• Journal of Ecology and Environment
• /
• v.30 no.2
• /
• pp.179-186
• /
• 2007

The diversity of spider communities was investigated in the pine forest of Pinus densiflora in Songri-san, where chemical pesticides had been applied to control pine gall midge (Thecodiplosis japonensis). Spider communities were surveyed in four areas: a pesticide-untreated natural forest (area A), a forest with vinyl-covered ground surface (area B), an aldicarb-treated forest (area C) and a forest treated with a systemic pesticide (phosphamidon) (area D). A total of 74 spider species from 17 families were collected from the four survey areas. There were 54 species from 15 families in area A, 27 species from 12 families in area B, 29 species from 9 families in area C and 34 species from 9 families in area D, respectively. The species diversity of spider communities was highest in pesticide-untreated area A, and much lower in the other three areas. The monthly species diversity of spider communities was highest in May and lowest in January. The similarity of the spider communities was highest in areas B and D. The monthly similarity of the spider communities was highest in November and February. The dominant species was Clubiona jucunda (12.71%, N=304 individuals). According to our results, the application of aldicarb and phosphamidon dramatically decreased spider diversity and the number of individuals in the forests. Thus, the application of these two pesticides to natural forests should be restricted, or alternative pesticides need to be developed. Our results also indicated that application of the pesticides should be avoided in May and June when high spider diversity is expected.

• Korean journal of applied entomology
• /
• v.33 no.3
• /
• pp.201-206
• /
• 1994

Trunk implantation method of phosphamidon 50% Lq.is commonly applied to control the pine needle gall midge (Thecodiplosis laponensts Uchida et Inouye) Since trunk implantaion is normally practiced during the late Spring, it is often difficult to accommodate necessay labor in mral area. As an alternative, aerial spraylng of less toxic ~nsecticide was designed. Usage of less toxic insecticide in the aenal control of pine needle gall midge can reduce the damage to forest ecosystem. The buproferin, one of the insect growth regulator, was selected at d~fferent rate of dilutions and the treatments effects ruere evaluated at different date and time When 50 t~mes diluted solution of buprofezin 40% SC was treated on different period, there was no significant difference in dficacies. the control efficacies of buproferin 40% SC was measured by occurrences (%) of gall formation of the pine needle gall midge using a ultra low volume (ULV) sprayer and the dilutions of 10X 30X and 50X of buprofez~n 40% SC gave efficacies. 72.4. 57.6 and 8.4, respectively.

• Korean journal of applied entomology
• /
• v.21 no.3 s.52
• /
• pp.163-166
• /
• 1982

The pine needle gall midge, Therodiplosis japonensis Uchida et Inouye, is the most important insect pest. It requires two different habitats for the development; on trees and under the ground. The habitat specific mortality rates ere $30\~40\%,\;and\;50\~60\%$ for the respective habitats. The key developmental stage is the prepupa, and the key mortality factor is the moisture contents of the soil and its variability. Since the insect is an exotic, the population status is the periphery and in the source of infestation are considerably different. Such a difference in habitats and the population status of the insect should be considered in relation to suppression of the insect. The control strategies should be directional and rational based on the reality of the pest status. There have been substantial information on the control methods of the pine needle gall midge, and each control method has an important place, but none has always provided a satisfactory solution to the many problems associated by this insect. These methods should be applied to a system based on the ecology of the insect. There should be continued support for directed effort on the development of operational management systems for the insect: specifically, estmation of the critical economic injury level, and of the absolute density of the insect.

• Journal of Korean Society of Forest Science
• /
• v.89 no.2
• /
• pp.256-259
• /
• 2000

D.B.H., height, crown length, crown width, crown form, crown area, and crown volume of dead and live trees were measured and the discriminant analysis was conducted to assess individual tree risk-rating in the pine forest seriously infested by the pine needle gall midge. Thecodiplosis japonensis. Crown length, crown form, crown area, and crown volume of live tree were significantly higher than those of dead tree, while D.B.H. and tree height were not different significantly. These results represent that the trees with higher and wider crown and larger crown volume have relatively higher probability to survive from the infestation by the pine needle gall midge. Variables selected in the functions of discriminant analysis were crown area, ratio of crown length, crown form, ratio of crown volume to crown area, and ratio of crown width.

• Journal of Korean Society of Forest Science
• /
• v.9 no.1
• /
• pp.45-48
• /
• 1969

The objective of this research was to investigate the seasonal trends in the population of the larvae of the Pine gall-midge in the spring at field. 1. The comparative ratio in the number of larvae of the Pine gall-midge was 100 in early spring, 29 at April 15th and 10 at May 4th. 2. Probably, the seasonal decrease in the number of larvae at field may be due to the gradual rising in the temperature and decreasing the relative Humidity season the experiment was conducted. 3. Water selection method gave best results in collecting the larvae from soil.

• The Korean Journal of Ecology
• /
• v.6 no.1
• /
• pp.33-44
• /
• 1983

Vegetatiion structure and population dynamcis of pine needle gall midge were investigated from 1980 to 1982 at the southern part of Palgong mountain near Daegu. The results of investigation at the areas of A (pure stand), B(30% mixed forest) adn C(60% mixed forest) were as follow; Vegeation of 3 areas were not classified by the species diversity, but by the unequal distribution of Alnus hirsuta, Robinia pseudo-acacia, Lespedeza cyrtobotrya, Quercus variabilis and vitality of Pinus densiflora at the area C was low, due to shadow by broad-leaf trees. Soil environmental factors at 3 areas not characteristic, but the average of humus contents showed high significance and the order was A

• Journal of Korean Society of Forest Science
• /
• v.79 no.2
• /
• pp.115-126
• /
• 1990

This study was performed to find differences in phototaxis response of the larva, adult emergence, sex ratio and gall formation rate of Thecodiplosis japonensis Uchida et Inouye between two areas, north and south. Larvae from these two areas, Hweng-sung in north and Moo-an in south, both considered to be the sities of severe outbreak of the insect recently, were collected from the floor and transported to the entomology larboratory, Won-Kwang University in Iri, then overwintered. These larvae were used for various experimental purposes on various dates. The following results were obtained. 1. The sizes of larvae reached 2.45 in length, 0.70 in width for north, and 2.50 in length, 0.72 in width for sourth. It seems that the differents were not significant. 2. It is known that Leaving gall of larvae to the ground for the hibernation usually occurs on rainy days. For the larvae dispersion, the phototaxis response of the larvae was hypothesized. To check this, the author manipulated some different illumination intensities adjusting the distance between the glass tube in which 100 larvae were contained and electric bulb. The glass tubes were blackened all but except a small portion. The phototaxis responses between two areas seemed to be different particularly at low light intensities, 45, 145 and 1000 lux, The larvae from north assembled to the clear portion of the glass tube were more than 30 out of 100, however less than 30 in south sample regardless of the time passage. In either cases, the saturation points came after about 8 to 10 hours. If temperature units were used, the phototaxis curve= after 1 hour illumination between two areas provided significant differences. 3. The adult emergence of south area was lagged 10 days later than that of north area. The accumulated effective day-degrees of temperature for adult emergence were $934^{\circ}C$ for north area and $1180^{\circ}C$ for south area. The emerging duration of north area appeared to be in late May through the early of July and the peak emergence occurred in middle June that was approximately 15days earlier than that of south area. The sex ratio of female to male, regardless of area, was approximately 3 : 1. 4. The rates of gall formation of the red pine(Pinus densiflora Siebold et Zuccarini), 6-year-old seedlings, were as low as 9.94% for north area and 8.87% for south area. Through the close observation, the author presumed that the population reduction was greatly affected during the prepupa stage by relative moisture content and predators, such as spiders and ants presented on the ground.

• Korean journal of applied entomology
• /
• v.18 no.2 s.39
• /
• pp.111-116
• /
• 1979

The experiments were carried out to evaluate the effectiveness of some insecticides in the control of the pine gall midges (Thecodiplosis japonensis Uchida et Inouye) when the low-volume of the insecticides were applied by the mist foliar sprayer. The insecticides, Salithion $(24\%\;Ec)$, Omethoate $(Folimat^{(R)}\;50\%\;Ec)$, Monocrotopos $(Azodrin^{(R)}24\%\;Ec)$, Acephate $(Ortran^{(R)}\;50\%\;Wp)$, Metalkamate $(Bux^{(R)}24\%\;Ec)$. BPMC $(Bassae^{(R)}50\%\;Ec)$ and MIPC $(Mipcin\;50\%\;Wp)$ were tested with 100, 200 and 400 times of water solution on the basis of single application at the six different intervals. Salithion was the most effective for the pressure of the gall formation by the pine gall midges and Omethoate, Monocrotophos and Metalkamate were relativey effective and others no effective. The most reliable concentration of the insecticides was 100 times of water solution, and the feasible timing of insecticide application on the basis of single application would be from May 9 to July 1 with Salithion, June 6 with Metalkamate and June 20 with Omethoate and Monocrotophos. The number of pine needles with the larval injured signs (no larvae in the needles) excluded the gall-formed needles were relatively higher in the treatments of Omethoate, Salithion and Monocrotophos than other insecticides. The treatments of Omethoate, Salithion and Monocrotophos caused the lower larval population in the gall than other insecticides.

• Journal of Korean Society of Forest Science
• /
• v.61 no.1
• /
• pp.20-26
• /
• 1983

Some aspects of the change in the rate of gall formation on the red pine, Pinus densiflora Siebold et Zuccarini, by the pine needle gall midge, Thecodiplosis japonensis Uchida et Inouye, were investigated at the coastal area in Chung Nam-Do from 1977 to 1982, and were analyzed with the nationwide survey data for 2 years from 1980 to 1981. The results obtained were as follows; the gall formation rate in several areas was compared between two consecutive generations. Four regression equations were established, with X as the gall formation rate in N year and Y as that in (N+1) year: 1) Y=11.2+1.15X (r=0.833) for the stands facing north on the phase of insect population increase, 2) Y=14.3+0.82X (r=0.739) for the stands facing south on the phase of population increase, 3) Y=7.3+0.46X (r=0.478) for stands facing north on the phase of population decrease and 4) Y=11.4+0.19X (r=0.086) for stands facing south on the phase of population decrease. After invasion of the pine needle gall midge into a red pine forest, gall formation rate increased for 6 consecutive generations and then decreased to low level within a period of another 6 years.

• Journal of Korean Society of Forest Science
• /
• v.9 no.1
• /
• pp.49-54
• /
• 1969

As one phase of the biological control of the Pine gall-midge, Thecodiplosis japonensis Uchida et Inouye, this investigation on birds as a vertebrte predator of the larvae of Pine gall-midge was carried out. Species of the birds as predator, number of the larvae as prey for individual birds and seasonal trends of the prey quantity were studied. This work was carried out during the late fall of 1967 and 1968 at Kwang Nueng Forest which is one of the heavily infested districts by the Pine gall-midge. 1. Korean Great-Tit, East China Marsh-Tit, Quelpart Coal-Tit, White-headed Long-tailed Tit, Varied Tit, Kamchatkan Rustic Bunting, Yellow-thrated Bunting, Chestnut Bunting and Korean Goldcrest were found to be the predator of the larvae of Pine gall-midge. 2. The average number of larvae as prey found from individual predator bird species were approximatly 108 for Kamchatkan Rustic Bunting, 17-64 for East China Marsh-Tit, 25-28 for Korean Great Tit and 36 for Quelpart Coal Tit. 3. The seasonal change in the number of the larvae which fell into the ground affected the seasonal trends of the prey quantity of the predator birds 4. Among the 380 birds examined, 157 birds were found to attack the larvae of Pine gall-midge.