Skip to main content
ARS Home » Research » Publications at this Location » Publication #80802
Title: USE OF AIRBORNE DIGITAL VIDEO IMAGERY TO MONITOR DAMAGE CAUSED BY TWO HONEYDEW-EXCRETING INSECTS ON COTTON

Author
item Summy, Kenneth
item Everitt, James
item Escobar, David
item Alaniz, Mario
item Davis, Michael

Submitted to: Biannual Workshop in Color Photography and Videography in Resource
Publication Type: Proceedings
Publication Acceptance Date: 4/30/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Research was conducted on cotton in the Lower Rio Grande Valley of Texas to evaluate the potential of airborne digital video imagery to monitor damage caused by cotton aphids and silverleaf whiteflies. Both pest species excrete copious quantities of honeydew (a waste product rich in sugars) which serves as a medium for sooty mold fungus (heavy deposits of which may yseverely retard photosynthesis and reduce plant vigor). Aphid and whitefl densities within a series of plots subjected to routine insecticidal application increased to levels substantially higher than those occurring within untreated controls (an effect attributed to disruption of natural enemies that normally maintain both pest species in check). Higher pest densities within treated plots were accompanied by the development of heavy deposits of sooty-mold fungus, which produced an effect that was highly visible at ground level. Damage caused by sooty-mold fungus was readily detectable using airborne video images (obtained at an altitude of 600 meters) using the black and white near-infrared (NIR) image band. Digital video images thus provided an objective means by which to compare the intensity of plant damage occurring in treated and untreated plots, even though the latter were relatively small and contiguous.

Technical Abstract: Airborne digital video imagery was used in conjunction with conventional sampling procedures to monitor infestations of cotton aphid, Aphis gossypii Glover, and silverleaf whitefly, Bemesia argentifolii Bellows & Perring, occurring on cotton in southern Texas. Routine application of broad-spectrum insecticide to one series of cotton plots resulted in an appreciable increase in densities of both pest species in treated plots relative to untreated controls (an effect attributed to disruption of natural enemy fauna that normally maintain the two pest species in check). The relatively high pest densities within treated plots was accompanied by a significantly higher incidence of plant damage caused by accumulations of honeydew (an insect waste product rich in sugars) and deposits of sooty-mold fungus (Capnodium spp.), which produced an effect that was highly visible at ground level. Differences among the treated and untreated plots were readily apparent in digital video images obtained at an altitude ca. 600 m, using the near-infrared (NIR) image band. Potential uses of this technology to monitor plant damage caused by infestations of honeydew-excreting insects on cotton and other crops are discussed.