The European bumblebee, Bombus terrestris, was introduced into Japan from Europe in 1991 for pollination of tomato plants. Many ecologists had warned of biological invasion by this species, and in 1996 a naturalized colony was found in Hokkaido, indicating that the species had become naturalized. The Ministry of the Environment effected a new law, the Invasive Alien Species Act, in 2005 to protect Japanese native fauna and flora from invasive alien species. Heated arguments arose between conservation ecologists and agriculturalists about whether the law should regulate B. terrestris. To reach a scientific decision, we began a study to reveal the ecological impacts of B. terrestris and to develop methods to control its naturalization. On the basis of our results, the Ministry of the Environment classified B. terrestris as invasive and requiring regulation by law, but its use would be permitted on the condition that it be used only for agriculture and that measures to prevent escape be taken. This legal control of B. terrestris in Japan is a revolutionary trial that aims to achieve a state of mutualism between biodiversity and agriculture.

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The earliest deliberate introductions of bumblebees to areas outside of their native range occurred over 100 years ago. Transportation of bumblebees accelerated in the late 1980s following the development of techniques for mass rearing them, and their widespread adoption as the preferred pollinator for a range of glasshouse crops, primarily tomatoes. There is now a worldwide trade in one species, Bombus terrestris dalmatinus, originating from south east Europe. Within North America, which does not allow the importation of B. terrestris, the trade is primarily in Bombus impatiens. Trade in B. t. dalmatinus threatens the integrity of other subspecies within Europe, such as B. t. audax which is endemic to Britain and Ireland. However, there is a conspicuous absence of data as to whether B. t. dalmatinus has established in the wild outside its native range, and whether it interbreeds with native subspecies. Perhaps a more significant risk associated with trade in bumblebees is the accidental spread of parasites, and the subsequent risk that native bumblebee species may be exposed to parasites for which they have little resistance. There is circumstantial evidence that catastrophic declines of several North American bumblebee species may have been triggered by the accidental introduction of pathogens from Europe. Even if commercial bumblebee colonies are reared locally, the high densities at which they are kept mean that glasshouse nests are likely to act as reservoirs for spread of disease to wild bumblebee populations nearby. There is clearly the need for tight quarantining of bee colonies before transportation, and a moratorium should be placed on the transport of bumblebees in cases where native species suitable for commercial rearing are readily available.

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An exotic species can appear in a community unexpectedly. It may therefore be necessary to decide quickly whether measures are required to mitigate the impact of the newly arrived exotic species on the native community. Here, I develop a collection of theoretical models that are intended to provide insight into the effects of newly arrived exotic pollinators on pollination systems. The models address the effects of the presence of an exotic pollinator on plant reproduction, including the both the degree to which seed set is pollen-limited and the level of outcrossing, and on numerical responses by native pollinator species, including switching of flower preferences by economically motivated flower visitors. The models are simplistic, but the majority have the virtue that their solution is feasible by using data that is easy to collect. The models provide first approximations that could be useful to ecologists and conservationists when they must guess the potential impacts of exotic pollinators. The results from the models should be interpreted under appropriate caveats by those who must make do with them until better information becomes available.

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Bombus terrestris is widely used as an agricultural pollinator in many countries, including Japan. In some of these countries, B. terrestris has become naturalized, and the risks of such invasions are a concern for the conservation of native ecosystems. In Japan, invasions of B. terrestris have occurred in Hokkaido, northern Japan, since 1996, and areas of naturalization are growing. Invasions of B. terrestris in Japan have predominantly occurred in human-modified areas, such as open agricultural areas, which are comparable to the preferred environments of the bumblebees' original distribution ranges. However, current affected areas also include natural habitats such as coastal and alpine grasslands. Important natural vegetation in Hokkaido is now suspected to suffer as a result of B. terrestris invasions, and therefore continuous monitoring is needed.

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The non-native bumblebee, Bombus terrestris, has recently become naturalized in Japan and is now dominant in some local communities. Here, we review previous studies reporting the effects of B. terrestris on native bees in both Japan and other countries. We also introduce our work to assess possible competitive exclusion by examining potential niche overlap, resource limitation for bumblebees, and the reproductive capacity of B. terrestris. Previous studies have reported the high niche overlap and some declines of native bees, indicating that competitive exclusion may be occurring. However, there is no indisputable evidence for this invader's ecological impacts on native species through competitive exclusion. Our studies showed that in terms of niche overlap for limited nest sites, two native species, B. hypocrita sapporoensis and B. diversus tersatus, were most likely to be affected through competitive exclusion. Feral colonies of B. terrestris produced a mean of 90.2 gynes and showed high reproductive capacity, which would presumably allow the species to outcompete native bumblebees. Field surveys demonstrated that these two native species have declined accompanied by an increase in B. terrestris. The present study provides strong circumstantial evidence for competitive exclusion of native bumblebees owing to the establishment of B. terrestris.

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Alien pollinators can disrupt mutualistic plant-animal interactions. Here we review studies on alien bee pollinators, demonstrating the ways in which invasive honeybees and bumblebees affect native plant seed production. Impacts of alien pollinators vary among pollination systems and among components of pollination success (visitation frequency, pollen transfer per visit, and pollen limitation). Reproduction of native bird-pollinated plants is little impacted by alien honeybees, because birds can pollinate even when honeybees visit target flowers. In bee-pollinated native plants, alien honeybee impacts on reproduction may be pervasive, but are not clearly defined in many cases; this lack of clarity arises because very few control sites without invasive bees are available, making comparative evaluation impossible. In bumblebee-pollinated plants, alien bumblebee effects are strong because native and invasive bee species are closely related congeners (of the genus Bombus) with similar pollinator mechanisms; alien bumblebees compete strongly with natives or replace them. In general, morphological, ecological, and behavioral similarities between native and alien pollinators are important for predicting their competitive interaction intensities and their effects on plant reproduction. The impacts of alien bees include (1) decreased pollen transfer per visit because of the loose morphological correspondence between flowers and alien bees, (2) increased competition for floral resources and exclusion of native pollinators because native and alien bees have similar ecological requirements, (3) changes in native pollinator visitation frequency and pollination efficiency caused by particular alien pollinator behavioral traits (such as stealing nectar or collecting previously-deposited pollen from stigmas). For a quantitative evaluation of invasion impacts, it is important to determine whether native plants suffer pollen limitation. To demonstrate pollen limitation, comparative studies with controls (that lack alien pollinators) are required. This approach is essential for discerning possible mechanisms responsible for observed patterns.

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The bumblebee Bombus terrestris is not only an effective pollinator but also a potential invasive species outside its native range. Interspecific crossing of B. terrestris with indigenous B. hypocrita sapporoensis and B. ignitus can cause inviable hybrid production under laboratory conditions. Additionally, nearly 30% of B. hypocrita sapporoensis and B. hypocrita hypocrita queens are estimated to copulate with B. terrestris males in the field, suggesting that genetic deterioration of indigenous bumblebees is possible through hybridization with the introduced species. We briefly review interspecific reproductive isolation mechanisms and discuss the negative impacts of B. terrestris on the reproduction of indigenous bumblebee species in Japan due to interspecific mating.

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Estimating colony numbers of invading Bombus terrestris in Japan is the most urgent task for eradicating the alien invasive species. Nests of bumble bees are hardly found in nature. A prospective alternative is estimating the number of nests with polymorphic genetic data of individuals foraging in the field. Full-sib reconstruction from such genetic data is NP-hard in a strict sense, but several heuristic methods have been proposed. Among them, likelihood methods have been often applied for reconstructing full-sibs in nature, but they require relatively large sample sizes for obtaining accuracy in allele frequencies. Alternative methods calculate genetic distances between paired individuals and cluster them into family groups, but there are also pros and cons for applying these methods against real data. We proposed another heuristic pairing and clustering method, Shared Loci Correspondence Analysis (SLCA), for reconstructing full-sib families of haplodipoid populations. In SLCA, genetic similarities among individuals are numbers of loci shared by the paired individuals. The similarity scores are sorted by the correspondence analysis for clustering them into full-sib families. SLCA could be applicable to quite small samples and succeeded to correctly estimate the number of bumble bee nests in the field. We also improved estimation accuracy of SLCA by blunting the similarity index among individuals. The modified SLCA performed almost perfectly against challenging problems when numbers of loci and alleles were equal or greater than eight. Future direction of improving SLCA is discussed.

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The 2004 Japanese Invasive Alien Species Act was enacted to control invasive alien species (IASs) and to prevent damage caused by IASs to ecosystems. The Act defines alien species recognized as or suspected of causing damage to ecosystems, human safety, agriculture, forestry and fisheries. IASs are regulated: raising, planting, keeping or transporting them is prohibited without the express permission of the relevant minister. The Act represents a revolutionary advance for biological conservation in Japan. However, enforcing the Act is problematic; dealing with the European bumblebee required resolving a bitter dilemma between biological conservation and agricultural productivity. The difficulties in the control of alien species in Japan stem from the reliance of the country on imports.

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The introduced Bombus terrestris has recently become naturalized in Japan and it may be responsible for the observed decline of native bumblebee populations. We compared the foraging ability of B. terrestris and a Japanese native bumblebee, B. ignitus, in an experimental cage. The 6-day experiment showed no significant difference in mean foraging load between them even though B. terrestris was significantly smaller than B. ignitus. However, B. terrestris was significantly more efficient, with a higher mean foraging load per unit time, and also brought back more forage per unit body mass than B. ignitus. The proboscis length of B. terrestris workers was more suited to the flower size of Salvia farinacea and the species may thus be more efficient in foraging. Once it has invaded a new region, B. terrestris can become the dominant bumblebee. When resources are low, B. terrestris, with a large number of superior foragers, can disadvantage native bees through resource depletion.

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A Japanese native bumblebee, Bombus ignitus, has recently been commercialized for crop pollination. To assess the risk of genetic disturbance of local bumblebee communities, despite the fact that B. ignitis is native, we analyzed a 1048-bp sequence of the cytochrome oxidase subunit 1 (CO1) region of mitochondrial DNA in B. ignitus specimens that were collected from various localities in Japan, China, and Korea. We detected 15 haplotypes, none of which were shared between Japanese and continental populations. Phylogenetic analyses confirmed that the Japanese populations constituted a distinct clade that is genetically divergent from the continental populations. The detection of a geographic pattern in the CO1 haplotype distribution within Japan suggests genetic differentiation among Japanese populations. These results indicate that the genetic endemism of B. ignitus should be taken into consideration before commercial colonies of this native bumblebee are distributed.

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Post-harvest losses caused by stored product pests are posing serious threats to global food security and safety. Among the storage pests, psocids were ignored in the past due to unavailability of the significant evidence regarding quantitative and qualitative losses caused by them. Their economic importance has been recognized by many researchers around the globe since the last few years. The published reports suggest that the pest be recognized as a new risk for global food security and safety. Psocids have been found infesting stored grains in the USA, Australia, UK, Brazil, Indonesia, China, India and Pakistan. About sixteen species of psocids have been identified and listed as pests of stored grains. Psocids generally prefer infested kernels having some fungal growth, but are capable of excavating the soft endosperm of damaged or cracked uninfected grains. Economic losses due to their feeding are directly proportional to the intensity of infestation and their population. The pest has also been reported to cause health problems in humans. Keeping the economic importance of psocids in view, their phylogeny, distribution, bio-ecology, management and pest status have been reviewed in this paper.

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Bombus terrestris L. (Apidae) is a native of temperate Eurasia and has been moved around the world since the 1800s. Dispersal of B. terrestris gained momentum in the 1980s when bees were reared artificially in Europe and supplied commercially for greenhouse pollination services. Very early after its commercial introduction, it was recognized that this species is invasive, can island hop to new locations and may disturb local ecosystems. The invasive characteristics of B. terrestris are: high migration ability, early seasonal emergence, high adaptability under adverse climatic conditions in various habitats, generalist or polylectic foraging strategies, enabling it to work a wide variety of flowers for resources, foraging over wide distances, a thermoregulatory metabolism that enables it to withstand low temperatures, no natural enemies to check population growth in areas outside its natural range, and it may develop two reproductive cycles in a year (bivoltine) in a newly colonized area. In addition, commercial bees produce more gynes and are better competitors than the local conspecific populations and may replace them in the likely event of an escape. The documented evidence on invasive impact of B. terrestris on natural ecosystems includes: negative interactions with local bee fauna, competition for nest sites with, and genetic contamination of, local Bombus spp., spread of parasites and pathogens and negative interactions with plant reproductive capacity. We discuss the possible measures that must be taken to minimize the B. terrestris invasion on local as well as on global levels.

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The West Indian sweet potato weevil, Euscepes postfasciatus, is a notorious pest of the sweet potato, Ipomoea batatas. We examined the potential presence of a bacterial endosymbiont in the pest weevil. The bacterial 16S rRNA gene and groEL gene were detected by PCR from the insects. Cloning, sequencing and molecular phylogenetic analyses of the bacterial genes demonstrated that E. postfasciatus is associated with a γ-proteobacterial endosymbiont of the genus Nardonella. In situ hybridization detected the endosymbiont in the female ovaries, indicating its transovarial transmission through host generations. This study is the first to identify Nardonella from the weevil subfamily Cryptorhynchinae. The potential relevance of the endosymbiont in the biology and management of E. postfasciatus is discussed.

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The flight and other behavior of the female Asian gypsy moth, Lymantria dispar, were observed in a net cage under natural photoperiodic conditions in May–August in Yokohama City, Japan. Both virgin and mated females moved by flight between 19:00 and 21:00, which coincided with one to two hours after sunset. Virgin females continued releasing pheromone, i.e., calling behavior, at the new site and sometimes copulated with males at night. If they could not copulate that night and in the subsequent daytime, they flew again the subsequent evening. Mated females started oviposition after their flight and thereafter did not move again. The mean flight speed of a virgin female was estimated as 21.3 m/min. The flight duration was approximately 10 min for both virgin and mated females, and therefore females could move 200 m on average and a maximum of 750 m during one night. These nocturnal activities of the Asian gypsy moth should be considered in order to establish effective control.

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Females of the white grub beetle, Dasylepida ishigakiensis, emit a highly volatile, hydrophilic sex pheromone 2-butanol and related compounds. To quantify these compounds, a new method using water to trap them was developed. Vapors of 2-butanol, 2-propanol and ethanol were trapped with water, extracted with an SPME fiber and then injected into GC-MS for analyses. Quantification curves of each alcohol showed good linearity within a certain range. The recovery rate of 2-butanol released from authentic lure tubes was estimated to be ca. 70%. These results indicated that the method tested would be applicable to measure the amounts of volatiles emitted by the beetles. Using this method, it was estimated that field-collected calling females emitted more than 200 ng 2-butanol, ca. 50 ng 2-propanol, and ca. 500 ng ethanol on average in the laboratory. In a second calling trial, however, the amount of 2-butanol emitted by females was reduced to 3% of the amount in the first calling trial. Trace amounts of 2-butanol were detected in volatile samples from males. Because 2-propanol and ethanol were emitted by both sexes in similar amounts, they may not be involved in sexual communication.

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The coconut hispine beetle Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae) is considered native to Indonesia and Papua New Guinea, and it has been established and causing serious leaf damages on Cocos nucifera (L.) in Asia, Australia and the Pacific Islands. Although this insect was found on only C. nucifera in the Yaeyama Islands, Japan in the 1980s, it was unknown whether it had established in the islands and whether it attacked the endemic palm Satakentia liukiuensis (Hatusima) H. E. Moore. We conducted field surveys in the Yaeyama Islands in 2007 to 2009 to determine whether B. longissima causes serious damages on S. liukiuensis in the islands. Although B. longissima infested leaves of the young trees in most nurseries or roadsides on Ishigaki, Iriomote and Kohama islands, no serious damage was observed on wild mature trees of the S. liukiuensis communities, which are protected as national natural monuments. All the developmental stages of B. longissima were found in November 2008 and May 2009. The present study first shows that B. longissima is common and attacks the endemic palm S. liukiuensis as a main host in the Yaeyama Islands where C. nucifera is very rare.

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The in vitro antibacterial properties of chitosan solution and its effect in protecting silkworms from bacterial septicemia disease were evaluated. The results showed that chitosan solution at concentrations of 0.01, 0.05 and 0.10 mg/ml exhibited strong antibacterial activity against two strains of Serratia marcescens. The antibacterial activity of chitosan solution against strain ZJS0801 of S. marcescens increased with the increase of chitosan concentration, while the antibacterial activity against strain ZJS0802 of S. marcescens was unaffected by chitosan concentration. The antibacterial activity of 0.10 mg/ml chitosan solution against S. marcescens increased with the increase of incubation time regardless of the tested strains. The mortality of larvae inoculated with the mixture of S. marcescens ZJS0801 and chitosan solution was significantly reduced compared to bacteria alone. In addition, the larvae mortality of silkworms inoculated with S. marcescens ZJS0801 was significantly reduced when silkworm larvae were fed on mulberry leaves treated with chitosan solution. Overall, the results indicated that chitosan solution had the potential for control of bacterial septicemia disease of silkworms.

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Fetal bovine serum (FBS), commonly used in the culture of many insect cell lines, is a source of both nutrients and bioactive compounds that promote cell growth; however, because the growth-promoting compounds contained in FBS are not considered to be identical to those produced by insects, the response of insect cells to FBS is likely to differ from responses to endogenous growth-promoting compounds. The present study examined whether primary cultures of Bombyx embryonic tissue fragments respond differently to silkworm egg extract and FBS. It was observed that, in primary cultures, Bombyx egg extract promoted the migration and growth of cells from embryonic tissue fragments more potently than FBS. These results indicate that the extract of silkworm eggs in an early developmental stage contains molecules that strongly promote cell migration and growth. The use of egg extracts could also shorten the time required to establish a novel cell line.

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Larvae of Glyphodes perspectalis were reared successfully on an artificial diet consisting of dried powder produced from box tree, Buxus microphylla, leaves and INSECTA F-II (Nihon Nosan Co., Ltd) at a ratio of 30 : 70. This artificial diet supported larval growth with a pupation rate of approximately 70%. This rate was comparable to that on conventional rearing using fresh host plant leaves. No significant difference in the larval period, pupal period, pupal weight, pupation rate, and emergence rate was noted between the two groups. The number of eggs laid by the resultant adult females, the preoviposition period, and the hatchability of eggs were also similar regardless of the diet; however, no larvae reached the pupal stage when they were given INSECTA F-II alone. Utilization of the artificial diet facilitates the stable rearing of G. perspectalis throughout the year.

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We examined the effect of the photoregime on the timing of male responsiveness to sex pheromones in the box tree pyralid, Glyphodes perspectalis. Circadian oscillation was observed in the male responsiveness of G. perspectalis, evidenced by the rhythmic expression of male responsiveness in the duration corresponding to the expected scotophase of the continuous light or continuous dark conditions, when males reared under 16L8D were transferred to continuous light or continuous dark conditions. When male responsiveness to the sex pheromone was measured throughout the scotophase under three different photoregimes, it was shown that the time to reach the maximal response after lights-off was rather constant (approximately 2 h), regardless of the duration of the scotophase in three cases of 6, 8 and 10 h. The maximal response in the three cases appeared to be maintained until the end of the scotophase. Furthermore, in an experiment involving ±2-h shifts of lights-on or -off from the usual 16L8D, male responsiveness peaked within 2 hafter lights-off, and persisted throughout the remaining dark period. These results suggest that, at least under the present experimental conditions, the diel rhythmicity of male responsiveness based on the endogenous circadian rhythm is coordinated by the light-dark regime, and lights-off cues are critical for the timing and expression of the response rhythm leading to increased responsiveness.

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Neoseiulus womersleyi is a potentially important biological agent for controlling Tetranychus urticae in apple orchards. However, overwintering sites of N. womersleyi in apple orchards have not been identified; therefore, the population dynamics of N. womersleyi and T. urticae on apple trees were investigated in Akita Prefecture, northern Japan, from April 2007 to March 2008. The population of T. urticae peaked on the leaves in mid-September. In contrast, the population of N. womersleyi rapidly increased and peaked in early October, and many adults were present until early November. Eggs of the predacious mite were not observed at all in early November. Adult females of N. womersleyi were found under rough bark in early December. N. womersleyi was significantly more abundant under rough bark containing many diapausing T. urticae females than under bark where the prey were few; however, the mean number of N. womersleyi early in March 2008 was significantly lower than in early December. Both N. womersleyi and T. urticae were collected using Phyto traps attached to apple twigs. Neither was captured between April and September, but the numbers of both increased rapidly in October.

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Using PCR in the direct diagnosis of bee virus infections has been shown to be an appropriate tool to overcome the difficulties of diagnosing bee virus infections. The occurrence of Israel acute paralysis virus (IAPV) and Kashmir bee virus (KBV) was investigated in honeybee colonies collected from ten different regions throughout Jordan by employing reverse transcription-PCR. The colonies were suffering from symptoms of depopulation, sudden collapse, paralysis, or dark coloring. The two viruses were identified in some of the collected samples: IAPV virus was present in 13% of samples, while KBV was present in 12%. The distribution of IAPV and KBV varied in the different geographic regions of investigation. The RT-PCR product for IAPV was 470–473 nucleotides, and for KBV was 408–409 nucleotides. Sequence analysis indicated that IAPV is most homologous to KBV.

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We investigated the overwintering sites of the predacious mite Neoseiulus californicus in two satsuma mandarin orchards on Jeju Island, Korea, in February 2008. Our objectives were to improve the biological control strategy with N. californicus in perennial crops and to develop effective methods for examining the overwintering situations of N. californicus in the field. Nearly all specimens of N. californicus collected in the orchards were adult females, and the numbers of adult males and juveniles were very low. Most N. californicus were collected on herbaceous plants on the ground rather than on satsuma mandarin trees or woody plants surrounding the orchards. Among herbaceous plant species, higher densities of N. californicus were consistently found on species with rosette-type leaves compared to those with non-rosette-type leaves. Our results suggest that rosette-forming herbaceous plants are effective overwintering sites for conserving N. californicus in orchards. Furthermore, these plants would also provide useful sites for examining the potential overwintering situations of N. californicus in the field.

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The functional response of the indigenous green lacewing Chrysoperla nipponensis (Okamoto) and the imported green lacewing Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) feeding on seven different densities of the cotton aphid Aphis gossypii (Glover) (Homoptera: Aphididae) was studied under laboratory conditions at 20°C. C. nipponensis and C. carnea have shown a Type II functional response based on logistic regression analysis. The maximum number of prey eaten by C. carnea was higher than C. nipponensis. Handling time decreased at 24 h for both species, but was higher for C. nipponensis at 12 and 24 h than for C. carnea. The attack coefficient of C. nipponensis was slightly higher than C. carnea in second and third instars. These results indicate that C. carnea may eat more aphids at high prey densities; however, C. nipponensis could be considered a prospective candidate for use as a commercial biological control agent for aphids in Japan. C. nipponensis will become more important than C. carnea from the viewpoint of environmental safety because it is a native species adapted to the Japanese environment, and non-target effects can be avoided.

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Yellow sticky flat traps were cut into six geometrical shapes (square, circle, semi-circle, diamond, triangle, and inverted triangle) to evaluate their attractiveness to Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). The square was used as a standard to compare with other shapes in the laboratory. Circle was the most effective, attracting 2.7 and 1.5 times more thrips in choice and no-choice experiments, respectively. Four different background colors were also employed in the circular trap, and their efficacies were compared. In both choice and no-choice tests, the circular yellow sticky trap on a black background attracted a significantly higher number of thrips than on a yellow, blue, or green background. In addition, the higher ratio of a black background to yellow sticky foreground enhanced thrips' attraction in the choice test. Based on these results, the efficacy of circular yellow sticky traps (5 cm diameter) on a black background (12 cm wide×12 cm length) was compared to commercial yellow sticky traps (5 cm wide×8 cm length) in a strawberry greenhouse. The modified trap attracted 2.3–21 times more F. occidentalis than the commercial yellow sticky trap. Therefore, the modification of yellow sticky flat traps to a circular shape on a black background would be a good addition to the thrips management program.

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Fitness elements (number and weight of emerging adults) and the success of parasitism (host mortality) in Dastarcus longulus were compared among three host stages (Monochamus alternatus larvae, pupae and adults). Different numbers of first-instar larvae were released onto single host individuals to determine the optimal host quality and rearing conditions needed to obtain large numbers of high-fitness individuals and to maximize the rearing efficiency of the parasitoid. Host mortality after the release of a single parasitoid larva was 88% on pupal hosts but <50% on larval and adult hosts. The numbers and weights of emerging adults per host were highest on pupal hosts. The estimated number of ovarioles in emerging adults was also the highest on pupal hosts. Pupae of M. alternatus thus provided the best host quality for rearing D. longulus. High host mortality was caused mainly by pupal immobility. A high feeding rate was associated with high parasitoid reproductive potential on pupal hosts. Although the release of 10 larvae onto a single pupal host resulted in the highest overall fitness of the rearing population of D. longulus, the release of two larvae onto each pupal host was the optimal procedure for maximizing the weight of individuals.

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To examine the feasibility of using endophytic fungi (/endophyte) as biological control agents against insect pests of host plants, the effect of Neotyphodium lolii, an endophyte living in perennial ryegrass, Lolium perenne L., was studied using two species of caterpillars: the Oriental corn borer, Ostrinia furnacalis (Guenee) (Lepidoptera: Pyralidae) and the pink borer, Sesamia inferens (Walker) (Lepidoptera: Noctuidae). Choice and no-choice feeding tests using endophyte-infected and endophyte-free clonal L. perenne indicate that endophyte-infected L. perenne have excellent resistance to O. furnacalis and S. inferens. Larvae of O. furnacalis significantly preferred endophyte-free to endophyte-infected grass. The ratio of surviving insects rapidly declined on infected grass and the survival curve on infected grass was similar to that of larvae of the no-food control. A similar trend occurred with S. inferens. These results indicate that N. lolii-infected L. perenne contains strong deterrent or toxic effects that affect O. furnacalis and S. inferens feeding and survival.

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