Author: (Heinemann, 1863)
Pine twig moth
Species Overview:
Adult: 14-18 mm wingspan; forewing ground colour silver-grey, with irregular reddish-brown markings, edged black basally and edged whitish terminally. Apical spot reddish brown edged with white. Hindwing brownish grey.
Larva: 11 mm long, cylindrical, hardly flattened; head and prothoracic plate brownish-black; abdomen brownish red, with short whitish-grey setae [Gravitarmata margarotana larva].
Pupa: Patocka, 1998, describes pupae that he suspects to be of Gravitarmata margarotana: 8.0-8.5 x 2.6-2.9 mm, shining reddish brown, exuvie paler. 10th abdominal segment broad, with many spines and 4 pairs of hooked setae.
Taxonomic Description:
Male:
Gravitarmata margarotana adult
G. margarotana adult
External characters: 14-18 mm wingspan; forewing ground colour silver-grey; markings reddish-brown, irregular, partly edged with black, edged whitish terminally. Basal fascia, subbasal fascia and median fascia narrow, the latter bifurcate at costa; pretornal marking sub-triangular; apical spot reddish brown edged with white. Hindwing brownish grey; cilia paler (Kennel, 1908-1921).
male genitalia G. margarotana
Genitalia: Uncus short, longitudinally divided into two rounded or oval lobes. Gnathos absent. Socii broad, highly sclerotized. Valva without clasper, with very deep notch in ventral margin, and with triangular cucullus.
Female:
External characters: similar to male.
female genitalia G. margarotana
Genitalia: Sterigma short, subdivided. A sclerotic collar-like structure situated in the membrane beyond eighth tergite. Ductus bursae short; cingulum large; corpus bursae with two signa that are clearly of different shape and size.
Biology:
In Europe, moths fly in April and May and larvae occur from the end of May till June. According to Razowski, 1989, the larvae hibernate; according to Kuznetsov, 1987, Escherich, 1931, and Kuan-sheng et al., 1974, diapausing pupae overwinter.
In China (Shensi province), the species has also one generation yearly, moths flying from mid April until May, being most abundant in late April and early May. The larvae attack host plants from early May to early June, being most serious in the middle part of May. In Korea the emergence period is from mid April to late May, and peaks in late April.
Host plants:
Pinus, Abies, Picea.
Damage:
Gravitarmata margarotana is a pest of pine. Larvae feed not only on shoots but also on cones and cause severe damage in spring.
Distribution:
Europe: from England to Austria and Poland; Baltic Region to Russia, China, Korea and Japan.
Pheromone:
12Ac : 3 *
E 9-12Ac : 1 *
Z 9-12Ac : 5 *
14 Ac : 1
E 11-14Ac : 2
Z 11-14Ac : 3
E 9-12OH : 1
14 OH : 0.2
E 11-14OH : 0.6
Z 11-14OH : 0.4
Components marked with * are involved in attraction (Löfstedt, 1986).
Parasitoids:
Dolophron nishiguchii Momoi (Ichneumonidae)