The almond bark beetle, Scolytus amygdali Geurin-Meneville, is responsible for significant loss of fruit production in almond orchards throughout the world. Here, we studied the damage and the incidences of S. amygdali attack on two different scales: (1) at the level of a single tree; and (2) in an entire orchard. Our results revealed no differences in attack level among four orientations (east, west, south and north sides) for the whole tree. However, the bark that was facing west side in the direction of the prevailing wind was found to be the most suitable for females to initiate attack in Stratum S2. Attack distribution remains the same among different strata (strata is vertical divisions of the tree from the ground to the uppermost twigs with ~40 cm intervals). More than 50% of attack was observed in the trunk of the tree and upper strata. However, multiplication rate (number of emerged adults/maternal gallery) varies significantly between strata. In addition, we studied attack intensity (holes produced by beetle per tree) comparing it to tree morphology (flowers, leaves and circumferences) and gum deposit. Our results revealed a positive correlation between attack intensity and gum deposits, and a negative correlation between attack intensity and tree morphology. This revealed that gum on the tree was an indicator for attack intensity. A positive correlation between attack intensity and the circumference of the tree revealed that older trees were more susceptible to S. amygdali attack. These results, while preliminary, aim to help in the monitoring of S. amygdali populations before deciding to apply any control measures.

A new libelluloid family from the Eocene Green River Formation (Colorado, USA) (Odonata, Anisoptera)

Scolytus amygdali is a polyphagous insect pest that feeds on fruit trees and forest trees. Our study assessed the host preference and reproductive potential of S. amygdali on four tree species: almond (Prunus dulcis), apricot (Prunus armeniaca), peach (Prunus persica), and plum (Prunus domestica). Females of S. amygdali produced maternal galleries that were longer on peach than the other three trees, and female fecundity was highest on peach. Females with longer maternal galleries produced more eggs, indicating a positive correlation between maternal gallery length and female fertility. The under-bark development time of S. amygdali is significantly shorter on plum (45 days) and almond (56 days) than on apricot (65 days) and peach (64 days). Despite this longer development time on peach, our results still suggest that, of the four types of tree tested, peach is the most preferred host for S. amygdali.

Investigations on gallery patterns of the Almond bark bettle (Scolytus amygdali Guerin-Méneville, 1847) (Coleoptera, Curculionidae) in Tunisia Abstract: The Almond bark beetle Scolytus amygdali Guerin-Meneville, 1847 is a serious beetle that can affect important economic crops in Tunisia. The species is morphologically similar to other bark beetles attacking fruit trees such as Scolytus mediterraneus. The gallery systems of both species are also generally hard to differentiate. A detailed study about gallery systems has carried out in the central region of Tunisia in order to give more details on beetle damage under the bark. Maternal and larval galleries from infested branches of almond were examined and measured. It is hoped that these details of the shape and measurements of the gallery systems of Scolytus amygdali will facilitate the identification of infestations of almond bark beetles attacking fruit trees in Tunisia. Keywords: Gallery systems, Scolytus amygdali, Tunisia Tunus’ta Badem yazıcı böceği (Scolytus amygdali Guerin- Méneville, 1847) (Coleoptera, Curculionidae)'nin galerileri üzerine araştırmalar Özet: Scolytus amygdali Guerin- Méneville, 1847, Tunus'da önemli ekonomik bitkilere zarar yapan bir kabuk böceğidir. Tür; Scolytus mediterraneus gibi meyve ağaçları üzerinde zarar yapan diğer kabuk böceklerine morfolojik olarak benzemektedir. Türlerin ağaçlar üzerinde meydana getirdikleri larva yollarını birbirlerinden ayırt etmek de oldukça güçtür. Bu detaylı çalışma kabuk altındaki böcek hasarı ve galeri sistemleri hakkında daha fazla ayrıntı vermek amacıyla Tunus merkez bölgesinde gerçekleştirmiştir. Zarar görmüş Badem dallarındaki ana ve larva yenik yolları incelenmiş ve ölçülmüştür. Scolytus amygdali galeri sistemlerindeki ölçümler ve yenik şekillerinin ayrıntıları; Tunus'ta meyve ağaçlarına saldıran kabuk böceklerinin teşhisini kolaylaştıracağı umulmaktadır. Anahtar Kelimeler: Galeri sistemleri, Scolytus amygdali, Tunus Received: 01 March 2015 - Revised: 10 March 2015 - Accepted: 10 March 2015 To cite this article: Zeiri, A., Ayberk, H., Braham, M., Braham, M., 2016. Investigations on gallery patterns of the Almond bark bettle (Scolytus amygdali Guerin-Méneville, 1847) (Coleoptera, Curculionidae) in Tunisia. Journal of the Faculty of Forestry Istanbul University 66(1): xx-xx. DOI: 10.17099/jffiu.67352