No abstract

The Indo-Malayan drywood termite, Cryptotermes cynocephalus (Light) (Kalotermitidae), is considered one of the most invasive drywood termites in the Southeast Asian region. Once infesting a timber, the colony of a drywood termite is very difficult to be controlled. Thus, the best way to mitigate a new infestation of a drywood termite is by applying chemical protection on wood. In recent years, particular attention has been given by researchers to develop and use organic termiticides, such as essential oils extracted from plants as active ingredients. The objective of the present study is to evaluate the repellency performance of several economically important essential oils from Indonesia, such as Clove (Eugenia caryophyllata), Cubeb Pepper (Piper cubeba L), and Lemon Grass (Cymbopogon winterianus Jowitt) against a drywood termite, C. cynocephalus. The test was performed by subjecting various concentrations of essential oil toward C. cynocephalus in the force-feeding test method. Sample weight-loss was evaluated after two weeks test. The results suggested that Clove oil has the highest repellence performance against C. cynocephalus, followed by Lemon Grass and Cubeb Pepper oils. The Termite mortality rate was also recorded to understand the toxicity performance of those essential oils.

We conducted surveys of termite assemblages and tree trunks damaged by termites in teakwood (Tectona grandis L.f.) plantations. The surveys were conducted in five-, six-, and nine-year-old plantations. We used a standardized belt-transect to collect termites and build tree inventories. Data of collected termites at the genus and functional-group levels and termites’ diversity between plantations were compared with their attack rate. The results showed that four genera of soil recycler termites belonging to groups IIf and III were present across the plantations. Distribution analysis suggested that termite communities might develop from a stochastic distribution to a nonrandom co-occurrence distribution over time. Diversity analysis showed an increased nestedness-resultant diversity contribution to the total dissimilarity over time. Observed attacks on tree trunks were superficial and limited to the outer bark, with group IIf as the main contributor. Furthermore, the level of damage done by termites to tree trunks was positively correlated with increases in the group IIf occupancy area and overgrown understory vegetation. Plantation management by maintaining an adequate understory might suppress termite attacks on fast-growing teakwood, although in the case of our study, termite attacks are inevitable when termites from group IIf were already present.

Powderpost beetles such as Lyctus africanus are a common pest group for dried cured wood, causing significant harm to wood and wood products. We examined the life span and effects of aging and mating status on pheromone production in the powderpost beetle L. africanus (Coleoptera: Lyctinae). Experiments compared starved and unstarved male groups, and chemical analysis was used to determine factors affecting pheromone production. Regarding lifespan, male beetles provided food survived up to 14 weeks, while starved beetles died before the fifth week. Thus, an adult L. africanus male may require food throughout its lifespan, and food availability may affect pheromone production. There was no significant difference in the quantity of two major pheromone compounds, compound 2 (3-pentyl dodecanoate) and 3 (3-pentyl tetradecanoate) between mated and un-mated males. On the other hand, a minor compound, compound 1 (2-propyl dodecanoate) showed increased quantity after mating. The two major compounds were produced in low amounts by young L. africanus beetles, increasing until the fifth week, and beginning to decrease at the ninth week. The minor compound was produced steadily without significant change up to 9 weeks. Our results represent a step forward in the knowledge of the chemical communication of this important pest.

No abstract

Cymbopogon nardus, Syzygium aromaticum, and Citrus sinensis have been well known to possess insecticidal activity. Here, we investigated the repellent activity of individual of three essential oils (C. nardus, S. aromaticum, C. sinensis) and a combination of essential oils (C. nardus + C. sinensis, C. nardus + S. aromaticum, and C. sinensis + S. aromaticum) against a dengue vector, Aedes aegypti and a filarial vector, Culex quinquefasciatus. The essential oils (1 mg) were smeared evenly on the surface of the left arm (three volunteers) and then subjected to 25 females of A. aegypti and C. quinquefasciatus in the cage. The number of landed mosquitos was observed every hour for 7 hours to determine the protection index (PI). The result showed that individuals of three essential oils and a combination of essential oils generated > 90% of PI until 7 hours of application for both mosquitos species tested. Overall, the data demonstrated that individual of three essential oils, i.e., C. nardus, S. aromaticum, C. sinensis, and various combinations of essential oils (C. nardus + C. sinensis; C. nardus + S. aromaticum; C. sinensis + S. aromaticum) are promising as repellent agents against A. aegypti and C. quinquefasciatus.

Ectoparasitic fungi grow on the body surface of termites, and they might effect on behavior, reproductive, and survival of host termites. There are two common species of ectoparasitic fungi found on termite: Laboulbeniopsis gallica Thaxt and Antennopsis gallica Buchli and Heim. In this study, the distribution of L. termitarius and A. gallica in Reticulitermes spp. colonies in Japan was observed. Meanwhile, the infection rate and strength of L. termitarius and A. gallica were discussed with references to the effects of environmental factors at the collections sites. In a total of 63 colonies of Reticulitermes spp. were collected from seventeen locations (from Hokkaido Prefecture to Okinawa Prefecture) in Japan. Five hundred workers and twenty soldiers from each colony were examined individually to see the infection of L. termitarius and A. gallica. The survey showed that L. termitarius distributed in whole Japan and A. gallica had a little bit restricted distribution. The infection rate of workers of Reticulitermes spp. varied among all locations: 0.10 – 16.10% for L. termitarius and 0 – 66.40% for A. gallica. No infected soldiers were observed. The negative relationship between temperature and infection rate was speculated in both fungi. Rearing the colonies in the laboratory might result in the spreading of the fungi in the colonies. Both fungi grew on any body parts of the termites. The trials for isolation and cultivation of Laboulbeniopsis termitarius and A. gallica with eight media did not succeed under the laboratory conditions.

Isolation of phytopahtogen and antagonistic fungi is important in the efforts for managing phytopathogen infestation in cacao plantations. It is related to developing studies to evaluate the association between the two types of organism in the context of establishing integrated pest management to manage widespread pest and disease in cacao crop. This research objective is to study and isolate phytopathogens and antagonistic fungi on cacao. Fungal isolation was conducted from black diseased-cacao pod and soil samples through surface sterilization and serial dilution, respectively. After several culture purification, four fungal isolates were identified through macroscopic colonies and microscope observation. Those fungal isolates are Curvularia, Fusarium, Aspergillus and Trichoderma. Further research is necessary to test their antagonistic and or synergistic associations in laboratory and field scales.