|Crop Knowledge Master|
Pentalonia nigroneruosa (Coquerel)
Ronald F.L. Mau, Extension Entomologist
Jayma L. Martin Kessing, Educational Specialist
Victoria L. Tenbrink, Research Associate
Arnold H. Hara, Entomologist
Department of Entomology
The preferred host of this aphid is banana. However, it will also infest many tropical and subtropical food and ornamental plants, including Alpinia purpurata (floral red and pink ginger), Xanthosoma (ape), cardamom, Heliconia, tomatoes, taro, Calla, Costus, kahili ginger, torch ginger, and Zingiber (Waterhouse, 1987; Zimmerman, 1948).
Probably native to Southeast Asia, the banana aphid is present just about everywhere banana is grown through the world. It occurs in tropical Africa, Atlantic Islands, Australia, California, Central America, Cook Is., Egypt, Fiji, Florida, Hawaii, Kiribati, India, Indonesia, Malaysia, Madagascar, Marshall, Is., Mauritius, Mexico, Micronesia, the Middle East, Mozambique, New South Wales, Papua New Guinea, the Philippines, Reunion, Samoa, northern South America, Taiwan, Tokelau, Tonga, Tuvalu, Vanuatu, Wallis Is., and much of the West Indies (Waterhouse, 1989).
The banana aphid was first recorded in the state in 1924 from Honolulu, but was previously known in the Islands as an undetermined species (Zimmerman, 1948). Although known to be on Oahu, Hawaii, and Kauai, it wasn’t recorded on Maui, until 1989 (Heu, unpublished data).
Like most aphids, the banana aphid is a phloem feeder that uses its long stylets to pierce plant tissues to suck the sap directly from the vessels. This can cause plants to become deformed; the leaves become curled and shriveled, and in some cases galls are formed on the leaves (Metcalf, 1962). Young plants may be killed or their growth checked if there is sufficient feeding by the banana aphid. However, direct damage by this aphid is generally negligible.
Like many other soft bodied insects, such as leafhoppers, mealybugs, and soft scales, aphids excrete honeydew. This sweet and watery excrement if 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, decreases photosynthetic activity, and decreases vigor of the host.
Aphids vector many plant diseases that cause substantially greater losses than that caused by direct feeding injury. This is often the most damaging feature of an aphid infestation. Both wingless (apterous) and winged (alate) aphids are able to transmit viruses. Transmission is usually in a nonpersistent manner where the virus is taken up into the aphid’s "mouth" while feeding on an infected plant and transferred to a healthy plant during subsequent feedings. In nonpersistent transmission, the virus reproduces in the plant, and aphids simply aid in transporting the virus. With these types of virus-vector associations, the aphid acquires the virus and is only able to transmit the virus temporarily. Once all the infective charge is reduced by feeding or the passing of time, the aphid is unable to transmit the virus until it feeds on infected tissue again.
Banana aphid vectors bunchy top disease of bananas. Symptoms of the disease include dark green streaking of the leaves, midrib, and petioles; progressive leaf dwarfing; marginal chlorosis; and leaf curling. Fruits of diseased plants are unsaleable because they are small and distorted.
In India, banana aphid vectors a mosaic virus of cardamom called "katte". The disease causes considerable losses to cardamom crops.
Reproduction in the banana aphid is entirely parthenogenetic (without mating). Females give birth to live female young. Males are not known for this species. The life cycle (nymph to adult) is completed in 9 to 16 days. The adult life span ranges from 8 to 26 days; there could be as many as 30 generations produced per year in Hawaii.
There is no egg stage. Young are born live.
Like most other aphid species, the banana aphid has four nymphal stages. Newborn nymphs are oval at first and become slightly elongated. They are reddish brown, with four segmented antennae, and measure 1/250 inch in length. The second stage nymphs are similar in appearance and measure approximately 7/250 inch long. The third nymphal stage individuals are light brown, measuring about 9/250 inch in length; the compound eyes are more noticeable beginning with this stage, and the nymphs have five-segmented antennae. The fourth stage nymphs have six-segmented antennae, are light brown in color, and are 1/25 inch long. The first, second, third, and fourth nymphal stages last 2 to 4, 3 to 4, 2 to 4, and 2 to 4 days, respectively (Rajan, 1981).
Adult banana aphids are small to medium sized aphids (1/25 to 1/12 inch), shiny, reddish to dark brown or almost black. They have six-segmented antennae that are as long as the body. Alates have prominent, dark (brown or black) wing veins.
Adults start producing young one day after reaching maturity. They can give birth to 4 aphids per day with an average production of 14 offspring per female.
Colonies of the banana aphid are commonly found in the upper leaf sheaths and lower flower bracts of the ginger stem. The entire inflorescence may be infested. Small colonies occasionally occur on the leaf blade.
Ants are associated with the banana aphid. The ants feed on the honeydew secreted by the aphid and, in turn, establish new aphid colonies and ward off natural enemies.
Winged adults often develop after 7 to 10 generations of wingless individuals. Dispersing winged adults establish new colonies on other new host plants. Although they are not strong fliers, they may be carried considerable distances by light winds. Flight activity peaks between 9:00 to 11:00 AM and 5:00 PM to dusk.
Bloated, tan colored mummies are evidence that braconid wasps are parasitizing the colony. Introductions of the braconid, Lysiphlebius testaceipes were made in 1923, 1953, and 1965 by the Hawaii Department of Agriculture to combat aphids. The sources of the introduced wasps include Japan, Cuba, California, and Mexico. This parasitoid is established on all populated Hawaiian Islands (Lai and Funasaki, unpublished data), and is a known parasite of the banana aphid (Waterhouse, 1987).
Biological control experts from the Hawaii Department of Agriculture have introduced ladybird beetles to the Islands to control insects. Coccinella 7-punctata var. brucki was brought in from Okinawa in 1958 and is established on the major Islands (Lai and Funasaki, unpublished data), and is listed by Waterhouse (1987) as a banana aphid predator . Other predators that have been successfully introduced to combat aphids are Coelophora inaequalis, C. pupillata, Hippodamia convergens, Scymnodes lividigaster, Diomus notescens (Coleoptera: Coccinelidae), and Nesomicromus navigatorum (Neuroptera: Hemerobiidae). The larvae, as well as the adults, of ladybird beetles and lacewings are very active aphid feeders, and have been found, along with syrphid fly larvae, in floral red ginger in Hawaii.
Immersing flowers and foliage in hot water at 49 degrees Centigrade for 10 minutes kills banana aphids. This treatment is safe for many commodities, but preconditioning may be required ( A. H. Hara, unpublished data).
Chlorpyrifos and acephate foliar sprays have been effective in reducing aphid populations and the attending ants (Hata et al., 1992, Hata & Hara, 1992).
Prewashing in a mild detergent or soap solution, opening tight bracts, followed by a 5 minute dip in an insecticidal soap or soap-pyrethroid combination at the label rate eliminates most aphids (Hansen, 1992).
Hansen, J. D., A. H. Hara & V. L. Tenbrink. 1992. Insecticidal dips for disinfesting commercial tropical cut flowers and foliage. Trop. Pest Manag. 38: 245-49.
Hata, T. Y. & A. H. Hara.1992. Evaluation of insecticides against pests of red ginger in Hawaii. Trop. Pest Manag. 38: 234-236.
Hata, T. Y., A. H. Hara, E. B. Jang, L. S. Imaino & V. L. Tenbrink. 1992. Pest management before harvest and insecticidal dips after harvest as a systems approach to quarantine security for red ginger. J. Econ. Ent. 85: 2310-2315.
Hill, D. S. 1983. Pentalonia nigronervosa Coq. p 203. In Agricultural Insect Pests of the Tropics and Their Control, 2nd Ed. Cambridge University Press. 746 pp.
Kolkaila, A. M. & A. A. Soliman. 1954. A Study of the Banana Aphid, Pentalonia nigronervosa Coq. (Hemiptera: Aphididae). Bull. Soc. Fouad. Ier Entomol. 38: 231-250.
Metcalf, R. L. 1962. Destructive and Useful Insects. McGraw-Hill Book Company: New York. 1087 pp.
Rajan, P. 1981. Biology of Pentalonia nigronervosa F. caladii van der Goot, vector of “katte” disease of cardamom. J. Plantation Crops 9: 34-41.
Waterhouse, D. F. 1987. Chapter 6. Pentalonia nigronervosa Coquerel. pp. 42-49 In Biological Control: Pacific Prospects. D. F. Waterhouse & K. R. Norris, Ed. InkataPress: Melbourne. 454 pp.
Zeck, E. H. 1929. The Banana Aphid (Pentalonia nigronervosa, Cog.). Agric. Gaz. NSW. 40: 675-680.
Zimmerman, E. C. 1948. Insects of Hawaii, vol 5. University of Hawaii Press: Honolulu. 464 pp.