Mediterranean flour moth: Difference between revisions

The '''Mediterranean flour moth''' or '''mill moth''' ('''''Ephestia kuehniella''''')<ref name=":1">{{Cite web|url=https://ipmworld.umn.edu/mill-moth|title=Mediterranean Flour Moth (Mill Moth)|last=|first=|date=|website=University of Minnesota|archive-url=|archive-date=|dead-url=|access-date=29 July 2015}}</ref> is a [[moth]] of the [[family (biology)|family]] [[Pyralidae]].<ref name=":0" />. It is a common [[Pest (organism)|pest]] of [[cereal]] grains, especially [[flour]]. This moth is found throughout the world, especially in countries with temperate climates.<ref name=":2">{{Cite journal|lastlast1=Jacob|firstfirst1=T.A.|last2=Cox|first2=P.D.|date=June 1976|title=The influence of temperature and humidity on the life-cycle of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)|url=|journal=Journal of Stored Products Research|volume=13|issue=3|pages=107-118107–118|viadoi=Elsevier Science Direct10.1016/0022-474x(77)90009-1}}</ref> It prefers warm temperatures for more rapid development, but it can survive a wide range of temperatures.<ref name=":2" />

The Mediterranean flour moth is frequently found in warm places with stored [[grain]] products, such as [[Gristmill|flour mills]] and bakeries, where it can breed year round. Flour mills have a particular problem with the Mediterranean flour moth because the [[Caterpillar|caterpillarscaterpillar]]s spin silk that clogs machinery. The most effective pest control strategy for this moth is sanitation of facilities and sealing grain containers to prevent infestation, but some [[Pesticide|pesticidespesticide]]s may also be used.<ref name="Jacobs" />

Adult Mediterranean flour moths have pale gray bodies. Their forewings are gray with black zigzag markings while the hindwings are an off-white color.<ref name="Jacobs">{{cite web|url=http://ento.psu.edu/extension/factsheets/mediterranean-flour-moth|title=Mediterranean Flour Moth|authorsauthor1=Steve Jacobs and |author2=Dennis Calvin |date=October 1988|publisher=Penn State College of Agricultural Sciences|accessdate=2013-09-07}}</ref> The wingspan is 1.5-2.6 &nbsp;cm.<ref name=":0">{{Cite web|url=https://www.butterfliesandmoths.org/species/Ephestia-kuehniella-?region=All&sort_by=field_recorddate_value&sort_order=ASC|title=Butterflies and Moths of North America|last=|first=|date=|website=|archive-url=|archive-date=|dead-url=|access-date=}}</ref> [[Larva|Larvae]]e (caterpillars) are white or pink with black spots and dark heads. [[Pupa|Pupae]]e are reddish brown.<ref name="Jacobs" />

''E. kuehniella'' females typically oviposit on the second night after emergence. This is because they require a few hours for the sperm to move from the bursa copulatrix to the vestibulum, where [[Fertilisation|fertilization]] occurs.<ref name=":3" /> Females will then lay anywhere between 116 and 678 eggs in a food source, such as flour, to which the eggs often become attached. When the eggs hatch, larvae spin silken tubes around themselves. They spend about 40 days maturing within these tubes. Full grown larvae disperse to new locations and spin silken cocoons in which they develop into pupae. Adult moths emerge in 8-128–12 days.<ref name="Jacobs" />

In hot weather, the moth's entire life cycle may take no more than five to seven weeks.<ref name="Jacobs" /> Though it prefers warm temperatures because it can develop more rapidly, ''E. kuehniella'' can complete development in temperatures ranging from 12&nbsp;°C to about 30&nbsp;°C.<ref name=":2" />

Mediterranean flour moths are infected by ''[[Wolbachia]]'', a [[genus]] of [[bacteria]] that affects the reproduction of its host species. These maternally-inherited bacteria cause [[cytoplasmic incompatibility]] in ''E. kuehniella'', which means that sperm and eggs cannot join to form a viable [[embryo]]. Infected males produce sperm that is only compatible with eggs from infected females, resulting in a decrease in [[Fitness (biology)|fitness]] for uninfected females. Different strains of ''Wolbachia'' cause different levels of cytoplasmic incompatibility. <ref>{{Cite journal|lastlast1=Sasaki|firstfirst1=Tetsuhiko|last2=Ishikawa|first2=Ishikawa|date=1999|title=Wolbachia Infections and Cytoplasmic Incompatibility in the Almond Moth and the Mediterranean Flour Moth|url=|journal=Zoological Science|volume=16|issue=5|pages=739–744|doi=10.2108/zsj.16.739|s2cid=85734865|viadoi-access=free}}</ref>

''E. kuehniella'' is parasitized by ''Nemeritis canascens'', a parasitic wasp of the family [[Ichneumonidae]] family. The larvae of this wasp are [[Parasitism|endoparasites]] of the moth during the moth's larval phase. Larvae of ''Nemeritis'' feed on the blood of the host caterpillars. ''Nemeritis'' remains in its first instar until the host caterpillar is in its last instar of development. The parasitic larvae feed more quickly as the host caterpillar gets older, accounting for rapid development in late final-instar caterpillars and delayed development in first instar caterpillars. The changing rate of feeding in the parasite is attributed to the changing composition of the host blood on which it feeds.<ref>{{Cite journal|last=Corbet|first=Sarah|date=September 1967|title=THE INFLUENCE OF EPHESTIA KUEHNIELLA ON THE DEVELOPMENT OF ITS PARASITE NEMERITIS CANESCENS|url=|journal=Journal of Experimental Biology |volume=|pages=|viaurl = https://www.researchgate.net/publication/255580855}}</ref>

The maturation of both male and female reproductive systems occurs soon after emergence.<ref name=":3">{{Cite journal|lastlast1=Xu|first=|last2=Wang|first2=|last3=He|date=2008|title=EMERGENCE ANDEmergence REPRODUCTIVEand RHYTHMSreproductive OFrhythms EPHESTIAof KUEHNIELLA''Ephestia kuehniella'' (LEPIDOPTERA:Lepidoptera PYRALIDAEPyralidae)|url=|journal= New Zealand Plant Protection Society|volume=61|pages=277–282|viadoi=10.30843/nzpp.2008.61.6806|doi-access=free}}</ref> Adult moths commonly mate on the day of emergence, which maximizes the reproductive success of females.<ref>{{Cite journal|lastlast1=Karalius|firstfirst1=V.|last2=Buda|first2=V.|date=November 1995|title=MATING DELAY EFFECT ON MOTHS’MOTHS' REPRODUCTION: CORRELATION BETWEEN REPRODUCTION SUCCESS AND CALLING ACTIVITY IN FEMALES EPHESTIA KUEHNIELLA, CYDIA POMONELLA, YPONOMEUTA COGNAGELLUS (LEPIDOPTERA: PYRALIDAE,TORTICIDAE, YPONOMEUTIDAE)|url= |journal=Pheromones|volume=5|pages=169-190169–190|viaciteseerx=10.1.1.71.6713 }}</ref> Female calling and male courtship behaviors peak just prior to peak mating -- thesemating—these behaviors are useful in successful mating. The Mediterranean flour moth is a [[protogynous]] species, so females emerge significantly earlier than males. This mechanism may be used to reduce inbreeding, as females will emerge and mate with other males prior to their brothers emerging.<ref name=":3" /> The optimal mating time for females is on the same day they emerge, because fertility decreases when mating occurs later. Females release pheromones as a type of calling behavior to demonstrate to males when they are most fertile.<ref>{{Cite journal|last1=Karalius|first1=V.|last2=Buda|first2=V.|date=1995|title=MATING DELAY EFFECT ON MOTHS' REPRODUCTION: CORRELATION BETWEEN REPRODUCTION SUCCESS AND CALLING ACTIVITY IN FEMALES EPHESTIA KUEHNIELLA, CYDIA POMONELLA, YPONOMEUTA COGNAGELLUS (LEPIDOPTERA: PYRALIDAE, TORTICIDAE, YPONOMEUTIDAE)|journal=Pheromones|volume=5|pages=169–190 |citeseerx=10.1.1.71.6713 }}</ref>

In a study of the effects of food shortage and larval crowding on male reproductive phenotype, it was found that males who emerged as adults from the population with the most crowding had smaller forewings, thorax, and head, as well as a lower body mass. It is worth noting, however, that these smaller males had larger forewings relative to their body mass. It is suggested that this may be beneficial in terms of mate searching at higher densities by promoting their dispersal. <ref name=":4">{{Cite journal|lastlast1=Bhavanam|firstfirst1=Santhi|last2=Trewick|first2=Steven|date=2017-03-01|title=Effects of larval crowding and nutrient limitation on male phenotype, reproductive investment and strategy in Ephestia kuehniella Zeller (Insecta: Lepidoptera)|url=http://www.sciencedirect.com/science/article/pii/S0022474X1730036X|journal=Journal of Stored Products Research|volume=71|issue=Supplement C|pages=64–71|doi=10.1016/j.jspr.2017.01.004}}</ref>

It was also found that while mating frequency did not seem to be affected by larval density, those from higher densities had a shorter adult lifespan and produced fewer eupyrene sperm. In order to increase their reproductive success at higher densities, and thus at higher levels of sperm competition, males maintain apyrene sperm production and mate more at a higher frequency.<ref name=":4" />

''E. kuehniella'' is a [[Polyandry in animals|polyandrous]] species.<ref name=":3" />

Larvae will attack stores of flour or other cereal grains as a source of food, but the most damage is done when they interfere with machinery in the mills. The web-like material that larvae spin clogs machines. Grain mills have had to shut down due to this issue. <ref name="Jacobs" /> They also cause damage by biting holes in silk screens used to sift flour.<ref name=":2" />

The most effective pest control method for the Mediterranean flour moth is preventing it from infesting stored grains. This involves basic [[sanitation]] practices such as thoroughly cleaning out bins and surrounding areas of the floors and walls to remove old grains and particles of dust. Sealing all cracks and crevices in the building and grain bins can prevent moths from entering. Checking grain bins frequently (especially in warm months) for hot spots, [[Mold (fungus)|mold]], and insects can also reduce risk of infestation.<ref>{{cite web|url = https://motten-weg.de/lebensmittelmotten-wissenswertes/ |title = Lebensmittelmotten |language = de}}</ref> Sanitation is generally the preferred strategy for preventing Mediterranean flour moth infestation.<ref name="Jacobs" />

[[Insecticide|Insecticides]]s are sometimes used as well as [[Fumigation|fumigants]] if infestation has already occurred. Both of these pest control options involve [[Toxicity|toxic]] chemicals and require safety precautions to use.<ref name="Jacobs" /> [[Methyl Bromide|Methyl bromide]] was commonly used as a pesticide in several countries, but was later banned for environmental reasons when it was classified as an [[Ozone depletion|ozone depleter]].<ref name=":5">{{Cite journal|lastlast1=Ayvaz|firstfirst1=Abdurrahman|last2=Karabörklü|first2=Salih|title=Effect of cold storage and different diets on Ephestia kuehniella Zeller (Lep:Pyralidae)|url=http://citations.springer.com.libproxy.wustl.edu/item?doi=10.1007/s10340-008-0192-2|journal=Journal of Pest Science|language=en|volume=81|issue=1|doi=10.1007/s10340-008-0192-2|year=2008|s2cid=19592424}}</ref> 

''[[Trichogramma]]'' [[Parasitoid|parasitoidsparasitoid]]s are a potential biological control for the Mediterranean flour moth, because they can kill the host in the egg stage, before it reaches the destructive larval phase. The success of ''Trichogramma'' in biological control programs is influenced by host diet and the resulting nutritional quality of the eggs. Temperature can also impact host suitability for the parasitoid.<ref name=":5" /><ref>{{Cite journal|lastlast1=Hansen|firstfirst1=L. S.|last2=Jensen|first2=K.-M. V.|title=Effect of Temperature on Parasitism and Host-Feeding of <I>''Trichogramma turkestanica</I>'' (Hymenoptera: Trichogrammatidae) on <I>''Ephestia kuehniella</I>'' (Lepidoptera: Pyralidae)|url=https://doi-org.libproxy.wustl.edu/10.1603/0022-0493-95.1.50|journal=Journal of Economic Entomology|language=en|volume=95|issue=1|pages=50–56|doi=10.1603/0022-0493-95.1.50|pmid=20345297|year=2002|pmc=2999447}}</ref>

[[Gamma Radiation|Gamma radiation]] is another biological control that has been considered as an alternative to pesticide use. Low-dose [[irradiation]] has been approved by the [[Food and Drug Administration|FDA]] as a safe pest control measure in foods. This method is fast and not temperature dependent. Irradiation treatment can prevent adult emergence or introduce [[Sex linked|sex-linked]] lethal mutations that cause inherited sterility.<ref>{{Cite journal|lastlast1=Ayvaz|firstfirst1=Abdurrahman|last2=Tunçbilek|first2=Aydın Ş.|title=Effects of gamma radiation on life stages of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)|url=https://doi-org.libproxy.wustl.edu/10.1007/s10340-006-0137-6|journal=Journal of Pest Science|language=en|volume=79|issue=4|pages=215–222|doi=10.1007/s10340-006-0137-6|year=2006|s2cid=39080685}}</ref>

== AdditionalFurther reading ==

{{commonsCommons-inline|Ephestia kuehniella}}

[[Category:InsectsMoths of TurkeyAsia]]

[[Category:InsectsMoths of Iceland]]