The Mating Behavior Of Rhynchophorus Ferrugineus(Oliver)

Rhynchophorus ferrugineus(Oliver)is one of the most damaging pest of the palm cultivations,which poses a great threat to palm industry and ecological safety.Owing to its aggregation behavior,extended reproductive duration,and the presence of several overlapping generation make the control of this pest more challenging.Therefore,once introduced into a new area,RPW has great ability to spread widely with its rapid population growth and acclimatize to the environment during the colonization and establish a successful invasion.Knowledge of the impacts of multiple mating on the female reproduction is important for predicting the population dynamic and the development of control methods such as the sterile insect technique(SIT).Here,firstly we studied the mating behavior of male and female and the mating rhythms.Secondly,the different mating times and its impact on female fitness and whether there exist an optimal mating time for females.Lastly,we studied the male mating strategies under different male individual competitor.Results are summarized as below:1.The results indicate that the mating starts from the male keep searching and approaching to female,a whole process of mating mainly includes two steps(1)copulation behavior which include approaching and contact with female and(2)mating behavior which starts from antennation,mounting,aedeagus insertion,and male mate protection.The female may refuse male copulation by escaping or hiding after receiving multiple mating.During any stage of the mating process,female and male may terminate the mating.There was no obvious mating peak occur at any time during 24 h and the average mating time was 13.76 ± 0.33 times per day and the average mating duration was 111.03 ± 2.49 s.The proportion of mating times in photoperiod was up to 58.01 ± 3.94%which was significantly higher than 41.99 ± 3.94%in scotophase.Although there was no significant mating peak in the 14 d of the adult periods,however,the number of mating times first increased and then had a slight decrease with aging of male and female.2.The multiple mating can obviously shorten the pre-oviposition period,extend the effective oviposition period,increase the number of eggs laid during the lifespan,egg hatchability and the longevity of male and female.Females mated only once had the longest pre-oviposition,4.44 ± 0.20 d and laid the least 77.35 ± 2.36 eggs.Polyandry significantly increased the effective oviposition period,fecundity,egg hatchability,and the life span of male and female adults.Females from C(what is C group)mating groups had the longest effective period,107.38 ± 3.37 d,laid the most 255.82 ± 8.78 eggs and had the highest egg-hatching rate,74.01 ± 1.21%.Moreover,the increase of mating frequency can significantly improve the life span of male adults,but the life expectancy of female increases with the increase of mating times and the female adults in the 15 mating treatment groups have the longest life expectancy,after that there is slight decrease with the increase of mating times.3.Male adults can strategically alter their mating behavior during mating when there are different number of other male individual exist.This mainly include:extending the mating incubation time,shortening the mating duration time,change the mate protect duration time,and reduce the gap duration time between the first mating completed and the second mating start.The number of total mating times also increased and male adults became more active to interfere the mating copulate by other male.With the male rival appearance,the male adults showed more insensitivity to females,it lasted 665.88±107.63 s for males to find and succeed copulate with females.The first mating duration time and the male mate protect duration time showing a trend of shortening with the number of male rival increased.The 1F vs 3M groups have the least duration time which was 74.70 ± 6.72 s and male protect duration time was 49.32 ± 8.26 s.When the male fell,the other male individual exist,male adult can obviously shorten the gap duration time.The males from 1F vs 2M groups have the shortest gap time,213.19 ± 38.95 s.During the experiment,the male adults that have the first mating experience with females will have a dramatic improvement in their continuous mating ability,mainly exhibited in the mating times 12.11 ± 1.01 and had obviously higher proportion 71.52 ± 4.50%of mating times than other male individuals in the total female mating times.