Development In Pre-Copulation Duration And Its Effects On Reproductive Behavior Of Monochamus Alternatus Hope(Coleoptera:Cerambycidae)

Monochamus alternatus(Coleoptera: Cerambycidae)is the main insect pest of pine trees,and the vector insect of pine wood nematode,Bursaphelenchus xylophilus which causes destructive disease to pine trees.Although biological characteristic,population dynamics and population management of M.alternatus had been reported in many studied,the effects of nutrition supplement in pre-copulation duration on the development and reproductive behavior of M.alternatus adults is still unclear due to the adult has longer pre-copulation duration.To clarify the scientific issue not only could provide theoretical basic information to analysz the sexual selection and its mechanisms,but also provide data support to develop the new technology for population management of M.alternatus growth and development of adult M.alternatus during the pre-copolation duration,mating behavior and its daily rhythm,effects of adult’s body weight on their sexual selection,mating behavior,and reproduction were syudied.The main results are as follows:(1)Mating behavior of M.alternatus couldn’t occurred at the first day crawling out of wood.Adults begain to mate on the 4th day after crawling out of wood,and all adults can complete their first mating on the10 th day after crawing out of wood.During the pre-copulation duration,the body weight of female and male of M.alternatus with nutrition supplement increased significantly,and the crude fat content decreased significantly.During the pre-copulation duration,the protein and carbohyrate content have an upward trend while the water content have an opposite trend,which are not reach the significant level.With nutrition supplement for male after crawling out of wood,the development of testis is obvious,and the size of testis was positive correlation with the body weight and body length of male.Mature sperm were formed in the testis of males on the 5th day crawling out of wood.With nutrition supplement for the female after emergence,the development of ovaries is obvious and the eggs were formed,but the changes of morphological characteristics of oviposition cannula,spicule,bursa copulatrix and spermatheca did not observed.(2)A successful mating process of M.alternatus include 3 stages,i.e.,encountering pair-bonding,ejaculation and post-copulatoryguarding,respectively.Leave or pair-bonding could happen when male meet another male,while females just leave each other when female meet another female.Total 4 phenomenon were detected,i.e.,Leave,fight against the mating male for mating right,pair-bonding with the mating male,and the mating female pair-bonding with the single male when a single male met a pair of mating adults.While a single female mets a pair of mating adults,the phenomenon leave,interference with mating,the mating female pair-bonding with single female could happen.Female have 5 types of mating refusal action,including rapid crawling,dropping from a height,shaking,arching the belly and kicking the feet.One or more times of insertional insemination behavior were observed during ejaculation stage of male.During the post-copulatory guarding stage,females can crawl and feed while males usually lie on the body of females(3)Mating behavior of M.alternatus could occur with 24 hours of the day under outdoor condition with 2 peaks of mating,i.e.,10: 00 ～13:00 and 18: 00 ～23: 00.(4)There is no mating preference of male for larger or smaller females during mating.Small-bodied males obtained higher mating success rate compared with large-bodied males to small-dodied females.The insertions times,insertion duration and volume of sperm delivery of small-bodied males mating with small-bodied females were significantly higher than that those mating with large-bodied females,while there was no significant difference for large-bodied males.Athough the insertions times,insertion duration and volume of sperm delivery of the large or small-bodied male who obtained mating right to large-or small-bodied female were no statistical difference,arge male usually obtain much more mating right than small individual.(5)The body of M.alternatus adult had no significant effect on the fecundity(egg production,egg hatching rate)of females.