Malays. Appl. Biol. (December 2004) ii(2): 59-66
VARIATIONS IN THE FECUNDITY AND PROGENY SEX RATIO
OF LIPOLEXIS SCUTELLARIS MACK. (HYMENOPTERA :
BRACONIDAE) WHEN INSEMINATED BY A MULTIPLE MATED MALE
*PANDEY, S. and SINGH, R.
Aphid Biocontrol Laboratory
Department of Zoology
DDU Gorakhpur University
Gorakhpur-273 009 U.P. India.
Email: rsing_gpu@ahoo. Com
ABSTRACT
Male Lipolexis scutellaris are always polygynous while females restrictedly monandrous and thus inseminates only once in her life. The results indicated following: (1) total progeny production by the female is decreased considerably (122.66±1.14 SD to 47.21±3.34 SD progeny/female-one hour rest copulation and 105.66±2.30 SD to 42.81±1.78 SD progeny/female-4 h rest copulation) (2) there is no variation in progeny sex ratio of the first four females copulated by a single male in a succession (0.33±0.01 SD to 0.36±0.01 SD) (3) the last female in series produced equal proportion of sons and daughters (4) the generalised reproductive index (GRI) shows that the most productive female, which was first in series, and successively decreased with multiple mated male. No significant variation was observed caused by 4 h rest given to males between two successive matings but only mean number of fecundity was affected. Regression of progeny sex ratio (Y) and total progeny (X) resulted significant negative linear correlation coefficients when the females were mated by a multiple mated males (Y = 0.6598 - 0.0016 X, r= -D.603, P < 0.001). So, results indicates that the males L. scutellaris have a great power of mating ability and ejaculate only that amount of sperms into the females that are sufficient enough to fertilise a considerable number of eggs retaining still a higher number of sperms for ejaculation in successive matings.
ABSTRAK
Lipolexis scutellaris jantan biasanya poliginos sedangkan yang betina adalah monandros iaitu membiak hanya sekali dalam seumur hidup. Hasil yang diperolehi menunjukkan bahawa: 1. Jumlah progeni yang dihasilkan oleh betina menurun (122.66±1.14 SD menurun ke 47.21±3.34 SD progeni/betina bila jantan diberi masa rehat 1 jam selepas mengawan; dan) 105.66±2.30 SD to 42.8111.78 SD progeni/betina oleh jantan yang direhatkan 4 jam); 2. Tiada perubahan nisbah jantina bagi progeni yang dihasilkan oleh 4 ekor betina mengawan dengan seekor jantan berturutan (0.33±0.01 SD to 0.36±0.01 SD); 3. Betina yang terakhir dalam siri menghasilkan progeni betina dan jantan yang sama banyak, dan, 4. Indeks pembiakan umum (GRI) menunjukkan bahawa yang pertama dalam siri dan akan menurun berturutan dengan jantan yang telah banyak kali mengawan. Tiada perubahan yang nyata yang disebabkan oleh masa rehat 4 jam diantara mengawan jantan kecuali min bagi fekunditi. Bila betina mengawan dengan jantan yang telah berulang kali mengawan, regresi nisbah jantina (Y) dan jumlah progeni (X) menghasilkan korelasi linear negatif (Y = 0.6598 - 0.0016 X, r= - 0.603, P < 0.001). Oleh yang demikian, hasil menunjukkan bahawa L. scutellaris, jantan berupaya mengawan beberapa kali dan dapat menghasilkan sperma yang cukup untuk mensenyawa telur setiap kali mengawan.
Key words: Progeny sex ratio, Lipolexis scutellaris, Aphis gossypii, multiple mating, parasitoid, aphid. bio-control
REFERENCES
Biswas, S. and Singh, R. 1995. Frequency of constrained sex allocation in field population of aphid parasitoids (Hymenoptera: Aphidiidae). Journal of Advanced Zoology 16: 16-20.
Dharmadhikari, P.R. and Ramasheshiah, G. 1970. Recent records of aphidiids (Hymenotpera: Aphidiidae) in India. Tech. Bull. Commonw. Insects. Biological Control. 13, 83-89.
Mishra, S. and Singh, R. 1991. Sex ratio of the aphid parasitoid Lysiphlebus delhiensis (Subba Rao and Sharma) (Hymenoptera: Aphidiidae) in field population. Journal of Appliea Entomology, 111, 72-77.
Pandey, S. and Singh, R. (2004a). Courtship and Mating behaviour of Lipolexis scutellaris Mack. (Hymenoptera: Braconidae) a parasitoid of Aphis gossypii Glov. (Homoptera: Aphididae) Uttar Pradesh Journal of Zoology, Muzaffarnagar, 24(1), Accepted.
Pandey, S. and Singh, R. (2004b). Influence of co-presence of male on the fecundity and progeny sex ratio of parasitoid Lipolexis scutellarh (Hymenoptera:Braconidae), Journal oj Applied Zoological Research, Cuttack, 15(2) Accepted.
Pandey, S., Upadhyay, B.S., Srivastava, P.N. and Singh, R. 1996. Progeny sex ratio oi Lysiphlebia mirzai Shuja-Uddin (Hymenoptera:Braconidae) inseminated by a multiple mated male. Journal of Aphidology 10, 43-48.
Schlinger, E.I. and Hall, J.C. 1960. The biology, behabiour, and morphology of Praon palitam Muesebeck, an internal parasite of the spotted alfalfa aphid, Tehrioaphis maculata (Buckton) (Hymenoptera: Braconidae :Aphidiinae). Annals of Entomological Society of America 54, 34-45.
Sekhar, P.S. 1957. Mating oviposition and discrimination of hosts by Aphidius testaceipes (Cresson) and Praon aguti Smith, primary parasites of aphids). Annals of Entomological Society of America 50, 370-373.
Shirota, Y., Carter, Rabbinge, R.N. and Ankersmit, G.W. 1983. Biology of Aphidius rhopalosiphi, a parasite of cereal aphids. Entomologia Experimentalis et Applicata 34, 27-34.
Shuja-Uddin, 1977. Observations on the normal and diapausing cocoons of the genus Lipolexis Forster (Hymenoptera:Aphidiidae) from India. Bull. Lab. Ent. Age. Portici34, 51-54.
Singh, R. and Agarwala, B.K. 1992. Biology, Ecology and control efficiency of the aphid parasiotids Trioxys indicus: a review and bibliography Biological Agriculture and Hortilcultrue 8, 271-298.
Singh, R. and Sinha, T.B. 1980. Bionomics of Trioxys (Binodoxys) indicus Subba Rao and Sharma, an aphidiid parasitoid of Aphis craccivora Koch. 7. Sex ratio of the parasitoid in field populaiton. Entomon 5, 269-275.
Singh, R., Singh, K. and Prasad, M. 2000a. Thermal influence on the development, reproduction and progeny sex ratio of Lipolexis scutellaris Mackauer (Hymenoptera: Braconidae; Aphidiinae) Proceedings of National Academy of Science. 70, 267-278.
Singh, R., Singh, K. and Upadhayay, B.S. 2000b. Honey dew as a food source for an aphid parasitoid Lipolexis scutellaris Mackauer (Hymenoptera:Braconidae) Journal of Advanced Zoology. 21, 76-82
Tripathi, R.N. and Singh, R. 1990. Mating behavour of Lysiphlebia mirzai Shuja-Uddin (Hymenoptera:Aphidiidae), a parasitoid of Rhopalosiphum maidis (Fitch) (Hemiptera: Aphididae), Entomon 15, 21-25.
Tripathi, R.N. and Singh, R. 1995. Host specificity and seasonal distribution of Lysiphlebia mirzai Shuja-Uddin (Hymenoptera: Braconidae). Biological Agriculture and Horticulture 2, 283-294.
