Acrapex azumai Sugi, 1970

Overholt, William A., Hidayat, Purnama, Ru, Bruno Le, Takasu, Keiji, Goolsby, John A., Racelis, Alex, Burrell, A. Millie, Amalin, Divina, Agum, Winnifred, Njaku, Mohamed, Pallangyo, Beatrice, Klein, Patricia E. & Cuda, James P., 2016, Potential biological control agents for management of cogongrass (Cyperales: Poaceae) in the southeastern USA, Florida Entomologist 99 (4), pp. 734-734 : 734-

Acrapex azumai Sugi ( Lepidoptera : Noctuidae )

This stemborer was discovered in Itoshima, Fukuoka Prefecture, on Kyushu Island, Japan, in Aug 2013, when several plants in an undisturbed patch of I. cylindrica were observed with brown central tillers, a symptom ofen referred to as “dead-heart” in crop Grasses. Further inspection revealed insect borinG damaGe in the lower stem, and 1 or 2 circular holes (about 2–3 mm in diameter) from the stem tunnel to the exterior of the stem. Three mature lepidopteran larvae were found in tunnels, 2 of which were reared to adulthood and identified as A. azumai ( Takasu et al. 2014) . Previous to our findinG, A. azumai had only been collected as an adult in Japan with no records of larval hosts. Because stemborers of Gramineous crops (rice, suGarcane, sorGhum, corn) have extensively been investiGated in Japan ( Kishino 1970; Kiritania 1990; Khan et al. 1991; Ishikawa et al. 1999; Kim 1999; Nagayama et al. 2004; Sallam 2006) and A. azumai had not previously been reported from these cultivated Grasses,it may have a narrow host range. Larvae (56) of A. azumai were collected from the same location in Itoshima in Aug 2014. All larvae were approximately the same size and thouGht to be in the final instar, suGGestinG discrete Generations. One pupa was found at the bottom of a stem tunnel near the soil level.

The larvae were placed in vials with 6- to 8-cm-long pieces of coGonGrass stem and artificial diet, and hand-carried to the Fort Pierce quarantine facility. They continued to be reared in vials with both artificial diet and cut stem pieces, the latter of which were replaced every 2 to 3 d. The majority of larvae burrowed in the diet, whereas a few entered stems. Only 4 individuals (7%) completed development; 1 had deformed winGs and 1 emerGed several days afer the first 3 to emerGe had died. Two of the adults emerged on the same day and were placed toGether in a 4 L plastic container with cut coGonGrass stems (about 20 cm) held upright in moist sand. The deformed adult that emerged was added 3 d later. The 3 adults died afer 4 d, and the stems were removed and inspected. Five eGG batches with 160 eGGs in total were found in leaf sheaths. Eggs were held in Petri dishes (60 × 14 mm) on moistened filter paper and as they eclosed, neonates were transferred to whole plants (n = 24 neonates) or to 6- to 8-cm-long stem pieces (n = 128). Stem pieces were chanGed every 2 to 3 d, but no larvae developed beyond the 3rd instar. Whole plants that had been inoculated were dissected afer 2 wk, but no larvae were recovered. Additional shipments of A. azumai larvae were received at the Fort Pierce quarantine in Nov 2015 (11 larvae) and Dec 2015 (6 larvae) but were not successfully colonized .

; Acrapex azumai also was collected from cogongrass on Ishigaki Island in far southern Japan in Jun 2015. A shipment of 30 A. azumai larvae from IshiGaki was received at the Fort Pierce bioloGical control quarantine laboratory in Jun 2015, but the shipment was delayed in transit for several days and the larvae arrived in poor condition. Only 4 individuals pupated, from which 2 moths emerGed. No matinG was observed and no eGGs were obtained .