Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-25T07:33:08.874Z Has data issue: false hasContentIssue false

The population dynamics of the white peach scale and its parasitoids in a mulberry orchard in Campania, Italy

Published online by Cambridge University Press:  10 July 2009

P.A. Pedata
Affiliation:
Dipartimento di Entomologia e Zoologia Agraria, Università di Napoli “Federico II”, Portici, Italy
M.S. Hunter
Affiliation:
Dipartimento di Entomologia e Zoologia Agraria, Università di Napoli “Federico II”, Portici, Italy
H.C.J. Godfray*
Affiliation:
Department of Biology and NERC Centre for Population Biology, Imperial College at Silwood Park, Ascot, UK
G. Viggiani
Affiliation:
Dipartimento di Entomologia e Zoologia Agraria, Università di Napoli, “Federico II”, Portici, Italy
*
H.C.J. Godfray, Dept. of Biology and NERC Centre for Population Biology, Imperial College at Silwood Park, Ascot, Berkshire, SL5 7PY, UK.

Abstract

White peach scale, Pseudaulacaspis pentagona (Targioni-Tozzetti) (Homiptera: Diaspididae), was a serious pest of mulberry until it was the subject of a successful biological control programme in Italy at the turn of the century. Since the 1950s it has returned as a sporadic pest of commercial peach and, more recently, kiwi fruit orchards. We sampled white peach scale in an unmanaged mulberry orchard in coastal Campania over a 17 month period to measure the impact, relative abundance, and interactions of the parasitoids in the absence of pesticides. Sampled scales were dissected, and the immature stages of the parasitoids identified. Mean densities of white peach scale varied with month from 3–15/9 cm2 on primary (interior) branches and 15–100/1.5–2 m secondary (exterior) branch. The generalist ectoparasitoid Aphytis proclia (Walker) was most abundant, followed by two specialist endoparasitoids, Encarsia berlesei (Howard) and Pteroptrix orientalis (Silvestri) (all Hymenoptera: Aphelinidae). Primary parasitism also varied with month from 25–85% on primary branches and 20–90% on secondary branches. Parasitism on primary branches was inversely density-dependent, but was densityindependent on secondary branches. Low levels of superparasitism were generally observed in E. berlesei and P. orientalis (0–6%), but were higher in A. proclia (0–21%). Multiple parasitism of hosts by E. berlesei and A. proclia was fairly common (up to 24% of E. berlesei immatures were found sharing a host with A. proclia), and A. proclia was the probable winner of within-host competitions. The hyperparasitoid Azotus perspeciosus (Girault) (Hymenoptera: Aphelinidae) parasitized late pre-imaginal instars of all three primary parasitoid species. There was no significant difference in hyperparasitism of the three primary parasitoid species, but the rate of hyperparasitism was inversely related to the total density of primary parasitoids.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Benassy, C. (1958) Étude bio-écologique de Pseudaulacaspis pentagona Targ. et de son parasite specifique Prospaltella berlesei How. en France. Annales INRA, Series Epiphities 9, 425496.Google Scholar
Bennett, F.D. & Brown, S.W. (1958) Life history and sex determination in the diaspine scale Pseudaulacaspis pentagona (Targ.) (Coccoidea). Canadian Entomologist 90, 317324.CrossRefGoogle Scholar
Chumakova, B.M. (1964) A review of the species of the family Aphelinidae (Hymenoptera)–parasites of coccid pests of tree cultures on the Black Sea coast of the RSFSR. Trudy Vsesojuznogo Instituta Zashchity Rastenij 21, 1439. (In Russian.)Google Scholar
Collett, D. (1991) Modelling binary data. pp. 245, London, Chapman & Hall.CrossRefGoogle Scholar
Collins, F.A. & Whitcomb, W.H. (1975) Natural enemies of the white peach scale, Pseudaulacaspis pentagona (Homoptera: Coccidae), in Florida. Florida Entomologist 58, 1521.CrossRefGoogle Scholar
Dean, H.A. (1982) Reduced pest status of the Florida red scale on Texas citrus associated with Aphytis holoxanthus. Journal of Economic Entomology 75, 147149.CrossRefGoogle Scholar
DeBach, P., Fisher, T.W. & Landi, J. (1955) Some effects of meteorological factors on all stages of Aphytis lingnanensis, a parasite of the California red scale. Ecology 36, 743755.CrossRefGoogle Scholar
DeBach, P., Rosen, D. & Kennett, C.E. (1971) Biological control of coccids by introduced natural enemies. pp. 165194in Huffaker, C.B. (Ed.) Biological control. New York, Plenum Press.Google Scholar
Garonna, A.P. (1990) Aspetti morfo-bio-etologici di Archenomus orientalis Silvestri (Hym.: Aphelinidae). PhD Thesis, Università di Napoli “Federico II”.Google Scholar
Garonna, A.P. & Viggiani, G. (1988a) Osservazioni sulla cocciniglia bianca del pesco (Pseudaulacaspis pentagona-Targ. Tozz.-) e i suoi nemici naturali in Campania. Annali della Facoltà di Scienze Agrarie dell' Università di Napoli in Portici 22, 110.Google Scholar
Garonna, A.P. & Viggiani, G. (1988b) Studi biologici sull’ Archenomus orientalis Silvestri: 1. Longevità degli adulti, fecondità, fertilità e progenie. Atti XV Congresso Nazionale Entomologia, L'Aquila, 859866.Google Scholar
Godfray, H.C.J. & Pacala, S.W. (1992) Aggregation and the population dynamics of parasitoids and predators. American Naturalist 140, 3040.CrossRefGoogle ScholarPubMed
Godfray, H.C.J. & Waage, J.K. (1991) Predictive modeling in biological control: the mango mealy bug (Rastrococcus invadens) and its parasitoids. Journal of Applied Ecology 28, 434453.CrossRefGoogle Scholar
Habibian, A. & Assadi, H.B. (1989) Some complementary studies of biological control with Pseudaulacaspis pentagona (Targ. Tozz.) in Guilan Province. p. 249in Mcfarlane, N.R. (Ed.) Progress and prospects in insect control. Farnham, UK, British Crop Protection Council.Google Scholar
Hanks, L.M. & Denno, R.F. (1993a) The white peach scale, Pseudaulacaspis pentagona (Targioni-Tozzetti) (Homoptera: Diaspididae): life history in Maryland, host plants and natural enemies. Proceedings of the Entomological Society of Washington 95, 7998.Google Scholar
Hanks, L.M. & Denno, R.F. (1993b) Natural enemies and plant water relations influence the distribution of an armored scale insect. Ecology 74, 10811091.CrossRefGoogle Scholar
Hassell, M.P. (1978) The dynamics of arthropod predator-prey systems. pp. 189, Princeton, New Jersey, Princeton University Press.Google ScholarPubMed
Hassell, M.P. (1984) Parasitism in patchy environments: inverse density dependence can be stabilizing. IMA Journal of Mathematics Applied in Medicine & Biology 1, 123133.CrossRefGoogle ScholarPubMed
Hassell, M.P., Waage, J.K. & May, R.M. (1983) Variable parasitoid sex ratios and their effect on host-parasitoid dynamics. Journal of Animal Ecology 52, 5767.CrossRefGoogle Scholar
Huffaker, C.B., Kennett, C.E. & Finney, G.L. (1962) Biological control of olive scale, Parlatoria oleae (Colvée), in California by imported Aphytis maculicornis (Masi) (Hymenoptera: Aphelinidae). Hilgardia 32, 541636.CrossRefGoogle Scholar
Kennett, C.E., Huffaker, C.B. & Finney, G.L. (1966) The role of an autoparasitic aphelinid, Coccophagoides utilis Doutt in the control of Parlatoria oleae (Colvée). Hilgardia 37, 255282.CrossRefGoogle Scholar
Liebregts, W.J.M.M., Sands, D.P.A. & Bourne, A.S. (1989) Population studies and biological control of Pseudaulacaspis pentagona (Targioni-Tozzetti) (Hemiptera: Diaspididae) on passion fruit in Western Samoa. Bulletin of Entomological Research 79, 163171.CrossRefGoogle Scholar
Lord, F.T. & MacPhee, A.W. (1953) The influence of spray programs on the fauna of apple orchards in Nova Scotia. VI. Low temperatures and the natural control of the oystershell scale, Lepidosaphes ulmi (L.) (Homoptera: Coccidae). Canadian Entomologist 85, 282291.CrossRefGoogle Scholar
McClure, M.S. (1977) Parasitism of the scale insect, Fiorinia externa (Homoptera: Diaspididae), by Aspidiotiphagus citrinus (Hymenoptera: Eulophidae) in a hemlock forest: density-dependence. Environmental Entomology 6, 551555.CrossRefGoogle Scholar
McCullagh, P. & Nelder, J.A. (1989) Generalized linear models. 2nd edn. pp. 376. London, Chapman & Hall.CrossRefGoogle Scholar
Murdoch, W.W. & Stewart-Oaten, A. (1989) Aggregation by parasitoids and predators: effects on equilibrium and stability. American Naturalist 134, 288310.CrossRefGoogle Scholar
Murdoch, W.W., Chesson, J. & Chesson, P.L. (1985) Biological control in theory and practice. American Naturalist 125, 344366.CrossRefGoogle Scholar
Murdoch, W.W., Nisbet, R.M., Gurney, W.S.C. & Reeve, J.D. (1987) An invulnerable age class and stability in delaydifferential parasitoid-host models. American Naturalist 129, 263282.CrossRefGoogle Scholar
Murdoch, W.W., Briggs, C.J., Nisbet, R.M., Gurney, W.S.C. & Stewart-Oaten, A. (1992) Aggregation and stability in metapopulation models. American Naturalist 140, 4158.CrossRefGoogle ScholarPubMed
Pacala, S., Hassell, M.P. & May, R.M. (1990) Host-parasitoid associations in patchy environments. Nature 344, 150153.CrossRefGoogle ScholarPubMed
Pedata, P.A. & Viggiani, G. (1991) Preliminary morphobiological observations on Azotus perspeciosus (Girault) (Hymenoptera: Aphelinidae), hyperparasitoid of Pseudaulacaspis pentagona (Targioni Tozzetti) (Homoptera: Diaspididae). Proceedings of the 4th European Workshop on Insect Parasitoids. Redia 74 Appendice, 343350.Google Scholar
Reeve, J.D. (1987) Foraging behaviour of Aphytis melinus: effects of patch density and host size. Ecology 68, 530538.CrossRefGoogle Scholar
Reeve, J.D. & Murdoch, W.W. (1985) Aggregation by parasitoids in the successful control of the California red scale: a test of theory. Journal of Animal Ecology 54, 797816.CrossRefGoogle Scholar
Rosen, D. & DeBach, P. (1979) Species of Aphytis of the world. 801 pp. The Hague, Dr W. Junk, BV Publishers (Series Entomologica 17).CrossRefGoogle Scholar
Smith, A.D.M. & Maelzer, D.A. (1986) Aggregation of parasitoids and density-independence of parasitism in field populations of the wasp Aphytis melinus and its host, the red scale Aonidiella aurantii. Ecological Entomology 11, 425434.CrossRefGoogle Scholar
Steinberg, S., Podoler, H. & Rosen, D. (1987) Competition between two parasites of the Florida red scale in Israel. Ecological Entomology 12, 299310.CrossRefGoogle Scholar
Summy, K.R., Gilstrap, F.E. & Hart, W.G. (1985) Aleurocanthus woglumi (Hom.: Aleyrodidae) and Encarsia opulenta (Hym.: Encyrtidae): density-dependent relationship between adult parasite aggregation and mortality of the host. Entomophaga 30, 107112.CrossRefGoogle Scholar
Tremblay, E. (1958) Ovoviviparità, comportamento delle femmine vergini, sesso delle larve e ghiandole cefaliche larvali della Diaspis pentagona Targ. Bollettino del Laboratorio Entomologia agraria Filippo Silvestri 16, 215246.Google Scholar
Tremblay, E. (1959) Osservazioni sui due tipi di uova e sulla origine dei micetociti nella Diaspis (=Pseudaulacaspis) pentagona Targ. Bollettino del Laboratorio Entomologia agraria Filippo Silvestri 17, 5188.Google Scholar
Viggiani, G. (1989) Il controllo integrato della cocciniglia bianca del pesco. L'Informatore Agrario 45 (26), 6165.Google Scholar
Viggiani, G. & Garonna, A. (1987) Preliminary observations on the biology of Archenomus orientalis Silvestri (Hymenoptera: Aphelinidae), parasite of white peach scale (Pseudaulacaspis pentagona-Targ. Tozz-). Bollettino del Laboratorio Entomologia agraria Filippo Silvestri 43 (Suppl.) (1986), 223227.Google Scholar
Viggiani, G. & Garonna, A.P. (1993) Le specie italiane del complesso Archenomus Howard, Archenomiscus Nikolskaja, Hispaniella Mercet e Pteroptrix Westwood, con nuove combinazioni generiche (Hymenoptera: Aphelinidae). Bollettino del Laboratorio Entomologia agraria Filippo Silverstri 48 (1991), 5788.Google Scholar
Williams, D.A. (1982) Extra-binomial variation in logistic linear models. Applied Statistics 31, 144148.CrossRefGoogle Scholar