Cucumber beetles

[RebelRidin]

Originally Posted by lakelady

Are all greenhouse cukes like that , don't require pollination? I have one Italian variety I got seeds for, maybe I will make a cover for it and keep it covered?

Carolyn, I recall you mentioning covering them. I just got a nice big piece of row cover made for insects and as soon as I figure out how I am growing them, (what size trellis or fencing) I will be sewing a cover. They will look silly, just like my covered tomato blossoms did, but who cares. Last year was a disaster.

As I understand it greenhouse varieties do not need polination. They are "Parthenocarpic" varieties and if unpollinated, they are seedless. However, they can be pollinated in which case they will not be seedless. Thus if your goal is seedless cukes having male flowers and bees around could spoil things.

I hope we get to see a picture of your cover Antionette.

[Tracydr]

Originally Posted by cajunman56

I have also seen a cucumber beetle for the first time this year. This year I'm trying a weekly application of Neem oil. Hopefully, that will take care of them.

Can you use neem in the heat? I'd like to have neem as an option because I've been afraid to spray anything once it gets to 90 degrees.
I had a neem mix from the store that also had some other oil in it and it burned my plants worse than anything.
I even had spinosad burn a few but that was my fault for spraying in late morning.
With our lack of dew, I'm not sure early morning or night is that helpful. No dew to which I always heard is why you're to spray at those times.

[Tracydr]

Originally Posted by chastom

try the cucumber beetle pheromone sticky traps traps ,I have just put them out and they are cover with cuc. beetles.

I didn't know they made those! Now, if they only had one for squash bugs. ( Not the borers)
The only thing that I found works for them is DE when they are still tiny. I rarely get the borers but the bugs can be a problem.

[kath]

Just found the first cuke beetles yesterday and have squished 12 in two days. In my garden they always go to the potato plants first. Strawberries and spinach are heavily infested with whiteflies and all other crops have at least some when you brush them- also today the first flea beetles and cabbage worm made an appearance. Will be spraying Bt for the latter but praying for the beneficials to increase quickly- have some flowering cilantro plants that overwintered and some parsley from last year is about to flower, too. Can't bear to spray since I found hatching lady beetle larvae yesterday on an apple tree in the garden.

I'm going out to cover the tiny cucumber seedlings- thanks for the tip, Carolyn

kath

[Sodak]

from the Ohio State University...
Striped cucumber beetles often fly from their hibernating sites early in the season, even before plants emerge. As soon as the cucumber, squash, pumpkin, melons and related seedlings push up through the soil, beetles can eat off the stems and cotyledons, frequently killing them. Adults later feed on the leaves, vines and fruits of plants that survive. Sometimes, deep pits are gnawed into the rind, making the produce unfit for consumption or market.
Damage is also caused by the larvae feeding on the roots of host plants, which weakens the plant and makes it susceptible to other problems. Adults also feed on beans, peas, corn and blossoms of other plants.
Most important, these beetles are vectors of a serious cucurbit disease known as bacterial wilt. Plants infected with the disease wilt quickly with leaves drying out prior to plant death. The causative bacteria, Erwinia tracheiphilia (E.F. Smith), overwinters in the bodies of hibernating beetles. These beetles introduce the bacteria into the plants through the fecal contamination of feeding wounds. This is the only natural method of infection known. Beetles also spread squash mosaic virus.
Identification

An adult striped cucumber beetle is oblong, yellowish-green in color, about 1/4 inch long, and marked by three slate-black stripes. The head and antennae are dark colored. Wings are covered with very small punctures clearly seen under magnification.
Eggs are light yellow or orange colored, and round to oval shaped. Larvae are worm-like and about 3/8 inch long when full grown. Larvae are white with a dark head and have three pairs of legs on the thorax. Pupae are whitish-yellow and about 1/4 inch long.
Striped Cucumber Beetle
Larva and Adult Life Cycle and Habits

Adult beetles overwinter and leave Their hibernating quarters in the spring when temperatures reach 65 degrees F or more. When cultivated cucurbit plants begin to emerge through the soil surface, large numbers of beetles may suddenly appear and feed on the seedlings or crawl into soil cracks in reach of sprouting seed. Beetles soon mate and continue feeding throughout the season. Eggs are laid 8-25 days after mating. Females deposit 225-800 in small clusters or singly into soil cracks at the base of cucurbit plants.
Eggs hatch 5-8 days later, widh larvae spending about 15 days feeding on the roots and stems of fruit that is in contact widh the soil. The pupal period is 6-7 days. The time from egg to adult for The first generation of beetles requires about 1 month and slightly longer for succeeding generations.
After cucurbit plants mature and cool autumn weather approaches, beetles migrate to wooded, bushy areas, crawling under litter to overwinter. Some may overwinter a mile from the hatching site. In Ohio, only 1 generation occurs while 2 or more generations may be produced in the Gulf states.
Control Measures

It is important to inspect newly planted cucurbit plants frequently for the presence of any adult striped cucumber beetles. Unfortunately, there is no control for The bacterial disease once tile infection has been introduced into the plants.
Prevention

Inspect plants frequency for beetle infestations. Row covers can provide protection, but during blossoming time, tile covers must be removed for several hours each day, to allow pollination. Plant wilt-resistant varieties and use trap crops, if appropriate.
Insecticides

Although There are several insecticides that control the beetle, only a few chemicals can be used on cucurbit plants because of their sensitivity to chemical injury. Application of an insecticide is usually recommended as soon as the plants begin to emerge through the soil. For prevention of bacterial wilt, it is often advisable to spray at 5-day intervals, beginning when seedlings emerge or after transplanting and continuing She schedule until vines run. If rain occurs within the 5-day period, repeat the treatment promptly and then return to the regular 5-day treatment interval.
Sprays prepared from wettable powders are less phytotoxic than sprays prepared from emulsifiable concentrates. Dusts are likewise effective if plants are Thoroughly covered. Rotenone 1% dust gives good beede control. Malathion may cause injury to plants if applied before they start to vine. Malathion may cause some foliar burning and should not be applied when plants are wet. Do not combine Malathion and Sevin for application to cucumbers due to possible phytotoxicity.
Recommended chemicals include rotenone, methoxychlor, malathion and carbaryl (Sevin) applied according to label directions and safety precautions.
Predators and Parasites

Natural predators include soldier beetles, tachinid flies, braconid wasps and certain nematodes.
This publication contains pesticide recommendations that are subject to change at any time. These recommendations are provided only as a guide. It is always the pesticide applicator's responsibility, by law, to read and follow all current label directions for the specific pesticide being used. Due to constantly changing labels and product registration, some of the recommendations given in this writing may no longer be legal by the time you read them. If any information in these recommendations disagrees with the label, the recommendation must be disregarded. No endorsement is intended for products mentioned, nor is criticism meant for products not mentioned. The author, The Ohio State University and Ohio State University Extension assume no liability resulting from the use of these recommendations.

[tjg911]

anyone ever water the plants with wood ashes? this kills cabbage maggots that chew the roots and make the leaves wilt on cabbages and will kill the plant. 1 watering with 1-2 tablespoons of wood ashes in 2 gallons of water immediately revives the plants (next day) and i assume immediately kills the maggots.

i wonder if this would kill cuke beetle grubs?

tom

[b54red]

The way my cucumber fences are set up covering them is not an option and probably not too good for them in our heat. The only thing I have found that works well on them is Sevin. Kinda like squash vine borers in that regard.

Bill