Voltinismis a term used in biology to indicate the number of broods or generations of an organism in a year. The term is most often applied to insects, and is particularly in use insericulture,wheresilkwormvarieties vary in their voltinism.
- Univoltine (monovoltine)– (adjective) referring to organisms having one brood or generation per year
- Bivoltine (divoltine)– (adjective) referring to organisms having two broods or generations per year
- Trivoltine– (adjective) referring to organisms having three broods or generations per year
- Multivoltine (polyvoltine)– (adjective) referring to organisms having more than two broods or generations per year
- Semivoltine– There are two meanings:
- (biology) Less than univoltine; having a brood or generation less often than once per year
- or (adjective) referring to organisms whosegeneration timeis more than one year.[1]
Examples
editThespeckled wood butterflyisunivoltinein the northern part of its range, e.g. northern Scandinavia. Adults emerge in late spring, mate, and die shortly after laying eggs; their offspring will grow untilpupation,enterdiapausein anticipation of the winter, and emerge as adults the following year – thus resulting in a single generation of butterflies per year. In southern Scandinavia, the same species isbivoltine[2]– here, the offspring of spring-emerging adults will develop directly into adults during the summer, mate, and die. Their offspring in turn constitute a second generation, which is the generation that will enter winter diapause and emerge as adults (and mate) in the spring of the following year. This results in a pattern of one short-lived generation (c. 2–3 months) that breeds during the summer, and one long-lived generation (c. 9–10 months) that diapauses through the winter and breeds in the spring. TheRocky Mountain parnassianand theHigh brown fritillaryare more examples of univoltine butterfly species.[2][3]
The bee speciesMacrotera portalisis bivoltine, and is estimated to have about 2 or 3 broods annually. During winter, individuals remain in diapause, in their pharate or prepupal stage. This diapause stage continues until metamorphosis in the next spring or summer, whereupon the bees emerge as adults.[4]Another example of a bivoltine species isCyclosa turbinatawhich is known to reproduce once in the late spring and once again in the fall.
TheDawson's burrowing beeis an example of aunivoltineinsect of the orderHymenoptera.The brood of one winter will remain dormant underground until the following winter, and then will surface from their burrows to mate once, and establish new nests.
Partial voltinism
editThe termpartial voltinismis used to refer to two different (but not necessarily exclusive) situations:
- An organism wherein generations overlap in time, and so are not completely reproductively isolated. For example, in bees of the subfamilyHalictinae,one generation is produced in the early summer and one in the late summer, but males produced in the early summer may alsomatein the late summer.[5]
- (More commonly) a population where the voltinism is mixed, because of genetic variation (e.g., in thehybrid zonebetween a univoltine and a bivoltine area) and/or because environmental stimuli do not induce bivoltinism in all individuals (or across all years). For example, far-northern populations of thegreen-veined whitebutterflyPieris napiare mostly univoltine, but some individuals may avertdiapauseand produce an additional generation under warm conditions.[6]
Evolution
editThe number of breeding cycles in a year is under genetic control in many species[7]and they are evolved in response to the environment. Manyphytophagousspecies that are dependent on seasonal plant resources are univoltine. Some such species have the ability to diapause for a large part of the year, typically during a cold winter.[8]Others that bore in wood or other low-grade, but plentiful, food material may spend nearly the entire year feeding, with only brief pupal, adult and egg stages to complete a univoltine life cycle. Yet other species that live in tropical regions with little seasonality may be highly multivoltine, with several generations feeding on constantly growing vegetation (such as some species ofSaturniidae), or continually renewed detritus, such asDrosophilaand many other genera of flies with a life cycle of just a week or two.[9]
See also
editReferences
edit- ^Vincent H. Resh and Ring T. Carde (2009). Encyclopedia of INSECTS. 2nd edition, Academic Press, Elsevier 1169 pp. Link:http://ibimm.org.br/wp-content/uploads/2017/05/enciclopedia-de-insetos-ingles.pdf
- ^abAalberg Haugen IM, Berger D, and Gotthard K. 2012. The evolution of alternative developmental pathways: footprints of selection on life-history traits in a butterfly. 12pp. Journal of Evolutionary Biology, 25:7, Available online:[1]
- ^Shepard, Jon; Guppy, Crispin (2011).Butterflies of British Columbia: Including Western Alberta, Southern Yukon, the Alaska Panhandle, Washington, Northern Oregon, Northern Idaho, and Northwestern Montana.UBC Press.ISBN9780774844376.
- ^Buchmann, Stephen L."Bees",Bees,Retrieved on 15 October 2015.
- ^Seger J. 1983. Partial bivoltinism may cause alternating sex-ratio biases that favor eusociality. 4pp. Nature, 301:59-62, Available online:[2]
- ^Kivelä SM, Svensson B, Tiwe A, and Gotthard K. 2015. Thermal plasticity of growth and development varies adaptively among alternative developmental pathways. 13pp. Evolution, 69:9, Available online:[3]
- ^Coates BS, Sumerford DV, and Hellmich RL. 2004. Geographic and voltinism differentiation among North AmericanOstrinia nubilalis(European corn borer) mitochondrial cytochrome c oxidase haplotypes. 9pp. Journal of Insect Science, 4:35, Available online:[4]
- ^Hunter, M.D. and J.N. McNeil. 1997 Host-plant quality influences diapause and voltinism in a polyphagous insect herbivore. Ecology 78: 977-986.[5]
- ^Timothy Duane Schowalter (2011).Insect Ecology: An Ecosystem Approach.Academic Press. p. 159.ISBN978-0-12-381351-0.