Key pests impact production of nuts, such as the pecan nut casebearer
Acrobasis nuxvorella Neunzig, the hickory shuckworm Cydia caryana (Fitch), the pecan weevil Curculio caryae (Horn), and numerous species of stink bugs; secondary pests attack the foliage, such as the pecan aphids Monellia caryella (Fitch), Melanocallis caryaefoliae (Davis), and Monelliopsis pecanis Bissell, the pecan phylloxera Phylloxera sp.
The very tiny parasitic wasps of the genus Trichogramma lay their eggs inside casebearer
eggs, turning them black and preventing the casebearer
larvae within from developing.
Anticipate that the pecan casebearer
caterpillar may be wreaking havoc on developing nutlets in early May, and ask your local extension office for organic spray programs.
Several moth larvae infest the husks and cotyledons of nuts, including the hickory shuck-worm (Cydia caryana), the filbertworm (Melissopus latiferreanus), the pecan nut casebearer
(Acrobasis nuxvorella), the navel orangeworm (Paramyelois transitella), and codling moths (Laspeyresia pomonella) (Moznette et al.
In the early 1930s, at the same time that USDA entomologist Phillip Dowden was obtaining foreign parasites to release against the gypsy moth, he was also initiating a program to control the larch casebearer, another European pest that presumably arrived in the United States on nursery stock and threatened our native eastern larch.
The Agathis wasp - less than one-eighth inch long - is known to attack only the casebearer, but the newspaper story illustrates the lack of understanding that accompanied this new tiny hero on the western scene.
Ryan's efforts to use biological control against the casebearer spanned 14 years.
One of these parasites was the Agathis wasp, which reduced the damage by casebearers so successfully that only low numbers of the pest still exist in the once heavily infested stands of eastern larch.
Chickens will also gobble wormlike larvae of such pests as the pecan nut casebearer
as they emerge in spring, as well as the grubs of other bugs.
Insecticides are still used to control the nut casebearer and shuckworm, but the most effective ones are no longer available because of environmental concerns.
Hickory shuckworms, pecan nut casebearers, and stinkbugs also attack pecans.
Aphids, shuckworms, pecan weevils, stink bugs, root borers, casebearers
, and mites can render a pecan crop practically worthless.