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Monellia caryella (Fitch)

Taxonomic placing: Insecta, Hemimetabola, Sternorrhyncha, Hemiptera, Aphidoidea, Aphididae.

Common name: Blackmargined aphid.

Geographical distribution: North America, Middle East.

Host tree: Pecan.

Morphology: The young are completely yellow, but the head, thorax and some abdominal segments of the alate are black, as are the margins of the forewings. Body length 1.2-2.1 mm.

Life history: The aphid overwinters as eggs deposited in tree buds or trunk and branch crevices. The eggs hatch in April and the emerging young move to and feed on young foliage. They develop to alate that reproduce parthenogenetically throughout the summer, raising about 20 generations, their numbers peaking in spring and autumn. By that time apterous females and winged males appear and mate, and these females lay the overwintering eggs.

Economic importance: Heavy infestations cause chlorophyll loss, leaf color changes and reductions in leaf size, sometimes followed by defoliations. Overall tree growth and fruit development are impaired and crop loss follows. In addition, the trees are damaged by the excessive amounts of honeydew excreted by aphids and the colonizing sootymold.

Management

Plant tolerance: Some pecan cultivars may bear a moderate number of these aphids without suffering economic loss.

Chemical control: Heavy infestations may be controlled with neem or with organophosphates.

{Biological control](entry/Biological_control): Various predators, especially spiders, chrysopids and coccinellids, may maintain the pest at low levels in the orchard. Other natural enemies include parasitoids of the families Aphidiidae (especially Trioxys pallidus, which may kill up to 90% of the pest population), Aphelinidae and Braconidae.

Reference

Honaker, J. (and 6 co-authors) 2013. Blackmargined aphid (Monellia caryella (Fitch); Hemiptera: Aphididae) honeydew production in pecan and implications for managing the pecan aphid complex in Texas. Southwestern Entomologist 38: 19-32.

Liao, H-T, Harris, M. K., Gilstrap, F. E. and Mansour, F. 1985. Impact of natural enemies on the blackmargined pecan aphid, Monellia caryella (Homoptera: Aphidae). Environmental Entomology 14: 122–126.

Mansour, F. 1987. Studies of the biology and phenology of the blackmargined aphid, Monellia caryella (Fitch), a new pest of pecan in Israel. Southwestern Entomologist 13: 19-29.

Mansour, F. 1988. Parasites of Monellia caryella (Hom.: Aphididae): phenology and effect on the aphid population in pecan orchards in Israel. Entomophaga 33: 371-375.

Mansour, F.A. 1993. Natural enemies and seasonal abundance of the blackmargined aphid (Monellia caryella) in pecan orchards in Israel. Phytoparasitica 21: 329-332.

Mansour, F., Harris, M.K., Stone, J.D. and Bueno, R. 1988. Releases in Israel of Aphelinus perpallidus, a recently introduced parasite of the pecan blackmargined aphid, Monellia caryella. Phytoparasitica 16: 171-174.

Website

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