Sap beetles, also known as driedfruit beetles, belong to the family Nitidulidae and are a complex of several closely related species. These small insects, ranging from 1/8 to 1/4 inch in size, can be found in various places, particularly in gardens or agricultural settings. Some common species include the Carpophilus hemipterus, Carpophilus freemani, and the confused sap beetle.
You might encounter sap beetles when you grow fruits or vegetables in your garden. These beetles are attracted to ripe, fermenting, or decaying produce and can cause significant damage. They also have a distinct feature: their antennae end in a club-like shape that can be helpful in identifying them.
Understanding the behavior, life cycle, and management methods for sap beetles is essential in dealing with these pests successfully. By the end of this article, you’ll be well-equipped with all the information you need to tackle any sap beetle issues that may arise in your garden or fields.
What Is a Sap Beetle?
A sap beetle, belonging to the family Nitidulidae, is a type of small insect that is attracted to sweet, overripe, or decomposing fruits and vegetables. You’ll often find them in gardens or farms where fruits and vegetables are grown. There are more than 180 species of sap beetles, and they come in various shapes and colors, usually black or dark.
For instance, a common sap beetle species is the four-spotted sap beetle, also known as the picnic beetle. This beetle is 1/4 inch long, shiny black, and has four yellowish dots on the wing covers. Another example is the strawberry sap beetle, which can cause damage to strawberry plants and fruits.
Sap beetles are general scavengers, and their diet can include sap, decaying plant materials, fungi, and sometimes even other insects. Due to their feeding behavior, sap beetles can be considered minor pests in gardens or farms.
Some key features of sap beetles are:
- Antennae with a club or knob at the end
- Usually dark-colored, black or brown
- Small in size, ranging from 1/8 to 1/4 inch in length
While sap beetles may be a nuisance to fruits and vegetables in your garden, they are also part of the natural ecosystem. Preventative measures like timely harvest of ripe crops and removal of decomposing plant materials can help reduce their presence.
Characteristics of Sap Beetles
Physical Attributes
Sap beetles are small insects with antennae, an oval shape, and wing covers. They are usually shiny black in color, with their abdomen slightly protruding. For example, the strawberry sap beetle measures about 1/8 inch long and has a more flattened oval shape.
Life Cycle
The life cycle of sap beetles consists of four stages: egg, larva, pupa, and adult. They usually overwinter as adults, meaning they survive the winter in their adult form.
Genera of Sap Beetles
Some common genera of sap beetles include the dusky sap beetle (Carpophilus lugubris) and the strawberry sap beetle (Stelidota geminata).
Sap Beetles as Pests
Sap beetles can be pests of various crops, including vegetables, corn, sweet corn, berries, and tomatoes. They can be secondary pests, but may act as primary pests if populations are high, as seen with corn crops.
Sap Beetle-Plant Interactions
These beetles are often attracted to ripe and overripe produce, as well as decaying fruit. They can be found on strawberries, fruit crops, muskmelon, field corn, raspberries, and more.
Damage Caused by Sap Beetles
Sap beetles can cause considerable damage to crops. They feed on corn silk, pollen, corn ears, fruit crops like strawberries, and fermenting plant juices. They can spread fungi, furthering decay and leading to infestation.
Control and Prevention of Sap Beetles
To control and prevent sap beetle infestations:
- Harvest crops promptly when ripe.
- Remove decayed and overripe fruits.
- Prevent damage from primary pests, such as corn earworms.
Following these steps can minimize the likelihood of sap beetle damage to your crops.
5 Comments. Leave new
I grow strawberries in Indiana. Last year, I had trouble with some small beetles picking out the largest ripest berry and burrowing into. Any chance this could be the same beetle? If not, any ideas what it could be?
We would suspect the Strawberry Root Weevil, but impossible to tell without a photo.
Hi, here vacationing in Barbados, my girlfriend found two of these beetles as we were enjoying our dinner, unfortunately squashed them before I could identify.
I came across this post from Googling “picnic beetles.” We now live in Michigan where they are not a problem, but years ago we lived in central Ohio, and had no end of trouble with these beetles that my wife – an avoid gardener – called picnic beetles.
They were about the size and shape of cucumber beetles (proportionately narrower than the picture) but were black, and had a white spot on each wing. They are the devil’s own spawn, eating off the plants what we eat. If there’s fruit, they eat the fruit; if you eat the leaves, they eat the leaves.
This was over 30 years ago, and pre-internet, so I was left to my reference books to try to find a natural control, but couldn’t even find mention of them buy that name. I found a natural control by accident. I was sitting out by our garden with a glass of wine and felt something on my hand. It was a picnic beetle, apparently attracted by the smell of the wine.
I went out a bought a couple bottles of cheap wine and poured it into a cookie sheet placed in the garden. The next day the cookie sheet was choked with drowned picnic beetles.
Hope this helps.
On a related note, whenever I try to sleep outside with my exposed buttocks covered with beer batter, I am woken up prematurely by these guys! What gives???