Author: (Lienig and Zeller, 1846)
Spotted shoot moth
Species Overview:
Adult: 15-19 mm wingspan; forewing ground colour silvery grey, strigulated with ferruginous-brown varying to dark chocolate-brown and with irregular and poorly-defined ferruginous-brown or ochreous-brown markings with an admixture of black. Hindwing fuscous.
Larva: head blackish brown or black; prothoracic plate blackish brown; abdomen reddish brown, strongly shagreened, spinules brown; anal plate brown. August to late April, overwintering in a hollowed-out bud. Feeding on Pinus sylvestris, usually in the young lateral shoots, hollowing out a shoot and causing slight resinous exudation. Abdominal legs without small sclerotized plate, with 15-23 crochets.
Pupa: head, thorax and wings dark brown, abdomen brown or reddish brown, paler ventrally. Anal segment with four hooked setae dorsally and four pairs of hooked setae ventrally; abdominal segments 2-8 without athwart excavation dorsally, frons with pointed process [ details pupa R. pinivorana; empty pupal case R. pinivorana ].
Taxonomic Description:
Male:
Rhyacionia pinivorana male
Rhyacionia pinivorana adults
External characters: 15-19 mm wingspan. Forewing with termen oblique; ground colour silvery grey, strigulated or weakly reticulate with ferruginous-brown varying to dark chocolate-brown, sometimes with a black admixture; markings ferruginous-brown or ochreous-brown with an admixture of black, irregular and poorly defined; basal and sub-basal fasciae moderately well developed, sub-basal fascia usually dilated medially; median fascia broad, indented on costa, constricted or interrupted below middle, obsolescent dorsally, usually confluent with a rather prominent, subquadrate or circular pre-tornal marking; subterminal fascia extending broadly from lower part of termen or tornus to costa before apex and narrowly along termen; cilia white suffused with grey, with a black sub-basal line. Hindwing fuscous; cilia grey, with a fuscous sub-basal line (Bradley et al., 1979).
male genitalia R. pinivorana
Genitalia: Uncus rudimentary; gnathos not developed. Socii rudimentary. Valva strong, with large basal excavation; cucullus with ventral lobe devoid of setose cover; sacculus terminates with acute process. Aedeagus with spinules on walls distally (3-6 disto-dorsal spinules and 1-2 disto-lateral dents).
Female:
External characters: Similar to male.
female genitalia R. pinivorana
Genitalia: Sterigma conical; posterior part of ductus bursae well sclerotized. Corpus bursae with two relatively large signa.
Variation:
The forewing markings are slightly variable.
Biology
Moths are on wing during May and early June. The biology is believed to be similar to Rhyacionia buoliana, although the adults emerge a month to six weeks earlier than this species and eight to ten weeks earlier than Rhyacionia pinicolana. The larva overwinters in a hollowed-out bud and is fully grown by the end of April. Since the buds at this stage have not flushed the species does not cause the 'posthorn' type of deformation. Pupation takes place in the larval habitation during May and June, the pupa then forces its way out of the bud and splits open to release the adult (Scott, 1972).
Host plants:
Pinus sylvestris.
Damage:
Larva attacks the leading shoot but the deformation is not of the 'posthorn' type.
Rhyacionia pinivorana is not an economically important species.
Distribution:
Northern and Central Europe to Eastern Russia, Korea and Japan.
Pheromone:
Pheromone unknown.
Parasitoids:
Macrocentrus marginator Nees (Braconidae)
Orgilus obscurator Nees (Braconidae)
Ephialtes ruficollis Grav. (Ichneumonidae)
Ephialtes sagax Htg. (Ichneumonidae)
Poemenia notana Hlmgr. (Ichneumonidae)
Campoplex difformis Gmel. (Ichneumonidae)
Campoplex ramidulus Brischke (Ichneumonidae)
Campoplex rufifemur Thoms. (Ichneumonidae)
Cremastus interruptotr Grav. (Ichneumonidae)
1. Rhyacionia piniana
Another species of Rhyacionia that is found on Scots Pine (Pinus sylvestris) is
Rhyacionia piniana
R. piniana male
Another species of Rhyacionia that is found on Scots Pine (Pinus sylvestris) is
Rhyacionia piniana. It occurs in Central Europe (from France to Austria, Hungary and Poland and in Western Russia).
Moths are significantly smaller then the other species of Rhyacionia (wingspan 9-11 mm). Larvae feed in buds.
male genitalia R. piniana
Male genitalia: socii curved outwards.
female genitalia R. piniana
Papillae analis broader; sterigma not conical.
2. Rhyacionia miniatana (Staudinger)
miniatana Staudinger, 1871 was synonymized with Rhyacionia pinivorana by Hannemann, 1962, but recalled from synonymy by Huemer, 1994).
Rhyacionia miniatana has distinctly reddish brown markings and the ground colour is white. The male genitalia differ in the number of disto-dorsal and disto-lateral spinules or dents on the aedeagus (1-2 disto-dorsal spinules and 0-1 disto-lateral dents in Rhyacionia miniatana, and 3-6 disto-dorsal spinules and 1-2 disto-lateral dents in Rhyacionia pinivorana). The species is at present only known from the South of France.
3. Rhyacionia maritimana Prösse
In Spain and Corsica, Rhyacionia maritimana occurs. It is common in the lowlands. Moths resemble those of Rhyacionia pinivorana.
male genitalia R. maritimana
Aedeagus broader than in R. pinivorana.
Ventral margin of valva before notch gradually rounded (protruding in R. pinivorana).
female genitalia R. maritimana
Sterigma broader than in R. pinivorana.