2016 Sorghum Sugarcane Aphid Research Exchange

1. Evidence of a Sexual Life Cycle
in Sugarcane Aphid
Gregory Bryan Wilson
Dr. David L. Kerns
Louisiana State University
Sorghum – Sugarcane Aphid
Research Exchange Meeting
New Orleans, LA
January 7 – 8, 2016

2. Introduction
1. In the United States, SCA are generally
considered to be obligate anholocyclic, as no
sexual forms have been observed and
reported.
However,
1. Reported observations of oviparous adults,
sexual reproduction, and eggs do exist.
2. A sexual cycle could help explain the rapid
host shift away from sugarcane.

3. Background
Historically reported as
• Aphis sacchari - 1897 - ~ 1970
• Longiunguis sacchari - ~1910 - ~ 1980
• Melanaphis sacchari - ~1980 to present
In 1974, Chaudhuri and Banerjee officially
synonymized both L. sacchari and A. sacchari
as Melanaphis sacchari (Zehntner) which
unified the nomenclature.
Roy Chaudhuri, D.N., Banerjee, C., 1974. A study of the genus
Melanaphis (Homoptera: Aphididae) with descriptions of new taxa from
India. Orient. Insects 8, 365–389.

4. Anholocyclic Species
Viviparous females
(winged and wingless)
Viviparous females
(usually overwinter as
apterae or nymphs)

5. Anholocyclic Overwintering
Historical OW hosts:
• Miscanthus sacchariflorous
• Andropogon spp.
• Pennisetum spp.
• Panicum spp.
In U.S., theorized to OW as viviparous
morph on Johnson grass, possibly on:
• whole plants in tropical zone
• rhizomatous tissue or host surviving
winter in temperate zone

6. Initial Testing
Rhizomatous tissue no-choice test for
sorghum isolates
• 10 day survey
• 3-4 in Johnson grass rhizome
• 1 leaf blade with ~50 aphids
• After 3 days no aphids survived
• Needs further testing

7. Holocyclic Literature
1. Wang, Y.S., 1961. Studies on the sorghum aphid,
Aphis sacchari Zehntner. Acta Entomol. Sin. 10,
363–380.
2. Yadava, R.L., 1966. Oviparity in sugarcane aphid,
Longiunguis sacchari Zehnt. (Aphidae:
Homoptera). Curr. Sci. 1, 18.
3. Setokuchi, O., 1975. Ecology of Longiunguis
sacchari (Zehntner) (Aphididae) infesting
sorghums. II. Observations on the oviposition.
Proc. Assoc. Plant Prot., Kyushu 21, 8–10.
4. David S.K., Sandhu G.S., 1976. New oviparous
morph of Melanaphis sacchari (Zehntner) on
sorghum. Entomologist's Record, 88(1):28-29.

8. Composite Key Learnings
• Oviparae appear after 16th generation
(Wang)
• Found Nov – Dec and Feb – Mar.
• Between 30º – 41º latitude
• Oviparous morphs were numerous and
conspicuous
• Average temperature 17.7º C
• Photoperiod 11:13 – 10:14
• Eggs found on Sorghum bicolor (Sorghum
vulgare) and Miscanthus sacchariflourus
• 3-5 eggs per clutch (Setokuchi)

9. Thank you
Questions? Feel free to
contact Greg Wilson at
gbwilson@agcenter.lsu.edu