Taxonomy and the comparison of gall-forming habits among pit galls induced by psyllids ( Hemiptrea: Psylloidea ) on eleven host plants

• Main Authors: Shih Shu Huang, 黃世樹
• Other Authors: Man- Maio Yang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/16691022130030162883

碩士 === 國立中興大學 === 生命科學院碩士在職專班 === 91 === Galls of psyllids could be generally divided into two major categories, the open and the enclosed types. The majority of open-type galls are pit-like and they are mostly formed by the psyllid genus Trioza. The focus of this study is the morphology, gall-forming biology and host specificity of pit gall-forming psyllids that generally found in central and northern Taiwan. Galls from 11 host species, belonging to 4 families, were collected. Fifth instar nymphs and adults of pit-gall forming psyllids that collected and reared from each host were examined. A total of eight species are determined and seven of them belong to Trioza. Two of them are new species, i.e.T. osmophloe sp. nov. on Cinnamomum osmophloeum Kanehira and T. acuminatissima sp. nov. on Neolitsea acuminatissima Hayata. The other six are recorded species, T. camphorae Sasaki on C. camphora (L.), T. inoptata Fang on Machilus zuihoensis Hayata and M. zuihoensis var. mushaensis (Lu), T. machilicola Miyatake on M. japonica Sieb. & Zucc. and M. thunbergii Sieb. & Zucc., T. syzgii Li and Yang on Syzygium jambos（L.）and S. samarangense Merr. et Perry, Cecidotrioza sozanica Boselli on Daphniphyllum glaucescens Blume. var. oldhamii and T. nigra Kuwayama on Styrax formosana Matsum. var . formosana. Distinct morphological differences are obviously found among psyllids from different host families or genera. However, psyllids from different host species belonging to a same genus are similar to each other, such as those pit gall formers from various host species of Machilus. It is evident that species of psyllids feed on a narrow range of host plants, usually within a single plant genus. Pit galls, which are less differentiated, could be classified as organoid or kataplasmatic galls. In addition to the above histological classification, three types of pit galls could be categorized based on their arrangement on the leaf lamina. The first type is that each gall is isolated and independent; most galls of the current study belong to this category. Galls of the second type are close to each other and forming a row on each side of the vein; the only member of this type is the pit gall on Neolitsea acuminatissima. Galls of the third type are close to each other on a leaf and formed a larger compound pit gall; the only member is the galls on Daphniphyllum glaucescens var. oldhamii. Pit galls on Styrax formosana var. formosana are unobvious and less modified in shape and color. Its gall former, Trioza nigra, is not absolutely sedentary like other pit-gall formers and may move about when disturbed. It is hypothesized that galls of T. nigra could be an intermediate stage between free-living and gall-forming ones. On the other hand, galls of Cecidotrioza sozanica of Daphniphyllum glaucescens var. oldhami formed a compound and nearly sub-globular galls which suggests that it might be a transition stage between monothalamous and polythalamous galls. There is a preference of gall-forming site on the leaf blade (76.6%) rather than on leaf margin or mid-rib. Most of the galls are distributed on the leaves numbered 1 ~ 5 counted from the base of a twig. There is no correlation between the number of galls and the leaf length, neither of that to the leaf width. The number of stomas on normal tissue is significantly higher than that of the pit gall tissue.