اثر مقایسه ای تراکم در نژادهای تک جنسی و دوجنسی زنبور Lysiphlebus fabarum، بر سوپرپارازیتیسم روی شته سیاه باقلا Aphis fabae

نوع مقاله : مقالات پژوهشی

نویسندگان

1 دانشگاه شهید چمران اهواز

2 اهواز

چکیده

درگذشته سوپرپارازیتیسم در میان پارازیتوئیدهای انفرادی به عنوان یک رفتار ناسازگار شناخته میشد، درحالیکه سوپرپارازیتیسم میتواند در شرایطی یک پدیدهی مطلوب باشد. به منظور تعیین اثر تراکم زنبور پارازیتوئید Lysiphlebus fabarum (Marshall) (Hym.: Braconidae) بر میزان سوپرپارازیتیسم، 40 پورهی سن دوم شته سیاه باقلا Aphis fabae Scopoli، به طور جداگانه در اختیار تراکمهای مختلف (1، 5، 10، 15، 20 و 30) نژادهای تک جنسی و دوجنسی زنبور قرار گرفتند. بعد از 24 ساعت، زنبورها حذف شدند و بعد از 5/2 روز شتهها تشریح و تعداد لارو زنبورها شمارش شدند. به منظور بررسی روند حذف لاروهای رقیب، آزمایش بالا تکرار و شتهها در روزهای 5/2، 5/3 و 5/4 تشریح شدند. مطابق با نتایج بهدست آمده، در هر دو نژاد، تراکم متفاوت زنبور منجر به اختلاف معنیدار در تعداد لاروهای موجود در شتههای پارازیته شد. مقایسهی تعداد لاروها، در تراکمهای مختلف نشان داد که در تراکمهای یک، 5 و 10 در نژاد دوجنسی به طور معنیداری تعداد بیشتری لارو نسبت به نژاد تک جنسی شمارش شد. در مقابل در تراکم 30، مادههای تک جنسی به نسبت میزبانهای خود را به تعداد بیشتری سوپرپارازیته کردند. در خصوص روند حذف لاروهای رقیب، در نژاد دوجنسی در تراکمهای 5، 20 و 30 همراه با گذشت زمان، حذف لاروهای رقیب مشاهده شد. در نژاد تک جنسی در هیچ یک از تراکمها تفاوت معنیداری در تعداد لارو بین سه روز تشریح مشاهده نشد. با تعیین نسبت مناسب زنبور به میزبان، نتایج تحقیق حاضر میتواند در پرورش انبوه دو نژاد L. fabaum مورد استفاده قرار گیرد.

کلیدواژه‌ها


عنوان مقاله [English]

Comparative Effect of Wasp Density in Unisexual and Bisexual Strains of Lysiphlebus fabarum, on Superparasitism in the Black Bean Aphid, Aphis fabae

نویسندگان [English]

  • leili Mohseni 1
  • Arash Rasekh 1
  • farhan kocheili 2
1 Shahid CHamran University of Ahvaz
چکیده [English]

Introduction: Lysiphlebus fabarum Marshall (Hymenoptera: Braconidae: Aphidiinae) is a common aphidiine parasitoid in central Europe, where it attacks more than 70 species of aphids. Although both unisexual (thelytokous) and bisexual (arrhenotokous) strains of L. fabarum have been reported in Iran, the former appear to be more widely distributed. Aphid control in Iran relies heavily on pesticides in both field and greenhouse settings, whereas any availability of new biological control agents such as L. fabarum would likely aid in reducing pesticide use. One of the most important aspects of implementing a parasitoid as a biological control agent is to determine the best density of parasitoid in the host access, in mass rearing. Parasitoid wasps display a wide array of strategies to dispose of host resources. Superparasitism is parasitism of a host by parasitoids of the same species. In solitary parasitoids, superparasitism almost occurs when hosts are limited or parasitoid density in a patch is high. Acceptance or rejection of a host usually depends on a female parasitoid’s ability to distinguish parasitized and unparasitized hosts. Previously, superparasitism was thought to be a maladaptive strategy, wasteful of both eggs and time, while it is now recognized as adaptive in a number of situations, e.g. under conditions of low host availability, as a mechanism for overwhelming the immune response of hosts.
Materials and Methods: In the present study, stock colonies of the unisexual and bisexual strains of the parasitoid were established from materials collected from Zanjan province and Khuzestan province fields, respectively. Both populations of the parasitoid were collected from parasitized black bean aphids feeding on the broad bean, Vicia fabae L. A stock colony of black bean aphids was established with material collected from bean fields in Khuzestan province. The synchronous cohorts of both strains of L. fabarum were produced at 21±1 ºC, 50–60% r.h., and L14:D10 photoperiod, and then introduced (one day old) separately into 40 2nd instar nymphs in different densities (1, 5, 10, 15 and 30). The females were removed after 24 hours and parasitized aphids were dissected three days after parasitism to determine the number of wasp larvae in each host. As well as, in another experiment the super parasitized aphids were dissected in three consecutive days (3.5, 4.5 and 5.5) to determine the process of competitors’ elimination.
Results and Discussion: According to results, in both strains, wasp densities affected on parasitism rates. In the bisexual strain, females parasitized more aphids in 20 and 30 densities treatments than one density treatment, while this rate did not differ significantly between 1, 5, 10 and 15 densities treatments. In the unisexual strain, single females significantly parasitized fewer hosts than other treatments, but there was no difference between other densities treatments. When in each density, percentage parasitism was compared between two strains, in the density of one female, bisexual females parasitized significantly higher than unisexual ones, in contrast to the density of 30, which significantly more larvae were counted in hosts of the unisexual strain than bisexual ones. In other densities, there was no significant difference between two strains. In the second experiment, which the rate of superparasitism was compared in different densities, in bisexual strain, the rate of superparasitism significantly was lower in the density of one female than other treatments. The number of larvae did not differ significantly between other densities treatments. In the unisexual strain, the rate of superparasitism significantly was lower in the density of one female than other treatments. The most rate of superparasitism was observed in 20 and 30 density treatments. When in each density, the rate of superparasitism was compared between both strains, in 1, 5 and 10 densities, bisexual females superparasitism significantly higher than unisexual ones, in contrast to the density of 30 females, which significantly more larvae were counted in hosts of the unisexual strain than the hosts of bisexual ones. In association with the process of competitors’ elimination, bisexual strain larvae eliminated rival larvae over time (in three consecutive days, including days 3.5, 4.5 and 5.5), as the numbers of larvae were decreased in densities of 5, 20 and 30 females. While in unisexual strain, elimination of rival larvae was not observed over time.
Conclusion: Wasp densities affected by parasitism rates and the rate of superparasitism in both strains. In mass rearing, the best density of wasps can be defined as the density that most available hosts are parasitized with a minimum of superparasitism, because superparasitism can depredate the time and eggs of female foragers. The results showed that densities of one and 5 females (for 40 individuals of 2nd instar nymphs) can be suggested as the proper densities of females in bisexual and unisexual strains, respectively. The results of this study can be useful in mass rearing and release of both L. fabarum strains.

کلیدواژه‌ها [English]

  • Mutual interference
  • Competition
  • Parasitoid
  • mass rearing
  • Braconidae
1- Ameri M. 2013. An investigation of some factors affecting foraging behavior in the thelytokous parasitoid, Lysiphlebus fabarum (Marshall) (Hymenoptera: Aphidiidae). M.Sc. dissertation. Shahid Chamran University of Ahvaz. 81 pp. (in Persian with English abstract).
2- Askew R.R. 1968. A survey of leaf-miners and their parasites on Laburnum. Transactions of the Royal Entomological Society of London, 120: 1-37.
3- Belshaw R., and Quicke D.L.J. 2003. The cytogenetics of thelytoky in a predominantly asexual parasitoid wasp with covert sex. Genome, 46: 170–173.
4- Boldt P.E., and Ignoffo C.M. 1972. Scanning electron microscopy of egg wounds inflicted by a Trichogramma wasp. Annals of the Entomological Society of America, 62: 760–762.
5- Chow F.J., and Mackauer M. 1985. Multiparasitism of the pea aphid: Stage of development of parasite determines survival of Aphidius smithi and Proan pequodorum (Hymenoptera: Aphidiidae). The Canadian Entomologist, 117: 133-134.
6- Cloutier C., and Mackauer M. 1979. The effect of parasitism by Aphidius smithi (Hymenoptera: Aphidiidae) on the food budget of the pea aphid, Acyrthosiphon pisum (Homoptera: Aphididae). Canadian Journal of Zoology, 57: 1605- 1611.
7- Cloutier C. 1984. The effect of host density on egg distribution by the solitary parasitoid, Aphidius nigripes (Hymenoptera: Aphidiidae). The Canadian Entomologist, 116: 805–811.
8- Crawley M.J. 1993. GLIM for Ecologists. Blackwell Scientific Publishing, Oxford, UK.
9- Desneux N., Barta R.J., Delebecque C.J., and Heimpel G.E. 2009. Transient host paralysis as a means of reducing self-superparasitism in koinobiont endoparasitoids. Journal of Insect Physiology, 55: 321–27.
10- Driessen G., and Hemerik L. 1991. Aggregative responses of parasitoids and parasitism in populations of Drosophila breeding in fungi. Oikos, 61: 96-107.
11- Fisher R.C. 1961. A study in insect multiparasitism. II. The mechanisms and control of competition for possession of the host. The Journal of Experimental Biology, 38: 605-628.
12- Fisher R.C. 1971. Aspects of physiology of endoparasitic Hymenoptera. Biological Reviews, 46:243–278.
13- Goubault M., Outreman Y., Poinsot D., and Cortesero A. 2005. Patch exploitation strategies of parasitic wasps under intraspecific competition. Behavioral Ecology, 16: 693–701.
14- Goubault M., Plantegenest M., Poinsot D., and Cortesero A.M. 2003. Effect of expected offspring survival probability on host selection in a solitary parasitoid. Entomologia Expermentalis et Applicata. 109: 123-131.
15- Hagen K.S. 1964. Developmental stages of parasites. In: DeBach, P. (Ed.), Biological control of insects, pests, and weeds. Chapman and Hall, London. pp. 168–246.
16- Hagvar E.B. 1988. Multiparasitism of the green peach aphid, Byzus persicae: competition in the egg stage between Aphidius matricariae and Ephedrus cerasicola. Entomologia Experimentalis et Applicata, 47:275–282.
17- Hagvar E.B., and Hofsvang T. 1988. Interspecific competition between the aphid parasitoids Aphidius colemani Viereck and Ephedrus cerasicola. Entomologia Experimentalis et Applicata, 47: 275–282.
18- Hassell M.P., and Huffaker C.B. 1969. Regulatory processes and population cyclicity in laboratory populations in Anagasta kuehniella (Zeller) (Lepidoptera: Phycitidae). III. The development of population models. Researches in Population Ecology, 11: 186–210.
19- Hofsvang T. 1988. Mechanisms of host discrimination and intraspecific competition in the aphid parasitoid Ephedrus cerasicola. Entomologia Experimentalis et Applicata, 48: 233–239.
20- Hubbard S.F., Marris G., Reynolds A., and Rowe G.W. 1987. Adaptive patterns in the avoidance of superparasitism by solitary parasitic wasps. Journal of Animal Ecology, 56:387–401.
21- Iwasa Y., Susuki Y., and Matsuda H. (1984) Theory of oviposition strategy of parasitoids. I. Effect of mortality and limited egg number. Theoretical Population Biology, 26: 205–227.
22- Kant R., Minor M.A., and Trewick S.A. 2012. Fitness gain in a koinobiont parasitoid Diaeretiella rapae (Hymenoptera: Braconidae) by parasitizing hosts of different ages. Journal of Asia-Pacific Entomology, 15: 83-87.
23- Mangel M. 1987. Oviposition site selection and clutch size in insects. Journal of Mathematical Biology, 25: 1–22.
24- Mangel M. 1989. Evolution of host selection in parasitoids: does the state of the parasitoid matter? American Naturalist, 133: 688–705.
25- Mohammadi Z. 2014. Impact of host developmental stage on offspring fitness and investigation of foraging behavior in Lysiphlebus fabarum (Marshall) (Hymenoptera: Aphidiidae). M.Sc. dissertation. Shahid Chamran University of Ahvaz. 116 pp. (in Persian with English abstract).
26- Pennachio F., Digilio M.C., and Tremblay E. 1995. Biochemical and metabolic alterations in Acyrthosiphon pisum parasitised by Aphidius ervi. Archives of Insect Biochemistry and Physiology, 30: 351-367.
27- Pexton J.J., and Mayhew P.J. 2002. Siblicide and life-history evolution in parasitoids. Behavioral Ecology, 13: 690–95.
28- Rakhshani E., Talebi A.A., Manzari S., Rezwani A., and Rakhshani H. 2006. An investigation on alfalfa aphids and their parasitoids in different parts of Iran, with a key to the parasitoids (Hemiptera: Aphididae; Hymenoptera: Braconidae: Aphidiinae). Journal of Entomological Society of Iran, 25(2): 1-14.
29- Rasekh A., Kharazi-Pakdel A., Michaud J.P., Allahyari H., and Rakhshani E. 2011. Report of a thelytokous population of Lysiphlebus fabarum (Marshall) (Hymenoptera: Aphidiidae) from Iran. Journal of Entomological Society of Iran, 30: 83-84.
30- Rasekh A., Michaud J.P., Kharazi-Pakdel A., and Allahyari H. 2010. Ant mimicry by an aphid parasitoid, Lysiphlebus fabarum. Journal of Insect Science, 10.
31- Salt G. 1960. Experimental studies in insect parasitism. XI. The haemocytic reaction of a caterpillar under varied conditions. Proceedings of the Royal Society (B), 151: 446-467.
32- Salt G. 1961. Competition among insect parasitoids. Symposia of the Society for Experimental Biology, 15:96–119.
33- Sequeira R., and Mackauer M. 1993. The nutritional ecology of a parasitoid wasp, Ephedrus californicus Baker (Hymenoptera: Aphidiidae). The Canadian Entomologist, 125: 423-430.
34- Sirot E., Ploye H., and Bernstein C. 1997. State dependant superparasitism in a solitary parasitoid: egg load and survival. Behavioural Ecology, 8: 226–232.
35- SPSS. 1998. SPSS 8.0 for Windows. Prentice Hall, Upper Saddle River, NJ, USA.
36- Streams F.A. 1971. Encapsulation of insect parasites in superparasitized hosts. Entomologia Expermentalis et Applicata. 14: 484-490.
37- Sutherland W.J. 1996. From Individual Behaviour to Population Ecology. Oxford University Press.
38- Van Alphen J.J.M., and Nell H.W. 1982. Superparasitism and host discrimination by Asobara tabida Nees (Braconidae: Alysiinae), larval parasitoid of Drosophilidae. Netherlands Journal of Zoology. 32: 232–260.
39- Van Alphen J.J.M., and Vet L.E.M. 1986. An evolutionary approach to host finding and selection. Insect Parasitoids (eds J. Waage & D. Greathead), pp. 23–61. Academic Press.
40- Van Alphen J.J.M. and Visser M.E. 1990. Superparasitism as an adaptive strategy for insect parasitoids. Annual Review of Entomology, 35: 59–79.
41- Van Dijken M.J., Van Stratum P., and Van Alphen J.J.M. 1992. Recognition of individual-specific marked parasitized hosts by the solitary parasitoid Epidinocarsis lopezi. Behavioral Ecology Sociobiology, 30:77-82.
42- Van Dijken M.J., and Waage J.K. 1987. Self and conspecific superparasitism by the egg parasitoid Trichogramma envanescens. Entomologia Experimentalis et Applicata, 30: 77–82.
43- Van Lenteren J.C. 1976. The development of host discrimination and the prevention of superparasitism in the parasitic Pseudocoilu bochei Weld (Hymenoptera: Cynipidae). Netherlands Journal of Zoology, 26:1-83.
44- Visser M.E. 1993. Adaptive self-superparasitism and conspecific superparasitism in the solitary parasitoid Leptopilina heterotoma (Hymenoptera: Eucolidae). Behavioral Ecology, 4: 22–28.
45- Visser M.E., Van Alphen J.J.M., and Hemerik L. 1992. Adaptive superparasitism and patch time allocation in solitary parasitoids: an ESS model. Journal of Animal Ecology, 61: 93–101.
46- Visser M.E., Van Alphen J.J.M., and Nell H.W. 1990. Adaptive superparasitism and patch time allocation in solitary parasitoids; the influence of the number of parasitoids exploiting a patch. Behaviour, 114:21-36.
47- Völkl W. 1992. Aphids or their parasitoids: who actually benefits from ant attendance? Journal of Animal Ecology, 61:273-281.
48- Völkl W., and Stechmann D.H. 1998. Parasitism of the black bean aphid (Aphis fabae) by Lysiphlebus fabarum (Hym., Aphidiidae): the influence of host plant and habitat. Journal of Applied Entomology, 122(5):201-206.
49- Waag J.K. 1986. Family planning in parasitoids: adaptive patterns of progeny and sex allocation. Insect Parasitoids (cd. by J. K. Waage and D. Greathead), pp. 63-95, Academic Press, London.
50- Waage J.K., and Godfray H.C.J. 1985. Reproductive strategies and population ecology of insects parasitoids. In Sibly R. M., and Smith, R. H. (eds.), Behavioural Ecology, Blackwell, Oxford, pp. 449–470.
51- Wajnberg E., Curty C., and Colazza S. 2004. Genetic variation in the mechanisms of direct mutual interference in a parasitic wasp: consequences in terms of patch-time allocation. Journal of Animal Ecology, 73:1179–1189.
52- Weisser W.W., and Houston A.I. 1993. Host discrimination in parasitic wasps: when is it advantageous? Functional Ecology, 7: 27–39.
53- Wigglesworth V.B. 1959. Insect blood cells. Annual Review of Entomology, 4: 1-16.
54- Yamada Y.Y., and Kazuma S. 2003. Evidence for adaptive selfsuperparasitism in the dryinid parasitoid Haplogonatopus atratus when conspecifics are present. Oikos, 103:173.
CAPTCHA Image