External morphology and microstructure of the compound eye of fire ants, Solenopsis invicta Buren

Abstract

The external morphology of the compound eye of the winged female and male Solenopsis invicta Buren and its microstructure in light and dark adaptations were observed using scanning electron microscopy and optical microscopy. The results indicated that the compound eye located on the lateral side of its head, is the a shape of a half ellipsoid and composed of approximately 510 ommatidia in the female, and a near hemisphere with about 805 ommatidia in the male. The ommatidium was made of a corneal lens, crystalline cone, 8 to 9 retinula cells and basement membrane. The cornea was a colorless, transparent and double convex lens. The crystalline cone, with an inverted cone shape, was approximately 14.50 m long, formed by four equal parts, and surrounded by many pigment granules. The rhabdom beneath the crystalline cone, was about 75.00 m long, with a thicker middle part and thinner ends. More pigment granules were scattered in the distal and proximal ends and less in the middle, and the basement membrane was on the most bottom area of the ommatidium. The primary pigment cells moved horizontally along the crystalline cone from its distal to proximal end during dark adaptation or moved reversely during light adaptation. There was no significant difference between the pigment granule distribution and the structure of the crystalline cone between female and male ommatidium under the same light or dark adaptation. It is concluded that the fire ant compound eye is an apposition eye, whose light-tuning mechanism is accomplished by the change of crystalline cone and the movement of the pigment cells.

Keywords

Solenopsis invicta Buren, compound eye, ommatidium / external morphology, microstructure

References

[1] Allen C R, Lutz R S, Demarais S (1995). Red imported fire ant impacts on Northern bobwhite populations. Ecol Appl, 5(3): 632-638

[2] Banks A N, Srygley R B (2003). Orientation by magnetic field in leaf-cutter ants, Atta colombica (Hymenoptera: Formicidae). Ethology, 109(10): 835-846

[3] Bernstein S, Finn C (1971). Ant compound eye: size-related ommatidium differences within a single wood ant nest. Experientia, 27(6): 708-710

[4] Callcott A M (2002). Range expansion of the imported fire ant: 1918-2001(updated). En: 2002 Annual Imported Fire Ant Research Conference, Athens, Georgia

[5] Fan F, Liu J, Qu P, Lv L H, Wei G Sh (2008). Compound eye morphology of the fire ants, Solenopsis invicta, invaded southern China observed with scanning electron microscopy. Chinese Bulletin of Entomology, 45(4): 642-646 (in Chinese)

[6] Chen H T, Luo L ZH, Xiong H L (2010). The outing activity of worker ants and nuptial flight of alates in the red imported fire ant, Solenopsis invicta (Hymenoptera: Form icidae) in Guangzhou area, Southern China. Acta Entomologica Sinica, 53(4): 449-456 (in Chinese)

[7] Harris R A, Hempel de Ibarra N, Graham P, Collett T S (2005). Ant navigation: Priming of visual route memories. Nature, 438(7066): 302

[8] Feng H L, Zhang X D, Chang T R, Guo W C, Zhang R C, Xin Y (1992). Antennal sensilla and compound eye of ant observed with scanning electron microscopy. Entomological Knowledge, 29(5): 292-294

[9] Klotz J H, Jetter K M, Greenberg L, Hamilton J, Kabashima J, Williams D F (2003). An insect pest of agricultural, urban and wildlife areas: The red imported fire ant. In: Daniel A Sumner, ed. Exotic Pests and Diseases: Biology and Economics for Biosecurity. Iowa City: Iowa State Press, 151-166

[10] Labhart T (2000). Polarization-Sensitive interneurons in the optic lobe of the desert ant Cataglyphis bicolor. Naturwissenschaften, 87(3): 133-136

[11] Meyer E P, Nassel D R (1986). Terminations of photoreceptor axons from different regions of the compound eye of the desert ant Cataglyphis bicolor. Proc R Soc Lond B Biol Sci, 228(1250): 59-69

[12] Moser J C, Reeve J D, Bento J M S, Della Lucia T M C, Cameron R S, Heck N M (1999). Eye size and behaviour of day-and night-flying leafcutting ant alates. J Zool (Lond), 264(1): 69-75

[13] Neese V (1966). Zur Bedeutung der Augenborsten bei der Fluggeschwindigkeitsregulation der Bienen. Z Vgl Physiol, 52(2): 149-154

[14] Shoemaker D D, Ross K G (1996). Effects of social organization on gene flow in the fire ant Solenopsis invicta. Nature, 383(6601): 613-616

[15] Trager J (1991). The fire ants of the Solenopsis geminata group. J NY Entomol Soc, 99(2): 141-198

[16] Menzi U (1987). Visual adaptation in nocturnal and diurnal ants. Journal of Comparative Physiology A, 160(1): 11-21

[17] Vinson S B (1997). Invasion of the red imported fire ant (Hymenoptera: Formicidae) Spread, Biology, and Impact. American Entomologist, 43(1): 23-39

[18] Wojcik D P, Aller C R, Brenner R J, Forys E A, Jouvenaz D P, Lutz R S (2001). Red imported fire ants: Impact on biodiversity. American Entomologist., 47(1): 16-23

[19] Gao Y, Luo L Zh (2005). Antennal morphology and sensiha of the fire ant, Solenopsis invica Buren invaded Southern China observed with scanning electron microscopy. Acta Entomologica Sinica, 48(6): 986-992 (in Chinese)

[20] Xu Z M, Shen J X (2000). A study on direct homing and underlying orientation mechanism in the ant Tetramorium caespitum. Acta Entomologica Sinica, 143: 242-24 (in Chinese)

[21] Xue D Y, Li H M, Han H X, Zhang R Z (2005). A prediction of potential distribution area of Solenopsis invicta in China. Entomological Knowledge, 42(1): 57-60 (in Chinese)

Acknowledgements

This research was financially supported by the Natural Science Foundation of Hebei Province, China (Nos. C2008000272, C2010000680), the Natural Science Foundation of Guangdong Province, China (No. 06025386), the Open Foundation of Key Laboratory for New Technology of Plant Protection of Guangdong Province, China (No. 2008-02), and the Dynamic and Distinctive Discipline Program of Hebei Province, China.

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg