Species Diversity in Space and Time

Preface 1. Introduction 2. Data and methodology 3. Parasitoid species richness 4. Taxonomic composition and generalist versus specialist parasitoids 5. Host mortality and the impact of parasitoids on host densities 6. Hyperparasitoids 7. Synthesis References Index.

Pattern and process in host-parasitoid interactions.

An urgent need exists to identify more brown planthopper (Nilaparvata lugens Stal, BPH) resistance genes, which will allow the development of rice varieties with resistance to BPH to counteract the increased incidence of this pest species. Here, using bioinformatics and DNA sequencing approaches, we identified a novel BPH resistance gene, LOC_Os06g03240 (MSU LOCUS ID), from the rice variety Ptb33 in the interval between the markers RM19291 and RM8072 on the short arm of chromosome 6, where a gene for resistance to BPH was mapped by Jirapong Jairin et al. and renamed as “Bph32”. This gene encodes a unique short consensus repeat (SCR) domain protein. Sequence comparison revealed that the Bph32 gene shares 100% sequence identity with its allele in Oryza latifolia. The transgenic introgression of Bph32 into a susceptible rice variety significantly improved resistance to BPH. Expression analysis revealed that Bph32 was highly expressed in the leaf sheaths, where BPH primarily settles and feeds, at 2 and 24 h after BPH infestation, suggesting that Bph32 may inhibit feeding in BPH. Western blotting revealed the presence of Pph (Ptb33) and Tph (TN1) proteins using a Penta-His antibody, and both proteins were insoluble. This study provides information regarding a valuable gene for rice defence against insect pests.

/pdf/bph32-a-novel-gene-encoding-an-unknown-scr-domain-containing-4pivklec57.pdf

Bph32 , a novel gene encoding an unknown SCR domain-containing protein, confers resistance against the brown planthopper in rice

In the fight against arthropod crop pests using plant secondary metabolites, most research has focussed on the identification of bioactive molecules. Several hundred candidate plant species and compounds are now known to have pesticidal properties against a range of arthropod pest species. Despite this growing body of research, few natural products are commercialised for pest management whilst on-farm use of existing botanically-based pesticides remains a small, but growing, component of crop protection practice. Uptake of natural pesticides is at least partly constrained by limited data on the trade-offs of their use on farm. The research presented here assessed the potential trade-offs of using pesticidal plant extracts on legume crop yields and the regulating ecosystem services of natural pests enemies. The application of six established pesticidal plants (Bidens pilosa, Lantana camara, Lippia javanica, Tephrosia vogelii, Tithonia diversifolia and Vernonia amygdalina) were compared to positive and negative controls for their impact on yields of bean (Phaseolus vulgaris), cowpea (Vigna unguiculata) and pigeon pea (Cajanus cajan) crops and the abundance of key indicator pest and predatory arthropod species. Analysis of field trials showed that pesticidal plant treatments often resulted in crop yields that were comparable to the use of a synthetic pesticide (lambda-cyhalothrin). The best-performing plant species were Tephrosia vogelii, Tithonia diversifolia and Lippia javanica. The abundance of pests was very low when using the synthetic pesticide, whilst the plant extracts generally had a higher number of pests than the synthetic but lower numbers than observed on the negative controls. Beneficial arthropod numbers were low with synthetic treated crops, whereas the pesticidal plant treatments appeared to have little effect on beneficials when compared to the negative controls. The outcomes of this research suggest that using extracts of pesticidal plants to control pests can be as effective as synthetic insecticides in terms of crop yields while tritrophic effects were reduced, conserving the non-target arthropods that provide important ecosystem services such as pollination and pest regulation. Thus managing crop pests using plant secondary metabolites can be more easily integrated in to agro-ecologically sustainable crop production systems.

/pdf/pesticidal-plant-extracts-improve-yield-and-reduce-insect-38qxhw977y.pdf

Pesticidal plant extracts improve yield and reduce insect pests on legume crops without harming beneficial arthropods.

In response to herbivory by arthropods, plants emit herbivory-induced volatiles that attract carnivorous enemies of the inducing herbivores. Here, we compared the attractiveness of eight cucumber varieties (Cucumis sativus L.) to Phytoseiulus persimilis predatory mites after infestation of the plants with herbivorous spider mites (Tetranychus urticae) under greenhouse conditions. Attractiveness differed considerably, with the most attractive variety attracting twice as many predators as the least attractive variety. Chemical analysis of the volatiles released by the infested plants revealed significant differences among varieties, both in quantity and quality of the emitted blends. Comparison of the attractiveness of the varieties with the amounts of volatiles emitted indicated that the quality (composition) of the blend is more important for attraction than the amount of volatiles emitted. The amount of (E)-β-ocimene, (E,E)-TMTT, and two other, yet unidentified compounds correlated positively with the attraction of predatory mites. Quantities of four compounds negatively correlated with carnivore attraction, among them methyl salicylate, which is known to attract the predatory mite P. persimilis. The emission of methyl salicylate correlated with an unknown compound that had a negative correlation with carnivore attraction and hence could be masking the attractiveness of methyl salicylate. The results imply that the foraging success of natural enemies of pests can be enhanced by breeding for crop varieties that release specific volatiles.

Variation in herbivory-induced volatiles among cucumber (Cucumis sativus L.) varieties has consequences for the attraction of carnivorous natural enemies

Extracts seeds, fruits, and leaves of Brucea javanica, Piper aduncum, and Tephrosia vogelii were tested separately and also in mixture (3:2.5:1) in the laboratory for their insecticidal activity against the cabbage head caterpillar, Crocidolomia pavonana. B. javanica, P. aduncum, and T. vogelii plant materials were extracted with ethyl acetate-methanol (9:1), ethyl acetate, and ethyl acetate respectively by using maceration method. Insecticidal bioassays were done by a leaf-residue feeding method. Second-instar larvae C. pavonana were fed extracttreated broccoli leaves for 48 hrs and then were presented untreated leaves until the surviving larvae reached the fourth-instar stage. Larval mortality was assessed at 5 days after treatment, and the data analyzed by the probit method. The results showed that larval mortality started at first day treatment and increased at second day’s treatment. After changing with untreated leaves the mortality decreased significantly. Based on LC50 and LC95 values, T. vogelii leaf extract was more toxic (LC50= 0.06%, LC95= 0.12%) than P. aduncum fruit extract (LC50 = 0.24%, LC95=0.32%) and B. javanica seed extract (LC50=0.17%, LC95=0.41%). Based on value of LC50 (0.03%) and LC95 (0.05%), the toxicity of a mixture of B. javanica, P. aduncum, and T. vogelii extract (3:2.5:1) against C. pavonana larvae was very toxic. Based on the combination index according to the independent joint action model, the extract mixture had a strongly synergistic joint action against C. pavonana larvae, at level LC50 and LC95, with a combination index of 0.225 and 0.190. The mixture extract worked better than each single extract against C. pavonana

Synergistic action of mixed extracts of Br ucea javanica (Simaroubaceae), Piper aduncum (Piperaceae), and Tephrosia vogelii (Leguminosae) against cabbage head caterpillar, Crocidolomia pavonana

Hymenoptera Parasitoid Community Structure on Non-crops Vegetation Around Rice fields in Cianjur Watershed, West Java. Hymenoptera parasitoids have an important role in agroecosystem because of their ability in suppressing pest population. Their presence in the field is seen as the key to agricultural ecosystem. Their presence can be influenced by the availability of non-crop vegetation. Some adult Hymenoptera parasitoids require food in the form of pollen and nectar of wild flowers to ensure effective reproduction and longevity. The objective of this research was to study Hymenoptera parasitoid communities in non-crop vegetation around rice fields at Cianjur Watershed. Samplings were conducted at three different landscape, i.e. Nyalindung, Gasol and Selajambe West Java. Insects were sampled by two trapping techniques (farmcop and sweep net) in two lines of transect for each landscape. A total of 257 species from 25 families of Hymenoptera parasitoids were collected in non-crop vegetation at Cianjur Watershed. Landscape structure, flowering vegetation, and pesticide application affected the species richness, diversity and evenness of Hymenoptera parasitoid in non-crop vegetation.

/pdf/struktur-komunitas-hymenoptera-parasitoid-pada-tumbuhan-liar-2p56ogzknf.pdf

Struktur komunitas hymenoptera parasitoid pada tumbuhan liar di sekitar pertanaman padi di daerah aliran sungai (das) cianjur, jawa barat

The objective of this study was to evaluate the physiological response of the cabbage head caterpillar Crocidolomia pavonana treated with an active fraction of Calophyllum soulattri bark extract. Extraction of the test plant materials were performed with maceration method using methanol, continued by counter-current distribution separation in ethylacetate and water. Methanol fractionation of C. soulattri was performed by vaccuum liquid chromatography and the bioassays were conducted by a leaf-feeding method. The results showed that the dichloromethane fraction of C. soulattri had strong insecticidal activity against C. pavonana larvae, with LC50 of 0.05%. Sublethal treatments with the active fraction at LC15, LC50, and LC85 reduced the relative growth rate of the fourth instars by 48.9-94.1%. The treatments with the fraction at LC15 and LC50 to the fourth instars reduced the activity of invertase and protease enzyme by 20.7-24.1 and 14.4-25.14%, respectively, but increased the activity of trehalase by 26.7-120% as compared with controls.

Respons Fisiologi Crocidolomia pavonana terhadap Fraksi Aktif Calophyllum soulattri

Analisis Spasial Lanskap Pertanian dan Keanekaragaman Hymenoptera di Daerah Aliran Sungai Cianjur Spatial Analysis of Agricultural Landscape and Hymenoptera Biodiversity at Cianjur Watershed

In tritrophic interactions between cucumber plants, the cucumber moth Diaphania indica Saunders (Lepidoptera: Crambidae) and a larval parasitoid Apanteles taragamae Viereck (Hymenoptera: Braconidae), female A. taragamae may use herbivore-induced plant volatiles (HIPVs) to locate their host. However, the specific compound or blend of chemicals attracting A. taragamae remains unknown. In this study, differences in volatiles released from uninfested, mechanically damaged and host-infested cucumber plants were examined by the headspace volatile collection method. Responses of the larval parasitoid A. taragamae to the volatile extracts were examined in a four-arm olfactometer. We also investigated the attraction of female A. taragamae to a single compound identified as an HIPV from host-infested cucumber plants. Parasitoids discriminated between the volatiles from uninfested, host-infested and mechanically damaged plants. Chemical analysis of headspace volatiles from host-infested cucumber plants showe...

Syafrida Manuwoto

Papers

Synergistic action of mixed extracts of Br ucea javanica (Simaroubaceae), Piper aduncum (Piperaceae), and Tephrosia vogelii (Leguminosae) against cabbage head caterpillar, Crocidolomia pavonana

Struktur komunitas hymenoptera parasitoid pada tumbuhan liar di sekitar pertanaman padi di daerah aliran sungai (das) cianjur, jawa barat

Respons Fisiologi Crocidolomia pavonana terhadap Fraksi Aktif Calophyllum soulattri

Analisis Spasial Lanskap Pertanian dan Keanekaragaman Hymenoptera di Daerah Aliran Sungai Cianjur Spatial Analysis of Agricultural Landscape and Hymenoptera Biodiversity at Cianjur Watershed

(E,E)-α-Farnesene as a host-induced plant volatile that attracts Apanteles taragamae (Hymenoptera: Braconidae) to host-infested cucumber plants