蒼蠅的幼蟲

或(huo)稱蠅(ying)(ying)蛆，呈(cheng)錐形，前端尖，后端鈍圓，有明(ming)顯的(de)(de)體(ti)節，通常為(wei)(wei)(wei)11節。 1 齡(ling)(ling)到(dao)(dao)(dao)3齡(ling)(ling)幼(you)(you)(you)蟲(chong)(chong)(chong)的(de)(de)體(ti)色逐漸由透明(ming)、乳白色變(bian)為(wei)(wei)(wei)乳黃色。幼(you)(you)(you)蟲(chong)(chong)(chong)從卵脫殼(ke)后，在(zai)(zai)(zai)飼(si)養缸(gang)里生(sheng)長(chang)發育，經(jing)過兩(liang)次蛻皮(pi)到(dao)(dao)(dao)老熟幼(you)(you)(you)蟲(chong)(chong)(chong)需4－6天 。當(dang)溫度(du)為(wei)(wei)(wei)30℃ 時，l 齡(ling)(ling)幼(you)(you)(you)蟲(chong)(chong)(chong)的(de)(de)生(sheng)長(chang)發育大約需 20 小時， 2 齡(ling)(ling)幼(you)(you)(you)蟲(chong)(chong)(chong)約為(wei)(wei)(wei) 24 小時，3齡(ling)(ling)幼(you)(you)(you)蟲(chong)(chong)(chong)約需 3 日(ri)。剛孵(fu)化(hua)出來(lai)(lai)的(de)(de)幼(you)(you)(you)蟲(chong)(chong)(chong)，體(ti)長(chang)為(wei)(wei)(wei) 1 一(yi) 3 毫米左右(you)，在(zai)(zai)(zai)飼(si)料(liao)充(chong)足情況下(xia)，最大可(ke)長(chang)到(dao)(dao)(dao) 1 . 5 厘米長(chang)。家(jia)(jia)蠅(ying)(ying)幼(you)(you)(you)蟲(chong)(chong)(chong)是(shi)多(duo)食性(xing)的(de)(de)，許多(duo)發酵(jiao)和腐(fu)敗的(de)(de)有機物質都可(ke)以成為(wei)(wei)(wei)它的(de)(de)食物，例如(ru)人(ren)畜禽(qin)糞便、垃圾、酒渣(zha)、豆渣(zha)等(deng)。幼(you)(you)(you)蟲(chong)(chong)(chong)非常活躍，喜歡鉆來(lai)(lai)鉆去，但其活動范圍一(yi)般不(bu)離開其原產卵場所，有較(jiao)強的(de)(de)負(fu)趨(qu)光性(xing)，一(yi)般群集(ji)潛伏在(zai)(zai)(zai)飼(si)料(liao)食物表層下(xia)2 一(yi) 10 厘米左右(you)處攝食。家(jia)(jia)蠅(ying)(ying)成蟲(chong)(chong)(chong)個體(ti)的(de)(de)大小取決于幼(you)(you)(you)蟲(chong)(chong)(chong)期(qi)營養條件的(de)(de)好壞；此外，家(jia)(jia)蠅(ying)(ying)幼(you)(you)(you)蟲(chong)(chong)(chong)期(qi)的(de)(de)長(chang)短(duan)除與溫度(du)、營養密切相關外，濕度(du)也起(qi)著重要作用。幼(you)(you)(you)蟲(chong)(chong)(chong)喜歡潮(chao)濕，在(zai)(zai)(zai)濕度(du)為(wei)(wei)(wei) 60 ％-80％物質中，有各齡(ling)(ling)期(qi)的(de)(de)家(jia)(jia)蠅(ying)(ying)幼(you)(you)(you)蟲(chong)(chong)(chong)，但在(zai)(zai)(zai)半液(ye)體(ti)狀的(de)(de)人(ren)、畜類便中，或(huo)含有很多(duo)液(ye)體(ti)的(de)(de)污水坑中，則(ze)看不(bu)到(dao)(dao)(dao)家(jia)(jia)蠅(ying)(ying)的(de)(de)幼(you)(you)(you)蟲(chong)(chong)(chong)。家(jia)(jia)蠅(ying)(ying)幼(you)(you)(you)蟲(chong)(chong)(chong)怕(pa)光，一(yi)般鉆在(zai)(zai)(zai)飼(si)料(liao)中，直到(dao)(dao)(dao)化(hua)蛹前才爬到(dao)(dao)(dao)表層。

蛹

幼(you)(you)蟲(chong)老熟后(hou)(hou)爬到較干操的(de)環(huan)境中(zhong)前(qian)后(hou)(hou)收縮(suo)變成蛹(yong)(yong)(yong)。化(hua)(hua)蛹(yong)(yong)(yong)場所一般為(wei)(wei)幼(you)(you)蟲(chong)孳生場所附(fu)近(jin)的(de)泥土中(zhong)，如果糞(fen)便表層(ceng)干燥(zao)，也可(ke)于(yu)其上化(hua)(hua)蛹(yong)(yong)(yong)。幼(you)(you)蟲(chong)快化(hua)(hua)蛹(yong)(yong)(yong)前(qian) 1 一 2 天，活(huo)動量、取食(shi)量和體(ti)內(nei)積(ji)存物都迅速地(di)減少，軀體(ti)顏色(se)逐漸由(you)灰白色(se)變為(wei)(wei)米黃色(se)的(de)半透(tou)明(ming)體(ti)，越接近(jin)化(hua)(hua)蛹(yong)(yong)(yong)期(qi)，身(shen)體(ti)透(tou)明(ming)度越高。蛹(yong)(yong)(yong)的(de)生活(huo)條(tiao)件與幼(you)(you)蟲(chong)相比需要較低的(de)溫(wen)(wen)(wen)度和較干燥(zao)的(de)環(huan)境，家蠅蛹(yong)(yong)(yong)發育期(qi)的(de)時(shi)間與幼(you)(you)蟲(chong)相仿。高溫(wen)(wen)(wen)高濕(shi)(shi)對蛹(yong)(yong)(yong)是不利(li)的(de)，溫(wen)(wen)(wen)度高于(yu) 40 ℃ 時(shi)大(da)部(bu)分(fen)死(si)亡，由(you) 41 ℃ 開始，溫(wen)(wen)(wen)度每增加 1℃ , 蛹(yong)(yong)(yong)的(de)死(si)亡率增加 1 倍， 45 ℃ 時(shi)蛹(yong)(yong)(yong)全(quan)部(bu)死(si)亡。蛹(yong)(yong)(yong)比幼(you)(you)蟲(chong)能耐受較低的(de)溫(wen)(wen)(wen)度，溫(wen)(wen)(wen)度在(zai)(zai) 12 ℃ 以下時(shi)，蛹(yong)(yong)(yong)停止發育。濕(shi)(shi)度過(guo)大(da)時(shi)，也會影響到蠅蛹(yong)(yong)(yong)的(de)發育，若相對濕(shi)(shi)度低于(yu) 75 % ，有部(bu)分(fen)蛹(yong)(yong)(yong)會干死(si)，濕(shi)(shi)度低于(yu) 40 ％蠅蛹(yong)(yong)(yong)很(hen)少能存活(huo)。蠅蛹(yong)(yong)(yong)在(zai)(zai)發育過(guo)程中(zhong)，外殼由(you)軟變硬(ying)，體(ti)色(se)變化(hua)(hua)為(wei)(wei)乳白色(se)→米黃色(se)→淺棕(zong)(zong)色(se)→深棕(zong)(zong)色(se)→褐色(se)，溫(wen)(wen)(wen)濕(shi)(shi)度適宜(yi)時(shi)即可(ke)羽化(hua)(hua)出成蟲(chong)。