The predatory bug Orius niger Wolff occurs throughout Iran in various climatic zones. Because of its apparent adaptation to these different climates, it is being considered as a potential biological control agent of the pest Thrips tabaci Lind. in various crops in Iran. We measured the basic life-history parameters of O. niger on a diet of corn pollen and eggs of the moth Ephestia kuehniella Zeller at 3 constant temperatures (26, 29 and 32°C under 16L–8D) to assess the possibility of culturing this predator for mass releases. Bean pods were supplied as oviposition sites. The intrinsic rate of increase was 0.113, 0.127 and 0.157 daughters/female/day at 26, 29, and 32°C respectively. Analysis of the mortality of eggs, juveniles and adults suggests that the population growth rate is restricted most by juvenile mortality. This mortality is probably caused by cannibalism, the occurrence of which should therefore be minimized in mass cultures.

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We confirmed the occurrence of interspecific hybridization between Liriomyza sativae and L. trifolii on kidney bean (Phaseolus vulgaris L.) at 25°C under a 15L–9D photoperiod regime. Among 48 replications of L. sativae females and L. trifolii males tested, females of 19 replications (39.6%) oviposited, but no eggs hatched. In contrast, among 115 replications of L. trifolii females and L. sativae males tested, females of 47 replications (40.9%) oviposited and progeny from 10 replications (8.7%) developed to adult eclosion. The hybrid offspring were obtained only when several L. trifolii females and several L. sativae males were placed together. The hatchability, pupation rate, and adult emergence rate of hybrid flies were 14.9%, 94.9%, and 61.8%, respectively. All the hybrid adults were female (n=127). When these females were backcrossed with males of either species, none oviposited. The mean adult longevity of a hybrid female was 19.2 d.

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In a previous study, the assay method was developed for determining easily and precisely whether cigarette beetles are knocked down by phosphine fumigation. In the study, it was shown that knockdown times and mortalities of adults exposed to phosphine fumigation were closely correlated to each other. However, it is important, for successful fumigation, to evaluate the susceptible level of eggs in the beetles' population beforehand because eggs are the least susceptible stage to phosphine of all the life stages of the beetle. Therefore, we investigated the correlation between the lethal concentration (LC) of eggs and the knockdown time (KT) of adults. The susceptible level to phosphine was investigated by a mortality test and a knockdown test for 15 strains. The correlation between the log LC of eggs and the log KT of adults was shown by the following logistic function showing a correlation coefficient of 0.933: log LC=0.370+(2.743−0.370) / [1+exp{−2.155×(log KT−2.521)}]. It was suggested that the substitution of the value of log KT_99.9 into the above logistic function yielded sufficient information for determination of the most appropriate phosphine concentration for successful fumigation.

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Pine wilt disease is one of the most serious diseases in the pine forests of Korea. Since the first report of the disease in Busan, Korea, in 1988, the disease has been gradually spreading into neighboring regions and now occurs in many regions of the southern part of the Korean Peninsula. The control of the disease is focused on the killing of the sawyer, Monochamus alternatus, an insect vector, by aerial insecticide spraying for adult control and by fumigation or burning infected trees for larval control. This study was conducted to evaluate the effects of aerial insecticide application on pine forest fauna by comparing ant communities in insecticide-sprayed and unsprayed areas. Samples were collected from five regions using three different sampling methods (pitfall trap, sweeping net, and shaking net). The results showed that community indices such as abundance, species richness and species diversity were not significantly different between insecticide-sprayed sites and unsprayed sites. According to a cluster analysis and a correspondence analysis, ant communities were generally grouped based on the location of the sampling sites with a slight variation of insecticide application, but not grouped by insecticide application, showing that ant community structures were not significantly different between the insecticide-sprayed sites and the unsprayed sites. Our results, overall, support the theory that the impact of the aerial insecticide application on pine forest fauna may be less severe than expected.

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The nest box is a powerful research tool for ecological and conservational studies of birds and several other cavity nesters. However, skilful predators such as martens sometimes invade nest boxes, thus disturbing researches. To protect nest boxes against predation by martens, we attached a small plate inside the nest box below the entrance hole, and we report here on the advantage of this device. In 1999 and 2000, respectively, 73.0% and 64.8% nest boxes were used by the Great Tit and the Varied Tit. After fitting boxes with the plate in 2000, the percentage of predated nests by martens decreased from 22.4% to 5.9%, and the percentage of successful nests increased from 29.3% to 43.8%.

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The dynamics of leafmines developed by Liriomyza trifolii (Burgess) larvae in greenhouse tomatoes were studied in Korea during 2003–2004 in order to construct and validate binomial sampling plans. An empirical P_T–m model, expressed as: ln(m)=α+β ln[−ln(1−P_T)], was used to relate between the proportion of infested leaves (P_T) and mean densities (m) at tally thresholds (T, the minimum number of leafmines present before a leaf is considered infested) of 1, 2, 3, 4 and 5 mines per leaf. To ensure the consistent selection of sample units, a sequence of reference pictures, with various levels of leafmine formation, was measured in advance by image analysis. The mines <0.4 cm² in area were excluded from counting in the greenhouses. There were no significant relationships between the total numbers of leafmines and individual mine areas. The binomial sampling plans were validated using resampling simulations with seven independent data sets. In an estimation of the density, the sampling precision (SE/mean) was found to increase with higher Ts; however, there were negligible improvements in the precision with T≥3 mines per leaf. Using T=3, over a wide range of mine densities, as few as 30 samples were necessary to achieve a precision of 0.30. In comparing binomial models with T=3 and 5, using seven independent data, the model with T=3 was a robust and relatively unbiased predictor of the mean density, whereas the T=5 model was generally biased towards over-prediction of the mean density. The binomial sampling plans presented here should permit rapid estimation of the mine density and enhance development for a damage assessment program in greenhouse tomatoes.

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This study was carried out to determine the nourishment preference and life table of the larvae and adults of Leptinotarsa decemlineata on the potato varieties of Agria, Pasinler, Marfona, Granola and Caspar. While the longest development duration in L. decemlineata was observed on the Granola variety, the shortest one was detected on the Caspar variety. The highest egg mortality in the Colorado potato beetle occurred on the Marfona variety, while the lowest mortality occurred on the Pasinler variety. The total mortality of immature stages of L. decemlineata was the highest on the Marfona variety and the lowest was on the Caspar variety. The highest larval mortalities were observed in the first larval stages. The highest daily fecundities on potato varieties were on the Granola variety and the highest total fecundities were on the Pasinler variety. However, the lowest values for both characteristics were on the Agria variety. The descending order of intrinsic rates of increase was Pasinler, Caspar, Agria, Marfona and Granola potato varieties. The highest net reproductive rates were on the Caspar variety and the lowest rates were on the Granola variety. The generation time was the longest in the Caspar variety and the shortest in the Pasinler variety. The Colorado potato beetle showed the least performance on the Marfona potato variety when considering the mortality of eggs and immature stages, total fecundity and net reproductive rate.

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Asphondylia yushimai, the soybean pod gall midge, completes its annual lifecycle with host alternation between fabaceous plants as summer hosts and Prunus zippeliana (Rosaceae) as a winter host. In the Tohoku District (northern Japan), however, A. yushimai needs an alternative winter host or hosts because the evergreen winter host, P. zippeliana, is not distributed in northern Japan. To find additional winter host plants of A. yushimai, five unidentified species of Japanese Asphondylia inducing galls on respective host plants in the winter season were examined based on DNA analysis, morphological observation, and ecological and distributional information. We concluded that Osmanthus heterophyllus (Oleaceae) is a winter host of A. yushimai. This paper reports these findings together with some biological and phenological information on A. yushimai and the winter host. Information on winter hosts will help to discover new control measures against A. yushimai.

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The distribution and food habit of the flatworm species Platydemus manokwari, which is known to be a predator of land snails, were examined on Chichijima Island of the Ogasawara (Bonin) Islands, Japan. P. manokwari was distributed over a wide area of the island. Few live land snails were found in the area where P. manokwari was distributed. Further, it was revealed that P. manokwari fed not only on live land snails including predatory species, but also on other food resources such as live flatworms or a land nemertean species and the carcasses of slugs and earthworms. Therefore, P. manokwari is expected to survive even if the populations of land snails are almost lost on Chichijima Island in the future, and so will affect the biodiversity of Chichijima Island.

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To search for a useful biological control agent and to determine the optimal rearing conditions for the green lacewings Mallada desjardinsi and Chrysoperla nipponensis, thermal effects on development, survival, and adult body size were examined at seven constant temperatures (15.0, 17.5, 20.0, 22.5, 25.0, 27.5, and 30.0°C) with a photoperiod regime of 16L : 8D (h). The developmental zero of M. desjardinsi larvae was higher than that of C. nipponensis larvae. The developmental zeros of C. carnea and C. nipponensis in earlier reports were similar to that of C. nipponensis in the present study. On the other hand, that of M. desjardinsi in earlier studies was somewhat higher than that of M. desjardinsi in the present study. A lower survival rate of C. nipponensis was observed in the cocoon stage at 15.0°C. On the other hand, lower survival rates of M. desjardinsi were observed in the egg stage at 30.0°C and in the cocoon stage at 15.0, 27.5 and 30.0°C. The body size of both green lacewings was affected by temperature throughout the range tested. Smaller body sizes of M. desjardinsi and C. nipponensis adults were observed at 15.0, 27.5 and 30.0°C. These results indicate that C. nipponensis has a wider optimum range of temperature for immature development than M. desjardinsi.

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We investigated the effects of a range of constant temperatures (18–30°C) on the development of eggs, nymphs and the pre-oviposition period of adult females in Leptocorisa chinensis (Dallas). The duration of all stages decreased as the temperature increased from 18 to 30°C. Developmental thresholds of 8.1, 10.1 and 9.6°C were estimated for the eggs, nymphs and pre-oviposition period, respectively. Thermal constants of 147 and 370 d-degrees above thresholds of 8.1 and 10.1°C were required for the development of the eggs and nymphs, respectively. The pre-oviposition period required 256 d-degrees above the developmental threshold of 9.6°C. After placing individuals collected in November and February in an incubator in the laboratory, 469.7 d-degrees above 9.6°C, a threshold for nondiapause female adults that was assumed to be equal to that of diapause female adults, were estimated to be required for the pre-oviposition period of individuals that had overwintered. The present results were useful to predict the field population phenology of L. chinensis in Hyogo Prefecture.

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The effect of eradication of the Oriental Fruit Fly, Bactrocera dorsalis, on the density of the Melon Fly, Bactrocera cucurbitae, was examined using data for the numbers of flies caught by monitor traps on islands and island groups of the Ryukyu Archipelago. A positive correlation was found between annual mean densities of B. cucurbitae and the number of years after eradication of B. dorsalis in three of four localities. Thus the density of B. cucurbitae seems to increase after eradication of B. dorsalis. This result suggests the possible effect of interspecific competition on islands where the two species coexist, but the effect is considered to be not very great. The density of B. dorsalis after eradication of B. cucurbitae seems to be not so different from the density on other islands where B. cucurbitae still exists. Attempts to eradicate a single species from localities where B. cucurbitae and B. dorsalis coexist can be planned, with careful examination of the density of a different species, as we did in the Ryukyu Archipelago.

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Oviposition site preference of the bamboo gall maker, Aiolomorphus rhopaloides Walker, was investigated in a bamboo stand in terms of plant-vigor hypothesis. Galls in branches were distributed contagiously due to the difference in branch length. More galls were found on longer branches. Survival rates within galls, nitrogen content and gall size did not differ with branch-length class, suggesting that oviposition preference on longer branches is not attributed to better progeny fitness. The phenology of the buds where females oviposit and the greater number of buds on longer branches might contribute to female oviposition site preference.

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EAG-active compounds in the virgin female extract of an olethreutid moth, Strepsicrates semicanella (Walker) (Lepidoptera: Tortricidae), were identified as (Z)-7-dodecenyl acetate (Z7-12:Ac) and (Z)-7-dodecen-1-ol (Z7-12:OH) by comparison of retention values measured by GC-EAG analyses, and only the former compound was confirmed to show attractiveness. The amounts of these compounds were estimated to be less than the noise level (<30 pg/female), since corresponding GC peaks were not observed. In the field, males were captured with traps baited with Z7-12:Ac but not with Z7-12:OH. The attractiveness of Z7-12:Ac was slightly increased by blending with Z7-12:OH, but the difference was not significant. Nevertheless, it was decided to use the 90 : 10 blend of Z7-12:Ac and Z7-12:OH for field attraction because of the clear EAG activity of Z7-12:OH. The 90 : 10 blend showed maximum attractions at 0.5–5 μg when loaded on rubber septa. GC-EAG analyses suggested the presence of dodecyl acetate and dodecan-1-ol in the extract, but these compounds showed neither a synergistic nor inhibitory effect on male attraction in the field. The unusually low optimum doses for male attraction suggest that communication disruption would be effective for control of this insect pest.

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The aggregation pheromone of the bean bug, Riptortus clavatus, consists of three components; (E)-2-hexenyl (Z)-3-hexenoate (E2HZ3H), (E)-2-hexenyl (E)-2-hexenoate (E2HE2H), and myristyl isobutyrate (MI). The role of each component to attract the bug was tested in the field using synthetic chemicals. The effectiveness of using E2HZ3H, E2HE2H, or MI alone to attract R. clavatus did not vary from that of the control. Blends of E2HZ3H+E2HE2H showed no attractiveness to R. clavatus, however, the addition of MI to E2HZ3H+E2HE2H (tertiary blend) showed significantly higher attractiveness to the bug than that of the control. The E2HE2H+MI blend was also equally attractive to the tertiary blend. A mixture of 7 mg MI with E2HZ3H (7 mg) and E2HE2H (36 mg) rivaled the single use of 100 mg MI in attractiveness. These findings indicate that MI can exert full attractiveness to the bug only in the presence of E2HZ3H and E2HE2H.

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In many spider species, spiderlings spend several days aggregated in a mass immediately after emerging from the egg sac. During this period, which is called the gregarious phase, spiderlings do not eat. In this study, we conducted two experiments to clarify the benefits of the gregarious phase in a wolf spider, Pardosa pseudoannulata Boes. et Str. In one experiment, we examined the effect of the fasting period on spiderling development (duration until molting to the next instar and increment of carapace width). The fasting period was set at 1 d in one treatment and at 5 d in another treatment. In a second experiment, we examined the effect of aggregation on spiderling development. In one treatment, spiderlings were individually reared from the next day of emerging from the egg sac. In another treatment, spiderlings were allowed to aggregate for 5 d before being reared individually. In both treatments, the fasting period was set at 5 d. Spiderlings that fasted for 5 d molted after a significantly shorter feeding period than those that fasted for 1 d, although we observed no effects of aggregation. The feeding period corresponds to the post-gregarious period when females no longer guard their spiderlings. Our results suggest that the gregarious phase functions to shorten the post-gregarious period during which the spiderlings are exposed to natural enemies.

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The compatibilities of 10 acaricides with Beauveria bassiana SG8702 varied significantly in 24 h liquid cultures including three chemical rates. Pyridaben, hexythiazox and propargite were found highly compatible with the fungus even at field application levels. Four bioassays were performed with Tetranychus cinnabarinus eggs using a non-touch leaf method. The ≤18 h-old eggs laid on detached fava bean leaves were exposed to gradient conidial sprays of B. bassiana alone in Assay 1 or together with the pyridaben rates of 0.05, 1.0 and 2.5 a.i. μg/ml in Assays 2–4, respectively. The percentages of hatched eggs decreased with the increase in conidial concentrations and increased over post-spray days at a given concentration but had no more change from Day 9 onwards. Final egg mortalities reached 65.4, 72.3, 77.7 and 85.3% at ~1,000 conidia/mm² in Assays 1–4. Ovicidal activity of B. bassiana [LC₅₀ with 95% CI: 546 (406–818) conidia/mm²] was enhanced significantly by fungal sprays including pyridaben [LC₅₀s: 322 (220–527), 199 (144–282), and 75 (48–103) conidia/mm²]. The effects of both agents and their interactions on the hatch rate of the mite eggs over post-spray days were illustrated by modeling the time-concentration-hatch relationship. The results indicate an alternative to utilize interactions of both agents against spider mites.

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The susceptibilities of five thrips species, Frankliniella intonsa, F. occidentalis, Thrips coloratus, T. hawaiiensis, and T. tabaci, to three isolates of an entomopathogenic fungus, Beauveria bassiana (isolates AZA38, GOM03, and KOG02), were investigated under laboratory conditions. Among the three fungal isolates, the five thrips species were the most susceptible to isolate KOG02 when inoculated with conidial suspensions at a concentration of 1×10⁷ conidia/ml. Females of F. intonsa were more susceptible to the fungi than males, while males of F. occidentalis and T. coloratus were more susceptible than females. Both males and females of T. hawaiiensis were highly susceptible to isolate KOG02. T. tabaci was highly susceptible to isolate KOG02, even by inoculation of the conidial suspension at a concentration of 1×10⁶ conidia/ml. Although isolates AZA38 and GOM03 exhibited weaker pathogenicity to the five thrips species than did isolate KOG02, the gross mortality increased significantly with the inoculation of these two isolates as compared with the control.

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Adult female Neoseiulus womersleyi feed on all stages of tetranychid mites, although they show a strong preference for eggs over adult females when both are available. We found that the oviposition rate of N. womersleyi females supplied with eggs of Tetranychus kanzawai or T. urticae was significantly higher than that of N. womersleyi females supplied with adult females of the respective prey species. The results suggested that the preference of N. womersleyi females for spider mite eggs simply reflected the optimal foraging of the females.

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Microplitis croceipes is a solitary larval parasitoid of Helicoverpa/Heliothis species in North America. Laboratory experiments were conducted to determine suitability of the non-natural host, a Japanese strain of Helicoverpa armigera for parasitism by M. croceipes. Females oviposited in the third instar of H. armigera. When the parasitized hosts were reared with artificial diet at 15–30°C with 16L:8D, 67–92% of them produced parasitoid pupae. However, only 9% at 13°C and 53% at 33°C produced parasitoid pupae, and none of those parasitoid pupae developed to adults at these temperatures. Mean time taken from oviposition to adult emergence varied from 14.8 d at 30°C to 53.2 d at 15°C for males and from 15.5 d at 30°C to 60.7 d at 15°C for females. The proportions of females in the emerged adults were 0.45–0.56. Mean lengths of forewings varied from 4.4 mm at 30°C to 4.9 mm at 15°C for males and from 4.3 mm at 30°C to 4.7 mm at 15°C for females. H. armigera was as suitable for parasitism by M. croceipes as H. zea and H. virescens, natural hosts of this parasitoid. The optimal temperature range for development of M. croceipes was 20–28°C.

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Wrong:Photoperiodic changes
Right:Photoperiodism changes

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