Comprehensive Investigation of Die-Back Disease Caused by Fusarium in Durian.

Durian (Durio zibethinus L.) is an economically important crop in the southern and eastern parts of Thailand. The occurrence of die-back disease caused by plant pathogenic fungi poses a serious threat to the quality and quantity of durian products. However, the identification of causal agents has been a subject of mixed information and uncertainty. In this research, we conducted a comprehensive investigation of die-back disease in nine durian plantations located in Thailand. By analyzing a total of 86 Fusarium isolates obtained from infected tissues, we aimed to provide clarity and a better understanding of the fungal pathogens responsible for this economically significant disease. Through a combination of colony characteristics, microscopic morphology, and a multilocus sequence analysis (MLSA) of the internal transcribed spacer (ITS) region, translation elongation factor 1-α (TEF1-α) gene, and RNA polymerase II gene (RPB2) sequences, we were able to identify and categorize the isolates into three distinct groups, namely, Fusarium incarnatum, F. solani, and F. mangiferae. Koch's postulates demonstrated that only F. incarnatum and F. solani were capable of causing die-back symptoms. This research represents the first report of F. incarnatum as a causal agent of die-back disease in durian in Thailand. Additionally, this study uncovers the association of ambrosia beetles and F. solani, highlighting the potential involvement of E. similia in facilitating the spread of die-back disease caused by Fusarium in durian.

Loboschiza Diakonoff (Lepidoptera: Tortricidae) from Thailand with descriptions of four new species.

Four new species of Loboschiza Diakonoff collected from the Nakhon Ratchasima, Chanthaburi, Nakhon Nayok, Sa Kaeo, Nakhon Si Thammarat, and Nakhon Pathom provinces of Thailand are described: Loboschiza spiniforma Anan and Pinkaew, n. sp.; Loboschiza bisulca Anan and Pinkaew, n. sp.; Loboschiza subrectangula Anan and Pinkaew, n. sp.; and Loboschiza lunata Anan and Pinkaew, n. sp. Loboschiza koenigiana (Fabricius) is redescribed. Illustrations of adults and genitalia are provided.

Fine structure of wing scales of butterflies, Euploea mulciber and Troides aeacus.

Wing scales of male Euploea mulciber (E. mulciber) and Troides aeacus (T. aeacus) butterflies were investigated from interest in photonic crystal by scanning electron microscopy and optical reflectance measurement. On the basis of the structural observation, the colouration in different areas in their wings was discussed. It was particularly deduced that a violet-green iridescence characteristic of E. mulciber's forewing is caused only in a wavelength range from ∼380 to ∼510nm by multiple interference from a highly tilted, triple-layered cuticle arrangement on the brown scales. It was also found that T. aeacus does not produce a blue-green sheen such as observed by Troides magellanus because its scales have no multiple cuticle layers but microrib layers unable to produce any backscattering diffraction.