玛绢金龟成虫在烟田的空间格局分析

在烟株上玛绢金龟成虫的空间格局进行了测定。采用Ｔａｙｌｏｒ幂法则,Ｉｗａｏ聚集格局回归分析法和负二项概率模型来处理调查数据。结果显示：３种方法的聚集指数都表明玛绢金龟在烟株上的空间格局为聚集分布,Ｔａｙｌｏｒ幂法则拟合田间数据优于Ｉｗａｏ聚集格局回归分析法。     

Virulence of the entomopathogenic nematodes Heterorhabditis bacteriophora, Heterorhabditis zealandica, and Steinernema scarabaei against five white grub species (Coleoptera: Scarabaeidae) of economic importance in turfgrass in North America

We compared the virulence of the entomopathogenic nematodes Steinernema scarabaei, Heterorhabditis zealandica, and Heterorhabditis bacteriophora (GPS11 and TF strains) against third instars of the Japanese beetle, Popillia japonica, the oriental beetle, Anomala (=Exomala) orientalis, the northern masked chafer, Cyclocephala borealis, the European chafer, Rhizotrogus majalis, and the Asiatic garden beetle, Maladera castanea, in laboratory and greenhouse experiments. The virulence of the nematode species relative to each other differed greatly among white grub species. H. bacteriophora and H. zealandica had similar modest virulence to P. japonica, A. orientalis, C. borealis, and M. castanea. But against R. majalis, H. zealandica showed low virulence with a clear concentration response whereas H. bacteriophora caused only erratic and very low mortality. In contrast, S. scarabaei had modest virulence against C. borealis, but was highly virulent against R. majalis, P. japonica, A. orientalis, and M. castanea with R. majalis being the most susceptible and M. castanea the least susceptible.     

Field efficacy of entomopathogenic nematodes against the beetle Maladera matrida (Coleoptera: Scarabaeidae)

Single, double and triple releases of the entomopathogenic nematode Heterorhabditis bacteriophora Poinar, reduced the population of the beetle Maladera matrida Argaman, infesting peanuts (’Shulamit’ cv.) by 70, 75 and 93% respectively in microplot tests. Simultaneous and late (2 weeks after infestation) applications reduced beetle numbers by 63 and 79% respectively, in the microplots, while early application (2 weeks prior to infestation) did not reduce the beetle population. In a field trial, reductions in insect population and damage to the crop were achieved by early treatment with the nematode as well as by Heptachlor, leading to reductions in the insect population of 60 and 90% respectively, when recorded 4 weeks after nematode application. However, the nematode treatment did not maintain its effectiveness for a longer period and pest damage increased to the same level as the untreated control after 7 weeks. When the nematodes were applied at different concentrations (0.25–1.0 x 10⁶ infective juveniles (IJs) m^‐2) their effectiveness was not related to the concentration level. The only significant (P < 0.05) reduction in insect levels was recorded in the treatment with 0.5 X 10⁶ IJs m^‐2. In a second field trial, both H. bacteriophora and Steinernema glaseri reduced insect populations significantly (P < 0.05) by approximately 50% in comparison to the control. In the third trial, treatment with H. bacteriophora resulted in a decrease in insect population of 90% while treatment with S. carpocapsae reduced the grub numbers by 40% in comparison to the control. A differential susceptibility of various grub developmental stages was recorded in the field. The small grubs (I‐4 mm long, lst‐2nd larval stage) were not affected by the nematode treatments while the numbers of medium and large size grubs were reduced by 2‐ and 3‐fold respectively in the various tests. Nematodes were recovered by ‘nematode traps’ containing Galleria mellonella larvae from treated field plots 78 days after application. The implications of the results from the present studies on the use of entomopathogenic nematodes are discussed in relation to the development of an integrated pest management programme.     

Comparison of Pratylenchus penetrans Infection and Maladera castanea Feeding on Strawberry Root Rot

The interaction of lesion nematodes, black root rot disease caused by Rhizoctonia fragariae, and root damage caused by feeding of the scarab larva, Maladera castanea, was determined in greenhouse studies. Averaged over all experiments after 12 weeks, root weight was reduced 13% by R. fragariae and 20% by M. castanea. The percentage of the root system affected by root rot was increased by inoculation with either R. fragariae (35% more disease) or P. penetrans (50% more disease) but was unaffected by M. castanea. Rhizoctonia fragariae was isolated from 9.2% of the root segments from plants not inoculated with R. fragariae. The percentage of R. fragariae-infected root segments was increased 3.6-fold by inoculation with R. fragariae on rye seeds. The presence of P. penetrans also increased R. fragariae root infection. The type of injury to root systems was important in determining whether roots were invaded by R. fragariae and increased the severity of black root rot. Pratylenchus penetrans increased R. fragariae infection and the severity of black root rot. Traumatic cutting action by Asiatic garden beetle did not increase root infection or root disease by R. fragariae. Both insects and diseases need to be managed to extend the productive life of perennial strawberry plantings.     

Does host range influence susceptibility of herbivorous insects to non-host plant proteinase inhibitors?

We examined the influence of proteinase inhibitors on digestive enzymes and development of oriental beetle,Exomala orientalis Waterhouse, European chafer,Rhizotrogus majalis (Razoumowsky),Phyllophaga white grub,Phyllophaga anxia (LeConte), cranberry root grub,Lichnanthe vulpina (Hentz), Japanese beetle,Popillia japonica Newman, Asiatic garden beetle, Maladera castanea (Arrow) (Coleoptera: Scarabaeidae), and the black cutworm,Agrotis ipsilon (Rottemburg) (Lepidoptera: Noctuidae). We demonstrated that all species within our test group had alkaline midguts that contained proteinase activity that could be inhibited,in vitro with serine proteinase inhibitors. Our data suggests that host range may influence the susceptibility to non-host inhibitors. Chronic ingestion of the serine proteinase inhibitor, Kunitz-soybean trypsin inhibitor (STI), significantly reduced proteolytic activityin vivo in those species with relatively specialized feeding habits (i.e., cranberry root grub, Japanese beetle, Asiatic garden beetle, and black cutworm). Chronic ingestion of STI also resulted in reduced larval growth and delayed pupation for black cutworm, and elevated larval mortality for Japanese beetle. However, chronic ingestion of STI did not influence larval survival for those species with relatively generalized feeding habits (i.e., oriental beetle, European chafer). Based on these results, we propose mechanistically-based criteria for selecting proteinase inhibitors for phytochemical defense against herbivorous insects.     

沂蒙山区东方金龟子发生危害特点及防治

1999～ 2 0 0 2年 ,对沂蒙山区东方金龟子发生危害特点及其防治进行了调查研究。东方金龟子 1年发生 1代 ,以成虫在土壤 40～ 5 0cm深处越冬。 3月下旬至 4月上旬成虫开始出土 ,4月中下旬气温达1 7 2℃～ 2 4 5℃时为出土盛期。成虫每日的活动危害期集中在接近日落到日落后 1h ,群集于树上啃食嫩芽、幼叶和花朵。成虫具假死性和趋光性。并提出了有效综合防治对策。     

Economic injury levels for the scarabaeid Maladera matrida infesting peanut fields in Israel

Control of Maladera matrida Argaman (Coleoptera: Scarabaeidae) in peanut fields in the Negev region, Israel, relies on the `rule of thumb' use of insecticides. The aim of this study was to develop an economic injury level (EIL) for a more judicious application of insecticides. Field studies were conducted from 1991 to 1993 to determine the relationship between the cumulative number of different immature stages and the damage of peanuts (Arachis hypogaea L.). Observed damage to peanut yield was found to relate best to second- and third-instars (white grubs). This was supported by grub infestation experiments on potted peanut plants. Three different EIL levels for second- and third-instars of M. matrida were established in connection with the peanut plant developmental stages as follows: an average of 13 grubs per soil sample (25 by 25 by 60 cm) taken during the first 3 weeks of nut development, of 4 grubs per soil sample during week 4 to 6, and of 1.5 grubs per soil sample from week 7 until harvest.     

Infectivity of beetle spiroplasmas for new host species

Five beetle spiroplasmas, the Colorado potato beetlespiroplasma (CPBS, strain LD-1), the Cantharis carolinusspiroplasma (CCBS, strain CC-1), the Ellychnia corrusca fireflyspiroplasma (FS, strain EC-1), the Diabrotica undecimpunctatacorn rootworm spiroplasma (CRS, strain DU-1), and the Spiroplasmafloricola fall flower spiroplasma (FFS), all associated withbeetles, were fed to beetles (Maladera matrida and Carpophilushumeralis) and mosquitoes (Aedes aegypti and Culex pipiens). CPBSand CCBS were also injected into M. matrida. Attempts to recoverspiroplasmas from regurgitates and hemolymph were conducted 1–10days after their introduction. After day 1, orally administeredspiroplasmas could not be recovered from M. matrida beetles;however, at 2–5 days, four out of five spiroplasmas wererecovered from adult C. humeralis. Injected spiroplasmas survivedin the hemolymph of M. matrida beetles for a relatively longperiod (at least 22 days). All five spiroplasmas were recoveredfrom mosquitoes 1 day post feeding, but only two (CCBS and CRS)survived for five or more days. The results show short andvariable persistence in orally challenged non-host insects, withgeneral failure to pass the gut barrier. Such evidence should beconsidered when attempting to use these microbes in biocontrolprograms.     

Evolution of Asian ‘lowland’ taxa in relation to the Alpine–Himalayan Tertiary orogenic belt – Insight from a cladistic analysis of Maladera (Cycloserica) (Coleoptera: Scarabaeidae: Sericini)

Among the south Asian Sericini only a very few endemic monophyletic lineages developed in the lowland areas, such as the taxa belonging to Maladera (subgenus Cycloserica). Twenty species of Sericini (Coleoptera: Scarabaeidae) representing the principal lineages of Maladera occurring in the Palearctic region were included in a parsimony analysis based on 37 morphological characters. Maladera (Cycloserica) was found be monophyletic, composed by a clade comprising (Maladera caspia (Cycloserica excisipes, Leucoserica arenicola)) being distributed in the Middle Asian lowlands and its sister group the Maladera quinquidens-group with four endemic species in the Himalayan and North Indian lowlands. The ranges of these two clades as well as of the sister group of Cycloserica reveal a separating effect by the uplifted Himalayan–Alpine belt. It is hypothesized that these two Cycloserica lineages existed before they dispersed into the two separated areas, the northern Indian subcontinent (Himalayas) and the Middle Asian lowland. Due to the sister group relationship of Cycloserica and Leucoserica, both nested deeply within the species of Maladera, it seems reasonable to consider both synonymous with Maladera. Based on this conclusion one new combination is necessary, Maladera (Cycloserica) arenicola, and Leucoserica Reitter, 1896, is placed in synonymy with Cycloserica Reitter, 1896).