By Alain VanRyckeghem, BCE
Red-legged ham beetles are cosmopolitan and have bee found throughout the US. They
are most frequently encountered in pet food storage areas of retail and distribution centers
and occasionally in production facilities where dried meats are being smoked, dried and
processed. Monitoring for them has been difficult as there are no pheromones identified for this pest. Various blends of prepared meats, such as pepperoni, pet foods, fish meal, etc. have been implemented as baits on floor level glue traps with inconsistent results. Careful
flashlight inspections can help locate infested materials which could be removed and fumigated or disposed of. Sanitation and removal of damaged bags and open containers can help prevent further spread of infestations.
These colorful beetles are iridescent blue green with bright to dark red legs and clubbed antennae. Two other similar species have other patterns of blue green or violet
iridescence without red legs. Adults are about 3/8 in. (6 – 7 mm) long with larvae measuring 3/8 – 1/4 in (8 – 10 mm) long. They are very capable fliers and are attracted to food odors from long distances. It has been reported that adult beetles are attracted to UV insect light traps, however it has rarely been observed flying indoors or found in light trap where there are infestations. It is considered tropical and can be found in greater abundance in warmer climates of the US.
The life span of adult beetles is 40–68 days with females living slightly longer than males. The average number of eggs produced by female is 70 – 100 eggs with a potential of 350 eggs on a dried meat diet. Females lay eggs continuously over their life span. Eggs require 4 – 6 days for development. Larvae molt two or three times over 17– 37 days at 70– 85°F (20 – 30°C). Larvae will move from infested foods to dark protective crevices to produce a white pupal chamber. They remain in the pupa chamber for 10 –13 days then emerge as adults to mate a few days later. It is unknown at this time if female beetles produce pheromones to attract males.
Red-legged ham beetles are also known as Copra beetles in other parts of the world where coconut is produced. These beetles are the most important pest of meat that has been dried or smoked in long term storage, such as smoked hams and fish. These pests will also infest copra (dried coconut), rancid peanuts, cheese, bacon, salt fish, dry egg yolk, bones and bone meal, moist pet foods and dry meat treats, carrion, dried figs, palm
nut kernels, insect collections and guano. In the absence of food, adults and larvae will be cannibalistic, feeding on their own eggs, larvae and other adults. In some instances the adults and larvae are predatory feeding on larvae of cheese skippers, and blow flies or eggs of hide beetles (Dermestes sp.). Feeding on this diet, a female has the potential to lay more than 1000 eggs.
Red-legged ham beetle larva