Identification of Thrips Species on Garlic Fields in Hamedan Province and Determination of Dominant Species

پژوهش های حفاظت گیاهان ایران

Article 1, Volume 30, Issue 2 - Serial Number 32, June 2016, Pages 209-218   

Document Type: Research Article

DOI: 10.22067/jpp.v30i2.41773

Author

Majid Mirab-balou^*

Ilam University

Abstract

Introduction: Garlic (Allium sativum) (family Amaryllidaceae) are one of important crops in Hamedan province. There are several insects and mites that by feeding on this plant cause to damage garlic yield. Among the insect pests, the most dangerous pests of garlic are thrips species (Insecta: Thysanoptera). In this group, onion thrips, Thrips tabaci Lindeman is widely distributed and is a dominant species. Its sap sucking causes tiny and silvery spots on the leaves that may spread all over the leaf surface with an unfavorable effect on yield production. In addition, imagoes and larvae living and feeding on this plant cause more serious damages. Due to serious damage of thrips in garlic fields of Hamedan province, it is necessary to identify thripsspecies for pest control programs.
Materials and Methods: Thrips specimens were collected on leaves of garlic in Hamedan province (Maryanaj and Heydareh) situated in the west of Iran, during 2012–2013. Herein, specimens were collected by shaking plants to white dish and specimens were kept in 70 % ethanol and transferred to the laboratory. All collected material was macerated in 5% KOH and subjected to dehydration in an ethanol series before being mounted onto glass slides. Subsequently, thrips specimens mounted onto slides in Hoyer’s medium form of the protocol given in Mirab-balou and Chen (2010). All descriptions, measurements and photos were made with a Leica DM IRB microscope, with a Leica Image 1000 system. Thrips specimens were identified by author in species level. Specimens are deposited in the collection of Department of Plant Protection, College of Agriculture, Ilam University, Iran (ILAMU). In addition, dominant thrips species were also determined. For this purpose, regular samplings were done in fields of two regions of Hamedan province every two weeks, and totally, 2040 specimens (adult) were collected.
Results and Discussion: The world fauna of Thysanoptera, are presently known to be consisted of about 6000 species placed in two suborders and nine families. A large number of thrips species are considered pests, because they feed on economical crops. In this study, a total of eight species in seven genera and three families were collected and identified, including Aeolothrips intermedius Bagnall and Rhipidothrips gratiosus Uzel from family Aeolothripidae, Aptinothrips rufus (Haliday), Frankliniella intonsa (Trybom), Scolothrips longicornis Priesner, Thrips alliorum (Priesner) and Thrips tabaci Lindeman from family Thripidae, and Haplothrips reuteri (Karny) from family Phlaeothripidae. All of the species existed in two years in both two regions. Thrips tabaci was the dominant species (64.89%) in garlic fields. Among the predatory thrips, Aeolothrips intermedius and Scolothrips longicornis were present in greater numbers. However, their number was not enough to reduce the number of phytophagous thrips. The predatory species feeds mainly on the larvae and imagoes of onion thrips but they feed on mites as well. An identification key for thrips species associated with garlic is also given.
Conclusion: In this study, eight species of thrips were collected on garlic fields of Hamedan province which Thrips tabaci was dominant species (64.89%); and three of which were identified as predatory species. Up to the present, several thrips were collected and recorded from Hamedan province by the author, but there is no study on thrips associated to garlic; therefore, this study was firstly carried out in Hamedan province. There are several insect pests on garlic, and T. tabaci was also reported as important pest on garlic fileds in this province. Onion thrips, T. tabaci is one of the important pests in the world, and it has more than 300 host plants. At present, it is widely distributed in Iran and is a key insect pest in most onion and cotton cultivation areas as well as ornamental plants. In addition, thrips species in the genera Thrips and Frankliniella spread plant diseases through the transmission of viruses, such as Tospoviruses, Tomato Spotted Wilt Virus, and the Impatiens Necrotic Spot Viruses; So, it is necessary to pay more attention to the management of T. tabaci . In garlic crops of Hamedan province, T. tabaci was established on the plant from earlier time to near harvest; and because of high damaging, the farmers used several insecticides within one year.

Keywords

Dominant species; Garlic pests; Hamedan; Iran; Phytophagous; Thrips

References

1- Bhatti J.S. 1989. The classification of Thysanoptera into families. Zoology (Journal of Pure and Applied Zoology), 2: 1–23.

2- Capinera J.L. 2001. Hand book of vegetable pest. 1st. ed. Academic Press, 729 pp.

3- Lewis T. 1997. Pest thrips in perspective. In: Thrips as crop pests, (Ed. Lewis, T.) 1–13. CAB International, UK.

4- Hosseinynia A., and Malkeshi H. 2004. Comparison of chemical, biological, and integrated methods for control of Thrips tabaci L. on carnation under greenhouse conditions. Proceeding of the 16th Iranian Plant Protection Congress, Tabriz, Iran, P. 300. [in Persian with English abstract]

5- Khanjani M., and Mirab-balou M. 2005. Study on phytophagous agents of garlic in Hamedan. Medical Plant Congress, Mashhad, Iran, pp. 243–244. [in Persian with English abstract]

6- Mirab-balou M., and Chen X.X. 2010. A new method for preparing and mounting thrips for microscopic examination. Journal of Environmental Entomology, 32(1): 115–121.

7- Mirab-balou M. 2011. A systematic study of Thysanoptera in Iran (Hexapoda: Insecta). Ph.D. thesis, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China, 643 pages.

8- Mirab-balou M. 2013. A checklist of Iranian thrips (Insecta: Thysanoptera). Far Eastern Entomologist 267: 1–27.

9- Mirab-balou M., and Chen X.X. 2012. Iranian thrips of family Aeolothripidae (Thysanoptera: Terebrantia), with four newly recorded species. Vestnik Zoologii, 46(6): 499–507.

10- Mirab-balou M., Tang P., and Chen X.X. 2011. The grass-living genus Aptinothrips Haliday, 1836 (Thysanoptera: Thripidae) from China. Far Eastern Entomologist, 232: 1–10.

11- Mirab-balou M., Minaei K., and Chen X.X. 2013a. An illustrated key to the genera of Thripinae (Thysanoptera, Thripidae) from Iran. Zookeys, 317: 27–52.

12- Mirab-balou M., Tong X.L., and Chen X.X. 2013b. A checklist of Thysanoptera (Insecta) in Hamedan province, Iran. Natura Montenegrina, 12(1): 71–95.

13- Mirab-balou M., Tong X.L., and Chen X.X. 2012a. A new record and new species of the genus Thrips (Thysanoptera: Thripidae), with a key to species from Iran. Journal of Insect Science, 12(90): 1–15.

14- Mirab-balou M., Tong X.L., and Chen X.X. 2012b. Iranian Haplothrips with forewings sub-basal setae arranged in a triangle (Tubulifera: Phlaeothripidae). Persian Gulf Crop Protection, 1(2): 15–21.

15- Mound L.A., and Marullo R. 1996. The Thrips of central and south America: An introduction (Insecta: Thysanoptera). Memoirs on Entomology, International, Vol. 6: 487 pages.

16- Nakahara S. 1991. Systematics of Thysanoptera, pear thrips and other economic species. Pp. 41-59. In: Parker, B.L., Skinner M., and Lewis, T. (Eds). 1991. Towards Understanding Thysanoptera. Proceedings International Conference on Thrips, 1989, Burlington, Vermont USA, 464 pages.

17- Palmer J.M., Mound L.A., and Heaumane G.J. 1992. Guides to insects of importance to man. Thysanoptera. CAB International Institute of Entomology and British Museum (Natural History), London.

18- Reyes C.P. 1994. Thysanoptera (Hexapoda) of the Philippine Islands. Raffles Bulletin of Zoology, 42: 107–507.

19- Sanchez J.A., Alkazar A., Lacasa A., Llamas and Bielzap A. 2000. Integrated pest management in sweet pepper plastichouses in the southeast of Spain.- IOBC/WPRS Bulletin. 23, 21-30.

20- Ulman D.E., Sherwood J.L., and German T.L. 1997. Thrips as vectors of plant pathogens. In: Thrips as crop pests (Ed. Lewis, T.) 539-565. CAB International, Wallingford.

21- Zargari A. 1997. Medicinal plants, volume 3. Tehran University Publications, 925 pages.