Controlling aphids, whiteflies and a number of other sucking pests that can be a major threat to pumpkin production is an ongoing challenge for growers who produce the one-shot, niche crop for Halloween.

Soil injected neonicotinoid insecticides can be an efficient way to get early season control of these pests. The problem has been getting the right amount of material to the plant’s root system. Researchers at Clemson University’s Edisto Agricultural Research and Extension Center in Blackville, S.C. are using a Dosatron to apply Admire, a neonicotinoid insecticide to the root system of pumpkins planted on plastic mulch.

Whiteflies, in particular, can be a double-threat to pumpkin and other cucurbit production, because these pests cause direct damage to the fruit and can vector other harmful viral diseases.

Whitefly adults congregate, feed, and mate on the under-surface of the leaves of the host plant and can occur in high enough populations to create white cloud-like materials when the insects are disturbed.

Direct crop damage occurs when whiteflies feed in plant phloem, remove plant sap and reduce plant vigor. With high populations plants may die. Whiteflies also excrete honeydew, which promotes sooty mold that interferes with photosynthesis and may lower harvest quality.

Plant disorders and virus transmission are of particular concern because they can occur even when a whitefly population is small. In general, the older the plant when infected with virus or the later the onset of plant disorders, the less damage to the crop, so preventative action is critical.

Not only can these tiny insects be deadly in small numbers, they are even more of a threat because they are known to attack over 500 species, representing 74 plant families. With pumpkins, which are typically planted in mid-summer and harvested prior to Halloween, many of these host plants are gone, leaving fewer options for whiteflies to attack.

Speaking at a recent field day at the Edisto Station, Extension pest management specialist Powell Smith showed more than 100 farmers in attendance the irrigation system rigged to inject Admire to control these pests.