Some Experimental Studies on Arthropods in Milk Powder

Abstract

With a view to reveal the process of existence of the pest insects of food and food product into milk powder, two series of experiments were carried out: one of them was done by the tmp-method, according to which the insects and other arthropods seemed most likely to exist in the milk powder stored for the ordinary housholds nursing were investigated at three different seasons, and the other was performed in such a manner that the survival days of the larvae of cockroach allowed to exist in the dry milk in process of production were investigated in the closed can. The results of the above mentioned experiments can be summarized as follows.
1. Species of Arthropods found in the trap with milk powder are as listed in Table 1, in which the pest insects and mite of food and food products, the pest insect of rice and the spider were 4 species, 1 species and 1 species respectively.
2. Comparison with the result from the earlier investigations conducted by the similar method for the confectionary pest insects showed the lower property of the milk powder for attracting the pest insects of food and food products.
3. 1 to 4 nymphal instars of cockroach (Periplaneta fuliginosa) put in the sealed can were found dead with no exception at 10th day, and no individual could be found survived by inspection done with the cans opened at 20th day, 30th day, 40th day and 50th day after sealing on the can.
4. Consideration of various factors of days from the completion of milk powder manufacture to the delivery to the consumer, the experimentally confirmed the survival days of various tested pest insects of food and food products in the sealed can, the fact that the troubles of the pest insects found in the milk powder by consumer more often concern the state the insects' survival and others favors the estimation of a large probability of the entrance of the insects and other arthropods in the milk powder after opening of the milk powder can by the consumer.