Most of these “bugs” have mouthparts like a hypodermic needle. They stick their needle-like mouth parts into the veins of plants and suck out the nutrient rich sap. As their populations build they can seriously impact the energy budget of your vegetable plants and limit your crops. Also, just like a mosquito sucking the blood from your arm to give you malaria, these insects can transmit serious diseases to your plants.

Very familiar to most gardeners, aphids (aka green flies in the U.K.) attack almost all vegetable crops. There are thousands of different species in different colors (green, black, gray, yellow or reddish-brown). Sedentary, they don’t move around much. They just sit still and suck. Some species transmit mosaic virus diseases.

Tiny thrips on an onion plant. They have rasping mouthparts. They file away the soft tissue from leaves and flowers causing silvery discoloration. Active flyers, thrips transmit tomato spotted wilt virus.

Mealybugs don’t even look like insects. They look more like q-tips in the leaf axils and undersides of leaves. They are sedentary. They transmit mealybug virus to pineapple plants.

Leafhoppers come in an astonishing array of colors, and some are quite pretty. Common garden variety leafhoppers are generally pale green, wedge-shaped, and jump away when disturbed. These are active flyers with sharp little beaks. They transmit aster yellows (a serious mollicute disease) and viruses like beet curly top and yellows virus.

It’s officially summertime. The solstice came and went. We’re tending our gardens, nurturing our vegetables and flowers. We all look forward to an abundant harvest of fantastic, home-grown, organic vegetables.

 Along the way we might run into beetles. Some beetles, like ladybugs (aka lady beetles), are good partners. Beneficial insects such as these help you achieve your goals by eating insects that damage to your plants. Other beetles damage your plants:

Japanese beetles. They’re busy eating holes in these leaves (well, they’re busy doing other things as well) and can seriously damage a very wide range of garden plants. These beetles only occur east of the Mississippi. The ones shown are the adults. Their babies (whitish grubs with brown heads that curl into a “C” shape) live in the soil and eat plant roots. You can hand pick the adults and knock them off the plants into a can of soapy water. Beneficial nematodes that also live in the soil attack and kill a wide variety of soil dwelling insects, including the larvae of Japanese beetles.

Colorado potato beetles. The adult is on the left and a baby (larva) on the right. The adults and larvae have voracious appetites for numerous garden plants and can be quite destructive. The soapy water trick works on adults and larvae alike. Bt san diego (Bacillus thuringiensis var. san diego), a parasitic bacterium that infects and kills beetles and only beetles, provides excellent control. Be careful to get the variety san diego for beetles. The more common variety of Bt is var. kurstaki which only kills caterpillars and will have no effect at all on your beetles.

Flea beetles. So called because they are very tiny and hop like fleas. These insects are too small to hand pick. They chew lots of small roundish holes in leaves and can make eggplant leaves look like lace. Their larvae live in the soil and eat plant roots. Thus beneficial nematodes make a good remedy for these beetles.

Curculio or Weevil. The long snout is the give-away.  This is a rose curculio on a ‘Harrison’s Yellow’ rose flower. They eat holes in the flower petals, chew up the stamens and lay their eggs in the flower. Hand-picking into soapy water works on these guys. The larva is a legless, whitish grub with a brown head. It drops to the ground when it’s ready to pupate to become an adult. Because it spends part of its life cycle in the soil it is also vulnerable to beneficial nematodes.

Ladybug (aka lady beetle). Not really a bug at all but a true beetle. There are many species of lady beetles and all of them are valuable partners in the garden. They are voracious predators of aphids and other soft bodied insects so they really do a good job of protecting your plants.

Every spring I’m frequently asked two questions by gardeners in northern states. The first is, “Why doesn’t my zucchini grow? It just sits there. What’s wrong with it?”  The second common question I get is, “What’s wrong with my zucchini (or cucumber, or melon)? It has lots and lots of flowers but no fruit. What’s up with that?”

Home gardeners love to grow members of the squash family, the Cucurbitaceae, called cucurbits for short. This big, important family includes all types of squash: winter (like acorn and butternut), and summer (like zucchini). It also includes cucumbers, pumpkins, melons in the genus Cucumis (cantaloupe, Persian, honeydew, casaba) and watermelon, in the genus Citrullus.

Keep in mind one very important fact about all these delicious vegetables and fruits:  they are all warm season crops. This means that they are sensitive to cold temperatures. And this sensitivity can cause stunting and lack of fruit.

Vegetable starts of warm season plants are readily available in nurseries and garden centers early in the season, when temperatures are really still too cold for them to thrive. As a result, when gardeners plant them too early, the plants simply sit, growing slowly or not at all, and become stunted. They usually begin to grow well when the weather warms up. So the answer to the first question is the squash doesn’t grow because it is still a bit too cold for it.

These two summer squash, each about 3 inches tall, wait for warmth. They’ve not grown significantly in the two months since they were planted. The photo also illustrates the second problem that crops up this time of year. Both plants above are flowering, but all the flowers are male. Male flowers do not make fruit. Only female flowers make fruit. All members of the squash family have female and male flowers on the same plant, but they produce only male flowers early in the season while temperatures are still cool. They start producing female flowers later in the season.

Here’s a female cucumber flower. See the spiny baby cucumber holding this flower up? That fat spiny structure below the petals (that is, closer to the plant) is the ovary of a female flower. The ovary is the thing that matures into a fruit, whether it’s an acorn squash or a zucchini. No female flowers, no fruit! And that’s the answer to the second question.

Look at the stalk holding up this male zucchini flower. It doesn’t look like a miniature zucchini at all. That’s because it isn’t. This stalk is merely a stalk. This flower does not have an ovary because it is a male flower and it will never mature into a fruit. The male flowers produce the pollen needed to fertilize the female flowers.

A female flower of a yellow summer squash clearly has a large yellow ovary underneath the flower petals. The ovary looks like a miniature squash. After the female flower gets pollinated it matures into a delicious squash.

 Next time you wonder why your cucurbit plants sit and sulk, or your zucchinis make flowers but no fruit, just be patient. Keep your vegetable starts where they are warm and have plenty of sun. Put them outside in the garden or a container when the weather warms up.