Click Here for More Images from iStock- 15% off with coupon 15FREEIMAGES 
Oak leaf with galls of Gall wasp, close-up.
These galls are produced by tiny Cynipid wasps, which go through a complicated life cycle involving two stages of development. In June, a generation of male and female wasps hatch from currant galls. The adults mate and the female lays fertilized eggs on the undersides of oak leaves. These cause the creation of the spangle galls, in which the grub matures. The spangle galls fall from the leaves in September and the wasp continues to grow within the leaf litter, producing a female-only generation in the following spring.
Plant Galls on a Oak Leaf, Sierra de Guadarrama National Park, Segovia, Castile Leon, Spain, Europe
The Valley Oak, can sometimes be riddled with large growths along the stem. Small wasps produce these oak apples or galls. The large oak apples, are induced by the gallwasp Andricus californicus. Shollenberger Park; Petaluma Wetlands; Petaluma; Sonoma County; California. Quercus lobata.
Oak gall
Green leaf with holes, Close-up
Oak galls on an oak leaf close-up
Colorful autumn leaves.
Oak galls, ink nuts on oak. Cynips quercusfolii
A tiny acorn growing on an oak tree in a forest.
Oak leaf with galls caused by Neuroterus quercusbaccarum insect (family Cynipidae), isolated on white background, copy space
Diseased sycamore tree leaves in close up in late summer.
Macro of galls, gall wasp, infestation of oak leaves in autumn, isolated on white background, Cynipidae, Neuroterus numismalis
Autumn leafs in Barcelona forest, Holy oaks, oaks and raspberries leafs changing colors to red..
Selective focus on gall mite, Aceria Quercina, on kermes oak with discolored leaf
Back side of autumn Oak leaves on a twig.
Oak galls on green oak leaves.
A single fruit capsule of a Coliguay Tree (Colliguaja odorifera) in late winter in central Chile, near the capital Santiago. The developing fruit has been invaded by the tiny Chalcid wasp, Aprostocetus colliguayae, that has caused a swollen gall to develop and protect the growing wasp larvae, effectively sterilising the fruit capsule of the Coliguay plant.
Close-up of large Galls on Common oak leaves created by gall wasp Cynips quercusfolii in Estonian boreal forest
Detail of a leaf that's been eaten
Biorhza pallida on Quercus robur
The gall wasp (Andricus quercuscalicis) lays its eggs inside the acorn itself, causing it to mutate. When the infestation first appeared some thought it might wipe out England's oak trees. However, although these galls affect individual acorns and their cups, the net effect is not disastrous. Knopper galls were first recorded in the UK in the 1960s. They have spread rapidly across the country, until now they are one of the commonest oak galls across all England. The name 'pedunculate oak' refers to the situation of the acorns, which arise from long stems (peduncles), as distinguished from the 'sessile oak', where the acorns sit directly on the oak twigs.
Symptoms of a disease caused by pathogenic bacteria on a sunflower leaf under high magnification.
The veins are the vascular tissue of the leaf and are located in the spongy layer of the mesophyll. The pattern of the veins is called venation. They were once thought to be typical examples of pattern formation through ramification, but they may instead exemplify a pattern formed in a stress tensor field. A vein is made up of a vascular bundle. At the core of each bundle are clusters of two distinct types of conducting cells: xylem and phloem.
Acorn on white background
Close-up of an eucalyptus leaf with Mycosphaerellaceae
Pear leaf (upper side) with Pear rust - disease caused by Gymnosporangium sabinae fungus, close up, white background
This is a photograph taken on a mobile phone outdoors of an autumn leaf close up Allegheny National Forest, Pennsylvania.
Detail of an oak leaf with clutch of gall wasps Cynipidae isolated on white
Fig Leaf
Free Images: "bestof:Galappel aan eikenblad.jpg Gall on a oakleaf caused by the agamic parthenogenetic generation of Cynips longiventris <br>Location Lucasgat Apeldoorn Netherlands"
Groene rups 4-5cm opgerold.jpg
Galappel aan eikenblad.jpg
Viervleklieveheersbeestje (Exochomus quadripustulatus).jpg
Viervleklieveheersbeestje (Exochomus quadripustulatus) solo.jpg
Terms of Use   Search of the Day