Anarsia lineatella Zeller
Taxonomic placing: Insecta, Holometabola, Lepidoptera, Gelechiidae.
Common name: peach twig borer (PTB)
Geographical distribution: Europe, Mediterranean basin, North America, China, India, Iraq and Pakistan.
Host plants: Stone fruits, especially apricot, nectarine, peach and plum.
Morphology: The dark-gray body of the adult PTB is 7-8 mm long, hindwings red-brown. The larva is dark-red with black head and legs, length about 10 mm.
Life cycle: The pest usually has four annual generations, beginning in April-May. During summer activity continues till autumn, each female producing about 150 eggs. Larvae (caterpillars) of the overwintering generation initially enter the flowers and buds, and then the twigs, boring mines 3–8 cm long and killing the buds and twigs. When twig tissue hardens in summer the pest moves into fruits, their damage increasing later in the season. The overwintering second or third instar larvae hide in bark crevices, in silken chambers, excavated in the inner bark of branches or twigs. The development of a meridic diet diet for PTB is facilitating life-history studies of this pest.
Economic importance: PTB is a serious pest of stone fruits, peach and apricot fruits in particular. The first generation larvae damage the shoots and flowers, whereas larvae of later generations feed mostly on fruits. Both types of damage may result in considerable economic loss. In Turkey PTB damage rates on peach twigs came to 38%, and to nectarine and apricot twigs to 18-22% and 14-16%, respectively. Damage rates on fruits were 14-29, 6-8 and 5-6% in peach, nectarine and apricot, respectively, damage to peaches being the greatest. Late ripening fruit is the most heavily damaged. Young host plants in nurseries may suffer considerable injury because their development can be seriously retarded.
Management
Monitoring: Male captures by sex pheromone traps are widely used for determining the beginning of infestations. Another method consists of direct observations in the orchard: shoot weakening and dropping (“flagging”) and crop damage. In Turkey the economic injury level is 20 or more males/week, and/or 5 infested twigs/tree and/or 2% fruit damage.
Mating disruption: The placing of 750-800 pheromone dispensers in apricot orchards in southern Turkey provided effective PTB control. In Israel pheromone dispensers that were kept in orchards during spring and summer reduced PTB numbers better than those that were applied only during one of the two seasons.
Cultural control: The pruning of shoots with signs of pest entry (“strikes”) in late spring and early summer, as soon as they are detected, will remove the infesting larvae.
Chemical control: Various pyrethroids, spinosads and avemectin formulations are in use, and may be combined with mating disruption.
Biological control: The overwintering and first-generation PTB larvae are often attacked by natural enemies, mostly hymenopterous parasitoids, parasitization rates coming up to 30-50%. An application of entomopathogenic nematodes was tried in Florida; although the nematodes reduced the pest’s population, the economic impact remains unknown.
References
Agudelo-Silva, F., Zalom, F.G., Hom, A. and Hendricks, L. 1995. Dormant season application of Steinernema carpocapsae (Rhabditida: Steinernematidae) and Heterorhabditis sp. (Rhabditida: Heterorhabditidae) on almond for control of overwintering Amyelois transitella and Anarsia lineatella (Lepidoptera: Gelechiidae). Florida Entomologist 78: 516-523.
Damos, P. and Savopoulou-Soultani, M. 2008. About the presence and abundance of beneficials in overwintering sites of Anarsia lineatella (Lepidoptera: Gelechiidae) in peach orchards of northern Greece. IOBC/wprs Bulletin 35: 44-50.
Damos, P. and Savopoulou-Soultani, M. 2010. Population dynamics of Anarsia lineatella in relation to crop damage and development of economic injury levels. Journal of Applied Entomology 134: 105–115.
Kehat, M., Anshelevich, L., Dunkelblum, E. and Greenberg, S. 1994. Sex pheromone traps for monitoring the peach twig borer, Anarsia lineatella Zeller: effect of pheromone components, pheromone dose, field aging of dispenser, and type of trap on male captures. Phytoparasitica 22: 291-298.
Kyparissoudas, D.S. 1989. Simultaneous control of Cydia molesta and Anarsia lineatella in peach orchards of northern Greece by combining mating disruption and insecticide treatments. Entomologia Hellenica 7:13-16.
Mamay, M., Yanık, E. and Doğramacı, M. 2014. Phenology and damage of Anarsia lineatella Zell. (Lepidoptera: Gelechiidae) in peach, apricot and nectarine orchards under semi-arid conditions. Phytoparasitica 42: 641-649.
McElfresh, J.S. and Millar, J.G. 1993: Establishment and rearing of Anarsia lineatella (Lepidoptera: Gelechiidae) on a meridic diet. Journal of Economic Entomology 86: 1399-1404.
Öztürk, N., Hazır, A. and Ulusoy, M. R. 2010. Efficacy of mating disruption technique against peach twig borer, Anarsia lineatella Zeller, 1839 (Lepidoptera: Gelechiidae) which is harmful on apricot in Mut District, Mersin Province. Turkish Journal of Entomology 34: 337–350 (in Turkish with English summary).
Reuveny, H., Oppenheim, D. and Zada, A. 2010. The efficiency of mating disruption technique in controlling Anarsia lineatella. Alon Hanotea 64: 26-31 (in Hebrew with an English abstract).
Talhouk, A.S. 1977. Contribution to the knowledge of almond pests in East Mediterranean countries. V. The fruit-feeding insects, Eurytoma amygdali and Anarsia lineatella. Zeitschrift für Angewandte Entomologie 83: 145-154.