Taxonomic information	Current valid scientific name: Amathynetoides nitidiventris (Hustache 1938) Synonyms: Adioristus nitidiventris Hustache, 1938; Amathynetes nitidiventris Kuschel, 1949; Puranius nitidiventris Kuschel, 1955; Macrostyphlus nitidiventris Kuschel, 1986 Name used in the EU legislation: N/A Order: Coleoptera Family: Curculionidae Common name: gorgojo del ulluco; ulluco weevil Name used in the Dossier: Amathynetoides nitidiventris
Group	Insects
EPPO code	N/A
Regulated status	The pest is not regulated in the EU, neither is listed by EPPO.
Pest status in Peru	Present. As a result of a diagnostic study carried out in the community of La Libertad, one of the main producing centres of ulluco in the central highlands, it was found that 96% of farmers consider the ‘ulluco weevil’ as the main pest of the culture, followed by the earthworms. The literature checked also points out that this species is one of the most important pests of ulluco (Alcazar et al., 2004; McCaffrey and Walker, 2012). The weevil causes at harvest between 2.5% and 50% of damage to tubers. The pest is also reported for Concepción and Junín.
Pest status in the EU	Absent (CABI CPC, online; EPPO online, Fauna Europaea, online).
Host status on U. tuberosus	U. tuberosus is reported as the main host plant of A. nitidiventris (Alcazar et al., 2004; McCaffrey and Walker, 2012).
PRA information	N/A
Other relevant information for the assessment
Biology	The life cycle of A. nitidiventris reared in the laboratory at 17 °C and 78% relative humidity has an egg‐adult life span of 243 days and the total cycle, including adult longevity, is 459 days (Aldana, 2003). Adult longevity averages 218.0 and 214.9 days for males and females respectively (Alcazar et al., 2004). The species has a pre‐oviposition phase lasting 18 days on average. Oviposition occurs during the months of October and November (lat 12°04′S 75°13′W), it lasts on average 155 days, during which the female lays a total of 373 eggs (Alcazar et al., 2004). Incubation lasts 28.8 days after which the larva emerges. The larval period has a duration of 102 days, going through 4 stages. The larvae feed on the tubers. After the larval period the species pupates passing through a pre‐pupal stage which lasts 31 days on average. During this period the larva stops feeding and exits or falls down the tuber to pupate in a pupal chamber made with soil at a depth of 16‐20 cm. Under laboratory conditions pupation can occur inside the tuber. The pupal stage lasts 32.3 days. It overwinters as adult between July and August (lat 12°04′S 75°13′W) in the soil inside the pupal chamber or inside the tubers in the field or in the warehouse. This phase ends when the adult emerges from the tuber or from the ground after the first rains in September‐October. To exit the tubers, the adults dig a hole both in storage and in the field. After emergence the adult weevils move looking for ulluco plants, being volunteer, the first option followed by migration to new fields. Adults feed on young leaves, rootlets, stolons and tubers close to the surface; very rarely they have been found feeding on stems. Females lay their eggs on the ground under soil clods in groups and in humid places near the plant. At harvest, almost 90% of the larvae remain in the soil representing the most important re‐infestation source for the next campaign, especially if ulluco is replanted. The remaining part of the larvae either fall from the tubers during storage or complete their development in the tubers (4%), being able to spread the pest to new growing areas.
Symptoms	Main type of symptoms	The larval stage causes greater damage in the field, feeding on the tubers producing holes, and subtracting quality. The adults are present in the field from September to July. The adult density in the field increases from the emergence of ulluco plants to reach its maximum in mid‐January, when the plant starts flowering, providing adults with food and shelter. Then the adult population begins to decline until July. The larvae of this weevil, cause holes on the tubers especially in the late stages of cultivation.
	Presence of asymptomatic tubers	It has been found that 4% of the larval weevil population infesting tubers in the field manage to complete their cycle within the tuber in warehouse. So, it is important to carefully select the ulluco seed tubers, avoiding planting damaged and infested tubers with weevil larvae. The holes made by the larvae can be of various size and although the selection process tries to eliminate the tubers with wounds, there are always tubers with small wounds that cannot be eliminated with the naked eye.
	Confusion with other pests	Premnotrypes spp., which attack potato, have been erroneously identified as ulluco weevil (Alcazar et al., 2004).
Host plant range	Although U. tuberosus is reported as the main host plant of A. nitidiventris, the species also attacks tubers and roots of oca, mashua, maca, carrot, fava bean and corn (Alcazar et al., 2004; McCaffrey and Walker, 2012).
Pathways	Infested tubers
Surveillance information	The applicant country declares to perform surveillance in accordance with the ‘Pest Prospecting Instructions’ and ‘Sampling and Handling Manual’ developed by SENASA to carry out the prospecting actions on ulluco, as well as the procedures for sampling and remission of samples to the laboratory of plant parts and/or pests. Personnel trained in SENASA regional offices travel daily to the crop‐producing areas for the identification of anomalies in their growth, which may be related to the presence of virus or other disease as well as the presence of insects which can be collected with vacuum cleaners, entomological meshes or plant parts. Specific details on sampling intensity and protocols applied were not provided in the Dossier. The samples collected in the field are registered in the database ‘Integrated System of Plant Health Management’ (SIGSVE) and sent to the Unit of Diagnostic Center of Plant Health of SENASA, under adequate conditions of protection. Laboratory analyses are performed by the SENASA Plant Health Diagnostic Centers Unit, which has diagnostic methods based on pest morphology, ELISA and molecular biology (conventional PCR, real time and sequencing).