عنوان مقاله [English]
Introduction:The subterranean termites make large damage to wood and cellulosic products. They can have the destroying effects on forest plantations, agriculture crop, and urban landscaping. According to the previous studies, Microcerotermesgabrielis Weidner is the most important termite of the Alborz province belong to the family Termitidae. This species is also reported in the central, the northeastern and the southern regions of Iran. MicrocerotermesvaraminicaGhayourfar, Amitermesvilis (Hagen), A. kharaziiGhayourfar, Anacantthotermesvagan (Hagan) have been also reported from Tehran province.Chemical control of termiteis the most conventional method ofcontrol. A few insecticides have acceptable termiticide effects. However more of them have negative effects on the other non-targets organisms in the environment, and may run off into groundwater. Thus we wouldconsiderthe other methods of termite control. Usage of native and natural resistant plant species can be reasonable strategy against termitesinafforestation. Plant species are food sources for termites, however, they differ in their palatabilityand can affect termite preference. There are some studies have reported differences in feeding rates and preferences of termite species amongdifferent species of woody plants. Tree Shalamzar Plantation, encompassing 54 ha in the southern Alborz mountain range have sustained termite damage since 2013. The objective of this study was to evaluate the natural resistance of eight different sapling species to termite´s damage in this region.
Materials and Methods: Termites were collected from four infested locations within Shalamzar Plantation, Karaj, Iran. Infested saplings with active termite tunnels were visited and soldier termites collected and transferred to the systematics lab for species identification using a systematic key of Iranian termites. Termite infestation rates were estimatedfor each of 8 sapling species. Ten saplings of each species were randomly selected and examined from the four infested locations. Termite-free saplings with no damage or mud tunnels were designated as healthy 'control' plants. Infestation rates were calculated based on the number of infested saplings per total number of each sapling species. The saplings were classified by the termite damage in five categories:1. health (0% damage ) 2. Low ((>0 to 25%) 3. Medium ((>25 to 50%), 4. High ((>50 to 75%) 5. Dead ((>75 to 100%). Data on percentage of infested saplings from each species were subjected to PROC GLM model in completely randomized design. Differences among means were analyzed using LSD Test (P≤0.05). Termite damage was analyzed using the Kruskal–Wallis test. Mean termite damage rates and frequency of damage groups in each plant species were estimated.
Results: The results showed that Microcerotermesgabrielis is only damaging termite species on the studied saplings in these regions. Juniper and mountain almond species had no termite infestation and were resistant to its attack. Silverberry and hackberry species were the most susceptible saplings to termite damage with a 65 and57.5 % infestation rate and 60.44 and55 % dead rate, respectively. Judas sapling plants had over 60% termite infestation rate, sustained 20% mortality. It is tolerant species to termite. Ash and barberry species hadless than 50% oftermite infestation and their dead plant rate was 35.42and 28.33 %, respectively. Thus, the species of juniper and mountain almond saplings can be replaced by dead saplings.
Discussion: Microcerotermesgabrielis is the primary sapling-damaging pest on the southern Alborz mountain slopes. This is the first report of termite attacking saplings in Iran. Susceptibility of saplings to termite damage varies with termite species. Microcerotermesspp. prefers to feed Faqus sp., whereas Microtermes sp. feeds more Piceasp. and Odontotermes spp.feeds live plant tissue and tree bark. Hackberry and silverberry saplings were preferred by M. gabrielis, whereas the species ofjuniper and mountain almond showed resistant totermite´s infestation. There are many factors affecting termite feeding preference. Wood moisture and densityaffect wood palatability to termite, and some plant chemicalssuch as phenol compoundsand lignin ofwood act as antifeedants and repellents on termite.
Conclusion: The species of juniper and mountain almond saplings were the most resistant to M. gabrielis.
Amongsaplings sustaining damage, Judas tree had also the lowest mortality. So, three species ofjuniper, mountain almond and Judas are recommended to be considered for tree planting in locations where M. gabrielis has infested the soil. It is prudent to identify the predominant tree-damaging termite species in areas designated for afforestation, and determines the plants and trees that are the highest levels of resistant to damage by indigenous termites prior to conducting planting operations.