Author: (Meyrick, 1906)
Black cowpea moth
Cowpea seed moth
larva: pink pod borer
Species Overview:
Adult: 12-15 mm wingspan; general colouration of forewing dark fuscous; interspaces between costal strigulae whitish, giving rise to short oblique leaden-metallic streaks posteriorly, one of which reaches termen beneath apex; ocellus marginated laterally by leaden-metallic streaks, and containing three elongate black dots. Hindwing grey, paler on costal margin.
Egg: ovoid, 0.45 x 0.35 mm, roug- surfaced, translucent, whitish in colour when freshly laid; red dots, which later coalesce to form a red ring within the egg, soon appear but this ring disappears by the fourth day when the egg colour changes to light yellow.
Larva: (first to fourth instar) body light yellow; head black; thoracic and anal shield brown; pinacula light brown; thoracic legs brownish. The full-grown larva is whitish to deep-red with various integrating colours; the thoracic and anal shields are spotted (whitish where background colour is reddish and brownish where background colour is whitish); pinacula concolorous with body.
Pupa: brown to deep brown, about 7 mm long; last abdominal segment with cremaster, recurved hooks and seven anal setae.
Taxonomic Description:
Male:
Leguminivora ptychora adults
External characters: 12-15 mm wingspan; head and thorax fuscous sprinkled with whitish ochreous. Palpi whitish ochreous, slightly sprinkled with fuscous; abdomen grey, slightly sprinkled with black. Forewing elongate, not dilated, costa gently arced, apex obtuse, termen slightly sinuate beneath apex, hardly oblique, rounded beneath. General colouration of forewing dark fuscous, finely irrorated with ochreous-whitish except towards costa posteriorly; interspaces between costal strigulae whitish, giving rise to short oblique leaden-metallic streaks posteriorly, one of which reaches termen beneath apex; ocellus marginated laterally by leaden-metallic streaks, and containing three elongate black dots; cilia dark fuscous, irrorated with ochreous-whitish. Hindwing grey, paler on costal margin, with a very slender submedian tuft of long scales from base, followed by a few dark grey scales, dorsal area rather broadly strewn with blackish grey scales, dorsal edge and cilia recurved upwards to form a pocket; cilia light grey (Meyrick, 1906).
male gen. Leguminivora ptychora
Genitalia: Socii small. Valva very broad distally, ventral margin without proper notch. Aedeagus long, coiled, bulbous medially but tapering proximally and also distally before finally enlarging to a bluntly pointed end.
Female:
External characters: Forewing similar to male; hindwing without tuft of long scales and dorsal fold.
female genitalia L. ptychora
Genitalia: Ovipositor fairly long, papillae analis small. Sterigma weakly sclerotized; ostium with short sclerite; ductus bursae fairly long, with transverse ridges; corpus bursae with two well developed signa which are equal in shape and size; surface of corpus bursae not smooth.
Biology
The species is polyvoltine. There is no evidence of hibernation in Leguminivora ptychora.
Oviposition starts about 2 days after mating. Eggs are laid singly or in small clusters, usually between the sepals and the pod, the base of the pod at its attachment to the peduncle or the suture at the pod tip. They hatch after about 5 days. Larvae feed on mature and drying seeds, either boring into them or excavating the surface and they are usually confined to one pod throughout development. A characteristic dry frass is produced in infested pods, as well as silken webs which bind frass and damaged seeds together. The number of larvae per pod varies with pod size and host variety. Up to ten larvae are found inside one cowpea pod. The larva undergoes five larval instars and then spins a whitish cocoon to pupate in. Pupation occurs in soil or debris inside dry pods (Perrin and Ezeuh, 1978; Olaifa and Akingbohungbe, 1981).
Host plants:
Glycine spp. (soy bean), Arachis hypogaea (ground nut), Vigna unguiculata (cowpea), Vigna sesquipedalis (yard long bean), Vigna radiata (green gram), Vigna mungo (black gram), Vigna vexillata, Vigna lancifolia, Phaseolus lunatus (lima bean), Phaseolus vulgaris (french bean), Mucuna pruriens (velvet bean), Cajanus cajan (pigeon pea).
Damage:
In cowpea, larvae either bore into or mine the seed within the pod, thus producing an unsightly characteristic frass. Such damaged seeds are usually rejected on the market. In Southern Nigeria for instance, it is estimated that more than one quarter of the total annual cowpea production is lost to this species alone (record from 1965, cited by Olaifa and Akingbohungbe, 1981)
Distribution:
Tropical Africa; India
Pheromone:
Pheromone unknown.
Parasitoids:
Bracon ?hancocki (Braconidae)
Bracon sp. (Braconidae)
Apanteles sp. (Braconidae)
Braunsia sp. (Braconidae)
Opius sp. (Braconidae)
Phanerotoma sp. (Braconidae)