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本文报导了在印度喀拉拉邦白蚁对在新近砍伐过的天然林地种植细叶桉Encalyptus tereticornis和巨桉E.grandis所造成损害的特点和影响破坏发生率的因素进行的一系列研究。一般,白蚁危害地表以下几厘米的植株主根和切断根系而导致植株死亡。可以识别三种类型的破坏:1)主要破坏健康生长的植株;2)第二类是破坏由于其它原因致死的植株;3)第三类则是白蚁的危害和其它因素的联合作用下导致植株的死亡。第一类型的破坏是造成植株多数死亡率的原因,在大多数桉树试验林内,有20～80％的植株死亡,虽然在某些试验林内损失低于10％。4～6月树龄的幼桉植株定植至大田后,多数的死亡出现在最初的4个月内。而在定植一年以后则几乎没有植株死亡。同通常的看法正好相反,在干旱和白蚁破坏发生率之间没有确切的联系。在本次研究中发现有9种白蚁取食生活桉树的根。这9种白蚁是笨白蚁属(Eurytermes)一种、近歪白蚁属(Pericapritermes)一种、蛮白蚁属(Microtermes)一种和土白蚁属(Odontotermes)五种。在其它小生境中也发现了取食根部的某些白蚁种类。少数白蚁种类对茎皮造成不足以死亡的危害。本文讨论了在桉树种植园的幼树中确定白蚁危害发生率方面各种生物学和环境因子的重要性,以及可以断定白蚁危害发生率受几种有效的联合因子影响。
This article reports on a series of studies conducted by termites in Kerala, India, on the characteristics of damage caused by Encalyptus tereticornis and E. grandis grown in freshly cut natural forests and the factors that influence the incidence of damage. In general, termites endanger the root of plant roots a few centimeters below the earth’s surface and cut off the root system, leading to plant death. Three types of disruption can be identified: 1) plants that primarily destroy healthy growth; 2) those that destroy plants that are lethal for other reasons; 3) the third category is the combination of damage from termites and other factors that lead to plant Death. The first type of damage is the cause of most plant deaths, with 20-80% of the plants dead in most eucalyptus test forests, although less than 10% is lost in some of the test forests. After 4 to 6 months old eucalyptus plants were planted in the field, the majority of deaths occurred within the first 4 months. After planting for one year, almost no plant died. Contrary to popular belief, there is no exact link between the incidence of droughts and the destruction of termites. In this study, nine kinds of termites were found to feed the roots of living eucalyptus. The nine termites are Eurytermes, a species of Pericapritermes, a species of Microtermes and five species of Odontotermes. Some other species of termites are also found in other niches. A few species of termites cause insufficient damage to the bark. This article discusses the importance of various biological and environmental factors in determining the incidence of termite damage in saplings of eucalyptus plantations, and can determine the incidence of termite damage affected by several effective combination factors.