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Aphis middletonii (Thomas) |
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| Erigeron Root Aphid | ||
| Hosts | Distribution | Damage | Biology | Behavior | Management | Reference | |
Authors
Ronald F.L. Mau, Extension Entomologist
Jayma L. Martin Kessing, Extension Specialist
Department of Entomology
Honolulu, Hawaii
Updated by: J.M. Diez April 2007
The preferred hosts of this species of aphid are plants belonging to the Aster genus. However, this aphid also attacks many other plants including: Achillea millefolium, Ambrosia trifida, Artemisia dracunculus, Aster spp., Bidens pilosa, Brassica nigra, Callistephus (Chinese aster), Coreopsis spp., corn, Cucurbita spp., Eleusine indica, Emilia flammea, Emilia sonchifolia, Erechtites heiracifolia, Erigeron spp., Galinsoga parviflora, Gnaphalium spp., Helianthus annuus, Hemizonia luzulaifolia rudis, iron weed, Oxalis stricta, Panicum spp., papaya, Plantago major L., Polygonum persicaria, Portulaca spp., Ranunculus californicus, Rumex spp., Setaria spp., Solanum nodiflorum, Sonchus oleraceus, Taraxacum oficinale, tomato and zucchini (summer squash).
This aphid was first described in 1879 from "iron weed" and Aster sp. roots in Illinois. It has since been found throughout the US Mainland. The erigeron root aphid is suspected to have been in Hawaii since 1909, and is present on all major islands except Lanai.
Aphids feed by sucking sap from their hosts. This often causes the plants to become deformed, the leaves curled and shriveled and, in some cases, galls are formed on the leaves (Metcalf, 1962). This species usually inhabits the roots of its host, although it may attack the bases of plants and foliage of some plants. On occasion the damage can be considerable.
Like other soft bodied insects such as leafhoppers, mealybugs and scales, aphids excrete honeydew. This sweet and watery excrement is fed on by bees, wasps, ants and other insects. The honeydew serves as a medium on which a sooty fungus, called sooty mold, grows. Sooty mold blackens the leaf and decreases photosynthesis. On fruit, sooty mold reduces the marketability of the fruit (Elmer and Brawner, 1975).
Aphids vector many plant diseases which cause substantially greater losses than caused by direct feeding injury. This is often the most damaging feature of an aphid infestation. This aphid transmits the Maize Dwarf Mosaic Virus (Pitre and Shaunak, 1971) and is a known vector of Watermelon Mosaic Virus 2 (WMV-2) and Zucchini Mosaic Virus (Adlerz, 1987).
Aphids reproduce in two ways. In warm climates like Hawaii, aphid colonies consist completely of females. Reproduction does not involve mating or egg laying. Females give birth to live female nymphs. In temperate climates, aphids reproduce as above during the warmer periods of the year. In the fall, the reproduction changes. Males are produced in response to a decrease in photoperiod or temperature (Blackman and Eastop, 1984). Mating occurs and females lay eggs. Aphids overwinter in the egg stage
There are many generations of this aphid throughout the year in Hawaii.
EGGS
Eggs are not produced in Hawaii. In temperate regions this aphid over winters as eggs.
NYMPHS
The immature erigeron root aphid resembles the adult except for its smaller size.
ADULTS
Adults are yellowish green or dark olive green with a frosty covering. The frosty covering resembles a network of small 5-sided shapes or reticulations. This frosty network is characteristic of the erigeron root aphid.
NON-CHEMICAL CONTROL
Many aphids are naturally controlled by predators, parasites and pathogens. The braconid wasp parasite, Lysiphelbus testaceipes (Cresson), preys on the erigeron root aphid and exhibits some control in Hawaii
High temperatures increase mortality.
CHEMICAL CONTROL
Insecticidal soaps offer some control against aphids. Applications should be applied at regular intervals.
Adlerz, W. C. 1987. Cucurbit Potyvirus Transmission by Alate Aphids (Homoptera: Aphididae) Trapped ALive. J. Econ. Entomol. 80(1): 87-92.
Blackman, R. L. and V. F. Eastop. 1984. Aphids on the World's Crop: An Identification and Information Guide. John Wiley & Sons: Chichester, New York. 466 pages.
Cook, E. F. 1984. Aphis (Homoptera: Aphididae) Recorded from Compositae in North America, with a Key to the Species East of the Rocky Mountains and Comments on Synonymy and Redescriptions of Some Little Known Forms. Ann. Entomol. Soc. Amer. 77(4): 442-449.
Elmer, H. S. and O. L. Brawner. 1975. Control of Brown Soft Scale in Central Valley. Citrograph. 60(11): 402-403.
Metcalf, R. L. 1962. Destructive and Useful Insects Their Habits and Control. McGraw-Hill Book Company; New York, San Francisco, Toronto, London. 1087 pages.
Pitre, H. N. and K. K. Shaunak. 1971. Alate Aphids Captured in Yellow Pans Placed Around a Corn Field in Northeast Mississippi. Florida Entomologist. 54: 167-170.
Zimmerman, E. C. 1948. Aphis middletonii Thomas. pp. 83-84. In Insects of Hawaii. A Manual of the Insects of the Hawaiian Islands, including Enumeration of the Species and Notes on Their Origin, Distribution, Hosts, Parasites, etc. Volume 5. Homoptera: Sternorhyncha. 464 pages.
MAR/1992.
A-MIDDLE
