page_title: Semelparity and iteroparity
section_title: Evolution in insects
hierarchical_section_title: Semelparity and iteroparity / Evolutionary advantages to semelparity / Current evolutionary advantages hypothesis / Evolution in insects
caption_attribution_description: English: Female earwig guarding eggs (Philippines)
context_page_description: Semelparity and iteroparity are two classes of possible reproductive strategies available to living organisms. A species is considered semelparous if it is characterized by a single reproductive episode before death, and iteroparous if it is characterized by multiple reproductive cycles over the course of its lifetime. Some botanists use the parallel terms monocarpy and polycarpy.
  In truly semelparous species, death after reproduction is part of an overall strategy that includes putting all available resources into maximizing reproduction, at the expense of future life. In any iteroparous population there will be some individuals who die between their first and second reproductive episodes, but unless this is part of a syndrome of programmed death after reproduction, this would not be called semelparity.
  This distinction is also related to the difference between annual and perennial plants. An annual is a plant that completes its life cycle in a single season, and is usually semelparous. Perennials live for more than one season and are usually iteroparous.
context_section_description: An interesting trait has evolved in semelparous insects, especially in those that have evolved from parasitic ancestors, like in all subsocial and eusocial aculeate Hymenoptera. This is because larvae are morphologically specialized for development within a host's innards and thus are entirely helpless outside of that environment. Females would need to invest a lot of energy in protecting their eggs and hatched offspring. They do this through such behaviours as egg guarding. Mothers that actively defend offspring, for example, risk injury or death by doing so. This is not beneficial in an iteroparous species because the female risks dying and not reaching her full reproductive potential by not being able to reproduce in all reproductive periods in her lifetime. Since semelparous insects only live for one reproductive cycle, they can afford to expend energy on maternal care because those offspring are her only offspring. An iteroparous insect does not need to expend energy on the eggs of one mating period because it is likely that she will mate again. There is ongoing research in maternal care in semelparous insects from lineages not descended from parasites to further understand this relationship between semelparity and maternal care.
caption: Earwig guarding eggs
exif: {"Image ImageDescription": "", "Image Make": "SONY", "Image Model": "DSC-W320", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image DateTime": "2011:04:30 12:55:37", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "258", "Image PrintIM": "[80, 114, 105, 110, 116, 73, 77, 0, 48, 51, 48, 48, 0, 0, 2, 0, 2, 0, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail Make": "SONY", "Thumbnail Model": "DSC-W320", "Thumbnail Orientation": "Horizontal (normal)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "EXIF ExposureTime": "1/100", "EXIF FNumber": "27/10", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "400", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2011:04:30 12:53:59", "EXIF DateTimeDigitized": "2011:04:30 12:53:59", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "3", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "23/8", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "47/10", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "500", "EXIF ExifImageLength": "323", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "5480", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal"}