The repellency of several insecticides to the nymphs of German cockroach, Blattella germanica was evaluated by observing the distribution of their feces in a test arena. Middle to last stage nymphs of the German cockroach excreted mean number of 14 spots of feces per day in the arena (radius 13cm, height 17cm) when they fed on mouse foods and water. When the arena was divided into four fan-shaped sections, 70% of the feces were excreted in the harborage section, while the rests were excreted in food, water or blank (harborage free) sections. When the harborages had been treated with 0.05% solution of several kinds of insecticide, the nymphs excreted more feces in the insecticide-free harborage sections than in the insecticide-treated sections. In particular, after use of permethrin EC, propoxur WP or fenitrothion EC, the number of feces in that section was much smaller and the mortality in 24 hours was low due to the repellency against those insecticides. After the use of cholorpyrifos-methy EC, diazinon EC or diazinon MC, the feces numbers were relatively large and the mortality was high.

View full abstract

To establish measures against outbreak of housefly, Musca domestica L., from organic fertilizers, inhibition effects of several agents known as stimulants to the human gustatory sense on the larval development have been studied. The emergence of 0-day-old larvae were completely inhibited, with 200mM of denatonium benzoate in water solution, 1,000mM of citric acid, 2,000mM of sodium chloride and 750mM of sucrose. The IC₅₀ values of these stimulants showed 35.44, 313.02, 331.39 and 218.02mM, respectively. The larval developments with denatonium benzoate and citric acid were similar to without medium. On the other hand, with sodium chloride and sucrose, the pupation and emergence rates of the 2-day-old larvae and the emergence rates of the 4-day-old larvae reduced to 14-66%, and deformed pupariums were appeared. The 0-day-old and 2-day-old larvae repelled the media with 100% inhibition concentration of the respective stimulants for the 0-day-old larvae. The most of larvae crawled out of the media with denatonium benzoate, citric acid and sodium chloride within 30 minutes, while 12-23% of the larvae stayed in the medium with sucrose. From these results, it is considered that the inhibition effect on the larval development was caused by the repellent action of denatonium benzoate and citric acid, by both of repellent action and the lethal effects of sodium chloride and sucrose.

View full abstract

The box trap used for capturing the tabanid-flies does not use the carbon dioxide (CO₂) originally. When this box trap used for ororo-tabanidfly in 2000, the result of capturing the tabanid-flies was good. In 2001, 10 times capture experiment was carried out from July 16^th to September 26^th with/without CO₂. In box trap with CO₂ were collected 14,634 flies, and in box trap without CO₂ were collected only 1,654 flies. Similarly, the number of collecting were the 10,751 flies vs. 511 flies in canopy trap. From the above result, it was shown that CO₂ was effective in order to capture tabanid-flies mainly ororo-tabanidfly, Hirosia iyoensis.

View full abstract

In order to grasp the habitation of cockroaches in city parks, observations were carried out from August 2000 through August 2001 in 52 parks in Minatoku, Tokyo. Cockroaches were checked at night, and species, the number of individuals, the discovery place, the species of trees on which cockroaches were found and their activity were recorded. Cockroaches were found at 24 (46%) in 52 parks. The species of cockroaches were the smoky brown cockroach, Periplaneta fuliginosa and Japanese cockroach, P. japonica. They were found on the ground and on big and old trees of 12 family 19 species in the parks. Smoky brown cockroaches inhabited ginkgo, zelkova, and cherry trees. Japanese cockroach inhabited chinquapin in big parks exceeding 6,000m², oak, zelkova, and hackberry trees. Many smoky brown cockroaches were seen from July through September. Japanese cockroaches were found all the year round. There were peaks of the number of larvae especially in April and November. Smoky brown cockroaches were seen eating the garbage, the excrement of birds, sap and cat food left in parks. Smoky brown cockroaches as well as Japanese cockroaches were seen to pass the winter in the city part of Tokyo. City warming may promote those smoky brown cockroach to live outdoors. Moreover, feeding cats and pigeons may increase the number of cockroaches in the parks.

View full abstract

The harborage material and the void number of the harborages influenced increasing in German cockroach population in a laboratory condition. In case of the harborage free the cockroach numbers were rather small compared with the existence of the harborages. The cockroach numbers increased notably with the harborages made of plywood, ceramic tile or plastic, and less numbers in metallic one. The void numbers were also related to increasing in the cockroach population. The initial numbers of three pair of the cockroaches increased up to 780 in total after three months with 5 void plywood harborages, whereas a similarly reared colony without any harborage attained only 94 individuals. In three months after, the young stage of nymphs was the majority in each condition. The results suggest that cockroach populations can recover quickly after incomplete control in case of abundant of cracks and crevices.

View full abstract

House-fold pesticides were certificated by the Ministry of Health and Welfare with approved concentration against German cockroaches. In choice tests with insecticide-treated harborages, Permethrin EC was not produced sufficient efficacy even double concentration than the approved concentration. This was due to repellent activities of the German cockroaches. They avoid the residua of Permethrin. Diazinon EC and MC, Fenitrothion MC and Cholorpyrifos-methyl EC were effective at the approved concentration. Microencapsulated formulations of Diazinon and Fenitrothion were more effective than emulsifiable concentration of those insecticides at the same concentration. Cholorpyrifos-methyl EC was the most effective against German cockroaches in the scope concentrations applied.

View full abstract

Invasion of food containers by first-instar larvae through a pinhole was inhibited by repellent activity of para-dichlorobenzene placed in the food containers. Oviposition by the adults on the surface of the containers was also greatly reduced by the presence of the chemical. The testing methods may be used for detecting repellent activity of chemicals on this speceis as well as on other pest insects.

View full abstract

Pheromone trap of the Indian meal moth has been used effectively for early detection at food processing plants, warehouses and grain storage facilities. Some tests were conducted to know whether the adult Indian meal moth attracted into room by pheromone traps affected the infestation of foods or not. In 4 weeks after the placement of pheromone trap in 30m³ room, 211 and 191 male moths were caught in the trap in 2000 and 2001, respectively. However no larva was observed in the 3 kinds of food baits placed in the room. The result is likely to indicate that pheromone trap of the Indian meal moth does not attract adult female moths into room and does not affect the infestation of foods.

View full abstract