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Spiders, scorpions and blister beetles in fresh produce

Although it is uncommon, pests may be found in fresh produce. On rare occasions, consumers have unknowingly brought black widow spiders into their kitchens in imported grapes; scorpions have been found in bananas and imported berries; and iron cross blister beetles have been found in imported leafy green vegetables.

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Black widow spiders in grapes

Black widow spiders are distinctive due to their shiny round body, brown or black colour and 2 reddish or yellowish triangles forming an hourglass on the underside of their abdomen. Their legs are long and slender.

Black widow spiders live in most warm regions of eastern and central U.S., North American deserts and southern Canada. They are occasionally found in imported grapes. The presence of spiders does not damage or poison the grapes. When grapes are harvested, they are carefully examined before being placed into their packaging; however, some spiders may camouflage with the grape vines and escape being found. Refrigeration of the product prior to being transported reduces the spiders' activity, making them harder to detect.

The black widow spider is not aggressive and may bite in self-defence. Its venom is poisonous and bites should be treated promptly with medical attention. In most cases, the symptoms of a black widow spider bite are a sharp pain followed by localized swelling and redness. In some cases, severe symptoms may appear within 30 to 60 minutes. These symptoms may include muscle cramps and spasms, chills, fever, nausea, headache, hypertension and abdomen or chest pain.

black widow spider

Scorpions in bananas and berries

Scorpions have several defining characteristics that are shared by all species: 4 pairs of legs, a pair of strong pincers, a segmented body and a long, segmented tail. Normally, the last segment at the tip of a scorpion's tail is the largest and can deliver a painful sting. In most species, the tail is thick and long, often curling up over the body of the scorpion. Scorpions are nocturnal predators, hiding during the day. When a product is harvested, scorpions may be gathered along with the produce. They are most common in warm and dry habitats, but are also found in rain forests and grassy prairies.

All known species of scorpions are venomous, however, the type of venom and degree of toxicity varies between species. Few have venom that is potentially lethal to humans. Most often, a scorpion sting may cause local pain, redness, tingling or numbness, burning and swelling similar to a bee sting. For these symptoms, wash the area with soap and water, then apply a cold compress to reduce pain and swelling. In more serious cases, symptoms can include dizziness, blurred vision, difficulty focusing and swallowing, swollen tongue, drooling, random eye movements and muscle twitching. If you are stung, seek immediate medical attention.


Iron cross blister beetles in leafy vegetables

The iron cross blister beetle is distinctive due to its colouring. It has a bright red/orange head and thorax, a yellow and black abdomen and bright yellow markings on the elytra, which are separated by a black "cross". Iron cross blister beetles live in most warm regions of eastern and central U.S. and North American deserts. They have been found in imported leafy vegetables (for example, pre-packaged salad mixes) from the southern United States. Insects are common at produce farms and most are removed when vegetables are examined during harvesting and processing. Insects on leafy greens may become inactive during refrigerated storage and become active once brought to room temperature by retailers and consumers.

Blister beetles release an irritating chemical called cantharidin in self-defence, if threatened or crushed during food handling. When released, cantharidin may cause severe burning blisters to humans when skin contact is made. If handling of the bug cannot be avoided, gloves should be worn. It is also toxic to mammals if ingested and has been known to cause death of livestock if consumed in a large enough quantity.

Blister Beetle

Product safety

Finding these pests may be unappealing, but they do not affect the safety of your produce. You can eat your produce after properly washing it.

What to do if you find these pests in food

If you find these pests in food, you should report it to the Canadian Food Inspection Agency (CFIA). Even though these are not regulated pests in Canada, we still recommend consumers report these insects to the CFIA to confirm species. In some situations, the CFIA may conduct follow-up activities.

When shopping for produce, it is important to visually inspect it for pests. Even after a visual inspection, these pests may still be brought into your home due to their ability to camouflage and their reduced activity due to refrigeration.

If you find a black widow spider, scorpion, or blister beetle promptly kill and carefully dispose of it. Ensure a barrier (such as gloves or a fly swatter) is used between the insect and your skin when killing and disposing a blister beetle.

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