Study On The Life Habit And Host Location Mechanism Of Otidognathus Sp.

China has a wide variety of bamboos and a wide range of distribution,Chongyang is one of the major bamboo products production areas in Hubei Province.The main economic bamboo species are Phyllostachys praecox,Phyllostachys edulis and Phyllostachys prominens.In recent years,the Otidognathus sp.has become an increasingly serious bamboo pest,seriously restricting the local economic development.Therefore,fully recognize the can provide a theoretical basis for effective comprehensive prevention and control to complement and improve the research significance and make sentences more fluent.However,studies on the olfactory molecular mechanism of Otidognathus sp.have not been reported so far.In this study,taking Otidognathus sp.as the subject investigated.We went through with observation in the forest and reared in lab,using SEM,GC-MS and transcriptome analysis,by which studied the biological and ecological of the species,defined the sensilla types,number,and distribution of Otidognathus sp..At the same time,the analysis of the proteins in Otidognathus sp.'s antenna which play roles in the sense of olfactory process,in order to find the mechanism of different olfactory genes impact the behavior of host selection.?1?Study on habits of the Otidognathus sp.We went through with observation in the forest and reared in lab,Otidognathus sp.adults and larvae were all harmful to bamboo shoots,It one life cycle in Chongyang every year.Overwintering with adults and was found in the second ten days of April the next year.In the third ten days of July,the adult disappeared in the forest.After the adults emerged,they took food,mated and oviposit immediately,the eggs hatched for 2 to 3days,larvae had five instars.The food intake of the 3rd instar larvae increased significantly.In the third ten days of May,the mature larvae enter the soil,and eclosion in the first ten days of July.The super-cooling point of the female Otidognathus sp.is?12.80? and the freezing point is?9.22?.The male super-cooling point is?12.46? and the freezing point is?8.24?.The females had lower super-cooling points and freezing points than the males,but there was no significant difference between male and female individuals.The eggs and larvae of Otidognathus sp.were raised at different temperatures,during 15³0?,eggs and larvae could develop normally.The developmental threshold temperature for the egg,and 1st to 4th instar larvae are: 8.28,12.44,15.42 and 12.28?respectively,and the effective accumulated temperature sums for them are: 68.05,26.93,36.05 and 93.58 degree-day respectively.Using linear daily,logistic and exponentialmodels to describe the relationship between the developmental rate and temperature of egg and larvae of the Otidognathus sp.,the results show that the logistic model fits better.?2?Study on population dynamic of Otidognathus sp.The peak period of Otidognathus sp.in the Phyllostachys prominens forest in Chongyang was from the end of April to the beginning of May,and the time of activity was basically consistent with the time of shoot out of Phyllostachys prominens bamboo shoots,showing a single peak type.It is found that the main limiting factor of Otidognathus sp.population dynamics is average temperature?X₁?,and the main determination factor is the maximum temperature?X₂?.The results of five kinds of fitting functions show that the best fit of the logistic model established by the average insect population density and the weekly average temperature and maximum temperature.?3?Effects of volatiles from bamboo shoots of Phyllostachys prominens on the behavior of Otidognathus sp.The selectivity of Odidognathus sp.odor sources was determined using a Y-type olfactometer.The results showed that the odor of Phyllostachys prominens bamboo shoots showed a very significant attractant effect on Otidognathus sp.,and the inducement rate was 72.5%.A total of 48 substances were discoverd by GC-MS,mainly alkanes?40?,accounting for 86.38% of the total volatiles.Followed by terpenoids?9.55%,6?and aldehydes?4.08%,2?.The relative content of terpenoids and aldehydes in the volatiles of bamboo shoots is low,but these two components are the main active substances.What kind of composition plays a regulatory role in Otidognathus sp.behavior,which needs further study.?4?Ultrastructural observations on sensilla of Otidognathus sp.We observed the antennae and their sensilla of Otidognathus sp.by scanning electron microscopy.In both sexes,there were nine types of sensilla found on Otidognathus sp.and contains 26 subtypes: sensilla trichodea?ST,4?,sensilla chaetica?SC,8?,sensilla basiconica?SB,4?,sensilla gemmiformium?SG,4?;sensilla cylindrical?SCY,3?,sensilla furcatea?SF?,sensilla hand-shaped?SH?,sensilla dippers?SD?and B?hm?BB?,respectively.There was no significant difference in the type,quantity and distribution of sensilla between male and female adults.The type and number of sensilla with antennae are the most abundant.Next is the foot.The sensilla on the feet are mainly concentrated on the third tarsite,and the sensilla is sensilla dippers.The head,pronotum and elytra were evenly distributed with sensilla gemmiformium.The outer margin of these parts are rimmed with hairs,and the sensilla is more abundant.?5?Antennal transcriptome analysis and bioinformatics analysis of olfactory genes in the Otidognathus sp.We present the first antennal transcriptome sequencing information for the Otidognathus sp.by Illumina HiSeq^TM 2000 sequencing platform.We got 25982 unigenes,average length 628 bp,from which 17247 unigenes were annotated successfully,accounting for 66.38% of the total unigenes.Based on the NR database function annotation result,the unigenes in Otidognathus sp.antenna are similar to Dendroctonus ponderosae most to 56.46%.Using transcriptome analysis of Otidognathus sp.antenna,we identified 72 putative olfactory related genes: 27 odorant-binding proteins?OBPs?,8 chemosensory proteins?CSPs?,16 odorant receptors?ORs?,18 ionotropic receptors?IRs?and 3 sensory neuron membrane proteins?SNMPs?.The putative olfactory related genes with other species build phylogenetic trees to analyze and predict the function of olfactory genes of Otidognathus sp.,which will lay a theoretical foundation for subsequent research on the olfactory behavioral mechanism of Otidognathus sp..