Biological Characteristics And Reproductive Behavior Of Copidosomopsis Nacoleiae(eady)

Diaphania angustalis(Snellen)is the most harmful defoliator of Alstonia scholaris(L.).Copidosomopsis nacoleiae(Eady)is an egg-larva parasitoid wasp of D.angustalis.The wasp mainly distributes in China(Guangxi)and Southeast Asia.In order to control the damage of D.angustalis,based on successful cultivation of experimental populations of D.angustalis,this thesis systematically studied the biological characteristics,reproductive behaviors and rhythms,as well as the ultrastructure of the antennal sensilla of adult C.nacoleiae.Combining with the investigations of the occurrence dynamics of C.nacoleiae in the field,this paper provided important references for breeding of large-scale colonies of C.nacoleiae to control D.angustalis.The main results are as follows:(1)At the condition of 25 ± 2℃,70 ± 5% RH,14 L: 10 D photoperiod,C.nacoleiae took 46.82 ± 0.48 d for one generation.The duration of egg-larva and pupal stages was 32.17 ± 0.20 d and 14.36 ±0.27 d,respectively.Adults needed nutritional supplements,and the longevity of the adults related to the nutrition they fed.When fed on 10%honey solution,the longevity of adults was the longest,with an average of 2.18 ± 0.09 d.The pre-copulation period of adults was 4.72 ± 0.24 h,and the adults could copulate 5.17±1.65 times within their lifetime;the pre-oviposition period of females was 2.80 ± 0.31 h,and the oviposition period was 4.52 ± 0.12 h.Females could oviposit 2～95 times within their lifetime,with an average of 12.75 ± 9.99 times;one female laid 107.55 ±28.38 eggs within its lifetime.(2)C.nacoleiae is an egg-larva parasitoid wasp of D.angustalis.The wasps laid their eggs in the eggs of D.angustalis.The eggs of wasps lived inside for the stages of eggs and larvae of hosts.Until the hosts entered the mature larval stage,the eggs of wasps hatched.The larvae of wasps occupied the body of mature larvae of hosts quickly,and consumed all of the substances in the body besides of air tubes.Then the larvae of wasps pupated inside.The average number of wasps per larva of D.angustalis was 1489.47 ± 77.54,with a maximum of 2024.The numbers of wasps were positively correlated with the body length of the mature larvae of hosts.(3)Parthenogenesis and gamogenesis are the two reproductive modes of C.nacoleiae.When females were parthenogenetic,their offspring were all males;when females were gamogenetic,their offspring were 24.65 ± 3.64% females,and 86.67 ± 5.75% males.And the sex ratio of gamogenetic offspring was 1:3.52.When the ratio of female wasps to host eggs was 1:10,the parasitism percentage of C.nacoleiae was the highest(92.72 ± 2.92%).(4)The numbers of eggs laid by female adult were related to their ages and the reproductive modes.The numbers of eggs laid by 1-day-old females in one egg of hosts were 8.84 ± 0.42,which were significantly more than those by 2-day-old females.The numbers of eggs laid by gamogenetic females in one egg of hosts were 8.33 ± 0.57,which were more than those by parthenogenetic females,without significant difference.(5)The reproductive behaviors of C.nacoleiae include courtship,copulation and oviposition.When a male was courting,it would tap and test the female with its antennae.After confirming that the female was suitable,it would hold the female with its forefoot and midfoot,extend its abdomen forward,and copulate with the female.After the copulation,the male released the female and left.The adults copulated mainly at10:00～13:00.One adult copulated 2～8 times within its lifetime,and the average was 5.17 ± 1.65 times.The average duration of copulation was9.88 ± 0.51 s.Females oviposited mainly at 10:00～15:00,and the oviposition behavior could occur both before and after copulation.Before the oviposition,females crawled near the eggs of hosts and frequently touched the surface of the eggs with their antennae.After confirming a suitable egg of hosts,the female stopped moving,raised its abdomen,punctured the egg of hosts with the needle of ovipositor and laid eggs inside.After oviposition,the female pulled out the needle by rotating its body and left quickly.Females preferred to lay eggs in 4-day-old eggs of hosts.(6)At the condition of 25 ± 2℃,70 ± 5% RH,14 L: 10 D photoperiod,the percentage of courtship of 1-day-old male C.nacoleiae reached the peak at 12:00,and the percentage was 44.45 ± 5.92%,significantly different from that of 2-day-old female.The percentage of copulation of 2-day-old female reached the peak at 10: 00,and the percentage was 38.89 ± 5.37%,significantly different from that of 1 day old female.The percentage of oviposition of 1-day-old female reached the peak at 12:00,and the percentage was 88.89 ± 5.17%,significantly different from that of 2-day-old female.(7)Observed by the electron microscope and transmission microscope,six types of sensilla were found on the antennae of adult C.nacoleiae,including sensilla trichodea,sensilla chaetica,sensilla basiconic capitate pegs,sensilla placodea,sensilla basiconica and B?hm’s bristles.The numbers of sensilla on the club of antennae were the most.On the club of antennae,the numbers of sensilla trichodea I and Ⅲ of female were significantly more than those of male,and the numbers of sensilla Ⅱ of male were significantly more than that of female.