1 材料与方法
1.1 材料
1.2 方法
1.3 数据处理
2 结果与分析
2.1 桑螟天敌寄生蜂种类及其自然寄生率
2.2 桑螟优势天敌寄生蜂—桑螟绒茧蜂的田间自然寄生率
表1 桑螟绒茧蜂田间自然寄生率Tab. 1 Parasitic rate of A. heterusiae in the field |
| 地点 Place | 时间 Time | 调查数量(头) Number of surveys (individual) | 寄生数量(头) Parasitic number (individual) | 寄生率 Parasitic rate/% | 平均寄生率 Average parasitic rate/% |
|---|---|---|---|---|---|
| 临高 Lingao | 3月 | 42 | 9 | 21.43 | 38.33 |
| 4月 | 52 | 12 | 23.08 | ||
| 5月 | 77 | 24 | 31.17 | ||
| 6月 | 98 | 33 | 33.67 | ||
| 7月 | 125 | 41 | 32.80 | ||
| 8月 | 68 | 43 | 63.24 | ||
| 9月 | 160 | 92 | 57.50 | ||
| 10月 | 131 | 71 | 54.20 | ||
| 11月 | 179 | 50 | 27.93 | ||
| 琼中 Qiongzhong | 5月 | 109 | 15 | 13.76 | 43.19 |
| 8月 | 136 | 84 | 61.76 | ||
| 10月 | 124 | 67 | 54.03 | ||
| 儋州 Danzhou | 5月 | 39 | 15 | 38.46 | 46.07 |
| 8月 | 150 | 78 | 52.00 | ||
| 10月 | 67 | 32 | 47.76 | ||
| 海口 Haikou | 5月 | 64 | 8 | 12.50 | 36.51 |
| 8月 | 142 | 78 | 54.93 | ||
| 10月 | 76 | 32 | 42.11 | ||
| 昌江 Changjiang | 5月 | 195 | 17 | 8.72 | 28.52 |
| 8月 | 85 | 34 | 40.00 | ||
| 10月 | 57 | 21 | 36.84 | ||
| 合计 | 2186 | 828 | 39.34 | 38.53 |
2.3 桑螟绒茧蜂对桑螟的寄生特性
表2 桑螟绒茧蜂对桑螟幼虫龄期和密度的选择性Tab. 2 Parasitism selection of A. heterusiae on larvae ages and density of G. pyloalis |
| 桑螟幼虫龄期 Larval instar of G. pyloalis | 桑螟数量(头) Number of G. pyloalis (individual) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| 1龄1st instar | ― | Y2 | Y1 | Y1 | Y3 | Y2 | Y2 | Y2 | Y4 | Y1 |
| 2龄2nd instar | ― | ― | ― | Y1 | Y2 | Y3 | Y2 | Y4 | Y3 | ― |
| 3龄3rd instar | ― | ― | ― | ― | Y1 | Y1 | ― | Y1 | ― | Y1 |
| 4龄4th instar | ― | ― | ― | ― | ― | ― | ― | ― | ― | ― |
| 5龄5th instar | ― | ― | ― | ― | ― | ― | ― | ― | ― | ― |
表3 不同数量桑螟绒茧蜂对单头不同龄期桑螟幼虫的寄生观察Tab. 3 Parasitism of different number of A. heterusiae on a single larva of G. pyloalis at different ages |
| 桑螟幼虫龄期 Larval instar of G. pyloalis | 桑螟绒茧蜂数量(对) Number of A. heterusiae (pairs) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| 1龄1st instar | ― | ― | ― | Y | Y | ― | Y | Y | ― | ― |
| 2龄2nd instar | ― | ― | ― | ― | ― | ― | ― | Y | ― | ― |
| 3龄3rd instar | ― | ― | ― | ― | ― | ― | ― | ― | ― | ― |
| 4龄4th instar | ― | ― | ― | ― | ― | ― | ― | ― | ― | ― |
| 5龄5th instar | ― | ― | ― | ― | ― | ― | ― | ― | ― | ― |
Note: Y means that the larvae of G. pyloalis were being parasitized; ― means no parasitism was observed. | |
注:Y代表桑螟幼虫被寄生;―代表未观察到寄生。 |
2.4 桑螟绒茧蜂的孤雌生殖观察
表4 桑螟绒茧蜂孤雌生殖观察Tab. 4 Parthenogenetic of A. heterusiae |
| 桑螟幼虫编号 Larva No. of G. pyloalis | 桑螟绒茧蜂化蛹数(头) Number of cocoon of A. heterusiae (individual) | 桑螟绒茧蜂羽化数(头) Eclosion number of A. heterusiae (individual) | 桑螟绒茧蜂雄蜂数(头) Number of male A. heterusiae (individual) | 桑螟绒茧蜂雌蜂数(头) Number of female A. heterusiae (individual) |
|---|---|---|---|---|
| 1 | 7 | 6 | 6 | 0 |
| 2 | 5 | 4 | 4 | 0 |
| 3 | 9 | 8 | 8 | 0 |
| 4 | 8 | 6 | 6 | 0 |
| 5 | 9 | 7 | 7 | 0 |
| 6 | 7 | 5 | 5 | 0 |
| 7 | 7 | 7 | 7 | 0 |
| 8 | 6 | 5 | 5 | 0 |
| 9 | 9 | 7 | 7 | 0 |
| 10 | 5 | 4 | 4 | 0 |
