Studies On Biology And Predacious Function Of Pyrocoelia Analis Fabricius)

Pyrocoelia analis Fabricius is widely distribution in Taiwan and Southwest of china and recorded in 1801.P.analis is a widespread insects,and its larvae,pupae,adults and eggs can be glowing.Its main prey on a variety of software pests such as snails and slugs,therefore,it has important application value.At present,there is no detailed description and related research on the biology and ecology of P.analis.In this paper,we makes an indepth study on the biology and predation function of P.analis,and provides a scientific basis for the protection and utilization of the species.1 Morphological characteristics of P.analisThe adults of P.analis were typically sexual dimorphism.Male adult length 15-.26-16.06 mm,wing length 8-9mm,Pronotum is light brown,A pair of antennae of 11 sections,and filamentous.Light emitting are located in the 6-7th abdominal,It can glows yellow green light.Adult female length 20.6-24.2mmWith short wing buds,lenth of 2-3mm;luminous are located in the 5-7th of the white abdominal,the 5-6th is a banded type and the 7th is the eight point type,which can glows yellow light.Both male and female pupae belong to free pupae,the female pupa abdominal obesity in male pupa,only a short wings teeth;Male pupa shard with wing membrane isometric,extend to abdominal the second section;The illuminator developed from the 5?6?7th of the abdominal ventrite,it can glows yellow light.The female pupae is white in the early stage of pupation,late the abdomen change to pale pink.The light emitting of larval and adult can coexist in the pupal stage.It divided into three parts: head,chest and abdomen.the mouthparts of larva is developed.Antennae shorter than adult antennae,which are 3th and filamentous.The head can be indented chest back,body back deep dark brown,dorsal body midline obvious.the just hatched larvae of P.analis were white after hatching about 24 hours,the color from white to gray and finally turned black.The abdomen is divided into 9sections,each section has a pair of valves,the eighth sides of the abdomen on both sides of the birth of the 1 pairs of eight point shaped light-emitting devices.The egg of P.analis is round,yellowish white,diameter of about 1.2mm.The head morphological traits of adult and larval of P.analis were observed by scanning electron microscope.there sults showed that the adult had developed composed compound eyes,but the mouthparts degradation.The larvae had well-developed three segments of antenna and a pair of lateral ocellus.The mouthpart of the larval was extremely developed,and composed of a pair of sharp and curved inward fusarium mandible,a pair of maxillarypalpu,a pair of labial palpus,and a pair of lacinia.2 The biological charateristics of P.analisP.analis is the complete metamorphosis of insects,it's a generation that undergoes four stages: egg,larva,pupa,and adult.In the Guizhou of Libo,P.Analis one generation a year,male and female adults began in late June to pupation and it is wintering in the way of mature larvae,with overlapping generations.The temperature had a significant effect on the egg period,28 ? was the optimum growth temperature,and the developmental period was 24.5 days.and the developmental period of P.analis is the shortest in the period of 28 ?,and the developmental duration is the longest at the temperature of 22?.The period of male adult is about 17 d,and the period of female adult is about12 d.Female adults began to mate with male adults on the second day after emergence,and began to lay eggs on the 4th day.The spawning time lasted about 3 to 4 days,and the amount of fecundity on the 4th day was relatively small.Amount of eggs each female mating after approximately 150 grains.In addition,there is a phenomenon that the female adults do not mate also can spawning,it is so-called invalid eggs,but can not normal incubation.The body color of female adults changed with the laying of eggs,and the body was plump and the color was white.Spawning early body relatively narrow,body color is yellowish-white.After the spawning,the body becomes dry,body color gradually becomes pale black,especially in the abdomen.In the course of mating,the male body is always on top of the female adult,and refuses to close to other male adults.With the increase of mating times,the action became slow,the frequency and brightness of the luminous gradually decrease and the flight capacity is gradually declining.In this study,the developmental duration and hatching rate of the eggs of P.analis were determined in the laboratory under the conditions of 19?22?25?28?31?,RH 75% and the photo period of 14 h: 10 h(light: dark).The developmental threshold temperature and effective accumulated temperature were calculated.The results were as follow.There was an inverse correlation between developmental duration and growth temperature,and there was a direction relationship between rate of development and growth temperature at 19?,22?,25? and 28?;The developmental threshold temperature of the eggs of P.analis was 13.52?,and effective accumulated temperature was 334.68 day-degree,At 31?,the developmental period of eggs did not decrease with the increase of temperature;The hatching rate did not increase with the increase of temperature;and there was not a direction relationship between rate of development and growth temperature.Under different temperature conditions to P.analis larvae body with,lenth and the age date of different age of instars statistics,By analysis of variance results indicate: Temperature of each of the body width,length and aging through period affect significantly,The body width,lenth,and age date are significant difference between different age of instars.3 Predatory functionP.analis larvae have a positive preference for Bradybaena ravida(Benson)and Agriolimax agrestis,and showed the more preference for B.ravida.In the range of22-31 ?,With the B.ravida were used as food,Temperature affects the weekly predation number of 3-5 inatars significantly,The weekly predation number significant different between 3-5 instars.