000, 6000 and 8000 r. The results revealed that the life span of moths after irradiating larvae, pupae and adults slightly decreased with the increase of the dose levels. In the case of irradiated eggs, the life span of emerged adults sharply decreased with the increase of dose levels.

The reproductive potential (expressed in terms of egg yield and egg viability) of the rice moth, Corcyra cephalonica (Stainton) is significantly lowered when the pest is exposed to vapours of neem oil emanating from 160 μl of the oil. Zusammenfassung Neem-Samenol als brauchbares Mittel zur Hemmung der Vermehrung der Reismotte, Corcyra cephalonica (Stainton) (Lepid., Galleriidae) Das Vermehrungspotential, ausgedruckt durch Eizahl und Ei-Lebensfahigkeit von C. cephalonica wurde signifikant verringert, wenn die Imagines Dampfen von Neem-Ol (160 μl) ausgesetzt waren.

Protein fractions from the whole body homogenates were separated on SDS-PAGE and the muscle actin band was identified by western blotting, using commercial antibody raised against chick back muscle actin (Sigma Chemical Co., USA). The antibody was found to be specific for muscle actin, as it did not cross react with cytoplasmic actin of the nervous system. The molecular weight of the muscle actin in Corcyra was found to be around 46 kDa. The concentration of actin was found to be more or less the same in penultimate and early-last instar larvae and it increased during mid and late-last instar development. Thereafter, it has dropped to its minimum during the pupal stage. But, once again it increased to its maximum in adults. Thorax-ligation in early and late-last instar larvae resulted in decreased synthesis of muscle actin and this was more pronounced after 48 h of ligation. Injection of 20-hydroxyecdysone to insects which were thorax-ligated for 24 and 48 h was found to significantly increase the concentration of actin, suggesting that the ecdysteroids mediate the muscle actin synthesis during the larval development of Corcyra.

The kinetic separation of the diastereomeric title alcohols is accomplished by their acylation with succinic anhydride in the presence of lipase Amano PS.

The synthesis of four stereoisomers of the female-produced sex pheromone [(2R,6R,10R)-, (2S,6R,10R)-, (2S,6S,10S)-, and (2R,6S,10S)-1a] of the rice moth (Corcyra cephalonica) was achieved by starting from (R)-2a, (R)- or (S)-3a, and (R)- or (S)-4 and using alkylation of alkyl phenyl sulfones as the coupling reaction. Behavioral bioassay of each isomer revealed (2R,6R,10R)-1a to be eight times more active than a diastereomeric mixture of equal amounts of the eight possible stereoisomers, indicating that (2R,6R,10R)-1a is probably the natural pheromone or at least the major component of the female blend. Electrophysiological bioassay also confirmed the high activity of (2R,6R,10R)-1a.

Experiments were conducted to evaluate the effect of storing wheat flour for various length of time at –10, 0, and 5 °C, on the mortality of the egg and larval stages of Corcyra cephalonica. Treating eggs with −10 °C for 10 h; 0 °C for 10 and more days; or 5 °C for 15 days, stopped all embryonic development, and hence 100% mortality of eggs was obtained. Also, 100% mortality was observed when first-instar larvae were treated with −10 °C for 2 h and more; or 0 or 5 °C for 5, 10, or 15 days. Storing egg-infested wheat flour at 0 °C for 5 days and more, or at 5 °C for 15 days prevented the development of immature stages and thus no adults emerged. I concluded that storing small quantities of flour at 5 °C for 15 days, or at 0 °C for 10 or 15 days would be effective in controlling C. cephalonica, if no pupae are present at the time of treatment. Zusammenfassung Zur Moglichkeit der Verwendung der Kalteempfindlichkeit von Eiern und Larven zur Bekampfung von Corcyra cephalonica (Staint.) (Lep., Galleriinae) Experimente mit Eiern und Larven verschiedenen Alters des Mehlzunslers Corcyra cephalonica (Staint.), welche unterschiedlich lange Temperaturen von 5, 0 und −10 °C ausgesetzt wurden, ergaben, das Eier bei Kurzzeitbehandlung (10 h) mit −10 °C oder bei Langzeitbehandlung (10 Tage mit 0°C, 15 Tage mit 5°C) zu 100% abstarben. Die Kaltebehandlung von Erstlarven fuhrte bei 2 h mit −10 °C oder 5 Tagen mit 5 °C zum volligen Absterben. Wurde mit verschiedenen Entwicklungsstadien (auser Puppen) von C. cephalonica befallenes Weizenmehl 5 Tage lang 0°C oder 15 Tage lang 5°C ausgesetzt, starben alle Stadien ab, so das keine Falter schlupften. Somit ist unter diesen Bedingungen eine wirksame Bekampfung des Schadlings in befallenem Mehl moglich, solange noch keine Puppen ausgebildet sind.

Development of the rice moth, Corcyra cephalonica (Stainton), from first instar larvae to adults in a whole wheat flour medium, took 40.9 and 43.5 days for males and females, respectively. Adult longevity was 9.1 and 7.0 days for mated and virgin males; 8.3 and 8.0 days for mated and virgin females, respectively. Virgin females laid more eggs than mated ones and as the number of moths per cage increases, the number of eggs decrases. Maximum mating response occurred during the second night after emergence. The mean number of matings per female was 0.9. The mean number of matings per male was 3.2 while that for females was 1.2 at a sex ralio of 4♀:1 ♂. Multiple mating occurred among about 16 % of the females. All investigations were carried out, at 28 °C, 65 % relative humidity, and LD 14:10 h. Zusammenfassung Laboruntersuchungen zu Entwicklung, Uberleben, Kopulation und Reproduktion der Reismotte, Corcyra cephalonica (Stainton) (Lep., Galleriidae) Die Entwicklung der Reismotte, C. cephalonica, dauerte von der Erstlarve bis zum Falter in Weizenmehl 40,9 bzw. 43,5 Tage fur Mannchen und Weibchen. Die Falter-Lebensdauer betrug 9,1, und 7,0 Tage fur kopulierte und nicht kopulierte Mannchen bzw. 8,3 und 8,0 Tage fur entsprechende Weibchen. Unbefruchtete Weibchen legten mehr Eier ab als befruchtete. Mit Zunahme der Falterzahl pro Kafig nahm die Zahl der Eier ab. Das Kopulationsmaximum zeigte sich wahrend der 2. Nacht nach dem Schlupfen. Die mittlere Zahl an Kopulationen pro Mannchen betrug 3,2 und fur Weibchen 1,2 bei einem Verhaltnis von 4:1 zugunsten der Mannchen. Mehrfachkopulation zeigten etwa 16 % der Weibchen. Alle Untersuchungen fanden bei 28,0 °C, 65 % rel. Luftfeuchte und 14:10 h Licht/Dunkelheit statt.