Retinia

Abstract: The Nantucket pine tip moth, Rhyacionia frustrana (Comstock), is one of the most common forest insects in the eastern United States. It was first discovered and studied on Nantucket Island, Massachusetts,63 where it was causing severe damage to pines and was described as the “frustrating Retinia” (= Rhyacionia).23 The taxonomic status of R. frustrana is generally clear except for its relationship with R. bushnelli Miller, thought by some to be a subspecies.59 The primary difference is that R. frustrana overwinters in infested shoots and R. bushnelli overwinters in the duff and soil beneath the trees.

Abstract: The aim of this paper is to present the non-target species caught in the traps baited with synthetic pheromones of the species Cydia pomonella, Grapholita funebrana, Grapholita molesta, Archips podana, Adoxophyes orana, Tortrix viridana and Gravitarmata margarotana, in the frame of some experiments conducted during the years 1989-1990 in order to identify sexual attractants for the main conophagous Lepidoptera in Romania. At the same time we assessed the selectivity of these products and identified the compounds which could be used as sexual attractants for different tortricid species. Deploying pheromone traps in coniferous mature tree stands or seed orchards having in their neighbourhood fruit trees or deciduous forests, only 5 reference species and 30 non-target species have been caught , 23 of them being tortricid moths. The selectivity (specificity) of the used synthetic pheromones was rather low. However, this should not be a problem in the current works accomplished with atraPOM, atraPOD, atraRET and atraVIR products, because the species attracted are quite easily distinguished using morphological characteristics. On the other hand, the people using atraFUN and atraMOL pheromones could have insurmountable difficulties to establish the abundance of target species and other aspects, because these pheromones attract moths of G. funebrana, G. molesta and Grapholita tenebrosana which have a very similar appearance. Consequently, the possibilities of pheromone specificity improvement are analyzed. The mixture of Z9-12Ac + E11-14Ac + Z11-14Ac + n-12Ac + n-14Ac (5:2:3:3:1) attracted the species Cnephasia alticolana, Pammene suspectana, Retinia perangustana, Retinia resinella and Enarmonia formosana, while Z8-12Ac + E8-12Ac + 12OH (0.970:0.030:3 and 0.930:0.070:3 respectively) attracted moths belonging to R. perangustana, Hedya dimidiana, Grapholita tenebrosana and Epiblema scutulana. The males of Eucosma campoliliana and Hedya salicella responded to E8,E10- 12OH and those of C. alticolana responded also to the blends Z11-14Ac + E11-14Ac (1:1) and Z9-14Ac + Z11-14Ac (6:4), but Cnephasia stephensiana was attracted by Z11-14Ac, like Dichelia histrionana. However, the last mentioned species is stronger attracted by the mixture of Z11-14Ac + Z9-12Ac (relative ratio 4:6).

Abstract: Pine stands younger than 15 years were examined for infestations by tip moths in three localities in southern and western Bohemia (360–510 m a.s.l.) in April-June 1985–1988. Rhyacionia buoliana (Den. et Schiff.) was predominant in south Bohemia, near Kolný and Třeboň, Blastesthia spp. [especially B. posticana (Zett.)] in west Bohemia, near Plzeň. Insolated aftergrowth proved to be a reservoir of R. buoliana (53.1% dominance), aftergrowth shaded by old trees was the reservoir of Retinia resinella (L.) (46.1% dominance). Blastesthia spp. were found in plantations as well as in naturally seeded stands, especially insolated ones. Their dominance (25.7%) was highest along the southern edges of plantations. Zusammenfassung Untersuchungen zur Verteilung der durch Rhyacionia, Blastesthia und Retinia (Lep., Tortricidae) verursachten Schaden in Abhangigkeit von der Lage der gepflanzten oder naturlich verjungten Kiefernbestande An drei Standorten in Sud- und Westbohmen (Kolný, 510 m, Třeboň-Vranin, 450 m, und Plzeň-Bolevec, 360 m) wurden von 1985 bis 1988 in den Monaten April bis Juni Kiefernbestande bis zum Alter von 15 Jahren auf Wicklerbefall untersucht. In Sudbohmen, in der Umgebung von Kolný, trat uberwiegend Rhyacionia buoliana (Den. & Schiff.) mit 4,4 Beschadigungen pro 100 Baumen auf. Auch in der Umgebung von Třeboň uberwog R. buoliana (3,8 Beschadigungen pro 100 Baume). In Westbohmen, in der Nahe von Plzeň dominierte die Gattung Blastesthia mit 3,9 Beschadigungen pro 100 Baume, davon 3,3 von B. posticana (Zett.) verursacht und 0,6 von B. turionella (L.). Besonnte Kiefernnaturverjungungen erwiesen sich als ein Reservoir fur R. buoliana; ihre Dominanz betragt hier 53,1%. Von Uberhaltern beschattete Kiefernnaturverjungungen werden von Retinia resinella (L.) bevorzugt (Dominanz 46,1%). Blastesthia spp. konnte sowohl auf Aufforstungsflachen wie in Naturverjungungen festgestellt werden, insbesondere, wenn diese Flachen besonnt waren. Diese Art erreicht mit 25,7% an den sudexponierten Randern der Aufforstungsflachen ihre hochste Dichte.