| Phytoseiid mites are among the most important mass produced natural enemies worldwide.They play important roles biological control of small piercing and sucking pests,such as spider mites,thrips,and whiteflies.As well as their potentials and values as natural enemies,some biological features of phytoseiid mites started to catch attentions lately.At present,the internal reproductive structure of phytoseiid and the structure of sperm transfer during mating are not well understood.This study targeted we choose Phytoseiulus persimilis which is the species with the most extensive application in the world and relatively more biological researches.Based on transmission electron microscopy,scanning electron microscopy and cell staining techniques.We studied the structure of reproduction and sperm transfer,And the process of sperm transfer from male to female during mating;we also studied the process of spermatophore production and sperm morphology and number in spermatophore during mating.The results of the experiment provide a possible method and basis for further understanding the regulation of reproduction and sex ratio and studying the reproductive mechanism.The results show that the internal reproductive structure of Phytoseiulus persimilis is composed of Ejaculatory apparatus,Seminal vesicle,Vas deferens and Testis.At the time of mating,the male’s Spermatodactyl extends from the top of the chelicerae,one of the Spermatodactyl bends down nearly 90degrees;The base of the Spermatodactyl is connected to the movable digit on the chelicerae.and there is a joint at the junction,so that the Spermatodactyl can rotate 180 °.and form a chain structure;There is a hollow cavity in the Spermatodactyl,and The end is a hole;The length of the attachment structure is about 2/3 of the Spermatodactyl.The insemination pore of female are located between foot III and foot IV near the sternum,the diameter is about 7 μm;During mating,one of the two Spermatodactyl enters the cystic structure of the female through the spermatozoa;The spermatheca of the female mite has a neck and is connected to a thin pipe.After the Spermatozoa of Phytoseiulus persimilis enter the Spermatophore,the spermatozoa are connected to the small hole at the base of the chelicerae with the assistance of the Spermatodactyl,and then the Spermatodactyl on the chelicerae connected to the Spermatophore enter the female insemination pore.As a result,the sperm completed the transfer from male to female mites.The spermatophore of P.persimilis is pyriform,and was produced from male genital opening within 3 mins since mating started.When produced,the spermatophore was transferred along the capitular groove to the cheliceral base,where it was adhered to one of the two small holes at the bases of the chelicerae.Seminal fluid passed through the hole,the hollow spermatodactyl,the opening on spermatodactyl tip,and enter the insemination pore to reach the spermatheca of the female.No sperm was observed in spermatophores obtained 5 mins after mating started.The number of sperms inside increased in the next 10 mins,reached its maximum(ca.52 sperms per spermatophore),and thendecreased.All sperms were released in 75 mins after mating started.Sperms are slender in shape with the mean length being 3.9±0.3 μm. |
