Academic Journal of Entomology 5 (3): 164-168, 2012 ISSN 1995-8994 IDOSI Publications, 2012 DOI: 10.5829/idosi.aje.2012.5.3.308 First Record in Egypt of two Thrips Species Infesting Cucumber Crop A.S. Abd EL-Wahab, S. Salah, S. Elnagar and M.A.K. El-Sheikh Department of Economic Entomology and Pesticides, Unit of Insect Virology, Faculty of Agriculture, Cairo University, Giza, Egypt Abstract: Field survey was made in four successive cucumber plantations (sown in mid April and mid August, 2010/2011) in Giza, Egypt. Direct inspection of weekly leaf samples revealed that two thrips species Chirothrips texanus Andre and Thrips palmi Karny were detected for the first time in Egypt, in addition to Thrips tabaci Lindeman and Frankliniella occidentalis (Pergande). The highest number of thrips species was recorded in August plantations for Thrips tabaci (923 individuals/25 leaves) followed by Ch. texanus (679 individuals/25 leaves). F. occidentalis recorded the lowest number (368 individuals/25 leaves). The present finding updates the list of thrips species in Egypt. Key words: Chirothrips texanus Cucumber Thrips Thrips palmi INTRODUCTION dusting them on a white paper sheet. Thrips were collected, categorized, counted and kept in 70% ethanol Cucurbitaceae and especially cucumber are important until examination by stereo-microscopy [5]. The vegetable crops in Egypt. Approximately 180.000 feddans specimens were prepared by temporarily mounting in (one feddan=042 ha) are cultivated with cucumber every Hoyer's medium [6]. Illustrations were made by projecting year [1]. It is common practice to cultivate cucumber in the specimens under a microscope at magnifications of successive plantations for local consumption as well as 10, 40, 100 times. Morphological identification of the adult export. All plantations are infested with piercing sucking thrips was carried out with Morphological key (Thrips ID) insects such as aphids and thrips. These insects may based on the Lucid professional software [7], as well as cause serious damage to host plants either directly by the key to the thrips on seedling cotton in the feeding on sap or indirectly through transmitting the Midsouthern United [8]. causative agents of virus diseases especially thripstransmitted viruses [2]. Worldwide, out of 5500 thrips RESULTS species, only one percent is described and about ten species have been confirmed as vectors of plant viruses Fig. 1a & b shows the seasonal abundance of the [3]. Thirps are known as efficient vectors of surveyed thrips species during 2010/2011 cucumber Tospoviruses, a few species known in Egypt like plantations. The sampling revealed the occurrence of 4 Thrips tabaci Lindeman and Frankliniella occidentalis thrips species, namely; T. tabaci, F. occidentalis, T. palmi (Pergande) [4]. The present investigation reports a new and Ch. texanus. The following are the morphological record in Egypt of two thrips species on cucurbits. description upon which the newly recorded thrips, T. palmi [7] and Ch. texanus [8] are identified. MATERIALS AND METHODS Thrips Palmi: is almost entirely yellow in color (Fig. 2), Thrips specimens were collected at random in the has a clear yellow body with no dark areas on the head, Giza region from cucumber plants during two plantations antenna always seven-segmented, segments I, II pale and sown in mid April and mid August, 2011. Samples were III yellow with apex shaded (Fig. 3), postocular setae II made weekly by collecting 25 leaves (5 leaves/plant) and and IV much smaller than remaining setae, ocellar setae III Corresponding Author: Abeer S. Abd EL-Wahab, Department of Economic Entomology and Pesticides, Unit of Insect Virology, Faculty of Agriculture, Cairo University, Giza, Egypt, P.O. Box: 12613. 164
Fig. 1: Seasonal abundance of different four thrips species occurred on cucumber plants during April and August plantations (2010/2011, Giza region, Egypt) standing either just outside of the ocellar triangle (Fig. 4), side distally (Fig. 8), in the thorax pronotum trapezoidal IV to VII brown but usually with base of IV V yellow; (Fig. 9), forelegs massive (Fig. 10), Forewing without veins forewings uniformly slightly shaded, prominent setae dark or any seta, the abdominal tergite IX, two pairs of (Fig. 5), thorax or abdomen (slightly thickened blackish campaniform sensilla (Fig. 11). body setae); Forewing first vein with three (occasionally two) distal setae. Abdominal tergites III to IV with setae, Seasonal Abundance of Thrips in Two Seasons abdominal tergite VIII with complete posteromarginal The field survey revealed that comb, long and fine, abdominal tergite IX usually with two T. Tabaci: Occurred on cucumber in April plantations and pairs of pores (campaniform sensilla) (Fig. 6). increased gradually to reach its maximum in the end of May (138 and 101 individual/25 leaves, for both seasons Chirothrips Texanus: The body is almost dark brown in coloration, head and pronotum with numerous short spines, only the posteroangular setae long (but difficult to see) (Fig. 7), second antennal segment extruded to one respectively). In August plantations, of both seasons, T. tabaci recorded their highest number on mid September (110 and 109 individual/25 leaves, for both seasons respectively). 165
T. Palmi: Appeared on cucumber in April plantations and plantation of both seasons 2010/2011 recorded the increased gradually to reach its maximum number in late highest number in mid August (92 and 103 individual/25 May, (138 and 101 individual/25 leaves, for both seasons leaves, respectively). respectively) while August plantation recorded the highest number in early August (91 individual/25 leaves). F. Occidentalis: Was recorded on cucumber in April plantation and increased gradually to reach its maximum Ch. Texanus: Appeared on cucumber in summer in early May of both seasons(139 and 136 individual/25 plantation and increased gradually to reach its maximum in mid June of both seasons, (100 and 132 individual/25 leaves, respectively) while August leaves, respectively) while the August plantation of both seasons 2010/2011 recorded the highest number in early August (69 and 73 individual/25 leaves, respectively). 166
DISCUSSION The Obtained results showed that T. tabaci has four peaks in the summer plantation in early, mid and the end of May which are parallel to the findings by Afsah [9] El-Dabi [10] and Nour El-Din [11]. However, more than 30 years ago, Yousef [12] mentioned that, in Egypt, T. tabaci population was high on May and June. The present change is probably due to the current gradual climate change; which worth further investigation. The present investigation confirms the presence of T. tabaci and F.occidentalis [4], while the two species; T. palmi 167
and Ch. texanus are detected here for the first time in 7. Moritz, G. and L.A. Mound, 1996. Common Egypt according to morphological identification. The Thysanoptera of Europe. An electronic Identification results of this study updates the thrips species's list in and Information System. CAB International, Egypt and focuses in future studies on their impact as Wallingford, UK. possible vectors too. 8. Jack, T.R., C. Allen, R. Bagwell, D. Cook, E. Burris, REFERENCES B. Freeman, R. Leonard and G. Lentz, 2006. A Key to the Thrips on Seedling Cotton in the Midsouthern United States, 11: 37-56. 1. Abdel Salam, M.M., H.A. Hussien, M.A. Abd Rabou 9. Afsah, A.G.F.E., 1993. Ecological studies on certain and M. Aboulfotouh, 2008. Vegetable cultivation insects attacking some vegetable crops in Gemmeza index (Watermelon, cucumber, squash, cantaloupe). region, Gharbia governorate. M.Sc. Thesis, Fac. Technical news no. (3), General Administration of Agric. Zagazig Univ. Egypt, pp: 98. Agricultural Culture (Issued in Arabic), pp: 5-64. 10. El-Dabi, R.M.A., 1999. Population and control studies 2. EPPO, 2008. URL: http://www.eppo.org/. Accessed on three sap sucking insects on different plantations 17 June 2010. of squash and cucumber in Giza Governorate. M.Sc. 3. Lewis, T., 1997. Thrips as crop pests. CAB Thesis, Fac. Agric. Cairo Univ. Egypt, pp: 90. International Oxford and New York, 1: 13-740. International standards for phytosanitary measures ISBN0-85199-178-5. (2009). Annex to ISPM No. 27 (Diagnostic protocols 4. Abd El-Wahab, A.S., M.A.K. El-Sheikh and for regulated pests) Thrips palmi, pp: 1-20. S. Elnagar, 2011. First record of Frankliniella 11. Nour El-Din, M.M.M., 1984. Ecological studies on occidentalis and Impatiens Necrotic Spot Virus in the insects attacking Cucurbitaceae. M.Sc. Thesis, Egypt. Journal of Life Science, 5: 690-696. Fac. Agric. Al-Azhar Univ. Egypt, pp: 145. 5. Palmer, J.M., 1992. Thrips (Thysanoptera) from 12. Yousef, K.E.H., 1976. Studies on some pests Pakistan to the Pacific: a review. Bulletin of the attacking cucurbit plants. Ph.D. Thesis, Fac. Agric., British Museum (Natural History). Entomology Alex. Univ. Egypt, pp: 156. Series, 61: 1-76. 6. Mound, L.A. and G. Kibby, 1998. Thysanoptera. An nd Identification Guide. 2 edition. Wallingford, UK, CAB International, pp: 70. 168