Accurate identification of Spodoptera frugiperda (Smith)

doi:10.7679/j.issn.2095-1353.2020.090

Abstract

Abstract:

[Objectives] To describe morphological characteristics that can be used to accurately identify the moth Spodoptera frugiperda, an invasive pest that has recently become established in China. [Methods] Stable, diagnostic, morphological characteristics of male and female moths, including male genitalia and female bursa copulatrix are described. [Results] Body size and other 20 morphological characteristics are too variable among individuals to be used to accurately identify S. frugiperda. In addition to 4 forewing characteristics, including black spots on the base of the forewing, 6 other morphological features, such as black scale bands on the labial palp, are found to be sufficiently invariant among individuals to serve as diagnostic features. An oblique orbicular spot in the middle of the forewing, and other 3 morphological characteristics are confined to males and females. The uniform color of humeral plates and 4 other features are confined to males, whereas the characteristic “same color of the inner part to the forewings” is confined to females. Four and two newly identified external morphological features accurately distinguish S. frugiperda from S. litura and S. exigua moths, respectively. Newly identified 6 diagnostic features of male S. frugiperda genitalia include juxta longer than wide, whereas newly identified 4 features of females bursa copulatrix include the base of the ductus bursae being obviously wider than the end. Three features of the male genitalia, and 3 of the female bursa copulatrix, accurately distinguish S. frugiperda from male S. litura and female S. exigua, respectively. [Conclusion] The results of this study not only provide morphological characteristics of the forewing but also additional morphological characteristics of other body part that allow the accurate identification of male S. frugiperda. Forewing features that allow the accurate identification of females are also provided for the first time. In addition, our results provide a useful reference on the genitalia of noctuids, including some newly described features of the male genitalia and female bursa copulatrix.

Key words: Spodoptera frugiperda, morphological characteristics, individual differences, male genitalia, bursa copulatrix

Bo FENG, Qian-Shuang GUO, Hao-Jie WANG, Lie-Ming PAN, Yong-Jun DU. Accurate identification of Spodoptera frugiperda (Smith)[J]. Chinese Journal of Applied Entomology, 2020, 57(4): 877-888.

Figures/Tables 6

References 16

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编号Number	形态特征 Morphological characters	变异类型 Variation of morphological characters
1	成虫体长Moth length	15-20 mm
2	前翅颜色Forewing color	灰色到深褐色、灰绿色 Gray to dark brown or grayish green
3	雄蛾领片颜色 Color of collar plates in male moth	均一的灰白色、灰黄色、灰褐色或者前部黑色、后部灰色Uniform grayish white, grayish yellow or grayish brown or front black and back gray
4	雄蛾肩板颜色 Color of shoulder plates in male moth	灰白色、灰黄色、灰褐色 Grayish white, grayish yellow or grayish brown
5	雄蛾前翅前缘5个浅色斑颜色 Color of 5 light spots on the front edge of male moth’s forewings	白色、灰色、灰黄色 White, gray or grayish yellow
6	雄蛾前翅中线内侧黑斑 Black spot before the midline of the male moth’s forewings	有或无With or without
7	雄蛾前翅前缘第1白斑 The first light spot on the front edge of male moth's forewings	大且长、可向臀角方向延伸至翅中部,也可以不长 Big and long, extending to middle part of wing toward to anal angle or not long
8	雄蛾前翅环形斑颜色 Color of orbicular spot of male moth’s forewings	灰褐色、红褐色、橙黄色、灰黄色 Taupe, reddish brown, orange or grayish yellow
9	雄蛾前翅环形斑内侧的暗色斜斑 The dark stripe before the orbicular spot of male moth’s forewings	长或短 Long or short
10	雄蛾前翅倒Y型白色剑形纹 The white inverted Y spot of male moth’s forewings	长或短 Long or short
11	雄蛾前翅肾形斑内测浅色斑颜色 The color of light spot before the reniform spot of male moth’s forewings	白色、灰色、灰黄色 White, gray or grayish yellow
12	雄蛾前翅顶角白斑 The white spot at the forewing apex of male moth	大小、形状和长短在不同个体间差异较大 The size, shape and length different among different individuals
编号Number	形态特征 Morphological characters	变异类型 Variation of morphological characters
13	雄蛾前翅亚缘线内侧深色斑 Dark spots on the inner side of submarginal line of male moth’s forewings	大小、颜色和形状在不同个体间差异较大 The size, shape and length different among different individuals
14	雄蛾前翅中线 Midline of male moth’s forewings	灰白色至灰褐色或无 Grayish white to grayish brown or inapparent
15	雄蛾前翅外线 Outer line of male moth’s forewings	白色、黑色、黑白双色或无 White, black, black and white or inapparent
16	雄蛾前翅基部小黑斑 Black spots on the base of male moth’s forewings	多个或无 Several or none
17	雄蛾前翅缘线和亚缘线间的黑斑形状 Shape of black spots between the marginal line and the submarginal line of male moth’s forewings	沙漏状、近方形、三角形等 Hourglass, subsquare, triangle, etc
18	雌蛾前翅的肾形斑 The reniform spot of male moth’s forewings	明显或不明显 Apparent or inapparent
19	雌蛾前翅的云状纹 Cloud pattern of the female moth’s forewings	明显或不明显 Apparent or inapparent
20	前足第2跗节背面颜色 Color of the dorsal part of the second tarsal segment of the foreleg	黑色或灰白色 Black or grayish white
21	中足第1跗节背面基部颜色 Color of the dorsal base of the first tarsal segment of the midleg	黑色或灰白色 Black or grayish white

编号Number	形态特征 Morphological characters	变异类型 Variation of morphological characters
1	成虫体长Moth length	15-20 mm
2	前翅颜色Forewing color	灰色到深褐色、灰绿色 Gray to dark brown or grayish green
3	雄蛾领片颜色 Color of collar plates in male moth	均一的灰白色、灰黄色、灰褐色或者前部黑色、后部灰色Uniform grayish white, grayish yellow or grayish brown or front black and back gray
4	雄蛾肩板颜色 Color of shoulder plates in male moth	灰白色、灰黄色、灰褐色 Grayish white, grayish yellow or grayish brown
5	雄蛾前翅前缘5个浅色斑颜色 Color of 5 light spots on the front edge of male moth’s forewings	白色、灰色、灰黄色 White, gray or grayish yellow
6	雄蛾前翅中线内侧黑斑 Black spot before the midline of the male moth’s forewings	有或无With or without
7	雄蛾前翅前缘第1白斑 The first light spot on the front edge of male moth's forewings	大且长、可向臀角方向延伸至翅中部,也可以不长 Big and long, extending to middle part of wing toward to anal angle or not long
8	雄蛾前翅环形斑颜色 Color of orbicular spot of male moth’s forewings	灰褐色、红褐色、橙黄色、灰黄色 Taupe, reddish brown, orange or grayish yellow
9	雄蛾前翅环形斑内侧的暗色斜斑 The dark stripe before the orbicular spot of male moth’s forewings	长或短 Long or short
10	雄蛾前翅倒Y型白色剑形纹 The white inverted Y spot of male moth’s forewings	长或短 Long or short
11	雄蛾前翅肾形斑内测浅色斑颜色 The color of light spot before the reniform spot of male moth’s forewings	白色、灰色、灰黄色 White, gray or grayish yellow
12	雄蛾前翅顶角白斑 The white spot at the forewing apex of male moth	大小、形状和长短在不同个体间差异较大 The size, shape and length different among different individuals
编号Number	形态特征 Morphological characters	变异类型 Variation of morphological characters
13	雄蛾前翅亚缘线内侧深色斑 Dark spots on the inner side of submarginal line of male moth’s forewings	大小、颜色和形状在不同个体间差异较大 The size, shape and length different among different individuals
14	雄蛾前翅中线 Midline of male moth’s forewings	灰白色至灰褐色或无 Grayish white to grayish brown or inapparent
15	雄蛾前翅外线 Outer line of male moth’s forewings	白色、黑色、黑白双色或无 White, black, black and white or inapparent
16	雄蛾前翅基部小黑斑 Black spots on the base of male moth’s forewings	多个或无 Several or none
17	雄蛾前翅缘线和亚缘线间的黑斑形状 Shape of black spots between the marginal line and the submarginal line of male moth’s forewings	沙漏状、近方形、三角形等 Hourglass, subsquare, triangle, etc
18	雌蛾前翅的肾形斑 The reniform spot of male moth’s forewings	明显或不明显 Apparent or inapparent
19	雌蛾前翅的云状纹 Cloud pattern of the female moth’s forewings	明显或不明显 Apparent or inapparent
20	前足第2跗节背面颜色 Color of the dorsal part of the second tarsal segment of the foreleg	黑色或灰白色 Black or grayish white
21	中足第1跗节背面基部颜色 Color of the dorsal base of the first tarsal segment of the midleg	黑色或灰白色 Black or grayish white