Spodoptera pecten Guenée 1852

Spodoptera pecten Guenee
Diagnosis. — Similar to S. mauritia but is slightly smaller (Sevastopulo 1941).
Color description. — Head olive brown; adfrontal and coronal sutures whitish; frons honey colored. Prothoracic shield with middorsal and dorsolateral stripes pale. Ground color pale brownish gray or greenish gray. Middorsal stripe pale. Segmental spots black, lunule-shaped. Dorsolateral stripe pale. Lateral stripe purple. Spiracular stripe pale. Spiracles black. Venter greenish gray. Thoracic legs pale brown. Prolegs greenish gray (Sevastopulo 1941).
Plant hosts. — S. pecten is a pest of corn in Malaysia (Yunas & Hua 1980) and of rice in Malaysia (Dammerman 1929), India (Chatterjee 1969), and China (Wu 1982). Hosts are not restricted to grasses, since the species has been reared from Brassicaceae (radishes), Euphorbiaceae (Aleurites montana Wilson), Fabaceae (Derris elliptica Benth.), and Malvaceae (Hibiscus rosa-sinensis L.) (Yunas & Hua 1980). Ten different host plants have been recorded.

Spodoptera pecten Guenee
Figs. 104, 194-203, 311, 341, 373, 405, 437, 525
Spodoptera pecten Guenee, in Boisduval & Guenee 1852a: 155; Walker 1856: 186; Hampson 1909: 252; Warren in Seitz 1914b: 320; Holloway 1976: 12; Holloway 1989: 134; Poole 1989: 925; Kononenko et al. 1998: 234.
Agrotis infixa Walker 1862a: 186. New synonym.
Spodoptera infixa; Poole 1989: 924.
Spodoptera insulsa Walker 1865a: 648; Poole 1989: 924.
New synonym. Spodoptera erica Butler 1880b: 675. Spaelotis unifortnis Swinhoe 1890: 226. Caradrina pectinata Hampson 1894: 264. Elydna speciosa Rothschild 1920: 117 [synonymized by
Poole 1989: 925].
Diagnosis. — Sexually dimorphic, male darker than female and with a more distinct wing pattern than in female. Male with antenna bipectinate (Fig. 19). Forewing ground color browner than in S. cilium. Male genitalia with ampulla moderately broad, curved distally with a pointed apex (Figs. 311, 341). Female genitalia with distal margin of ventral plate of ostium bursa straight Description. Adult Male. — Head: Basal segment of labial palpus black with longer ventral scales cream; median segment black, variably mixed with brown and cream, apex cream (lightly speckled with brown); apical segment black, apex cream. Frons with short scales cream to brown; long scales cream to light brown; lateral spots at eye margin absent; vertex cream to pale rufous. Antenna bipectinate; scape cream to light brown; flagellum cream annulated brown, becoming completely cream toward apex.
Thorax: Patagium cream to brown, or grayish brown mixed with fuscous and fuscous median band. Mesothorax cream to light brown, or gray mixed with fuscous scales. Underside of thorax white. Prothoracic femur fuscous and cream; tibia with lateral scale tufts not extending beyond first tarsal segment, cream and fuscous, subapical spot black; tarsal segments fuscous, proximal and apical ring cream on segment 1, apical rings on segments 2 and 5 cream, no apical rings on segments 3 and 4. Mesothoracic femur cream and rufous; tibia cream and rufous, inner spur more than twice length of outer spur, mediolateral surface thinly devoid of scales on both spurs; tarsal segments fuscous with cream apical rings. Metathoracic femur cream and rufous; tibia cream and rufous; tarsal segments cream, segments 2-5 pale fuscous at base.
Forewing: Length, 12-14 mm; ground color light brown to brown; basal line black (indistinct); R vein not contrasting in color; basal scale patch between R and Cu veins absent; basal half circle scale patch below Cu vein absent; antemedial line
black; claviform spot absent; basal scale patch absent; gray patch covering anal cell and half of cell CuA2 absent; oblique brown mark from fifth outer marginal spot to vein CuA2 absent; curved white line from antemedial line to postmedial line absent; orbicular spot oval, indistinct, cream, outlined in brown (can be absent); reniform spot round, black; white scales along Cu vein and bases of M3 and CuAl veins absent; postmedial line brown, indistinct, outlined in white in posterior third; postmedian band undifferentiated (a few specimens can have an indistinct round spot along subterminal line); black scale patches in middle of cells M2 to CuAl, indistinct, with or without faint patches in Ml in postmedian area; subterminal line white, indistinct; apex lacking a white patch; black trapezoidal-shaped spots along outer margin; fringe gray. Underside ground color light brown to brown; outer margin with black spots; reniform spot darker, indistinct.
Hindwing: Ground color white; apex, outer margin to vein CuA2, and distal ends of veins Rs to CuA2 with light brown scales; fringe light brown to pale gray at apex and median line, becoming white toward anal veins. Underside ground color white; costal cells C and Sc cream, speckled with pale gray scales; outer margin with a few faint gray spots in middle of cells Sc to CuAl; no spot on underside.
Abdomen: Dorsum cream to pale gray; venter cream; disto-lateral black spots on sternites (indistinct); 8th tergite with spiculate patches absent on caudal margin.
Genitalia: Uncus curved in basal half; maintaining width throughout three-fourths length, narrowing to pointed apex; setae numerous. Scaphium elongate, weakly developed. Tegumen lacking a pair of projecting arms on upper third. Costa bent in basal fifth (Figs. 311, 341). Costal process a minute knob; in middle of costa; perpendicular to costa of valve. Cucullus apex round; produced. Anellifer with lightly sclerotized plate bearing setae absent. Ampulla elongate, slightly curved with a pointed produced apex; extending moderately below apex of valve
sent. Sacculus broadest at base, gradually tapering distally; apex truncate. Valvula narrower than valve; slightly differentiated from valve, apex not separate; apex pointed; indentation pronounced, ventral margin well sclerotized. Coremata re
duced, closely appressed to sacculus; no distinct lobes. Juxta a rectangular band, median process elongate, expanding into an apical plate, ventral margin straight to convex. Anellus membranous. Vinculum U-shaped with a narrow base. Aedoeagus straight; coecum equal in diameter to shaft; patch of spines absent on apex of membranous sheath surrounding aedoeagus. Vesica curving ventrally; short, less than 0.75 length of aedoeagus; apicobasal cornutal patch a narrow ribbon; length moderate, not quite extending to middle of vesica; cornuti in form of minute flat granules; lateral cornutal patch a narrow elongate ribbon; large spines; dense cornutal patch on apical diverticulum; distal cornutus absent.
Adult Female. — Essentially as described for male except:
Thorax: Prothoracic femur cream and fuscous; tibia with lateral scale tufts not extending beyond first tarsal segment, light brown and rufous, subapical spot fuscous; tarsal segments fuscous, proximal and apical ring cream on segment 1, apical rings on segments 2 and 5 cream, no apical rings on segments 3 and 4. Mesothoracic femur cream; tibia cream; inner spur more than twice length of outer spur, spurs completely scaled; tarsal segments cream. Metathoracic femur cream and rufous; tibia cream and rufous; tarsal segments cream, segments 2-5 pale fuscous at base.
Forewing: Length, 11-14 mm. Basal line absent; antemedial line absent; black scale patches in middle of cells in postmedian area absent; minute black spots along outer margin; fringe light brown.
Abdomen: Disto-lateral black spots on sternites absent. Fine dense scales on 8th segment whitish.
Genitalia: Ventral plate of ostium bursa with height greater than width; distal margin straight; ventrolateral invaginated pocket of 8th sternite absent. Ductus bursae elongate (length greater than 3 times width); completely sclerotized. Appendix bursae partially sclerotized. Corpus bursae bulbous, length less than twice width; a few striae. Signum in apical half of corpus bursae; elongate, length greater than 1.15 mm; forming less than a 30 degree angle to vertical axis of corpus bursae.
Larva. — See description, p. 104.
Type material. — Spodoptera pecten Guenee. The holotype 8 [BMNH] is labeled: Java 8 E.I.C.;
Noctuidae genitalia slide No. 3810 8. Type locality: Java, Indonesia.
Agrotis infixa Walker. The type(s) are deposited in the University Museum, Oxford University. Type locality: Borneo, Sarawak, Indonesia.
Spodoptera insulsa Walker. The holotype 9 [BMNH] is labeled: [No locality label on specimen]; Holotype; Spodoptera insidsa 1954/432; Noctuidae genitalia slide No. 3813 9 . Type locality: Java, Indonesia.
Spodoptera erica Butler. The lectotype 9 [BMNH, here designated] is labeled: Formosa, Talkow, H. E. Hobson, 80-115; Noctuidae genitalia slide 3812 9. The lectotype is designated to ensure nomenclatural stability in this confusing group of species and is illustrated in Fig. 198. Type locality: Taiwan. The following syntypes become paralectotypes: (1), 9, Label data: Formosa [Taiwan], Talkow, H. E. Hobson, 80-115. (2), 8, Label data: Formosa [Taiwan], Talkow, H. E. Hobson, 80-115.
Spaelotis uniformis Swinhoe. The lectotype 9 [BMNH] is labeled: Burma, Bhamo, X. 82, 91-55; Noctuidae genitalia slide No. 3472 9 . Type locality: Bhamo, Burma. Swinhoe (1890: 226) described uniformis from one specimen of unknown sex, from Bhamo, Burma. Hampson (1909: 253 listed "18 type uniformis" from his list of specimens from Burma. This can be inferred as a lectotype designation and this specimen is the one mentioned above and is illustrated in Fig. 203.
Caradrina pectinata Hampson. The holotype 8 [BMNH] is labeled: Naga Hills, 1500 ft., Sept.-Oct. 1889, W. Doherty; Caradrina, pectinata, Hmpson. holotype 6; 1954/479; Noctuidae genitalia slide No. 3471 8 . Type locality: Naga hills, India.
Eh/dna speciosa Rothschild. The lectotype 9 [BMNH, here designated] is labeled: Pasir Ganting, W. Sum. lat. 2° S, June 1914, (Robinson & Kloss); Rothschild, Bequest, B.M. 1939-1; Elydna, speciosa, Rothsch. Type; Rothschild, Bequest, B.M. 1939-1; Noctuidae genitalia slide No. 3873 9 . The lectotype is designated to ensure nomenclatural stability in this confusing group of species and is illustrated in Fig. 202. The following syntype becomes a paralectotype: 9, Label data: Pasir Ganting, W. Sum.[atra] lat. 2° S, June 1914, (Robinson & Kloss); Rothschild, Bequest, B.M. 1939-1.
Material examined. — Specimens were examined from the following countries: Burma, China, India, Indonesia, Japan, Malaysia, Nepal, Papua
New Guinea, Philippines, Singapore, Sri Lanka, Taiwan, Thailand, Vietnam.
Distribution (Fig. 525). — This species is distributed in eastern and southeastern Asia from Nepal to Sri Lanka and east to Vietnam, Malaysia, China, Japan, and Taiwan. In the Indo-Pacific area it is found in Indonesia and the Philippines.

Spodoptera pecten is a moth of the family Noctuidae found from the Indo-Australian tropics to New Guinea. It has also been recorded from Japan and Hawaii.

The larvae feed on various grasses, but have also been recorded feeding on the seeds of Shorea curtisii.

The fully grown larva is brownish or greenish grey with paler dorsal and subdorsal stripes, the latter edged above with black lunules. There is a pale spiracular stripe edged above by purple.

Pupation takes place in the soil in a slight earthen cocoon.