| Carpophilus lugubris | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Suborder: | Polyphaga |
| Infraorder: | Cucujiformia |
| Family: | Nitidulidae |
| Genus: | Carpophilus |
| Species: | C. lugubris |
| Binomial name | |
| Carpophilus lugubris Murray, 1864 | |
Carpophilus lugubris, commonly known as the dusky sap beetle, is a species of beetle in the genus Carpophilus . It is an agricultural pest of corn and tomato.
A long-lived species, the dusky sap beetle can live as an adult for up to 300 days. [1] Measuring 3.3-4.5 mm, this beetle is primarily brown but has orange colouration on its elytra. [2] Depressions can be seen on each side of the pygidium, which is a characteristic of males. [2] Additionally, the genital capsule, which is quite distinct, cannot be seen from an overhead view. [2] Eggs produced by adults are white and oval in shape. [1] Similarly, the larvae can be white or yellow in body colour, with a brown head. [1] This image, taken from Marini 2013, can provide a better look at the adult morphology and colouration.
Like other sap beetles, fruit secretions are the primary food source, but they will also consume fungi, decomposing fruit and even pollen. [1] Carpophilus lugubris is capable of feeding on undamaged fruits as well, corn being its primary food source. [1] The species is long-lived, so they will take up shelter in adverse environmental conditions. One such refuge is the bottom of beehives, which are often located close to crops. [2] Going underground during the pupa and adult stages allows them to survive the winter. [1] Larva and adults will often have overlapping niches, with the larva developing on the ears of the corn and eventually feeding on the kernels. [2]
Native to North America, C. lugubris can be found throughout southern Canada, the United States, and as far as South America. [1] Reports have even indicated its spread to southern European countries, such as Italy. [2] Only very cold climatic regions are free of the genus Carpophilus. [3]
Like the typical beetle life cycle, C. lugubris has four life stages: egg, larva, pupa and adult. Eggs are often laid on the silk of corn and have a generation time of 2–4 days. 3-5 eggs will be laid at a time and the optimal temperature is 21 °C. [1] The larval stage begins feeding on corn kernels and undergoes 3-4 instars before entering the pupa stage. This stage will often last for roughly 3 weeks. [1] When ready to pupate, the larva falls to the ground and buries itself. Pupation may last 9–10 days before reemerging, but it can be longer if overwintering becomes necessary. [1] Once exiting from the ground, the adult will use pheromones to locate a new food source and possible mating location. [1]
The ability to attack undamaged fruits and vegetables makes the genus Carpophilus a large threat to economic crops. [3] Dusky sap beetle is a common pest of corn in North America, but tomato plants are also at risk. [2] Larvae present in corn kernels often go undiscovered and this can lead to their rejection and subsequent discarding. [1] The beetles can also act as vectors for fungi transfer to crop plants. [1] Related species act as vectors for disease, such as oak wilt. [4]
The use of the dusky sap beetle to fight fungal infections is a possibility as well. This involves using the beetle to deliver Bacillus subtilis , a bacterium which kills the fungus Aspergillus flavus . [5]
Insecticides are not often applied in direct response to C. lugubris, but they are still effective when targeting other species. [1] A more effective approach is to ensure that crops are not left unharvested, as these plants will provide food for overwintering individuals. [1]
The use of pheromones by Carpophilus species has influenced traps and lures to protect crops. [4]
Radio frequency irradiation is a possible way of killing larvae hidden in the fruit. [6]
In North Carolina, early corn planting has been shown to reduce the number of damaged plants when compared with later planting. [1]
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