Resistance of Lepidopteran Egg Parasitoids, Trichogramma japonicum and Trichogramma chilonis, to Insecticides Used for Control of Rice Planthoppers.

Trichogramma wasps are commonly used as biocontrol agents to manage lepidopteran rice pests in rice fields. However, lepidopteran pests synergistically occur with rice planthoppers which are not targeted by Trichogramma. The use of Trichogramma parasitoids in field-based pest control efforts is greatly affected by the application of insecticides targeting planthoppers.

Screening Sugars Can Benefit the Parasitoid Cotesia chilonis (Hymenoptera: Braconidae) Without Benefiting Its Host, Chilo suppressalis (Lepidoptera: Crambidae).

Most adult parasitoids depend on carbohydrate-rich food as an energy source for longevity, fecundity, and mobility. Thus, providing sugars has been proposed as a technique to maximize the biological control efficacy of parasitoids. However, the sugars provided for parasitoids need to be carefully selected because herbivore hosts might also benefit.

The rice planthopper parasitoid Anagrus nilaparvatae is not at risk when feeding on honeydew derived from Bacillus thuringiensis (Bt) rice.

Background: Honeydew is a sugar-rich excretion produced by sap-feeding Sternorrhyncha and is an important source of carbohydrates for natural enemies, especially for parasitoids. Honeydew derived from genetically modified (GM) crops can contain amounts of the transgene product. Thus, it is a possible route of exposure for natural enemies feeding on honeydew.

Bt cotton producing Cry1Ac and Cry2Ab does not harm two parasitoids, Cotesia marginiventris and Copidosoma floridanum.

Cabbage looper, Trichoplusia ni (Hübner) is an important lepidopteran pest on many vegetable and greenhouse crops, and some field crops. Although there are no commercial transgenic Bt vegetable or greenhouse crops, T. ni is a target of Bollgard II cotton, which produces Cry1Ac and Cry2Ab.

Assessing the effects of Cry1C rice and Cry2A rice to Pseudogonatopus flavifemur, a parasitoid of rice planthoppers.

Transgenic rice producing insecticidal proteins from Bacillus thuringiensis (Bt) could help protect the plants from damage by lepidopteran pests. However, one concern is the potential of Bt rice to harm non-target natural enemies, which play a vital role in pest control. In the present study, the potential effects of Cry1C rice and Cry2A rice on different life-table parameters and population dynamics of Pseudogonatopus flavifemur, a parasitoid of rice planthoppers, were evaluated under laboratory and field condition.

The Effects of Temperature and Host Age on the Fecundity of Four Trichogramma Species, Egg Parasitoids of the Cnaphalocrocis medinalis (Lepidoptera: Pyralidae).

The Cnaphalocrocis medinalis (Guenée) is one of the most important rice pests in Asia and is difficult to control by chemical insecticides due to its rapid development of resistance. To screen potential species for biological control of C. medinalis, we investigated the effects of temperature (20, 24, 28, 32, and 36 °C) and host age (1-, 2-, 3-, and 4-d-old) on the fecundity of four Trichogramma spp.

[A banker plant system of 'Leesia sayanuka-Nlilaparvata muiri-Tytthus chinensis' to control rice planthoppers].

In order to clarify the feasibility of the banker plant system "Leesia sayanuka-Nlilaparvata muiri-Tytthus chinensis" to control rice planthooper, the effects of the combination of rice, L. sa-yanuka, N. lugen and N.

Different Performance of Two Trichogramma (Hymenoptera: Trichogrammatidae) Species Feeding on Sugars.

Most parasitoids depend on carbohydrate-rich foods to maximize their longevity and reproduction potential. These food resources are commonly from floral nectar, extra-floral nectar, and honeydew, which contain monosaccharides, disaccharides, and oligosaccharides. Here, we report an experiment to explore the effects of 12 naturally occurring sugars on the gustatory response, longevity, and fecundity of Trichogramma japonicum and Trichogramma chilonis These two parasitoid species differed in their responses to the tested sugars.

Bt crops benefit natural enemies to control non-target pests.

Crops producing insecticidal crystal (Cry) proteins from Bacillus thuringiensis (Bt) control important lepidopteran pests. However, pests such as aphids not susceptible to Cry proteins may require other integrated pest management (IPM) tactics, including biological control. We fed aphids on Bt and non-Bt plants and analyzed the Bt protein residue in aphids and compared the effects of Bt plants and a pyrethroid, lambda-cyhalothrin, on the performance of three natural enemies (predators: Coleomegilla maculata and Eupeodes americanus; parasitoid Aphidius colemani) of the green peach aphid, Myzus persicae.

The interaction of two-spotted spider mites, Tetranychus urticae Koch, with Cry protein production and predation by Amblyseius andersoni (Chant) in Cry1Ac/Cry2Ab cotton and Cry1F maize.

Crops producing insecticidal crystal (Cry) proteins from the bacterium, Bacillus thuringiensis (Bt), are an important tool for managing lepidopteran pests on cotton and maize. However, the effects of these Bt crops on non-target organisms, especially natural enemies that provide biological control services, are required to be addressed in an environmental risk assessment. Amblyseius andersoni (Acari: Phytoseiidae) is a cosmopolitan predator of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), a significant pest of cotton and maize.

Changes in Endosymbiotic Bacteria of Brown Planthoppers During the Process of Adaptation to Different Resistant Rice Varieties.

The specific primers of five species of endosymbiotic bacteria were designed to determine their numbers in three virulent populations of brown planthopper, Nilapavata lugens Stål, and to assess changes during adaptation to different resistant varieties using fluorescent quantitative PCR. The results showed that Chryseobacterium was the dominant bacteria in all three populations of brown planthopper, followed by Acinetobacter in TN1 population, Arsenophonus and Serratia in Mudgo population, and Arthrobacter and Acinetobacter in ASD7 population. When the TN1 population of brown planthopper was transferred to ASD7 (with resistant gene bph2) rice plants, Chryseobacterium was still the dominant bacteria, but the originally subdominant Acinetobacter declined to a level that was not significantly different from that of other endosymbiotic bacteria.

[Ecological responses of brown planthopper, Nilaparvata lugens, to triazophos and deltamethrin on transgenic Bt rice lines and their non-Bt parental rice].

In this study, the brown planthopper (BPH), Nilaparvata lugens (Hemiptera: Delphacidae), cultured on Bt rice lines (T1C-19 with cry1C gene and T2A-1 with cry2A gene) and their parental rice MH63, were treated with a series of concentrations of triazophos and deltamethrin when they developed up to the third instar for the evaluation of the effects of Bt rice on BPH resurgence induced by pesticides. The results indicated that BPH nymphal duration decreased with the increasing concentration of deltamethrin, while no significant differences of BPH nymphal duration were observed on the same rice variety treated with the different concentrations of triazophos. Furthermore, the survival rate of BPH significantly declined and their fecundity significantly increased with the increasing concentration of insecticides.

[Effects of plant viruses on vector and non-vector herbivorous arthropods and their natural enemies: a mini review].

Plant viruses transmitted by arthropods, as an important biotic factor, may not only directly affect the yield and quality of host plants, and development, physiological characteristics and ecological performances of their vector arthropods, but also directly or indirectly affect the non-vector herbivorous arthropods and their natural enemies in the same ecosystem, thereby causing influences to the whole agro-ecosystem. This paper reviewed the progress on the effects of plant viruses on herbivorous arthropods, including vector and non-vector, and their natural enemies, and on their ecological mechanisms to provide a reference for optimizing the management of vector and non-vector arthropod populations and sustainable control of plant viruses in agro-ecosystem.

Transgenic cry1C or cry2A rice has no adverse impacts on the life-table parameters and population dynamics of the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae).

Background: Transgenic rice producing the insecticidal protein from Bacillus thuringiensis Berliner (Bt) is protected from damage by lepidopteran insect pests. However, one of the main concerns about Bt rice is the potential impact on non-target herbivores. In the present study, the ecological impacts of two Bt rice lines, T1C-19 expressing Cry1C protein and T2A-1 expressing Cry2A protein, on the non-target herbivore brown planthopper (BPH), Nilaparvata lugens (Stål), were evaluated under laboratory and field conditions.

Effects of Bt cotton on Thrips tabaci (Thysanoptera: Thripidae) and its predator, Orius insidiosus (Hemiptera: Anthocoridae).

Laboratory studies were conducted to investigate tritrophic transfer of insecticidal Cry proteins from transgenic cotton to an herbivore and its predator, and to examine effects of these proteins on the predator's development, survival, and reproduction. Cry1Ac and Cry2Ab proteins from the bacterium Bacillus thuringiensis (Bt) produced in Bollgard-II (BG-II, Event 15985) cotton plants were acquired by Thrips tabaci Lindeman (Thysanoptera: Thripidae), an important sucking pest of cotton, and its generalist predator, Orius insidiosus (Say) (Hemiptera: Anthocoridae). The average protein titers in BG-II cotton leaves were 1,256 and 43,637 ng Cry1Ac and Cry2Ab per gram fresh leaf tissue, respectively.

Tri-trophic studies using Cry1Ac-resistant Plutella xylostella demonstrate no adverse effects of Cry1Ac on the entomopathogenic nematode, Heterorhabditis bacteriophora.

The potential impacts on natural enemies of crops that produce insecticidal Cry proteins from Bacillus thuringiensis (Bt) are an important part of an environmental risk assessment. Entomopathogenic nematodes are important natural enemies of lepidopteran pests, and the effects of Bt crops on these nontarget organisms should be investigated to avoid disruption of their biological control function. The objective of this study was to investigate the effects of Cry1Ac-expressing transgenic Bt broccoli on the entomopathogenic nematode, Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), under tri-trophic conditions.

Using resistant prey demonstrates that Bt plants producing Cry1Ac, Cry2Ab, and Cry1F have no negative effects on Geocoris punctipes and Orius insidiosus.

Geocoris punctipes (Say) and Orius insidiosus (Say) are generalist predators found in a wide range of crops, including cotton (Gossypium hirsutum L.) and maize (Zea mays L.), where they provide important biological control services by feeding on an array of pests, including eggs and small larvae of caterpillars.

Eliminating host-mediated effects demonstrates Bt maize producing Cry1F has no adverse effects on the parasitoid Cotesia marginiventris.

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is an important pest of maize in the United States and many tropical areas in the western hemisphere.

Bt crops producing Cry1Ac, Cry2Ab and Cry1F do not harm the green lacewing, Chrysoperla rufilabris.

The biological control function provided by natural enemies is regarded as a protection goal that should not be harmed by the application of any new pest management tool. Plants producing Cry proteins from the bacterium, Bacillus thuringiensis (Bt), have become a major tactic for controlling pest Lepidoptera on cotton and maize and risk assessment studies are needed to ensure they do not harm important natural enemies. However, using Cry protein susceptible hosts as prey often compromises such studies.

Transgenic Cry1Ab rice does not impact ecological fitness and predation of a generalist spider.

Background: The commercial release of rice genetically engineered to express a Cry1Ab protein from Bacillus thuringiensis (Bt) for control of Lepidoptera in China is a subject of debate. One major point of the debate has focused on the ecological safety of Bt rice on nontarget organisms, especially predators and parasitoids that help control populations of insect pests.

Methodology/principal Findings: A tritrophic bioassay was conducted to evaluate the potential impact of Cry1Ab-expressing rice on fitness parameters of a predaceous ground spider (Pardosa pseudoannulata (Bösenberg et Strand)) that had fed on Bt rice-fed brown planthopper (Nilaparvata lugens (Stål)) nymphs.

Using field-evolved resistance to Cry1F maize in a lepidopteran pest to demonstrate no adverse effects of Cry1F on one of its major predators.

Spodoptera frugiperda (JE Smith) represents the first documented case of field-evolved resistance to a genetically engineered crop expressing an insecticidal protein from Bacillus thuringiensis (Bt). In this case it was Cry1F-expressing maize (Mycogen 2A517). The ladybird beetle, Coleomegilla maculata, is a common and abundant predator that suppresses pest populations in maize and many other cropping systems.

Bt rice expressing Cry1Ab does not stimulate an outbreak of its non-target herbivore, Nilaparvata lugens.

In this study, the non-target effects of Bt rice "KMD2" expressing a Cry1Ab protein on the performance of the brown planthopper (BPH), Nilaparvata lugens, over multiple generations were evaluated under laboratory and field conditions. In the laboratory, BPH was reared to observe the impact of the Bt rice as compared to its parental non-Bt cultivar Xiushui 11, while the population dynamics and oviposition performance of BPH were investigated in the field. The survival of BPH nymphs fed Bt and non-Bt rice did not differ significantly.

Transgenic rice plants expressing a fused protein of Cry1Ab/Vip3H has resistance to rice stem borers under laboratory and field conditions.

Six transgenic rice, Oryza sativa L., lines (G6H1, G6H2, G6H3, G6H4, G6H5, and G6H6) expressing a fused Cry1Ab/Vip3H protein, were evaluated for resistance against the Asiatic rice borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae), and the stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) in the laboratory and field. The bioassay results indicated that the mortality of Asiatic rice borer and S.