Several species of insects that feed on peaches early in the growing season cause a gnarling and distortion of the fruits called catfacing. Plant bugs and stink bugs, largely responsible for this type of injury, suck the sap from the fruit. If the peaches do not fall as a result of this attack, fruit development is inhibited in the area of the punctures, while the surrounding healthy tissue continues to grow thereby causing catfacing.
Although catfacing insects invade plum trees early in the season, injury similar to that on peaches does not appear. The damaged plums probably fall before maturing.
Plant bugs and stink bugs in the adult stage overwinter under dead leaves, in ground debris and in cover crops. In the spring, the adults emerge and feed on the buds of peach, plum and other plants. Egg-laying, which begins shortly after adult emergence, occurs principally on vegetables, weeds and legumes. Occasionally, eggs are deposited in peach trees and a few individual insects develop.
PLANT BUGS, Lygus spp.
These insects appear in peach trees during the pink bud stage. The adults are about 1/5 inch long and range from shades of brown to tan or nearly black. Following their feeding activities, damaged buds, blossoms and small fruits usually fall. Large peaches develop sunken, corky areas. Populations decline shortly after petal fall, as the bugs are attracted to other hosts. Occasionally they are found in peach trees after shucksplit.
SMALL GREEN STINK BUGS
These stink bugs are the first species of economic importance to attack peaches in the spring. The adults are about 3/8 inch long and usually light to dark green. They emerge from hibernation and fly to peach trees in increasing numbers from the late-bloom stage until about the week after shucksplit. They migrate to other plant hosts during the following 3 weeks.
Damage caused by stink bugs is particularly severe, because they attack early in the season when the fruit is small. By harvest time, the injured peaches become folded and distorted. Usually, corky areas do not appear on the fruit.
BROWN STINK BUGS
Brown stink bugs are in the orchard about a week after petal fall. They are 3/8 to 1/2 inch long and light to dark brown because of closely spaced indentations which are brown on a yellow or light-gray background.
The adults appear in largest numbers about a month after shucksplit. Unlike the small green stink bugs, many remain in the trees throughout the season.
Fruits attacked at an early stage develop depressed, corky areas similar to those produced by plant bug feeding. Those damaged later in the season become only slightly deformed.
SOUTHERN GREEN AND GREEN STINK BUGS
These bright green stink bugs are the last to appear in damaging numbers in peach orchards each season. They are about 1/2 inch long, appear when the fruits are in the shucksplit stage and increase in number until harvest. Peaches on trees along orchard margins, bordering fields and woodlands, are damaged most severely. The bugs feed in groups, usually attacking some of the fruits but not injuring others on the same tree. Feeding damage is different from that caused by the brown stink bugs. Corky areas and gnarled, misshapen fruit do not develop, but damaged peaches appear watersoaked and dimpled. Frequently, strings of gum exude from the feeding punctures.
Suggested Control of Catfacing Insects on Peaches
Prevention of injury by catfacing insects largely depends on early-season spray applications. Control of these insects as they emerge from hibernation reduces the damage to young fruits. An application at petal fall of an approved insecticide followed by another application at shucksplit, usually provide satisfactory initial control of plant bugs, brown stink bugs and small green stink bugs.
Succeeding sprays applied for curculio control also prevent the development of destructive populations of green and brown stink bugs.
Commercial producers may refer to TAEX publication B-1689 Insects and Disease Control on Peaches, Apricots, Nectarines and Plums for insecticide, rates and remarks. Homeowners please refer to TAEX publication B-5041 Homeowner’s Fruit and Nut Spray Guide.