Olfactory Responses to Flavour Substances on Larvae of Indian-meal moth, Plodia interpunatella Hübner (preliminary report)

Abstract

The chemotaxis of the larvae of the Indian-meal moth, Plodia interpunctella Hübner were examined by means of the Y-tube olfactometer (Fig. 1).
The experiments herein reported, in which about 59 odourous chemicals chosen were tested, have demonstrated the following point regarding attraction and repellency to the Indian-meal moth.
A definite amount of chemicals (0.01cc for liquids or 10mg for solids) suspending in 100cc distilled water was tested. From the results obtained chemicals were classified into attractants (+), repellents (-), and ineffective substances (±). The power of attraction or repellency of the substance tested is represented by the following ratio:
(I: index A: odorous side R: odorless side N: total) A and R are the numbers of the larvae traveled to the odorous and odorless sides respectively, when 3 hours passed after the start of the test, and 20-40 indicates the total number of larvae tested in two or three times replicated (Table 1).
The results obtained are as follows.
Attractive flavour substances: Iso-amyl propionate, citral, ethyl cinnamate.
Repellentive flavour substances: Allyl cyclohexyl propionate, eugenol, iso-amyl formate, decyl aldehyde, diacetyl, jasminal, linalol, ethyl iso-valerate, citronellal, isoamyl iso-valerate.