Exp Appl Acarol (2007) 41:251–254 DOI 10.1007/s10493-007-9063-4 SHORT COMMUNICATION
Attack by Pyemotes johnmoseri (Acari: Pyemotidae) on Hypoborus ficus (Coleoptera: Scolytidae) in fig trees in Turkey Tu¨lin Aks¸ it Æ Ibrahim C ¸ akmak Æ John Moser
Received: 4 May 2005 / Accepted: 21 February 2007 / Published online: 22 March 2007 Ó Springer Science+Business Media B.V. 2007
Introduction The Aegean Region of Turkey is one of the largest dried fig producers in the world. A Turkish cultivar sarilop (Ficus carica cv. Calimyrna L.) possesses good qualities for drying process, and has been grown extensively for many years in Turkey. Hypoborus ficus is the most common xylophagous insect attacking fig trees in Aydin (Aks¸ it et al. 2003). This pest attacks weakened trees, accelerates withering, and can cause death of branches and trees if present in high numbers. Infestations occur throughout the entire year. H. ficus is widespread in the Mediterranean region (Talhouk 1969) and was first documented by Iyriboz (1940) at Izmir in the Aegean region of Turkey. Pyemotes johnmoseri was first noted as a parasitoid of H. ficus in the Ukraine (Khaustov 1998). Populations of this mite were first found at Aydin, Turkey in 2003 and 2004 (C¸akmak et al. 2006). P. johnmoseri belongs to the scolyti group of Pyemotes, and is most closely related to Pyemotes scolyti (Oudemans), an external parasitoid of Scolytus spp. Only the female is parasitoid, and the attack by a single female is sufficient to kill a host. Some pyemotid species, e.g. Pyemotes tritici (Lagre´ze-Fossat and Montagne´), have shown potential as biological control agents for a variety of insects (Bruce and Wrensch 1990). Although bites of P. tritici are toxic to man, those of the scolyti group are not (Moser 1975). This study evaluates the infestation of P. johnmoseri on H. ficus and population fluctuations in a fig orchard in Turkey between 2003 and 2004.
T. Aks¸ it I. C¸akmak (&) Department of Plant Protection, Faculty of Agriculture, University of Adnan Menderes, Aydin 09100, Turkey e-mail:
[email protected] J. Moser USDA Forest Service, Southern Research Station, 2500 Shreveport Hwy, Pineville, LA 71360, USA
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Materials and methods This study was conducted in a 20-year old fig orchard (sarilop) at 30 km from Aydin in Incirliova district (Isafakilar, altitude 600 m, 378580 22@ N, 278410 50@ E). Weakened (i.e. leafless and fruitless, but the tissue is alive) and dead shoots infested with H. ficus were selected from each one of four trees in the fig orchard. Weakened and dead shoots (length 30–40 cm, diameter 1–1.5 cm) were cut and placed in plastic bags, and taken to the laboratory in an ice-chest. After removal of the cortex H. ficus larvae, either infected or uninfected with P. johnmoseri, and P. johnmoseri adults and juveniles were counted under a stereo-binocular microscope (magnification 20x) in a 10-cm piece of shoot. Samples were taken from the fig orchard once or twice per month between November and February, and three or four times per month between March and October. In total 10 of the 40 trees in the fig orchard were sampled. Results Population fluctuations of Hypoborus ficus and Pyemotes johnmoseri In 2003 the number of H. ficus larvae in weakened shoots reached a maximum in February (316 individuals/10 cm) (Fig. 1). Most H. ficus larvae on dead shoots were observed at the 350
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Fig. 1 The population density of Hypoborus ficus in weakened shoots
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Number s of Hy pobor us ficus infected with Py emotes johnmos er i / 10 c m s hoot
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end of March (39 individuals/10 cm) (Fig. 2). The parasitoidation rate by P. johnmoseri on fig bark beetles in weakened and dead shoots was 1.8%, and 5.8%, respectively. Infested beetle larvae were seen throughout the year (Figs. 1 and 2). Pyemotes johnmoseri infestation rate on weakened shoots was highest in June (14 individuals/10 cm) and on dead shoots in October (8 individuals/10 cm). In 2004, most larvae of H. ficus were found in June in weakened (231 individuals/ 10 cm) and dead shoots (114 individuals/10 cm) (Figs. 1 and 2). The parasitoidation rate by P. johnmoseri was 9.0% in weakened shoots, and 9.3% in dead shoots. P. johnmoseri infestation rate was highest in July on weakened shoots (37 individuals/10 cm) and in August on dead shoots (9 individuals/10 cm).
The infestation rate of Pyemotes johnmoseri on Hypoborus ficus Based on the two years, a total of 933 females of P. johnmoseri were counted on H. ficus. The rate of H. ficus larva infestation with one, two, three or four mites was 87.7%, 10.5%, 1.4% and 2.1%, respectively. Of all P. johnmoseri infesting H. ficus stages, 90.5% were found on larvae, 3.7% on pupae, 5.5% on eggs and 0.4% on teneral adults. The mean number of swollen females found feeding on a larva or pupa of the host insect was 1 (max. 4). Swollen females produced on average 14 (4–52) offspring (n = 52). 140
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Number s of Hy pobor us ficus infec ted with Pyemotes johnmos er i / 10 c m s hoot
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Fig. 2 The population density of Hypoborus ficus in dead shoots
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Discussion The highest population levels of H. ficus in both weakened and dead shoots were found between January and June. Bernabo (1993) also assessed that H. ficus was dominant in spring in Italy. H. ficus density was clearly higher in weakened than in dead shoots. Pyemotes johnmoseri was abundant and widespread in the H. ficus galleries in Aydin province. Numbers were higher in 2004 than in 2003, and mites were present in every month of the year. Mite infestation rates were highest from July to December, when host numbers were lower. This study showed that P. johnmoseri usually fed on larvae (90.5%), and occasionally on eggs or pupae of H. ficus. We also observed a physogastric female on a teneral adult of H. ficus in its pupal chamber. We have never observed phoretic females of this mite on flying adults of fig bark beetles (n = 100). Cross and Moser (1975) reported that Pyemotes spp. belonging to the scolyti group fed only on bark beetle brood or immature stages of other beetles; none fed on adults. The potential of P. johnmoseri to reduce populations of H. ficus should be tested in further studies. References ¨ zsemerci F, C Aks¸ it T, O ¸ akmak I (2003) Studies on determination of harmful fauna in the fig orchards in Aydin province (Turkey). Turk Entomol Derg 27:181–189 (Turkish, with English summary) Bernabo E (1993) Brief notes on the biology of Liparthrum mori (Aube) and on the xylophagous celoeopterous fauna of fig (Col.). Mem Soc Entomol Ital 71:543–549 Bruce WA, Wrensch DL (1990) Reproductive potential, sex ratio and mating efficiency of the straw itch mite (Acari: Pyemotidae). J Econ Entomol 83:384–391 _ Aks¸ it T, C¸obanog˘lu S (2006) Pyemotes johnmoseri (Khaustov) (Acari: Pyemotidae) as a paraC ¸ akmak I, sitoid of xylophagous insects from Aydin, Turkey. J Entomol 3:34–39 Cross EA, Moser JC (1975) A new, dimorphic species of Pyemotes and a key to previously-described forms (Acarina: Tarsonemoidea). Ann Entomol Soc Am 68:723–732 _ Iyriboz N (1940) Incir Hastalıkları. Ziraat Vekaleti Nes¸ riyatı Umumi Sayı: 489, Mahsul Hastalıkları Sayı: 4, _ Ku¨ltu¨r Basımevi, Izmir, p 85 Khaustov AA (1998) Mites of the genus Pyemotes (Acariformes, Pyemotidae) associated with bark beetles (Coleoptera: Scolytidae) in the Crimea. Zool Zhurn 77:1419–1424 (Russian, with English summary) Moser JC (1975) Biosystematics of the straw itch mite with special reference to nomenclature and dermatology. Trans R Entomol Soc Lond 127:185–191 Talhouk, AMS (1969) Insects and mites injurious to crops in Middle Eastern Countries. Monographien zur angew. Entomologie Nr. 21, p 239
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