A total of 102 foreign materials related with arachnids found in various products were examined at the technical research institute, Teiso Toyoka Co., Ltd. from 2002 to 2013. The spiders as contaminant were found in different kinds of products. The most commonly and highly contaminated products with spiders were food products (36 samples; 35.3%), followed by film products (17 samples; 16.7%), and glass containers (13 samples; 12.7%). Other products such as plastic containers, medical and pharmaceutical products, fiber products, paper products, and cosmetic products were less than 10%, respectively. 87 spider samples out of 102 found from products consisted of 17 families. Salticidae was most dominant (29 samples; 33.3%), followed by Araneidae (12 samples; 13.8%) and Pholcidae (9 samples; 10.3%). In terms of lifestyles of spiders, the ratio of hunters (57.5%) exceeded than that of snarers (42.5%). Among 87 samples of the spiders, 39 samples were classified into 20 species. Both Scytodes thoracica (5 samples; 12.8%) and Heteropoda venatoria (5 samples; 12.8%) were the most dominant species, followed by Plexippus setipes (4 samples; 10.3%), Pholcus phalangioides (3 samples; 7.7%) and Neoscona nautica (3 samples; 7.7%). More than 60% of those spiders were indoor species seen through the year.
The Indian meal moth (Plodia interpunctella) is normally observed indoors in human residences; the infection of this species by microsporidia has been reported overseas. However, the infection status of P. interpunctella by microsporidia has so far not been reported in Japan.
We therefore investigated, over about three months, the microsporidia infection status of P. interpunctella captured in pheromone traps in five houses in suburban housing in Tokyo city, Japan. We isolated 16 strains of microsporidia from 5,358 captured P. interpunctella individuals. The results of 10 strains of small subunit rDNA sequence analyses suggest that these microsporidians are classified in the same array as the Nosema / Vairimorpha genus cluster.
In September and October 2016, we observed 2 baskets made of rattan, having been used for general household purposes, suffering heavy boring damage. We identified the responsible insect as Dinoderus bifoveolatus (WOLLASTON) (Bostrichidae: Dinoderinae). The two infested rattan baskets were imported from Socialist Republic of Vietnam to Japan. These had been manufactured simultaneously in Vietnam. We speculated that after D. bifoveolatus oviposition on the raw materials in Vietnam, they were manufactured to baskets, transported to Japan, sold to consumers, and found infested as adult beetles emerged out.