- 期刊
非洲菊斑潛蠅繁殖時同齡幼蟲與成蟲在菜豆本葉上之種內競爭
Intraspecific Competition among Same-aged Larvae and Adults of Liriomyza trifolii (Diptera: Agromyzidae) in Field Bean Primary Leaves: Effects on Colony Production
摘要
非洲菊斑潛蠅［Liriomyza trifolii（Burgess）］（Diptera：Agromyzidae）為世界性重要之園藝與蔬菜作物害蟲，進行該蠅生物防治與藥劑防治研究之前，必先建立其適當繁殖方法。本文利用菜豆（Phaseolus vulgaris var. communis Aeschers）苗飼育非洲菊斑潛蠅，希冀瞭解在菜豆苗本葉（primary leaf）不同葉寬下，該蠅同齡幼蟲與成蠅各在不同密度繁殖時之種內競爭，以提供該蠅及其寄生蜂較優之繁殖方法。試驗方法為在25℃下，以三種葉寬等級之菜豆苗本葉（小型葉寬6.0－7.0cm、中型葉寬7.1－8.0cm及大型葉寬8.1－9.0cm）、17種斑潛蠅幼蟲密度（每葉第三齡幼蟲數11－95隻範圍內，自11隻起每增加5隻幼蟲即區分為一個等級，共分17個等級，另每葉1－10隻第三齡幼蟲者為0級對照組）及5種斑潛蠅成蠅密度（依成蠅10、20、30、40及60對與20株菜豆苗之比例分為5個密度：0.5、1.0、1.5、2.0及3.0對／株）進行試驗。結果得知菜豆苗本葉葉寬與幼蟲密度，除均對幼蟲存活率與蛹長等級（I－V級蛹長各為1.85－2.11、1.67－1.82、1.49－1.63、1.31－1.45及1.05－1.27mm）有直接影響，且第三齡幼蟲間之競爭屬利用型競爭（exploitation-type competition）外；二者亦可經由蛹長等級間接影響羽化率、成蠅體長、雌性比、壽命、生育力（fertility）及取食刻點數。成蠅密度則顯著影響雌蠅之壽命與生育力。因而建議當繁殖非洲菊斑潛蠅時，在25℃下，首日以30株無真葉（mature leaf）豆苗（發根後10－11d，本葉寬7.1－9.0cm），供80隻第2日齡已交尾雌蠅產卵7h，次日後每日需另補充20隻已交尾第2日齡雌蠅，以維持該蠅繁殖時定量之總雌蠅數。經6d後，可選擇每豆苗本葉上第三齡幼蟲密度為15－20隻者，供非洲菊斑潛蠅繼代繁殖；20－30隻者，則供該蠅幼蟲寄生蜂異角釉小蜂［Hemiptarsenus varicornis（Girault）］與華釉小蜂［Neochrysocharis formosa（Westwood）］之繁殖。
並列摘要
The agromyzid leafminer, Liriomyza trifolii (Burgess), is a major pest of vegetables and ornamentals throughout the world. For its biological and chemical control studies, the suitable rearing methods of this leafminer must be established. This study investigated the intraspecific competition among same-aged larvae and adults in three width grades of field bean primary leaves (Phaseolus vulgaris var. communis Aeschers) for providing better production methods of this leafminer and its parasitoids. The experiments were conducted at 25℃ under three grades of primary leaf width, i.e., the small, middle, and large leaf width was 6.0-7.0, 7.1-8.0, and 8.1-9.0 cm, respectively. In 17 larval densities, 11-95 third-instar larvae were divided into 17 grades at intervals of 5 larvae, the control treatment being 0 grade including 1-10 larvae, while, in 5 adult densities, numbers of pairs of adults in proportion to numbers of seedlings conducted in laboratory were 10:20, 20:20, 30:20, 40:20, and 60:20, respectively. The results showed that the larval survival and pupal length grades of L. trifolii were directly affected by grades of primary leaf width and leafminer larval density, the pupal length of I, II, III, IV, and V grades being 1.85-2.11, 1.67-1.82, 1.49-1.63, 1.31-1.45, and 1.05-1.27 mm, respectively. Exploitative competition occurred among third-instar larvae. The emergence of pupa, size of adult, female proportion, longevity, fertility and number of feeding stipples were all indirectly affected by grades of primary leaf width and leafminer larval density through leafminer pupal length. The longevity and fertility of this female leafminer were also affected by the adult density. This study indicates that the suitable rearing methods of Liriomyza trifolii are as follows: 30 seedlings without mature leaves of field bean in which 10- and 11-d-old, primary leaf width was 7.1-9.0 cm are placed in a screen cage (75 by 55 by 50 cm, 92 meshes) containing 80 2-d-old and mated females that are allowed to oviposit for 7 h at 25℃, but another 20 females are added daily to maintain the uniform number of females. After 6 days, when eggs develop to third-instar larvae, 15-20 larvae/leaf are suggested to provide for the successive production of this leafminer, and 20-30 larvae/leaf are for its larval parasitoids, Hemiptarsenus varicornis (Girault) and Neochrysocharis formosa (Westwood), respectively.