Abstract

MARIN-CRUZ, Victor H. et al. Biology of Lycoriella ingenua and Bradysia impatiens (Diptera: Sciaridae). Madera bosques [online]. 2015, vol.21, n.1, pp.113-128. ISSN 2448-7597.

Lycoriella (Lycoriella) ingenua (Dufour, 1839) and Bradysia impatiens (Johannsen, 1912) (Diptera: Sciaridae) are two black fungus gnats species studied that harm Pinus montezumae (Lamb, 1832) seedlings in forestry nurseries. These dipterous were morphological and molecularly identified and are mentioned for the first time as a pest in Mexico’s forestry nurseries. The proportion of sexes to Lycoriella ingenua was of one male per 1.25 females; to characterize this species eggs, pupas, larvae and cephalic capsules were measured. The morphometric data of body length and cephalic cage width of larvae through the hierarchical conglomerated method determined the larval instars of the species. For B. impatiens there are 2.4 females per male. In the definition of the larval instars, the best parameter was that of the cephalic capsule. Both species presented four larval instars. Both species were bred under lab conditions at 21 °C ± 2 °C. The whole cycle of L. ingenua required 30.5 ± 3.5 days. For B. impatiens the time to conclude biological cycles was of 27.5 ± 2.5 days. It was determined that both species of larvae consume Pinus montezumae root. The fungi associated to larvae and fungi of both species were identified. Fusarium circinatum was the most important and it is registered for the first time in nurseries of Pinus montezumae; this species was morphological and molecularly identified.

Keywords : biological cycle; larval instars; associated fungi; black fungus gnats; sex proportion.

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