Condition: Waxy Breakdown (an abiotic disorder) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: Waxy breakdown of garlic is a physiological condition that sometimes affects garlic, though typically only rarely in Maine. Development of the condition is not fully understood but often associated with very high temperatures and/or sunscald damage around harvest

Disease: Powdery Mildew of Cucurbits (Podosphaera xanthii and Erysiphe cichoracearum) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: Management options: Powdery mildew is a common disease of pumpkins and winter squash. All cucurbits are susceptible, but many common cucumber and melon varieties have had powdery mildew resistance bred into them. The disease

Pest: Hornworms (Manduca sexta, M. quinquemaculata) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: Hornworms are probably the most destructive insect that attacks tomatoes. They are giant caterpillars that grow rapidly and can do a vast amount of eating in a very short amount of time. Sometimes it seems that healthy-looking tomato

Pest: Scarab beetles (Asiatic Garden, Japanese, Oriental, Chafers) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: There are several species of scarab beetles that are common in New England turf, fruit and vegetable crops. These were all introduced to the United States. Japanese beetles are the most common and widely distributed. Below

Pest: Basil Downy Mildew (Peronospora belbahrii) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: Downy mildew of basil was first reported in Uganda back in 1930. Relatively recently it spread to Italy in 2004, France in 2005, United States (Florida) in 2007 and by 2009 had made its way to New England.

Pest: Tortoise beetle (species in the Cassidinae subfamily) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: These beetles are typically only a very minor pest. They do not typically cause serious damage and do not warrant spraying. The numbers are usually small and the beetles can be picked off by hand, and

Blossom End Rot Blossom end rot is a familiar sight for many tomato growers, but it can affect other crops as well, such as peppers and squash. Though it may look like a disease, and it sometimes allows infection by secondary decay organisms, blossom end rot is an abiotic growth disorder caused by stressful growing

Disease: Early blight on tomato (Alternaria) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: Early blight is a serious problem in tomatoes and potatoes, but rarely affects peppers and eggplants. In most years, it is very common; much more common than late blight, which is usually rare in Maine. All aboveground portions

Pest: Anthracnose (Colletotrichum fioriniae) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: The fungus pathogen that is responsible for anthracnose on garlic scapes (Colletotrichum fioriniae), is the same fungus that causes celery anthracnose — described in this pest report from 2019. One theory for the relatively recent appearance of the disease is

Pest: Cutworms (many species) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: Cutworms are occasional pests of many crops early in the season, including carrots, peas, onions, spinach, broccoli and the list goes on and on. Some years they result in major losses, other years result in no loss at all. They

Pest: Cucurbit downy mildew (Pseudoperonospora cubensis) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: Cucurbit downy mildew can be very destructive of cucumbers, squash, pumpkins and melons, if conditions are favorable to it. This disease does not overwinter here, and its severity in any given season is often dependent upon when it

Pest: Squash Bug (Anasa tristis) Pest identification and lifecycle, most common symptoms and crops affected: Squash bugs are serious pests of pumpkins and squash throughout North America. Plant damage, and bug survival, are low on watermelon, very low on cucumber and muskmelon, and highest on squash and pumpkin. Both adults and nymphs feed by inserting

Pest: Squash vine borer (Melittia cucurbitae) Pest identification and lifecycle, most common symptoms and crops affected: Squash vine borer moths are day-flying moths with a 1 to 1.5 inch wingspan and bright orange-red markings. In flight, they look like wasps. There is thought to be only one generation per year in New England with adults

Pests: Tarnished Plant Bug (Lygus lineolaris) and Four-Lined Plant Bug (Poecilocapsus lineatus) Pest identification and lifecycle, most common symptoms and crops affected: The tarnished plant bug is a small (6 mm), bronze, brown and black bug that feeds on a very wide variety of plants (up to 300 different species). They overwinter as adults under

Pest: Potato Leafhoppers (Empoasca fabae) Pest identification and lifecycle, most common symptoms and crops affected: The potato leafhopper has been arriving here in New England earlier and earlier. If you see unexplained yellowing of leaves of beans or potatoes, check for the critter. They primarily feed on beans, potatoes, eggplants, strawberries and alfalfa, but will

Pest: Striped cucumber beetle (Acalymma vittatum) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: Striped cucumber beetle is our most serious early-season pest in cucurbit crops. These beetles spend the winter in plant debris in field edges and with the onset of warm days and emergence of cucurbit crops they rapidly move

Pest: Colorado Potato Beetle (Leptinotarsa decemlineata) Pest identification and lifecycle, most common symptoms and crops affected: As with most other insects and plants, there is a direct relationship between higher temperatures (in the range between about 55 and 90 degrees) and faster rate of development. That includes egg-laying, egg hatch, larval growth and feeding rates.

Pests: Seedcorn maggot (Hylemya platura), Onion maggot (Delia antiqua), Cabbage maggot (Delia radicum) Pest identification and lifecycle, most common symptoms and crops affected: Seedcorn maggot larvae feed on seeds and young seedlings of many crops (including corn, beans, beets, peas, spinach, onions and Brassicas). The first symptoms are usually poor germination (or failure of seedlings

In the early spring, when most plants are still in greenhouses — a much more controlled setting than gardens and fields — a lot of the problems that arise are abiotic (i.e., not infectious). Sometimes abiotic issues are transient (e.g., cold temperatures) so it’s good to both check new growth to see how it looks

Pests: Leek Moth (Acrolepiopsis assectella) Pest/disease identification and lifecycle, most common damage symptoms and crops affected: Leek moth is a newer invasive pest of allium crops like onions, garlic, shallots and chives, and, as the name suggests, they are particularly fond of leeks. As with most moth pests the crop damage is from its larval