Eucalyptus grandis Hill.ex. Maiden injuries caused by Ctenarytaina spatulata Taylor.

Abstract

The injuries of Ctenarytaina spatulata Taylor, 1977, were characterized through observations in field,  laboratory and greenhouse. The first injuries of C. spatulata in Eucalyptus grandis are caused during  oviposition. At the point where the egg is inserted, a   small black spot appears, which may grow larger, causing the bud death. The insect eliminates large  amount of honeydew, accumulating on leaves and  apical parts, which starts the proliferation of sooty mold,  and fitopathogenic fungi. Leaves of the attacked  lants become deformed, smaller than the  normal ones, distorted, or with flaws among the ribs and sooty mold reducing the photosynthetic capacity.  Due to damages provoked by the bites, oviposition,  sooty mold accumulation and other fungi, the sprout  die and the plant loses the apical dominance, which  induces an over sprouting. In addition, the attack of C. spatulata causes a decrease of diameter growth and the formation of shorter internodes, resulting in a  higher fragile area. Anatomical cuts of the seedlings,  infested with C. spatulata where there was an over  sprouting, presented areas with larger number of  gelatinous fibers, less  lignified. These fibers are less  resistant, turning the stem more fragile and susceptible  o breaking due to wind or even its own weight. Besides, the attacked  plants presented anatomical modifications in pores arrangement and thicker bark.