Japanese Journal of Environmental Entomology and Zoology Vol. 15(2004) No. 4

A post-treatment survey of intestinal helminth infection was conducted in three villages on Sumbawa Island, Indonesia in August 1997. A total of 199 subjects, who were given a dose of albendazole in December 1996 and / or January 1997, took part in this study by submitting fecal samples. The overall prevalence of infection was 31%, with no significant differences between males (32%) and females (30%), or between children (30%) and adults (over 15 years) (32%). The highest prevalence was seen in Utan village (42%) followed by Labanka village (39%) and Penyaring village (16%). Trichuris trichiura was the most common parasite detected, followed by hookworm, Ascaris lumbricoides and others. The mixed infection rate was very low (5%), as was the infection intensity.

Attempts to evaluate the mutagenecity of twelve commercial and seven home-made pyroligneous acid (PA) products employing the umu test were unsuccessful because of the presence of anti-bacterial components in the products, which inhibited the growth of S. typhimurium, the bacteria used for the test. When the assay was conducted with diluted solutions of three selected products in the range 1∼10⁶ ppm, positive reactions were obtained in the presence of metabolic activator S-9 Mix, although the A₆₃₀ values obtained were too low to confirm their mutagenecity. However, when several PA products were subjected to the umu test after removal of the anti-bacterial components on Sep-pak tC18 column, they all showed a positive reaction for mutagenecity. The simple clean-up method employed in the present study appears useful for evaluations of mutagenecity of samples such as PA products that consist of multiple components.

Adult population sizes of ground beetles (Carabidae) in a forest and vegetable field in Nagano Prefecture, Japan were estimated using the removal method. Removal collections using 15 pitfall traps with a lactic acid beverage were conducted at 40-m² survey sites enclosed by a thick plastic sheet for 10 days in September 2002 in the forest site and October 2003 in the field site. Dominant species were Synuchus cycloderus, Pterostichus subovatus and S. nitidus in the forest, and Harpalus griseus, H. sinicus and Amara simplicidens in the field. Population sizes within the 40-m² sites and the density (/m²) of total carabid beetles and dominant species were estimated by the regression and maximum likelihood methods. A total of 250 and 176 carabid beetles were caught in the forest and field sites, and estimates by the regression method were 254 and 180 individuals, respectively. Estimates of dominant species and total carabid beetles by the maximum likelihood method were almost equal to those obtained by the regression method. The observed numbers caught from 10 trappings were almost the same as the estimated values. The correlation coefficients between the number of individuals captured during the ith trapping and the total number captured prior to the ith trapping were less than -0.9, and the precision level of the estimations was less than 0.12. The prerequisite for the removal method and appropriate number of trappings required for estimating carabid population size were discussed in relation to the precision level of the estimations.

Females of the pea blue butterfly Lampides boeticus fly to the young flower buds of the yam bean plants Pachyrrhizus erosus and the lablab bean plants Dolichos lablab, and equally lay eggs on them. No damage to the yam bean induced by the butterfly larvae was observed. But the larvae gave serious damage to the lablab bean growing up in the vicinity of the yam bean. Distinct difference of damages between both plants seemed to be caused by the defense mechanism of the yam bean plants using natural toxins. Possible defense principles were isolated and identified as four rotenoids cis-12a-hydroxymunduserone, cis-12a-hydroxyerosone, cis-12a-hydroxyrotenone and rotenone from flower buds, seeds and leaves of the yam bean on the base of the larvicidal toxicity toward the common armyworm Mythimna separata. The activity of each principle was quantitatively evaluated. In addition, the relationships between herbivores and the presence of principles were discussed.

The infestation of houses by Incisitermes minor (Hagen) was surveyed in Kansai and Hokuriku areas (9 prefectures) by means of a postal questionnaire sent to termite control companies. Of the 96 companies that responded, 31 of them, located among Hyogo, Osaka, Wakayama, Toyama, and Fukui Prefectures, reported finding I. minor attacks in houses they had inspected. Approximately 83% of the infested houses were wooden post and beams constructions. Worker (nymph) castes were the most commonly found caste in infested houses. The infestation was usually detected by fecal pellets under the infested timbers. Roofing materials such as rafters, trim, boards, beams, pillars, and lathing boards, and interior materials such as window frames, door frames, pillars, poles, and paper doors were the most susceptible parts. Spraying with insecticide was the most common countermeasure taken to combat infestation.

We observed that the larvae of coffee bean weevil Araecerus fasciculatus DeGeer (Coleoptera: Anthribidae), a cosmopolitan pest infesting various stored crops such as cottonseed, coffee bean and orange fruits, bored into dead stems of the giant ragweed Ambrosia trifida (Asteraceae) at the riverbank of the Yamato River, Osaka City, central Japan. The larvae fed on the pith of the giant ragweed, pupated and eclosed in the pith and exit from it. Judging from the size of the larvae that were found in the field and developmental period which has been reported so far, oviposition may have occurred from autumn to early winter when the giant ragweed ceased its growth. The giant ragweed may function as a breeding site for A. fasciculatus in natural setting, resulting in infestation to orange fruits and stored crops.

Butterfly communities were studied in four urban housing complexes: Satsukigaoka-danchi (Satsukigaoka), Higashitoyonaka-daiichi-danchi (Higashitoyonaka), Asahigaoka-danchi (Asahigaoka), and Kori-danchi (Kori), in northern Osaka in 1998. The numbers of species and densities (km^-1) ranged from 16-25 and 14.1-24.6, respectively. The most abundant species was Pseudozizeeria maha in 3 sites, and Pieris rapae in Kori. Rebuilding of a housing complex led to the reduction of species and density. For example, densities in new building areas were 0.3-0.4 times those in old ones. This reduction is considered to be due to the loss of the grass around buildings.