page_title: Gall adelgid
section_title: Infection
hierarchical_section_title: Gall adelgid / Infection
context_page_description: The gall adelgid is an adelgid species that produces galls in spruce trees. They infect the new buds of native spruce trees in the[foothills of the Rocky Mountains in the spring. They also attack blue spruce to a lesser degree. The insects complete two generations within the year. They require two different trees for its life cycle, the second being the Rocky Mountain Douglas-fir. They may also attack Sitka, Engelmann, or white spruce. The many different species of adelgids produce different galls on different spruce species.
  The Cooley spruce gall adelgid is mainly a western species that usually alternates between white spruce and Douglas fir. It is rare in eastern Canada. In Ontario, the galls are found mostly on Colorado spruce.
context_section_description: In the fall, the immature female adelgid, small, globular, and wingless (1.2-1.7 mm), finds a spruce on which to overwinter. In the spring when the winter thaw occurs, the female matures and lays some eggs in what resembles sacks (totalling several hundred eggs) on the branches near the developing buds. These, in fact, are not sacks, but individual tufts of white waxy threads that protect the eggs. The females prefer areas on the spruce where they have greater protection from the elements, especially wind. These female individuals have an obvious patch of white wax wool as a covering. Their mouthparts consist of thread-like stylets which are used to penetrate into vascular bundles for feeding.
  Once hatched, the young nymphs begin feeding around the base of the needles in a new bud. The nymphs' saliva introduced into the plant trigger the changes in development of the plant, distinguished by the thickening and expansion of the basal portion of needles towards the characteristic gall form. When  infections are incomplete, the side of the bud facing the ground will be infected first. Only partially afflicted buds can support new growth after the affected tissue has died.
  The chamber at the base of each needle is not connected with any other chamber in the gall. This differentiates this infection from that caused by the woolly adelgid genus Pineus, where the chambers are interconnected.
  The nymphs are light brown when first hatched, becoming black when settled in gall chamber; they are flattened oval in shape and secrete a fringe of white wax. If a gall is opened in June, this white wax will be easily visible.
caption: The end of a gall that had partial infection. Growth continues, but it is convoluted.
exif: {"Image Make": "PENTAX Corporation", "Image Model": "PENTAX Optio 555", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Optio 555 Ver 1.00", "Image DateTime": "2006:06:04 18:28:50", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "462", "Image PrintIM": "[80, 114, 105, 110, 116, 73, 77, 0, 48, 50, 53, 48, 0, 0, 12, 0, 1, 0, 22, 0, ... ]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "4084", "Thumbnail JPEGInterchangeFormatLength": "6568", "EXIF ExposureTime": "1/60", "EXIF FNumber": "14/5", "EXIF ISOSpeedRatings": "64", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2006:06:04 18:28:50", "EXIF DateTimeDigitized": "2006:06:04 18:28:50", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "5", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "3", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "39/5", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "2592", "EXIF ExifImageLength": "1944", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "1006", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "0", "EXIF FocalLengthIn35mmFilm": "37", "EXIF SceneCaptureType": "Standard", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal", "EXIF SubjectDistanceRange": "1"}