Mayetiola destructor (Say)
Taxonomic placing: Insecta, Holometabola, Diptera, Nematocera, Cecidomyiidae.
Common name: The Hessian fly, barley midge.
Geographical distribution: Europe, North Africa, Asia, North America, Oceania; New Zealand.
Host plants: Wheat, barley and rye, as well as Agropyron, Elymus, and Aegilops, which are not greatly infested.
Morphology: The adult is about 4 mm long, with a dark-red body and black wings, legs as long as or longer than body. The young larva is orange-red, later becoming white with a green stripe along its body, about 4-5 mm long.
Life cycle: The pest usually raises 2-3 annual generations, sometimes more. Females mate soon after emergence and start to oviposit, laying 250-300 eggs, which are placed end-to-end on host leaves, often where the stems are covered by leaves. They pupate within a protective structure, the flaxseed; the emerging adults are weak fliers and live only for 2-4 days.
Economic importance: The Hessian fly is one of the most destructive pests of wheat. A single larva, feeding for three days, is capable of permanently stunting a young plant or tiller, damage being due to feeding and to an excreted salivary toxin. Seedlings attacked at the one-leaf stage may be killed outright. Wheat infested later will be severely stunted, with the first tillers killed and growth delayed. The pest also causes much damage to barley and rye. Severe infestations have caused crop shortages; estimated wheat yield losses in North Africa come to around 40%.
Management:
Monitoring: Observations in the field can reveal infested plants with thickened and darker leaves, as well as stunted, dead or dying tillers. Flaxseeds can be found at the bases of leaves, where they are attached to the stem. Trapping the pest with its female-produced sex pheromone can be used to follow its populations through the year.
Horticultural practices: Disking or burning wheat remains, and removal of volunteer plants, and practicing crop rotation, avoiding the cultivation of wheat in fields with wheat stubble. In northern countries delaying the autumn sowing in order to escape the infestation of overwintering crops.
Plant resistant: Many resistant wheat cultivars are available and in use. However, in response to these cultivars virulent insect biotypes (or strains) may develop and overcome the plants’ resistance. (The gene-for-gene interaction). Hessian fly populations in the field should therefore be constantly monitored to determine which wheat genes (cultivars) remain resistant in different geographic regions. For instance, the most virulent biotype, worldwide, has been found in Syria, with only 2 genes (cultivars) remaining resistant.
Chemical control: Systemics, like imidacloprid, used as seed dressings, can be highly effective in protecting wheat seedlings. Foliar treatments of long residual pyrethroids applied shortly after wheat emergence control the pest, as do essential oils extracted from various plants of the family Labiatae.
Biological control: More than 50 parasitoids, assignable to several hymenopterous families, are known to attack the Hessian fly in various parts of the world, and may kill up to 70-80% of the pests. For instance, In North America the egg parasitoid Platygaster hiemalis Forbes (Platygasteridae) shows great promise. Members of the families Eupelmidae and Pteromalidae were most abundant in several North American states. There is little information on how to increase the effect of these parasitoids.
References
Anderson, K. M., Y. Hillbur, J. Reber, B. Hanson, R. O. Ashley, and M. O. Harris. 2012. Using sex pheromone trapping to explore threats to wheat from Hessian fly (Diptera: Cecidomyiidae) in the Upper Great Plains. Journal of Economic Entomology 105: 1988–1997.
Bullock, D.G., Bosque-Pérez, N.A., Johnson, J.B. and Merickel F.W. 2004. Species composition and distribution of Hessian fly (Diptera: Cecidomyiidae) parasitoids in northern Idaho. Journal of the Kansas Entomological Society 77: 174-180.
El Bouhssini, M., Chen, M., Lhaloui, S., Zharmukhamedova, G. and Rihaoui. F. 2009. Virulence of Hessian fly (Diptera: Cecidomyiidae) in the Fertile Crescent. Journal of Applied Entomology 133: 381-385.
Gahan, A.B. The serphoid and chalcidoid parasites of the Hessian fly. USDA Miscellaneous Publications #174.
Giladi, Y., Naftaliyahu, U. and Richker, E. 2013. Wheat and fodder cultivation for seeds and fodder. Nir VaTelem 44: 14 (in Hebrew).
Johnson, A.J., Weintraub, P.G., Katoch, R., Schemerhorn, B.J. and Shukle, R.H. 2012. Biological and molecular characterization of Hessian fly (Diptera: Cecidomyiidae) from Israel. Bulletin of Entomological Research 102: 632-43.
Lamiri, A., Lhaloui, S., Benjilali, B. and Berrada, M. 2001. Insecticidal effects of essential oils against Hessian fly, Mayetiola destructor (Say). Field Crops Research 71: 9-15.
Naber, N. (and 8 co-authors). 2000. Genetic variation among populations of the Hessian fly Mayetiola destructor (Diptera: Cecidomyiidae) in Morocco and in Syria. Bulletin of Entomological Research 90: 245–252.
Schuster, M.F. and Lidell, M.C. 1990. Distribution and seasonal abundance of Hessian fly (Diptera: Cecidomyiidae) parasitoids in Texas. Journal of Economic Entomology 83: 2269-2273.
Stuart. J.J., Chen, M.S., Shukle, R. and Harris, M.O. 2012. Gall midges (Hessian flies) as plant pathogens. Annual Review of Phytopathology 50: 339-57.
Wilde, G.E., Whitworth, R.J., Claassen, M. and Shufran, R.A., 2001. Seed treatment for control of wheat insects and its effect on yield. Journal of Agricultural and Urban Entomology 18: 1-11.
Withers, T.M. and Harris, M.O. 2005. Influence of grass species on the foraging behavior of Platygaster hiemalis, a parasitoid of the Hessian fly, Maytiola destructor. New Zealand Plant Protection 58: 197-201.