Ladybirds, also called lady beetles, are favoured insects by gardeners. These small beetles protect fruit and vegetables by consuming small pests such as aphids and sap eaters. For ladybirds there may be slight differences in length and colour. Some ladybirds do not even have spots. However since there are beetles that are similar in some physical characteristics to the ladybug, people can become confused.
Multicoloured Asian Lady Beetle
The Asian lady beetle can range in colour from yellow and orange to red. These beetles may or may not have black spots on the wing cover. You can tell the difference between a ladybug and an Asian lady beetle by looking at the markings behind the head. There is a small dark "m" or "w" mark behind the head. This beetle, like the ladybug, is beneficial to plants since it also feeds on small pests. However, unlike the ladybug, the Asian lady beetle will hibernate in the winter. Homeowners may find this beetle to be a nuisance since it can infest homes looking for a warm place to hibernate.
Mexican Bean Beetle
Mexican bean beetles physically resemble larger ladybirds. Their bodies are either orange or copper coloured and are decorated with eight spots on each wing cover. These beetles measure about 1/4 inch in length. These beetles, however, are not beneficial to a gardener like ladybirds. Mexican bean beetles will destroy crops since they feed on plant pods, stems and the underside of leaves.
Pink Spotted Lady Beetle
Pink spotted lady beetles can measure 1/4 inch in length. Though these ladybirds are not yellow or orange, they are often confused by many as a true ladybug. Pink spotted lady beetles have oblong pink to red bodies that are marked with six black spots on each wing cover. Like their ladybug counterpart, they also eat small pests. The only difference between a pink spotted lady beetle and a ladybug is the additional component to a pink spotted beetle's diet. Pink spotted beetles consume plant pollen, which makes up 50 per cent of their diet.
Squash beetles have the same round shape as the ladybug, however they are much larger than ladybirds, often measuring about 3/8 inch in length. These beetles are yellow coloured and can have up to seven black spots on their wing cover. These beetles are not garden friendly and will destroy crops and plants belonging to the melon family. This can include squash, pumpkin, cucumber and other melons.
- UK College of Agriculture: Asian Lady Beetle Infestation of Structures; Michael F. Potter et al.
- URI Landscape Horticulture Program: Mexican Bean Beetle
- Bug Lady Consulting: Pink Spotted Lady Beetles; Suzanna Wainwright Evans
- Purdue University: Vegetable Insects: Squash Beetle on Cucurbits; Frankie Lam et al.