Twenty-four different combinations of six temperatures (15°, 20°, 25°, 30°, 35°, and 40°C) and four relative humidity (RH) (60%, 70%, 80%, and 90%) conditions were used for pseudergates of the western dry-wood termite Incisitermes minor (Hagen). The feeding activities of the termites were monitored by the detection of generated acoustic emission (AE) events from feeder wood blocks in a test chamber. Temperature and RH showed independent and interactive significant effects on the feeding activity of I. minor. The optimal temperature and RH conditions for the feeding activities were 35°C and 70%, respectively, and the optimal combinations were 35°C-70% and 35°C-80% with an exceptionally higher feeding activity at the combination condition of 30°C-70%.

Abstract. Indrayani Y, Muin M, Yoshimura T. 2016. Crude extracts of two different leaf plant species and their responses against subterranean termite Coptotermes formosanus. Nusantara Bioscience 8: 226-231. Crude extracts of plants consist of various chemical compounds useful for many purposes and their effectiveness depend on the comprising active ingredients and applied concentrations. This study was conducted to determine the chemical compounds of plant leaf extracts and examine their responses against subterranean termite Coptotermes formosanus Shiraki. Two tropical plant species [clove (Syzygium aromaticum) and cajuput (Melaleuca leucadendra)] were extracted with 70% ethanol solvent. As the two different plant crude extracts contain eugenol, though to have termiticidal performance, various concentrations (0.1%, 0.05%, and 0.01%) based on their eugenol contents were prepared with filter paper samples for the test. The termite mortality and mass loss of extract-treated and untreated control filter paper samples were determined after four weeks exposure. Results showed that crude extracts of different plant species showed different responses against the subterranean termites although they were applied at the same eugenol-based concentration. At the concentration of 0.1%, the crude extract of S. aromaticum caused termite mortality and consumption rates of 100% and 0.3%, respectively. Whilst, the crude extract of M. leucadendra caused significantly lower termite mortality (36.8%) and higher consumption (9.1%). Samples with lower eugenolbased concentration showed lower termite mortality and may have attractive effects on termites as indicated by higher consumption at the concentration of 0.01% compared to untreated controls. These results suggested that crude extracts of different two leaf species had different effects on subterranean termite C. formosanus eventhough they were applied at the same eugenol-based concentrations.

Indrayani Y, Muin M, Yoshimura T. 2017. Short communication: Diversity of tropical plants and their attractant properties for subterranean termite Coptotermes curvignathus. Biodiversitas 18: 1353-1357. The effectiveness of bio-based attractant from different leaves of tropical plants on subterranean termites Coptotermes curvignathus was examined under laboratory conditions. Five kinds of leaves of tropical plant such as cajuput (Melaleuca leucadendron L.), cinnamon (Cinnamomum burmannii (Nees & Th. Nees) Nees ex Blume, clove (Syzygium aromaticum (L.) Merr. & L.M. Perry), bay (Syzygium polyanthum Wight) and basil (Ocimum sanctum L.) were serving as termite feeding bio-based attractants for C. curvignathus. Bio-based attractants were obtained by cross cut dry leaves into smaller particles (dry weight 200 g) and dipped in 70% ethanol solution for 3 x 24 hrs. The extracts were then subjected to a rotary evaporator at 60 ºC until the extract changed to gel condition. 50 workers and five soldiers of C. curvignathus were tested in a no-choice test bioassay to determine their preferred bio-based attractant under the concentration of 10% and 50%. No-choice bioassays chambers were assembled by connecting two clear plastic glasses (bottom diameter 5 cm, top diameter 7 cm) with clear plastic hoses (inner diameter 3 mm, outer diameter 5 mm). Clear plastic hoses connectors allowed termites to move freely between glasses. A laboratory bioassay determined that the response of subterranean termite C. curvignathus on clove leaf was greater than other five leaves as indicated by termite moving time, and did not differ significantly between concentrations. No direct relationships were noted between the speed of the first termite moving time and number of termites recruited to the bio-attractant chamber.

Nowadays, the use of agricultural fibers for panel composite materials attracts great intention. Further, it is desirable to develop of natural adhesive derived from non fossil resources to be safe adhesive without using harmful chemical substances. In this study, citric acid application as natural adhesive was investigated for medium density fiberboard (MDF) manufacture from pineapple leaf fiber. The ratio of citric acid and sucrose and adhesive content was 25-75 and 20 wt%, respectively. Two different types of board consisting of three layers with t a r ge t d e n s i t y o f 0.8 gr/cm 3 were prepared. The board was hot pressed at 200ºC and 4.5 MPa for 10 min. Additional boards with same structure were prepared using citric acid only. The biological properties of the boards such as their resistance against subterranean termite attack have been examined. The results indicate that generally, there was a significant effect of impregnation with mixture of citric acid and sucrose and citric acid only on the susceptibility of the MDF board specimens. With regards to the percentage of specimen mass losses, fiber orientation had no significant effect on the termite resistance against Coptotermes formosanus Shiraki. Utilization of natural adhesive, citric acid was promising to be used for MDF manufacturing. Our findings show that the total adhesive content of 20% of the type a board could be used for agricultural fiber product applications to protect structures from degradation by termites.

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