29 Aug 2016

Ephestia kuehniella, Mediterranean Flour Moth


The Mill moth, Ephestia kuehniella is one of the most serious stored grain pests within the food industry.

E. kuehniella is a major economic insect of corn milling plants, grout mills, bakeries and other gain processing sites. The mill moth is believed to have originated from India but is now found within populations worldwide. It is common pest in flour mills and bakeries, where the moths are to be found resting on walls and windows by day. The species is rarely found outdoors and moths can be found any time but are unlikely to be present during extreme cold periods.

 

OVERVIEW

The Mediterranean flour moth, Indian flour moth or mill moth is a moth of the family Pyralidae. Ephestia kuehniella is a common pest of dry plant produce and is found around the world where it feeds primarily on dry cereals and other grains causing significant damage to the food product.

Ephestia kuehniella, the Mediterranean flour moth adult will begin mating immediately after emergence. The adult stage is completed after 10-14 days. During this period the adult female can lay between 300-350 eggs which are stuck to various foods by a sticky secretion.

The eggs of Ephestia kuehniella, the Mediterranean flour moth hatch within 28 days. Larvae of the mill moth are white or pinkish-white and spin silken tubes in which they live. After 3-5 moults the larvae are full grown and the full grown larval size is about 15-19 mm long.

In colder climates the Mediterranean flour moths overwinter as larvae but, in contrast to other species, usually remain within the foodstuff. The larval stage typically lasts about 40 days. Moths pupate within 7-16 days in the dark corners of buildings or machinery where they seek shelter.

The larval stage is the most damaging stage of the Mediterranean flour moth life cycle. The mill moth larvae typically prefer wheat flour, but will also feed on other grains, cereals, seeds, dried fruits, nuts and almonds if available.

The newly emerged larvae migrate towards the stored products where they will feed voraciously whilst producing a web or silk. During this period of feeding the larvae can produce an unpleasant smell in the infected product and leave frass that contaminates the food stuff. Additionally, the webbing produced by the larvae can cause serious blockages in provender mills subsequently resulting in damage to the machine. The larvae are able to spin a protective tube in which they feed and produce frass.

Russell IPM manufactures and supplies pheromone lures, traps and complete monitoring systems for the mill moth, Ephestia kuehniella. Pheromone traps provide early warning of the infestation and will alter the pest controller to enable timely and effective treatment.

Dismate PE works by reducing the likelihood of successful mating between Ephestia kuehniella and other stored product food moths. Utilising nature identical sex pheromones, the males are confused and unable to find the females. This results in a rapidly declining population as females fail to mate and produce offspring. Dismate PE does not require factory downtime or leave residues, as is associated with chemical spraying and fumigation. It is a safe, cost-effective and successful means of managing Ephestia kuehniella.

Recent Literature

Závodská, R. (2012) Is the Sex Communication of two Pyralid Moths, Plodia interpunctella and Ephestia kuehniella under circadian clock regulation? J Biol Rhythms.

Females of the Indian meal moth, Plodia interpunctella, and females of the Mediterranean flour month, Ephestia kuehniella (both Lepidoptera: Pyralidae), exhibit daily rhythms in calling behaviour. The peak in P. interpunctella calling occurs at dusk, whereas E. kuehniella calls preferentially at dawn. This behaviour turned arrhythmic in P. interpunctella females in constant darkness (DD) and remained arrhythmic in constant light (LL), whereas E. kuehniella females showed a persistent rhythm in DD and suppression of the behaviour in LL, indicating regulation by a circadian clock mechanism. The rhythm of male locomotor activity corresponded well with the sexual activity of females, reaching the peak at dusk in P. interpunctella and at dawn in E. kuehniella. An immunohistochemical study of the pheromone biosynthesis activating neuropeptide, corazonin, and pigment dispersing factor revealed distinct sets of neurons in the brain-subesophageal complex and in the neurohemal organs of the 2 species.

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Stafanos, A. S. et al., (2012) Cold hardiness of immature and adult stages of the Mediterranean flour moth, Ephestia kuehniella. Journal of Stored Products Research.

The cold hardiness profile of immature and adult stages of the Mediterranean flour moth, Ephestia kuehniella was investigated in the laboratory. Supercooling point (SCP) of early instars, late instars, pupae and adults of E. kuehniella was determined using a circulating bath Main effects of temperature, exposure time and developmental stage on mortality proved to be significant. Two-way interactions as well as the three-way interaction between all tested factors also proved to be significant in most cases. Generally, pupae and adults were the most cold-tolerant, followed in decreasing order by late instars, early instars and eggs. However, when exposure temperature declined to −12.5 °C, no significant differences were observed between the developmental stages in any exposure, suggesting that temperatures as low as −12.5 °C are equally detrimental to all developmental stages. Complete mortality was observed only when early instars, late instars and adults were exposed to −12.5 °C for 120 min. In all tested temperature regimes mean lethal time (LTime50) of pupae was higher compared to the other developmental stages. Similarly, in all exposure times mean lethal temperature (LTemp50) of pupae was lower in relation to the other stages. Non-freezing injury above the SCP was well documented for all stages of E. kuehniella indicating a pre-freeze mortality. The potential of using low temperatures to control E. kuehniella is discussed.

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