Antimicrobials: ‘Safe’ levels in a synthetic diet of an insect, Agria affinis

Effect of Antifungal Agents on Biological Fitness of <I>Lygus hesperus</I> (Heteroptera: Miridae)

“…Other investigators have found the rate of larval development to be the most sensitive criterion for measuring the effect of antimicrobials in insect diet (Clark et al 1961, Ouye 1962, Singh and House 1970. We found delays in development, decreased insect size (mass), decreased fecundity, and an increase in insect death in our tests of different antifungal agents.…”

“…Methyl paraben, while widely used with great success with other insect species (Kishaba et al 1968, Hedin et al 1974, was shown to have signiÞcant negative effects in L. hesperus. Ethanol is used as the solvent for methyl paraben and has been shown to interfere with the normal development of some insects (Bass andBarnes 1969, Singh andHouse 1970). Ethanol, used alone as a dietary additive, is detrimental to L. hesperus biological Þtness (J.A., unpublished data).…”

“…Many antimicrobials have been shown to have detrimental effects on some insects (Ouye 1962, Kishaba et al 1968, Bass and Barnes 1969, Toba et al 1969, Singh and House 1970. At concentrations above ÔsafeÕ levels determined by Singh and House, many antimicrobials delayed development and increased mortality in larval and pupal stages of Agria affinis (Singh and House 1970). White fringed beetles, Graphognathous spp., have been difÞcult to rear due to antifungal toxicity problems.…”

“…Often antimicrobials are added to artiÞcial diets based more on traditional insect diet recipes rather than taking into account the additiveÕs effect on insect health or the effectiveness of the compound in suppressing microbial growth. Many antimicrobials have been shown to have detrimental effects on some insects (Ouye 1962, Kishaba et al 1968, Bass and Barnes 1969, Toba et al 1969, Singh and House 1970. At concentrations above ÔsafeÕ levels determined by Singh and House, many antimicrobials delayed development and increased mortality in larval and pupal stages of Agria affinis (Singh and House 1970).…”

An Introduction to the Use and Preparation of Artificial Diets with Special Emphasis on Diets for Phytophagous Lepidoptera

“…Since the presence of moulds and bacteria will often make itself f e l t in a matter of hours, and since, even i f the diet i s still palatable to the insect it will have been altered in some unknown and uncontrollable manner, some other means of control i s necessary. Chemical suppressants are often the only remedy and although the real criteria are the sensitivity of the insect being cultured, and the local mould and bacterial flora (which can vary enormously), useful information on the properties of suppressants i s available (Greenberg, 1970;Singh and House, 1970;Smith, 1966;Ouye, 1962). Nipagen-M (methyl phydroxybenzoate), sorbic acid, and forrnalin are tolerated by many insects and are widely used.…”