Aphis craccivora Koch
Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Sternorrhyncha, Aphidoidea, Aphididae.
Common name: Cowpea aphid.
Geographical distribution: Cosmopolitan; CIE Map # 99, 1983 (revised).
Host plants: Polyphagous, with a preference for legumes.
Economic importance: The feeding of this aphid on clover and alfalfa causes plant wilting as well as blackening, due to the pests’ honeydew and the ensuing sootymold fungi. Such damage is quite serious on ornamentals, because it detracts from their external appearance. The cowpea aphid transmits several plant viruses.
Morphology: The bodies of female apterous and alate cowpea aphids, including the siphunculi and cauda, are mostly black. The antennae are shorter than the body, which is about 1.5-2.3 long.
Life cycle: In the Middle East the cowpea aphid reproduces by parthenogenesis the year around and no sexual forms have so far been found. The populations of A. craccivora increase in spring and decline during summer. The females are attracted to green plants and seem to distinguish between the odor of their original host-plant and others.
Management:
Plant resistance: High levels of resistance to the cowpea aphid were found in some cowpea cultivars.
Chemical control: Organophosphates and carbamates control the cowpea aphid, as do various formulations of neem.
Biological control: The cowpea aphid is attacked by several endoparasitoids of the family Aphidiidae, and infected by entomopathogenic fungi that kill the pest.
References:
Abdel-Baky, N.F. and Abdel-Salam, A.H. 2003. Natural incidence of Cladosporium spp. as a bio-control agent against whiteflies and aphids in Egypt. Journal of Applied Entomology 127: 228-235.
Annan, I.B., Tingey, W.M., Schaefers, G.A., Tjallingii, W.F., Backus, E.A. and Saxena, K.N. 2000. Stylet penetration activities by Aphis craccivora (Homoptera: Aphididae) on plants and excised plant parts of resistant and susceptible cultivars of cowpea (Leguminosae). Annals of the Entomological Society of America 93: 133-140.
Pettersson, J., Karunaratne, S., Ahmed, E. and Kumar, V. 1998. The cowpea aphid, Aphis craccivora, host plant odours and pheromones. Entomologia Experimentalis et Applicata 88: 177-184.
Swirski, E. and Amitai, S. 1999. Annotated list of aphids (Aphidoidea) in Israel. Israel Journal of Entomology 33: 1-120.
Ward, A., Morse, S., Denholm, I., Thompson, R. and McNamara, N. 2002. Foliar insect pest management on cowpea (Vigna unguiculata Walpers) in simulated varietal mixtures II. Pest resistance management implications. Field Crops Research 79: 67-80.
Dimetry, N.Z. and Elhawary, F.M.A. 1995. Neem AZAL-F as an inhibitor of growth and reproduction in the cowpea aphid Aphis craccivora Koch. Journal of Applied Entomology 119: 67-71.
Ulrichs, C., Mewis, I. and Schnitzler, W.H. 2001. Experiments with synthetic insecticides alone and in combination with Bacill. thur. and Trichogramma evan. to control Vigna pests under conditions in tropic lowlands. Anzeiger für Schadlingskunde 74: 117-120.