Diabrotica speciosa, also known as the cucurbit beetle and in Spanish as vaquita de San Antonio (this common name is also given to many ladybugs) is an insect pest native to South America.

[4][5] Their native land is South America in countries such as Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Paraguay, Peru, Uruguay and Venezuela.

[4] Their current distribution is in Central America including countries such as Costa Rica, Mexico, and Panama.

[6] D. speciosa can move locally by adult flight, and by movement of eggs, larvae or pupae in soil contaminating vehicles or farm machinery.

Larvae could be associated with ground crops like groundnuts or potatoes, and the underground parts of maize, wheat or soybean because they are unlikely to be moved.

[4] In their native and newly acquired habitats, D. speciosa is an important pest throughout southern South America (except Chile), but, being highly polyphagous (feeds on various foods), qualitative reports of its impact on different crops vary in different regions.

In southern Brazil, IPM programs combine no-till agriculture, rotation of soybeans with maize or wheat, and use of insecticides only when damage is evident.

[10] D. speciosa then transitions to larvae stage (8.5 mm long at maturity, subcylindrical; chalky white; head capsule dirty yellow-light brown) where it requires seven, five, and four days for development of first, second and third instars, respectively or a total of 2-3 ½ weeks for complete larval development.

[10] Once transitioning to pupae (5.8–7.1 mm long; white, formed in an 8 × 4 mm oval cell in the soil), a pair of stout spines is present on the tip of the abdomen and smaller spines are found on the dorsal side of other abdominal segments.

The beetle overwinters during the adult stage near buildings, wood lots or in fence rows.

[10] The larvae of D. speciosa feed on roots of maize, wheat, groundnut, soybean and potato, and various other crop and non-crop hosts.

In maize, their feeding on newly emerging silks prior to pollination is most serious, resulting in sparsely filled ears.

Serial reduction in the number of ripening kernels from the tip of the ear to the base can often be observed at harvest.

[10] The plants affected by D. speciosa include cucumber, cantaloupe, squash, gourd, pumpkin, corn, soybean, cotton, beans, potato, grape, sweet potato, tomato, cassava, rice, sorghum, wheat, cabbage, amaranth, peanut, watermelon, bell pepper, mulberry, pea, beet, okra, onion, lettuce, and oats.

They can move locally by adult flight, and probably by movement of eggs, larvae or pupae in soil contaminating vehicles or farm machinery.