Light Reflection by Cuticles of Chrysina Jewel Scarabs: Optical Measurements, Morphology Characterization, and Theoretical Modeling

Cuticles of some Chrysina scarabs are characterized by flat, graded, and twisted structures of nanosized chitin fibrils. As inferred from SEM images, each species has its own spatial period or pitch P which is dependent on the depth z through the cuticle. From Berreman’s formalism, taking into account the corresponding P(z) dependence, we evaluate reflection spectra of C. aurigans and C. chrysargyrea scarabs. The spectra display the main spectral features observed in the measured ones when small sections of the cuticles are illuminated with non-polarized light, for wavelengths between 300 and 1100 nm. By considering these twisted structures as 1D photonic crystals, an approach is developed to show how the broad band characterizing the reflection spectra arises from a narrow intrinsic photonic band width, whose spectral position moves through visible and near infrared wavelengths. The role of the epicuticle that covers the twisted structures is analyzed in terms of a waxy layer acting as an anti-reflecting coating that also shows low levels of light scattering.

Species and Occurrence of Scarab in Sweet Potato Growing Areas of Xuzhou,Jiangsu

Frequency-vibrancy pest-killing lamp was used to calculate the numbers and types of scarabs during the growing period of sweet potato in Xuzhou area, thus to study the occurrence regularity of scarab and effect of meteorological factor on its occurrence, which provided a reference and guidance for the control of grub in sweet potato field. The monitoring results indicated that scarabs in sweet potato planting area of Xuzhou mainly included Anomala corpulenta, Holotrichia parallela Motschulsky, Maladera verticalis and Holotrichia trichophora Fairm. Holotrichia tri- chophora Fairm has entered into its late stage at the early cultivation stage of sweet potato with a few occurrence quantities. The elongation stage of sweet potato vine is the full incidence period of imagoes of Maladera verticalis and Anomala cor- pulenta. Full incidence period of Holotrichia parallela Motschulsky is from late June to middle August, the outbreak cycle of which is long. The unearthed imagoes fol- low the regular change ＂many-few-many-few＂. Effects of meteorological factor on the activities of various scarabs are different. The activities of various scarabs are fre- quent in warm and windless sunny days. In rainy days, Holotrichia parallela Motschulsky, Holotrichia trichophora Fairm and Maladera verticalis are inactive. The numbers of Anomala corpulenta in cloudy days but not rainy days are higher than that in sunny days.

Scarabaeid Larvae- and Herbicide-Resistant Transgenic Perennial Ryegrass (Lolium perenne L.) Obtained by Agrobacterium tumefaciens-Mediated Transformation of cry8Ca2, cry8Ga and bar Genes

Insect pest and weeds are two major problems for forage and turf grasses. In this study, scarab larvae- and herbicide-resistant transgenic perennial ryegrass （Lolium perenne L.） was obtained by transforming it with cry and bar genes simultaneously via the Agrobacterium-mediated method. To optimize the callus induction and plant regeneration conditions, various concentrations of 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine were assayed. The transformation efficiencies of different Agrobacterium suspension media, used during Agrobacterium-mediated transformation, were compared. Then, plasmids of pCAMBIA3301 containing cry gene （cry8Ca2 or cry8Ga） and bar gene, driven by ubiquitin promoter, were transformed into perennial ryegrass. The transformants were generated and confirmed by both Southern hybridization analysis and Western hybridization analysis. Further, the resistance of transgenic perennial ryegrass plants to scarab larvae and herbicide were analyzed. After 30 d of co-cultivation with scarab larvae, the damage to the root system of transgenic plants was less than that of non-transgenic control plants. Additionally, the leaves of transgenic plants were resistant to Basta, while leaves of the wild plants wilted after Basta spraying. These results show that cry gene and bar gene were successfully transferred into perennial ryegrass by the Agrobactgerium-mediated method, and convey resistance to scarab larvae and herbicide in transgenic perennial ryegrass plants.

Prophaenognatha,a New Aclopinae Genus from the Yixian Formation,China and Its Phylogenetic Position Based on Morphological Characters(Coleoptera:Scarabaeidae)

Prophaenognatha robusta gen.et sp.nov.(Scarabaeoidea:Scarabaeidae:Aclopinae),the best-preserved aclopine fossil so far,is described and illustrated from the Upper Jurassic-Lower Cretaceous Yixian Formation of the Jehol Biota,western Liaoning Province,NE China.The key to extinct and extant genera of Aclopinae is given and the monophyly of extant and fossil Aclopinae lineages is supported by five character states.The new taxon provides evidence about the evolution of Scarabaeoidea with its phylogenetic position inferred based on 68 morphological characters.

White grubs, Holotrichia rustica and Holotrichia mucida （Coleoptera： Scarabaeidae） as pests of teak （Tectona grandis L. f.） seedlings

Field observations were carried out between 2002 and 2005 on bio-ecology of white grubs infesting teak （Tectona grandis Linn. f.） seedlings at Ramdongari Forest Nursery, Forest Development Corporation of Maharashtra, Nagpur in central India. The study collected the data required for an integrated pest management strategy against the white grubs. The species damaging teak seedlings were Holotrichia rustica （Burmeister） and H. mucida Gyllenhal. The beetles （adults） of both these species began to emerge just after the pre-monsoon showers and when the relative humidity had risen rapidly over several days, but before the first monsoon rains. While the adults fed and mated on naturally growing bushes of Ziziphus jujuba, Z mauritiana, Z. xylopyra, Acacia leucophloea and A. catechu immediately after the emergence from the teak beds in the nursery, the immature stages （grubs） of both species fed on roots of the teak seedling, leading to plant death. This is the first report of （i） damage caused to teak seedlings by grubs ofH. rustica and H. mucida, and （ii） of Z.jujuba and Z. mauritiana being hosts for the beetles ofH. mucida and H, rustica. It is also the first detailed report on the field bio-ecology of the H. rustica and H. mucida as major pests ofteak. White grubs are among the toughest-to-manage pests of economic importance and information presented here on the pest incidence and damage ofH. rustica and H. mucida is important to researchers and nursery field managers for the management of these pests on teak.