These feathery beige moths are responsible for the loss of 25 - 50% of each year’s California coastal artichoke crop. If you are lucky enough to live in desert areas, this pest isn’t a problem. Otherwise, read on!
But, before we start learning about this pest, I have to comment on its scientific name. If you read this blog regularly, you know that I always try to include the Latin names. Some of them can be pretty entertaining, such as carrot’s Daucus carota. Any coincidence to Bugs’ “What’s up, doc?” Hard to say for sure, but this plume moth’s scientific name just begs to be, well, something. I mean, Platyptilia carduidactyla just screams platypus pterodactyl to me. Ok, maybe not.
Artichoke plume moth description
Adult moths are brownish beige to beige, with a wingspan of 3/4” to 1-1/2”. The wings are unique for a couple of reasons. First, they look very narrow when moths are at rest, with ends that are wider or “footed”. If you can look closely, you will see that the hind wings are fringed. Also, both sets of wings are lobed, creating the illusion that they have several wings. First instar larvae are pale yellow and only 1 mm long, so they are difficult to see. Later instars are larger, with the final instar reaching a little over 1/2” in length, and a more pinkish color. Eggs are only 0.5mm long and shiny. They start out a pale greenish yellow and turn a darker orangish-yellow before hatching.
Artichoke plume moth lifecycle
Female moths lay an average of 245 eggs singly on the underside of leaves and on stems, usually close to unopened buds. When they hatch, larvae begin feeding on leaves, stems, and buds. After their first molt, larvae borrow into your precious artichoke plants. With three or four overlapping generations a year, plume moths can inflict some serious damage!
Controlling the artichoke plume moth
Back in the 1940’s and 50’s, DDT was used to control these pests. Luckily, those days are behind us. Research has shown that good sanitation and cultural controls are very effective, although insect growth regulators (IGR) and pheromone traps are used on many commercially grown crops. You can protect your artichokes from the plume moth with these practices:
Have you seen this pest in your yard? Let us know in the comments!
It’s not unusual to see a spot on a leaf. No big deal, right? Maybe.
A single spot on a leaf might be nothing, or it can be home to more fungal spores than we can count. Each of those spores can catch a ride on a breeze or a raindrop to infect nearby leaves and plants. Before you know it, your garden has a fungal problem.
Symptoms of leaf spot
Symptoms can be insignificant spots, solitary bumps, or entire patches of brown, black, purple, or yellow over most of a leaf. You can determine what causes leaf spot by considering the plant species affected. Once you identify the cause of leaf spots in your garden, you will be better able to help your plants.
Alternaria leaf spot
The cabbage family, escarole, mango, calendula, and marigolds are susceptible to Alternaria leaf spot. Also known as Alternaria leaf blight, this disease starts out looking like other leaf spot diseases. But it can become a bigger problem, distorting and damaging broccoli and cauliflower heads.
Bacterial leaf spot in almonds
Bacterial spot (Xanthomonas arboricola pruni) is a relatively new disease that can severely reduce your almond crop. Symptoms begin in spring when dark spots develop where water collects, turning yellow and causing premature leaf drop. This bacteria also attacks the nuts, causing reddish lesions that later ooze an amber-colored gum. The nut inside shrivels up and becomes inedible. Lesions and cankers also occur on young twigs. Remove all infested leaves, cut away infected wood, and remove mummies. You can also interrupt this bacterium’s lifecycle by removing all the leaves before the rainy season hits. Fixed copper sprays in late January and again in late March can protect your almond trees from future infestations.
Bacterial leaf spot in spinach
Spinach leaves with water-soaked, angular areas of damage probably have bacterial leaf spot (Pseudomonas syringae spinaciae). What starts as tiny dark spots grow into large (3/4”) angular damaged areas that can merge with nearby areas for complete leaf loss. Infestations are visible on both the top and the bottom of the leaf. Overhead watering is the most common cause of bacterial diseases.
Common leaf spot in cane fruits
Your blackberry or raspberry plants may play host to the Mycosphaerella rubi fungus. Common leaf spot can also appear in gooseberry, boysenberry, dewberry, and olallieberry. The leaf spots are brown and circular with dark brown or purple margins and white centers. Oval lesions also occur on canes. Improved air circulation is the best treatment. Copper and sulfur sprays may also provide some control.
Common leaf spot in strawberries
Strawberries are vulnerable to a fungal disease called common leaf spot (Ramularia tulasneii). Symptoms include tiny purple dots on the upper leaf surfaces. These dots can grow to 1/4” in diameter, turning brown, gray, and white. Lesions may form on stems (petioles), stolons (runners), and fruit clusters (trusses). The lesions block the flow of water and nutrients in the vascular bundles. Common leaf spot is the most destructive leaf spot disease of California strawberries. Commercial growers use a fungicide called chlorothalonil (Bravo, Echo, and Daconil) on plants in the nursery to eliminate this pathogen. The use of resistant cultivars is the only option available to home growers.
Entomosporium leaf spot fungus in pomes
Apples, crabapples, loquat, pears, and quince are all vulnerable to the Entomosporium leaf spot fungus (Entomosporium mespili, aka Diplocarpon mesophilic). Symptoms of Entomosporium leaf spot include reddish spots with dark purple, red, or yellow halos, pale glossy specks in the center of these lesions, and early leaf drop. Fixed copper sprays can help reduce the infection.
Septoria leaf spot in tomatoes
Septoria leaf spot affects celery, chicory, cucumber, other cucurbits, parsley, and tomatoes. Plants infected with Septoria develop tiny yellow spots on leaves. These may be angular or round, with a reddish or yellow halo. These spots eventually merge and turn brown, killing leaves. Remove infected plants and throw them in the trash.
Leaf spot controls
Since fungicides are not considered justifiable for most causes of leaf spots, these cultural controls are your best bet:
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