Parasitization efficacy of Aphytis melinus debach (Hymenoptera:Aphelinidae) as affected by host size and size distiribution of aonidiella aurantii (Maskell) homoptera:Diaspididae) in a lemon orchard

Limon ağaçlarında Aphytis melinus DeBach (Hymenoptera: Aphelinidae)' un parazitleme etkinliğinin konukçusu Aonidiella aurantii (Maskeli) (Homoptera: Diaspididae)'nin irilik ve irilik dağılımına göre değişimi Kırmızı kabuklubit (Aonidiella aurantii), Doğu Akdeniz Bölgesi turunçgillerinin en önemli zararlılarından birisidir. Birçok doğal düşmanı olan bu zararlının baskı altına almamasında en yaygın doğal düşmanı olan parazitoit Aphytis melinus'un önemli bir yeri vardır. Bu çalışmada A. melinus'un Kırmızı kabuklubit'i parazitleme etkinliğine konukçu iriliği ve irilik dağılımının etkisi incelenmiştir. Kırmızı kabuklubit yoğunluğu en fazla meyveler üzerinde olmuş (1.00 adet /I cm2) bunu sırasıyla yaprak (0.61 adet /1 cm2), sürgün (0.05adet /1 cm2) ve gövde (0.01 adet /1 cm2) izlemiş, aralarındaki fark istatistiki olarak önemli bulunmuştur. Bitki organlarına göre değerlendirildiğinde Kırmızı kabuklubit'in ikinci nimf dönemlerinin irilikleri arasında fark ortaya çıkmazken, çiftleşmemiş dişi dönemde en iri bireylere meyve üzerinde rastlanmıştır. Parazitleme oranları açısından da bitki organları arasında fark ortaya çıkmış olup, en fazla parazitlenme meyve üzerinde (%12.6) saptanmış bunu sırasıyla yaprak (% 8.6) ve sürgün (%1.0) izlemiş, gövde üzerinde ise parazitlenme olmamıştır. Kırmızı kabuklubit'in 2. dönem nimflerinin kabuk iriliği 0.06 - 0.30 mm2, çiftleşmemiş dişi bireylerinki ise 0.30 - 0.70 mm2 arasında değişmiştir. Toplam Kırmızı kabuklubit populasyonunun %54.2'si 0.30 mm2'den küçük bireylerden oluşmuş ve bunların sadece %9.5'i parazitlenmiştir. Asalak tarafından tercih edilen 0.40 mm2'den daha büyük olan kabuklubitlerin toplam populasyon içindeki oranı %20.4 olmasına rağmen bunların %52.3'ü parazitlenmiştir.

Limon ağaçlarında Aphytis melinus debach (Hymenoptera:Aphelinidae)'un parazitleme etkinliğinin konukçusu aonidiella aurantii (Maskell) homoptera:Diaspididae)'nin irilik ve irilik dağılımına göre değişimi

Aonidiella aurantii (Maskeli) (Homoptera: Diaspididae) is a major pest of citrus in the east Mediterranean region of Turkey. Among many predators and parasitoids attacking the California red scale (CRS), Aphytis melinus DeBach (Hymenoptera: Aphelinidae) is the most common natural enemy of CRS. In this study we used host size and hoşt size distribution of A. aurantii on mature lemon trees to determine possible causes on efficacy of A. melinus observed in field. CRS density was significantly higher on fruits (1.00 CRS/cm2) than on leaves (0.61 CRS/cm2), twigs (0.05 CRS/cm2) and trunks (0.01 CRS/cm2). Virgin females tend to be larger in size on fruits, whilst size of second stage larvae was independent from tissue substrate. Significantly more CRS were parasitized by A. melinus on fruits (12.6%) and leaves (8.6%) than on twigs (1.0%); none of the individuals on trunks was parasitized. Distribution analyses of A. aurantii scale cover size showed two distinct groups of host sizes; the larval stages ranging between 0.06 - 0.30 mm2 and the virgin females being 0.30 - 0.70 mm2 in size. About 54.2% of the total A. aurantii population comprised of individuals smaller than 0.30 mm2 and only 9.5% of them were parasitized. Individuals larger than 0.40 mm2 are highly accepted for parasitization, but "constituted of only 20.4 % of total population and 52.3% were parasitized by A. melinus.

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Atkinson, P. R. (1977) Preliminary analysis of a field population of citrus red scale, Aonidiella aurantii (Maskell), and the measurement and expression of stage duration and reproduction for life tables. Bull. Ent. Res., 67: 65-87.
Carrol, D.P. and Luck R.F. (1984a) Within-tree distribution of California red scale, Aonidiella aurantii (Maskell) (Homoptera: Diaspididae) and its parasitoid Comperiella bifasciata Howard (Hymenoptera: Encyrtidae) on orange trees in the San Joaquin Valley. Environ. Entomol., 13: 179-183
Carrol, D.P. and R.F. Luck, 1984b. Bionomics of California red scale, Aonidiella aurantii (Maskell) (Homoptera: Diaspididae) on orange fruits, leaves and wood in California's San Joaquin Valley. Environ. Entomol., 13: 847-853.
DeBach, P., 1969. Biological control of diaspine scale insects on citrus in California. Proceedings first international symposium, Vol.,2. 801-815.
Eronc, H.H., 1971. Studies on species, distribution, biology, host plants and control of Aonidiella in Adana. Agricultural Research Institute Region, Ministry of Agriculture, Plant Protection and Quarantine General Directorate, Research Serial, Technical Bull. No.: 32: 103p. (in Turkish).
Jones, E. P., 1936. The bionomics and ecology of red scale- Aonidiella aurantii Mask.- in Southern Rhodesia. Mozoe Citrus Experimental Station Annual Report for 1935. The British South Africa Company Publication No.: 5: 11-52
Karaca, I. and Uygun, N., 1990. Natural enemies of Aonidiella aurantii (Maskell) (Homoptera: Diaspididae) in East Mediterranean citrus areas and their population development on different citrus varieties. Proc. 2nd Turkish National Congress of Biological Control. 4: 97-108 (in Turkish).
Luck, R. F. and Podoler, N., 1985. Competitive exclusion Aphytis lingnanensis by A. melinus potential role of host size. Ecology, 66: 904-913.
Moreno, D.S., W.A. Gregory and L.K. Tanigoshi, 1984. Flight response of Aphytis melinus (Hymenoptera: Aphelinidae) and Scirtothrips citri (Thysanoptera: Thripidae) to trap color, size and shape. Environ. Entomol.,13: 935-940.
Opp, S. B. and R.F. Luck, 1986. Effects of host size on selected fitness components of Aphytis melinus and A. lingnanensis (Hymenoptera: Aphelinidae). Ann. Entomol. Soc. Am., 79: 700-704.
Orphanides, a M., 1982. Biology of the California red scale Aonidiella aurantii (Maskell) (Homoptera: Diaspididae), and its seasonal availability for parasitization by Aphytis spp. Cyprus Bull. Lab. Ent. Agrar Filippo Silv., Portici., 39: 203-212.
Soylu, 0. Z. and N. Gird, 1977. Investigations on parasites and predators of the pests that cause damage on citrus plantations in the south Anatolia region. Bitki Koruma Bill., 17 (2-4): 77-112 (in Turkish).
Seker4u, E., N. Uygun and I. Karaca, 1989. The effect of irrigation systems on population dynamics of California red scale (Homoptera: Diaspididae) on lemon trees in Adana, Turkey. Turkish J. Entomol., 13: 147-152 (in Turkish).
Uygun, N., 1. Karaca and E. Sekeroglu, 1995a. Population dynamics of Aonideilla aurantii (Maskell) (Homoptera: Dispsididae) and its natural enemies on citrus in the Mediterranean region of Turkey from 1976-1993, In: Proc. VII Int. Symposium of Scale Insects Studies, ISSIS-VII (Ascher, K. R. S. and Ben-Dov, Y. eds). Isr. J. Ent., XXIX: 239-246.
Uygun, N., 1. Karaca, M.R. Ulusoy and N.Z. Tekeli, 1995b. Status of citrus pests and their control in Turkey. IOBC/WPRS Bulletin, 18 (5): 171-183.
Yu, D. S., 1986. The interactions between California red scale, Aonidiella aurantii (Maskell), and its parasitoids in citrus groves of inland Southern California. Ph D. Thesis, University of California, Riverside. 105pp.
Zhao, J., 1990. An advanced study on the biology and ecology of California red scale, Aonidiella aurantii (Mask.) (Hemiptera: Diaspididae), and its natual enemy, Aphytis melinus DeBach (Hymenoptera: Aphelinidae). Contribution of the Biological Control Research Institute, Fujian Agricultural College, Special Publication No.: 3: 245 pp