Oviposition preference of Anoplophora glabripennis emerging from five host tree species under field conditions

The Asian longhorned beetle （ALB）, Anoplophora glabripennis （Motschulsky） is a polyphagous woodborer of hardwood trees. In order to well understand the oviposition preference of A. glabripennis emerging from different larval host tree species, we selected five common host tree species in the field and evaluated its oviposition preferences. The five host tree species are Acer negundo （AN）, Salix matsudana f. lobato-glandulosa （SM）, Populus nigra L. var. thevestina （Dode） Bean （PN）, P. simonii × P. pyramidalis cv. Opera 8277 （PS） and P. alba var. pyramidalis （PA）. Results show that adult beetles emerging from these five tree species almost have the same oviposition phenomenon. All adult beetles, except those emerging from PS, chewed the highest potential sites and laid most eggs on AN trees. Adult beetles emerging from AN, PN, PS and PA did not chew any sites nor laid any eggs on PA trees. These results showed that adult A. glabripennis emerging from the five host tree species did not show any clear oviposition preference for their larval host tree species in the field but they did present the most obvious preference for AN and the lowest preference for PA.

Preferential feeding of an anthocorid predator Blaptostethus pallescens Poppius on different stages of cotton mealybug

Blaptostethus pallescens Poppius (Heteroptera:Anthocoridae),which is amenable to mass rearing,has proved to be a potential predator of sucking pests like mites and thrips.Recently,the cotton mealybug Phenacoccus solenopsis Tinsley emerged as a serious pest on cotton in India.Laboratory studies indicated that B.pallescens could feed on the cotton mealybug.Hence,further investigations were conducted to understand the stage of the predator which is most potential and the pest stage preferred by the predator.Mature nymphs and adults of B.pallescens could predate equally well on the neonates of cotton mealybug.Young (three to four-day-old) nymphs of the predator could not feed on any stage of the cotton mealybug.Mature nymphs (seven-day-old and above) and adults could effectively predate on both young and mature cotton mealybug crawlers,though preference was more for the younger crawlers.However,nymphs and adults of B.pallescens could not predate on the adult stage of the mealybug.Different predator:pest ratios were tested in cage studies and it emerged that B.pallescens adults released against the mealybug crawlers at a ratio of 1:5 and nymphal release at 1:10 caused maximum mortality of the mealybug crawlers.Considering the fast multiplication rate of cotton mealybug and the large number of predators which have to be released to manage them,further detailed studies are necessary on utilizing B.pallescens to target the neonates and younger stages of the cotton mealybug in field conditions.

Evidence of active oviposition avoidance to systemically applied imidacloprid in the Colorado potato beetle

Agricultural pests can develop behavioral resistance to insecticides by choosing to feed or oviposit on insecticide-free hosts.As young larvae have relatively low mobility,oviposition preferences from female adults may play a critical role in shaping the evolu-tionary trajectory of pest populations.While oviposition avoidance of insecticide-treated hosts was found in different agriculture pests,it remains unclear whether female adults actively choose to occupy insecticide-free hosts.To address this question,we investigated feeding and oviposition preferences between imidacloprid-treated and imidacloprid-free plants in the Colorado potato beetle,Leptinotarsa decemlineata Say,a major potato pest.We performed behavioral choice assays on two strains that differed in both fecundity and insecticide resistance.We found that one strain preferred to feed on the insecticide-free plants and that this preference is not innate.Meanwhile,the other strain chose plants for feeding and oviposition randomly.Further analyses of the moving patterns of the beetles suggested that the oviposition preference in the first strain is likely due to active learning.

Analysis of a malaria model with mosquito host choice and bed-net control

A malaria model is formulated which includes the enhanced attractiveness of infectious humans to mosquitoes, as result of host manipulation by malaria parasite, and the human behavior, represented by insecticidetreated bed-nets usage. The occurrence of a backward bifurcation at R0 = 1 is shown to be possible, which implies that multiple endemic equilibria co-exist with a stable disease-free equilibrium when the basic repro- duction number is less than unity. This phenomenon is found to be caused by disease- induced human mortality. The global asymptotic stability of the endemic equilibrium for R0 〉1 is proved, by using the geometric method for global stability. Therefore, the disease becomes endemic for R0〉 1 regardless of the number of initial cases in both the human and vector populations. Finally, the impact on system dynamics of vector＇s host preferences and bed-net usage behavior is investigated.

Divergence in the ovipositional behavior of the Papilio glaucus group

This study contrasts the ovipositional profiles of four members of the Papilio glaucus group, P. glaucus, P. multicaudatus, P. canadensis, and P. rutulus. We used seven choice oviposition bioassays containing leaves from hosts in seven plant families utilized by members of the P. glaucus group. Specifically, we contrast the overall ovipositional profiles of these species and their acceptance of a host in a novel plant family （Populus tremuloides： Salicaceae） and a host in a putatively ancestral host plant family （Liriodendron tulipifera： Magnoliaceae）. Significant differences were observed between the ovipositional profiles of P. glaucus and P. multicaudatus relative to each other and to P. canadensis and P. rutulus. In contrast, no significant differences were observed between the ovipositional profiles of P. canadensis and P. rutulus, which were also the only species that accepted P. tremuloides. Unlike the acceptance of P. tremuloides, the acceptance of L. tulipifera was present throughout the group despite the inability of the larvae of most species in the group to utilize this host. These results support the prediction of the ＂hierarchical threshold model＂ that ancestral host plants are likely to be retained in the ovipositional hierarchy while novel hosts should only be accepted by derived populations.

Factors shaping community structure of endophytic fungi–evidence from the Pinus-Viscum-system

Endophytic fungal communities have been shown to be highly diverse in almost every host plant species analyzed so far.However,the factors shaping their compositions are largely unknown.To elucidate the impact of various factors,10 independent replicates of DNA extracts from each of 17 surface-sterilized leaf and stem samples were analyzed by pyrosequencing of fungal ITS1 rRNA gene amplicons.Altogether,154 fungal OTUs(operational taxonomic units),represented by 953,385 sequences,were found in at least 2 samples from Viscum album ssp.austriacum and/or its host Pinus sylvestris.Deviating from earlier,cultivation-based assessments,the communities were dominated by OTUs related to the genus Mortierella and OTUs not assignable to a certain fungal phylum.However,Ascomycota were still the most diverse group in terms of OTU richness and already hypothesized organ and host preferences of certain endophytic Xylariaceae isolated from the Pinus-Viscum-system could be confirmed.Host species and organ type were also the major factors shaping the detected fungal communities.The two plant species clearly differed according to the endophytic fungal communities,but only stems and needles of Pinus were inhabited by significantly different fungal assemblages.Interestingly,only the 1 and 3 year old stem sections differed according to the endophytic fungal community,while differently aged leaves of both plants were indistinguishable in this regard.Size of the organs had no impact on fungal communities in Pinus,but shorter internodes and smaller leaves showed at least a tendency to differ from the corresponding larger organs in Viscum.Fungal communities also differed slightly between the two sampling sites,lying 200 km apart,and between the three sampling campaigns.Because the samples were drawn within 15 days,this finding indicates that seasonal shifts clearly outweigh aging effects in host plant with perennial leaves.The results therefore provide strong evidence against a linear development of the endophytic fungal communities in Pinus sylvestris and Viscum album over the years.The communities seem to establish themselves already in the year the respective organs emerge.Further study is required to clarify whether they predominantly establish anew each year,or if the core community persists throughout subsequent years.The most abundant endophytic OTUs are known from soil and/or dead plant material and are supposed to represent latent decomposers.The study reveals for the first time that host and/or organ preferences of putatively saprotrophic fungi are predominantly responsible for compositional differences in the endophytic fungal communities between host plants and organs.While the analyses are shown to provide rather robust results,the significance of genetic abundance,as revealed by high-throughput sequencing analyses,remains an unsettled issue.This is discussed in detail,as well as the challenges in assigning taxonomic names to OTUs.

Occurrence and geographical distribution of mangrove fungi

This is a multidimensional review of mangrove fungi occurring as saprobes,pathogens and endophytes of a wide range of host substrates and those isolated from the water columns and sediments in mangroves.Eight-hundred and fifty taxa including 658 that are supported by both morphology and molecular data and 192 with only morphological data are listed.These constitute Ascomycota,the dominant group with 773 species,and 58 Basidiomycota,one Blastocladiomycota,five Chytridiomycota,and 13 Mucoromycota.This study also includes data on mangrove yeasts 103 Ascomycota,39 Basidi-omycota and 193 taxa isolated from sediments.Endophytes isolated from submerged parts of mangrove plants total 38.The most specious orders of mangrove fungi are Pleosporales 133,Saccharomycetales 102,Microascales 101,Eurotiales 87,Hypocreales 60 and Xylariales 54.Speciose genera include Candida 39,Aspergillus 53,Penicillium 17 and Corollospora 16.The highest number of mangrove fungi have been recorded from the Pacific Ocean 553,which is the largest ocean,followed by Indian 408 and Atlantic Oceans 259.Geographical distribution of mangrove fungi varied from ocean to ocean with only 109 taxa common to the Atlantic,Indian and Pacific Oceans.Of the various countries reported for mangrove fungi,India accommodates the highest number(339)followed by Thailand 303,Malaysia 171,Florida Everglades,USA 134 and Brunei 134.A total of 60 different mangrove plants and their associates have been surveyed for mangrove fungi.These results are discussed and compared with previous studies.

Modeling transmission dynamics of lyme disease: Multiple vectors, seasonality, and vector mobility

Lyme disease is the most prevalent tick-borne disease in the United States,which humans acquire from an infected tick of the genus Ixodes(primarily Ixodes scapularis).While previous studies have provided useful insights into various aspects of Lyme disease,the tick's host preference in the presence of multiple hosts has not been considered in the existing models.In this study,we develop a transmission dynamics model that includes the interactions between the primary vectors involved:blacklegged ticks(I.scapularis),white-footed mice(Peromyscus leucopus),and white-tailed deer(Odocoileus virginianus).Our model shows that the presence of multiple vectors may have a significant impact on the dynamics and spread of Lyme disease.Based on our model,we also calculate the basic reproduction number,R 0,a threshold value that predicts whether a disease exists or dies out.Subsequent extensions of the model consider seasonality of the tick's feeding period and mobility of deer between counties.Our results suggest that a longer tick peak feeding period results in a higher infection prevalence.Moreover,while the deer mobility may not be a primary factor for short-term emergence of Lyme disease epidemics,in the long-run it can significantly contribute to local infectiousness in neighboring counties,which eventually reach the endemic steady state.