Araecerus fasciculatus (De Geer)

Bustillo, Alex, 2015, Part II. Pests, Compendium of Coffee Diseases and Pests, United States of America: The American Phytopathological Society, pp. 45-60 : 59

This weevil, Araecerus fasciculatus (De Geer) ( Coleoptera : Anthribidae ),

has a pantropical distribution and is a pest of stored coffee. The adult is 3-5 mm long, dark brown, and mottled with whitish to yellowish scalelike setae and has a varied pattern and a short broad beak or rostrum. The wings are slightly shorter than the abdomen, and the three terminal segments of the antennae are thickened.

Eggs are laid singly in the parchment coffee or dried pulp if present. This stage lasts 4-7 days. The larva is a white, legless grub, similar to many weevil larvae. It initially feeds on the pulp but later perforates the bean. The larval stage lasts 33-40 days at 23°C. The pupa is white with numerous setae in the body and survives 5-11 days. Adults are dark brown. Males are 2.5-3.5 mm long and females are 3.5-4.5 mm long. Under laboratory conditions, they can live up to 115 days. They mate 4-5 days after emergence of the adults, and the females almost immediately lay eggs by inserting them into the stored coffee beans. The average number of eggs laid is 52 at a rate of three per day.

Damage

A. fasciculatus damages stored beans, especially old coffee kept at high humidities. The adult perforates the dried coffee bean and lays eggs and then the larvae develop inside and de ­ stroy the bean completely. The main loss is the contamination of the stored coffee, which considerably reduces the commercial value.

Population Management

To control the coffee bean weevil, coffee should not be stored in wet areas. Sun drying the coffee may kill the insect since it cannot survive temperatures above 37°C. Parchment coffee with a moisture level below 12% is seldom attacked by this insect. Direct control measures include cleaning the warehouses and fumigating. Fumigation provides good control but does not eliminate the infestation of the coffee beans. Methyl bromide and ethylene dibromide are effective but are now being phased out. Natural enemies, such as the parasitoids Anisopteromalus calandrae (Howard) , Cephalonomia gallicola (Ashmead) , and a Plastanoxus sp. , are commonly found attacking the larval stages of this pest, but their impact is not sufficient for satisfac ­ tory control.