Author: (Meyrick, 1905)
Species Overview:
Adult: 12-14 mm wingspan; forewing olive-fuscous basally, more whitish tinged posteriorly, with scattered blackish-fuscous strigulae, a longitudinal patch of dark fuscous above middle of wing and a dark subbasal spot. Hindwing fuscous. 4th and 5th tergite with tufts of androconial scales.
Egg: elongate with rounded ends, about 0.5 x 0.25 mm; creamy white with a greenish tinge when fresh, becoming yellow as it develops, with small reddish patches, usually forming two interrupted reddish longitudinal markings.
Larva: about 1 mm long when newly-hatched; abdomen uniformly yellow, head black, prothoracic shield small, shining dark brown. The larva changes only slightly in colour as it grows; a full-grown larva is about 10 mm long, yellowish, with a few scattered hairs on each segment; head shiny yellow; prothoracic shield shiny, brownish yellow; legs yellow; spiracles rounded, rimmed with brown.
Pupa: about 6 mm long, yellow-brown, tapering posteriorly, but rather blunt at anal extremity; anal segment with six white cremastral setae.
Taxonomic Description:
Male:
Pammene critica adults
External characters: 12-14 mm wingspan; head and thorax grey, slightly ochreous-tinged, shoulders mixed with dark fuscous; abdomen grey. Forewing elongate, costa gently arced, apex obtuse, termen slightly sinuate, slightly oblique, rounded beneath. Forewing olive-fuscous basally, more whitish tinged posteriorly, with scattered blackish-fuscous strigulae; angulated outer margin of basal patch indicated by dark fuscous suffusion; median fascia suffused, dark fuscous, narrow on costa, broad and ill-defined in disc, obsolete towards dorsum; veins posteriorly lined with dark fuscous; a longitudinal patch of dark fuscous above middle of wing; a silvery metallic transverse mark before middle of termen, proceeded by four elongate black dots; apex blackish, edged beneath by curved whitish strigula. Cilia pale fuscous, more or less irrorated with whitish, towards apex mixed with dark fuscous. Hindwing fuscous; cilia whitish grey with grey sub-basal shade; dorsum with fringe of long blackish scales (Meyrick, 1905).
4th and 5th tergite with tufts of androconial scales.
male genitalia Pammene critica
Genitalia: Tegumen rounded apically; valva fairly slender, ventral margin with large notch; cucullus rounded apically. Aedeagus fairly broad.
Female:
External characters: Forewing colouration and markings similar to male.
female gen. Pammene critica
Genitalia: Papillae analis short; ductus bursae slender, fairly long; antrum a slender sclerotized band; no further sclerites present in ductus bursae. Corpus bursae with two signa which are unequal in size and shape: one smaller thorn-like signum; the other larger, curved.
Biology
On Cajanus indica, females deposit their eggs singly, or close to one another in a row, on any part of the food plant (upper or lower surface of leaves, petioles, stem), but a groove or depression is always preferred as a suitable place for oviposition. On Cajanus cajan, the female appears to prefer the lower surface of leaves. The egg-stage lasts about three days, the larva gnawing a hole at one end and bursting open the egg-shell longitudinally. Following description of larval habits concerns a record from Cajanus indica. The young larva moves to the tender top-leaves. When these leaves are still folded, the larva burrows into them and feeds from within. If the leaves are already unfolded, the larva begins to gnaw a midrib and the adjacent tissue on the upper surface of a leaf. Soon the larva hides itself under a very thin transparent, gummy layer, to which dust-like gnawed particles of the leaf remain attached, which stretches over the midrib and larva onto the two halves of the leaf. It works upwards until the two halves of the leaf become folded together. For its entire life, the larva remains hidden, whether feeding on leaves, flowers, or pods. As it grows it joins almost all the top-leaves of a shoot or adjacent shoots and binds them together in a crumpled mass, within which it feeds. These spun top-shoots are fairly conspicuous.
Hibernation takes place in the larval stage. Pupation occurs in a thin, papery, whitish, silken cocoon which usually lines a hollow space within a crumpled mass of spun leaves. It may also be found inside a flower-bud or within a few dried flower-petals rolled together or inside a pod when the larva has fed. In the latter case an exit hole is prepared for the moth, this hole being covered with silk and frass. The pupal period lasts four to six days.
In Madhya Pradesh, India, the pest is active from the third week of July to the last week of August, with a maximum larval population in the second week of August. According to Ghosh, 1981, larvae are most abundant in early September in West Bengal. According to Singh and Singh, 1978, this is the case in September-October in Delhi. Ghosh suspects that this is probably due to variation in time of sowing of the crop and difference in the prevailing climatic conditions.
(Perrin and Ezeuh, 1978; Lateef and Reed, 1990; Bainbrigge Fletcher, 1920; Khandwe et al., 1994; Ghosh, 1981; Singh and Singh, 1978).
Host plants:
Cajanus indica, Cajanus cajan, Crotalaria juncea.
Damage:
This species is a pest of pigeon pea or red gram (Cajanus cajan). Its incidence is evident by the damage symptoms of folding of apical leaves along with the growing apex. This pest is most abundant during the preflowering stage of the host (Ghosh, 1981).
Distribution:
India, Sri Lanka.
Pheromone:
Pheromone unknown.
Parasitoids:
Apanteles machaeralis (Hymenoptera)